Add Storable 0.7.2 from Raphael Manfredi,

plus the patch from

Subject: Re: someone with too much time and a 64-bit box and interest in Storable?
Message-ID: <Pine.LNX.4.10.10008210258160.1292-100000@busy.netsoft.ro>

plus changes to get Storable to compile with
picky ANSI compilers.

p4raw-id: //depot/perl@6734

7 files changed, 5615 insertions, 0 deletions

diff --git a/ext/Storable/ChangeLog b/ext/Storable/ChangeLog
new file mode 100644
index 0000000000..3f130a9a24
--- /dev/null
+++ b/ext/Storable/ChangeLog
@@ -0,0 +1,366 @@
+Mon Aug 14 09:22:04 MEST 2000   Raphael Manfredi <Raphael_Manfredi@pobox.com>
+
+. Description:
+
+	Added a refcnt dec in retrieve_tied_key(): sv_magic() increases
+	the refcnt on the mg_ptr as well.
+
+	Removed spurious dependency to Devel::Peek, which was used for
+	testing only in t/tied_items.t.  Thanks to Conrad Heiney
+	<conrad@fringehead.org> for spotting it first.
+
+Sun Aug 13 22:12:59 MEST 2000   Raphael Manfredi <Raphael_Manfredi@pobox.com>
+
+. Description:
+
+	Marc Lehmann kindly contributed code to add overloading support
+	and to handle references to tied variables.
+
+	Rewrote leading blurb about compatibility to make it clearer what
+	"backward compatibility" is about: when I say 0.7 is backward
+	compatible with 0.6, it means the revision 0.7 can read files
+	produced by 0.6.
+
+	Mention new Clone(3) extension in SEE ALSO.
+
+	Was wrongly optimizing for "undef" values in hashes by not
+	fully recursing: as a result, tied "undef" values were incorrectly
+	serialized.
+
+Sun Jul 30 12:59:17 MEST 2000   Raphael Manfredi <Raphael_Manfredi@pobox.com>
+
+	First revision of Storable 0.7.
+
+	The serializing format is new, known as version 2.0.  It is fully
+	backward compatible with 0.6.  Earlier formats are deprecated and
+	have not even been tested: next version will drop pre-0.6 format.
+
+	Changes since 0.6@11:
+
+	- Moved interface to the "beta" status.  Some tiny parts are still
+	  subject to change, but nothing important enough to warrant an "alpha"
+	  status any longer.
+
+	- Slightly reduced the size of the Storable image by factorizing
+	  object class names and removing final object storage notification due
+	  to a redesign of the blessed object storing.
+
+	- Classes can now redefine how they wish their instances to be serialized
+	  and/or deep cloned.  Serializing hooks are written in Perl code.
+
+	- The engine is now fully re-entrant.
+
+Sun Apr  2 23:47:50 MEST 2000   Raphael Manfredi <Raphael_Manfredi@pobox.com>
+
+. Description:
+
+	Added provision to detect more recent binary formats, since
+	the new upcoming Storable-0.7 will use a different format.
+	In order to prevent attempting the de-serialization of newer
+	formats by older versions, I'm adding this now to the 0.6 series.
+
+	I'm expecting this revision to be the last of the 0.6 series.
+	Unless it does not work with perl 5.6, which I don't use yet,
+	and therefore against which I cannot test.
+
+Wed Mar 29 19:55:21 MEST 2000   Raphael Manfredi <Raphael_Manfredi@pobox.com>
+
+. Description:
+
+	Added note about format incompatibilities with old versions
+	(i.e. pre 0.5@9 formats, which cannot be understood as there
+	was no versionning information in the file by then).
+
+	Protect all $@ variables when eval {} used, to avoid corrupting
+	it when store/retrieve is called within an exception handler.
+
+	Mistakenly included "patchlevel.h" instead of <patchlevel.h>,
+	preventing Perl's patchlevel from being included, which is
+	needed starting from 5.6.
+
+Tue May 12 09:15:15 METDST 1998   Raphael Manfredi <Raphael_Manfredi@grenoble.hp.com>
+
+. Description:
+
+	Fixed shared "undef" bug in hashes, which did not remain shared
+	through store/retrieve.
+
+Thu Feb 10 19:48:16 MET 2000   Raphael Manfredi <Raphael_Manfredi@pobox.com>
+
+. Description:
+
+	added last_op_in_netorder() predicate
+	documented last_op_in_netorder()
+	added tests for the new last_op_in_netorder() predicate
+
+Wed Oct 20 19:07:36 MEST 1999   Raphael Manfredi <Raphael_Manfredi@pobox.com>
+
+. Description:
+
+	Forgot to update VERSION
+
+Tue Oct 19 21:25:02 MEST 1999   Raphael Manfredi <Raphael_Manfredi@pobox.com>
+
+. Description:
+
+	Added mention of japanese translation for the manual page.
+
+	Fixed typo in macro that made threaded code not compilable,
+	especially on Win32 platforms.
+
+	Changed detection of older perls (pre-5.005) by testing PATCHLEVEL
+	directly instead of relying on internal symbols.
+
+Tue Sep 14 22:13:28 MEST 1999   Raphael Manfredi <Raphael_Manfredi@pobox.com>
+
+. Description:
+
+	Integrated "thread-safe" patch from Murray Nesbitt.
+	Note that this may not be very efficient for threaded code,
+	see comment in the code.
+
+	Try to avoid compilation warning on 64-bit CPUs. Can't test it,
+	since I don't have access to such machines.
+
+Mon Jul 12 14:37:19 METDST 1999   Raphael Manfredi <Raphael_Manfredi@pobox.com>
+
+. Description:
+
+	changed my e-mail to pobox.
+
+	mentionned it is not thread-safe.
+
+	updated version number.
+
+	uses new internal PL_* naming convention.
+
+Fri Jul  3 13:38:16 METDST 1998   Raphael Manfredi <Raphael_Manfredi@grenoble.hp.com>
+
+. Description:
+
+	Updated benchmark figures due to recent optimizations done in
+	store(): tagnums are now stored as-is in the hash table, so
+	no surrounding SV is created. And the "shared keys" mode for
+	hash table was turned off.
+
+	Fixed backward compatibility (wrt 0.5@9) for retrieval of
+	blessed refs. That old version did something wrong, but the
+	bugfix prevented correct retrieval of the old format.
+
+Mon Jun 22 11:00:48 METDST 1998   Raphael Manfredi <Raphael_Manfredi@grenoble.hp.com>
+
+. Description:
+
+	Changed benchmark figures.
+
+	Adjust refcnt of tied objects after calling sv_magic() to avoid
+	memory leaks.  Contributed by Jeff Gresham.
+
+Fri Jun 12 11:50:04 METDST 1998   Raphael Manfredi <Raphael_Manfredi@grenoble.hp.com>
+
+. Description:
+
+	Added workaround for persistent LVALUE-ness in perl5.004. All
+	scalars tagged as being an lvalue are handled as if they were
+	not an lvalue at all.  Added test for that LVALUE bug workaround.
+
+	Now handles Perl immortal scalars explicitely, by storing &sv_yes
+	as such, explicitely.
+
+	Retrieval of non-immortal undef cannot be shared. Previous
+	version was over-optimizing by not creating a separate SV for
+	all undefined scalars seen.
+
+Thu Jun  4 17:21:51 METDST 1998   Raphael Manfredi <Raphael_Manfredi@grenoble.hp.com>
+
+. Description:
+
+	Baseline for Storable-0.6@0.
+
+	This version introduces a binary incompatibility in the generated
+	binary image, which is more compact than older ones by approximatively
+	15%, depending on the exact degree of sharing in your structures.
+
+	The good news is that your older images can still be retrieved with
+	this version, i.e. backward compatibility is preserved. This version
+	of Storable can only generate new binaries however.
+
+	Another good news is that the retrieval of data structure is
+	significantly quicker than before, because a Perl array is used
+	instead of a hash table to keep track of retrieved objects, and
+	also because the image being smaller, less I/O function calls are
+	made.
+
+Tue May 12 09:15:15 METDST 1998   Raphael Manfredi <Raphael_Manfredi@grenoble.hp.com>
+
+. Description:
+
+	Version number now got from Storable.pm directly.
+
+	Fixed overzealous sv_type() optimization, which would make
+	Storable fail when faced with an "upgraded" SV to the PVIV
+	or PVNV kind containing a reference.
+
+Thu Apr 30 15:11:30 METDST 1998   Raphael Manfredi <Raphael_Manfredi@grenoble.hp.com>
+
+. Description:
+
+	Extended the SYNOPSIS section to give quick overview of the
+	routines and their signature.
+
+	Optimized sv_type() to avoid flags checking when not needed, i.e.
+	when their type makes it impossible for them to be refs or tied.
+	This slightly increases throughput by a few percents when refs
+	and tied variables are marginal occurrences in your data.
+
+	Stubs for XS now use OutputStream and InputStream file types to
+	make it work when the given file is actually a socket. Perl
+	makes a distinction for sockets in its internal I/O structures
+	by having both a read and a write structure, whereas plain files
+	share the same one.
+
+Tue Jun  3 09:41:33 METDST 1997   Raphael Manfredi <Raphael_Manfredi@grenoble.hp.com>
+
+. Description:
+
+	Thanks to a contribution from Benjamin A. Holzman, Storable is now
+	able to correctly serialize tied SVs, i.e. tied arrays, hashes
+	and scalars.
+
+Thu Apr  9 18:07:51 METDST 1998   Raphael Manfredi <Raphael_Manfredi@grenoble.hp.com>
+
+. Description:
+
+	I said SvPOK() had changed to SvPOKp(), but that was a lie...
+
+Wed Apr  8 13:14:29 METDST 1998   Raphael Manfredi <Raphael_Manfredi@grenoble.hp.com>
+
+. Description:
+
+	Wrote sizeof(SV *) instead of sizeof(I32) when portable, which
+	in effect mangled the object tags and prevented portability
+	accross 32/64 bit architectures!
+
+Wed Mar 25 14:57:02 MET 1998   Raphael Manfredi <Raphael_Manfredi@grenoble.hp.com>
+
+. Description:
+
+	Added code example for store_fd() and retrieve_fd() in the
+	man page, to emphasize that file descriptors must be passed as
+	globs, not as plain strings.
+
+	Cannot use SV addresses as tag when using nstore() on LP64. This
+	was the cause of problems when creating a storable image on an
+	LP64 machine and retrieving it on an ILP32 system, which is
+	exactly what nstore() is meant for...
+
+	However, we continue to use SV addresses as tags for plain store(),
+	because benchamarking shows that it saves up to 8% of the store
+	time, and store() is meant to be fast at the expense of lack
+	of portability.
+
+	This means there will be approximately an 8% degradation of
+	performance for nstore(), but it's now working as expected.
+	That cost may vary on your machine of course, since it is
+	solely caused by the memory allocation overhead used to create
+	unique SV tags for each distinct stored SV.
+
+Tue Jan 20 09:21:53 MET 1998   Raphael Manfredi <Raphael_Manfredi@grenoble.hp.com>
+
+. Description:
+
+	Don't use any '_' in version number.
+
+Tue Jan 13 17:51:50 MET 1998   Raphael Manfredi <Raphael_Manfredi@grenoble.hp.com>
+
+. Description:
+
+	Updated version number.
+
+	added binmode() calls for systems where it matters.
+
+	Be sure to pass globs, not plain file strings, to C routines,
+	so that Storable can be used under the Perl debugger.
+
+Wed Nov  5 10:53:22 MET 1997   Raphael Manfredi <Raphael_Manfredi@grenoble.hp.com>
+
+. Description:
+
+	Fix memory leaks on seen hash table and returned SV refs.
+
+	Storable did not work properly when tainting enabled.
+
+	Fixed "Allocation too large" messages in freeze/thaw and added.
+	proper regression test in t/freeze.t.
+
+Tue Jun  3 09:41:33 METDST 1997   Raphael Manfredi <Raphael_Manfredi@grenoble.hp.com>
+
+. Description:
+
+	Updated version number
+
+	Added freeze/thaw interface and dclone.
+
+Fri May 16 10:45:47 METDST 1997   Raphael Manfredi <Raphael_Manfredi@grenoble.hp.com>
+
+. Description:
+
+	Forgot that AutoLoader does not export its own AUTOLOAD.
+	I could use
+
+		use AutoLoader 'AUTOLOAD';
+	
+	but that would not be backward compatible. So the export is
+	done by hand...
+
+Tue Mar 25 11:21:32 MET 1997   Raphael Manfredi <Raphael_Manfredi@grenoble.hp.com>
+
+. Description:
+
+	Empty scalar strings are now "defined" at retrieval time.
+
+	New test to ensure an empty string is defined when retrieved.
+
+Thu Feb 27 16:32:44 MET 1997   Raphael Manfredi <Raphael_Manfredi@grenoble.hp.com>
+
+. Description:
+
+	Updated version number
+
+	Declare VERSION as being used
+
+	Fixed a typo in the PerlIO_putc remapping.
+	PerlIO_read and perlIO_write inverted size/nb_items.
+	(only relevant for pre-perl5.004 versions)
+
+Thu Feb 27 15:58:31 MET 1997   Raphael Manfredi <Raphael_Manfredi@grenoble.hp.com>
+
+. Description:
+
+	Updated version number
+
+	Added VERSION identification
+
+	Allow build with perl5.003, which is ante perlIO time
+
+Mon Jan 13 17:53:18 MET 1997   Raphael Manfredi <Raphael_Manfredi@grenoble.hp.com>
+
+. Description:
+
+	Random code fixes.
+
+Wed Jan 22 15:19:56 MET 1997   Raphael Manfredi <Raphael_Manfredi@grenoble.hp.com>
+
+. Description:
+
+	Updated version number in Makefile.PL.
+
+	Added "thanks to" section to README.
+
+	Documented new forgive_me variable.
+
+	Made 64-bit clean.
+
+	Added forgive_me support to allow store() of data structures
+	containing non-storable items like CODE refs.
+
diff --git a/ext/Storable/MANIFEST b/ext/Storable/MANIFEST
new file mode 100644
index 0000000000..8833380179
--- /dev/null
+++ b/ext/Storable/MANIFEST
@@ -0,0 +1,7 @@
+README                      Read this first
+MANIFEST                    This shipping list
+Makefile.PL                 Generic Makefile template
+Storable.pm                 The perl side of Storable
+Storable.xs                 The C side of Storable
+patchlevel.h                Records current patchlevel
+ChangeLog                   Changes since baseline
diff --git a/ext/Storable/Makefile.PL b/ext/Storable/Makefile.PL
new file mode 100644
index 0000000000..3b5aa2ced5
--- /dev/null
+++ b/ext/Storable/Makefile.PL
@@ -0,0 +1,23 @@
+# $Id: Makefile.PL,v 0.7 2000/08/03 22:04:44 ram Exp $
+#
+#  Copyright (c) 1995-2000, Raphael Manfredi
+#  
+#  You may redistribute only under the terms of the Artistic License,
+#  as specified in the README file that comes with the distribution.
+#
+# $Log: Makefile.PL,v $
+# Revision 0.7  2000/08/03 22:04:44  ram
+# Baseline for second beta release.
+#
+
+use ExtUtils::MakeMaker;
+use Config;
+
+WriteMakefile(
+    'NAME'			=> 'Storable',
+    'DISTNAME'		=> "Storable",
+    'VERSION_FROM'	=> 'Storable.pm',
+    'dist'			=> { SUFFIX => 'gz', COMPRESS => 'gzip -f' },
+    'clean'			=> {'FILES' => '*%'},
+);
+
diff --git a/ext/Storable/README b/ext/Storable/README
new file mode 100644
index 0000000000..4c574a0f68
--- /dev/null
+++ b/ext/Storable/README
@@ -0,0 +1,81 @@
+                         Storable 0.7
+               Copyright (c) 1995-2000, Raphael Manfredi
+
+------------------------------------------------------------------------
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the Artistic License, a copy of which can be
+    found with perl.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    Artistic License for more details.
+------------------------------------------------------------------------
+
+       *** This is beta software -- use at your own risks ***
+
++=======================================================================
+|                     PLEASE NOTE CAREFULLY
+|
+|   The serialization format changed between 0.5 and 0.6, and the module
+|   is NOT backward compatible.  Think about it when upgrading from a
+|   pre-0.5@9 version -- images from versions 0.5@9 could still be read
+|   by 0.6, but have not been tested with 0.7.
+|
+|   The next release (0.8 or 1.0) will DROP support for pre-0.6 format.
+|
+|   The serialization format changed between 0.6 and 0.7, and the module
+|   is fully backward compatible, meaning 0.7 can read binary images from
+|   0.6, although it only generates new ones.  If you encounter a situation
+|   where  it is not AND can duplicate it via a small test case, please
+|   send it to me, along with a patch to fix the problem if you can.
++=======================================================================
+
+The Storable extension brings persistency to your data.
+
+You may recursively store to disk any data structure, no matter how
+complex and circular it is, provided it contains only SCALAR, ARRAY,
+HASH (possibly tied) and references (possibly blessed) to those items.
+
+At a later stage, or in another program, you may retrieve data from
+the stored file and recreate the same hiearchy in memory. If you
+had blessed references, the retrieved references are blessed into
+the same package, so you must make sure you have access to the
+same perl class than the one used to create the relevant objects.
+
+There is also a dclone() routine which performs an optimized mirroring
+of any data structure, preserving its topology.
+
+Objects (blessed references) may also redefine the way storage and
+retrieval is performed, and/or what deep cloning should do on those
+objects.
+
+To compile this extension, run:
+
+    perl Makefile.PL [PERL_SRC=...where you put perl sources...]
+    make
+    make install
+
+There is an embeded POD manual page in Storable.pm.
+
+Raphael Manfredi <Raphael_Manfredi@pobox.com>
+
+------------------------------------------------------------------------
+Thanks to:
+
+    Jarkko Hietaniemi <jhi@iki.fi>
+    Ulrich Pfeifer <pfeifer@charly.informatik.uni-dortmund.de>
+    Benjamin A. Holzman <bah@ecnvantage.com>
+    Andrew Ford <A.Ford@ford-mason.co.uk>
+    Gisle Aas <gisle@aas.no>
+    Jeff Gresham <gresham_jeffrey@jpmorgan.com>
+    Murray Nesbitt <murray@activestate.com>
+    Albert N. Micheev <Albert.N.Micheev@f80.n5049.z2.fidonet.org>
+    Marc Lehmann <pcg@opengroup.org>
+
+for their contributions.
+
+There is a Japanese translation of this man page available at
+http://member.nifty.ne.jp/hippo2000/perltips/storable.htm,
+courtesy of Kawai, Takanori <kawai@nippon-rad.co.jp>.
+------------------------------------------------------------------------
diff --git a/ext/Storable/Storable.pm b/ext/Storable/Storable.pm
new file mode 100644
index 0000000000..15d194ceb0
--- /dev/null
+++ b/ext/Storable/Storable.pm
@@ -0,0 +1,627 @@
+;# $Id: Storable.pm,v 0.7.1.2 2000/08/14 07:18:40 ram Exp $
+;#
+;#  Copyright (c) 1995-2000, Raphael Manfredi
+;#  
+;#  You may redistribute only under the terms of the Artistic License,
+;#  as specified in the README file that comes with the distribution.
+;#
+;# $Log: Storable.pm,v $
+;# Revision 0.7.1.2  2000/08/14 07:18:40  ram
+;# patch2: increased version number
+;#
+;# Revision 0.7.1.1  2000/08/13 20:08:58  ram
+;# patch1: mention new Clone(3) extension in SEE ALSO
+;# patch1: contributor Marc Lehmann added overloading and ref to tied items
+;# patch1: updated e-mail from Benjamin Holzman
+;#
+;# Revision 0.7  2000/08/03 22:04:44  ram
+;# Baseline for second beta release.
+;#
+
+require DynaLoader;
+require Exporter;
+package Storable; @ISA = qw(Exporter DynaLoader);
+
+@EXPORT = qw(store retrieve);
+@EXPORT_OK = qw(
+	nstore store_fd nstore_fd retrieve_fd
+	freeze nfreeze thaw
+	dclone
+);
+
+use AutoLoader;
+use vars qw($forgive_me $VERSION);
+
+$VERSION = '0.702';
+*AUTOLOAD = \&AutoLoader::AUTOLOAD;		# Grrr...
+
+#
+# Use of Log::Agent is optional
+#
+
+eval "use Log::Agent";
+
+unless (defined @Log::Agent::EXPORT) {
+	eval q{
+		sub logcroak {
+			require Carp;
+			Carp::croak(@_);
+		}
+	};
+}
+
+sub logcroak;
+
+bootstrap Storable;
+1;
+__END__
+
+#
+# store
+#
+# Store target object hierarchy, identified by a reference to its root.
+# The stored object tree may later be retrieved to memory via retrieve.
+# Returns undef if an I/O error occurred, in which case the file is
+# removed.
+#
+sub store {
+	return _store(\&pstore, @_);
+}
+
+#
+# nstore
+#
+# Same as store, but in network order.
+#
+sub nstore {
+	return _store(\&net_pstore, @_);
+}
+
+# Internal store to file routine
+sub _store {
+	my $xsptr = shift;
+	my $self = shift;
+	my ($file) = @_;
+	logcroak "not a reference" unless ref($self);
+	logcroak "too many arguments" unless @_ == 1;	# No @foo in arglist
+	local *FILE;
+	open(FILE, ">$file") || logcroak "can't create $file: $!";
+	binmode FILE;				# Archaic systems...
+	my $da = $@;				# Don't mess if called from exception handler
+	my $ret;
+	# Call C routine nstore or pstore, depending on network order
+	eval { $ret = &$xsptr(*FILE, $self) };
+	close(FILE) or $ret = undef;
+	unlink($file) or warn "Can't unlink $file: $!\n" if $@ || !defined $ret;
+	logcroak $@ if $@ =~ s/\.?\n$/,/;
+	$@ = $da;
+	return $ret ? $ret : undef;
+}
+
+#
+# store_fd
+#
+# Same as store, but perform on an already opened file descriptor instead.
+# Returns undef if an I/O error occurred.
+#
+sub store_fd {
+	return _store_fd(\&pstore, @_);
+}
+
+#
+# nstore_fd
+#
+# Same as store_fd, but in network order.
+#
+sub nstore_fd {
+	my ($self, $file) = @_;
+	return _store_fd(\&net_pstore, @_);
+}
+
+# Internal store routine on opened file descriptor
+sub _store_fd {
+	my $xsptr = shift;
+	my $self = shift;
+	my ($file) = @_;
+	logcroak "not a reference" unless ref($self);
+	logcroak "too many arguments" unless @_ == 1;	# No @foo in arglist
+	my $fd = fileno($file);
+	logcroak "not a valid file descriptor" unless defined $fd;
+	my $da = $@;				# Don't mess if called from exception handler
+	my $ret;
+	# Call C routine nstore or pstore, depending on network order
+	eval { $ret = &$xsptr($file, $self) };
+	logcroak $@ if $@ =~ s/\.?\n$/,/;
+	$@ = $da;
+	return $ret ? $ret : undef;
+}
+
+#
+# freeze
+#
+# Store oject and its hierarchy in memory and return a scalar
+# containing the result.
+#
+sub freeze {
+	_freeze(\&mstore, @_);
+}
+
+#
+# nfreeze
+#
+# Same as freeze but in network order.
+#
+sub nfreeze {
+	_freeze(\&net_mstore, @_);
+}
+
+# Internal freeze routine
+sub _freeze {
+	my $xsptr = shift;
+	my $self = shift;
+	logcroak "not a reference" unless ref($self);
+	logcroak "too many arguments" unless @_ == 0;	# No @foo in arglist
+	my $da = $@;				# Don't mess if called from exception handler
+	my $ret;
+	# Call C routine mstore or net_mstore, depending on network order
+	eval { $ret = &$xsptr($self) };
+	logcroak $@ if $@ =~ s/\.?\n$/,/;
+	$@ = $da;
+	return $ret ? $ret : undef;
+}
+
+#
+# retrieve
+#
+# Retrieve object hierarchy from disk, returning a reference to the root
+# object of that tree.
+#
+sub retrieve {
+	my ($file) = @_;
+	local *FILE;
+	open(FILE, "$file") || logcroak "can't open $file: $!";
+	binmode FILE;							# Archaic systems...
+	my $self;
+	my $da = $@;							# Could be from exception handler
+	eval { $self = pretrieve(*FILE) };		# Call C routine
+	close(FILE);
+	logcroak $@ if $@ =~ s/\.?\n$/,/;
+	$@ = $da;
+	return $self;
+}
+
+#
+# retrieve_fd
+#
+# Same as retrieve, but perform from an already opened file descriptor instead.
+#
+sub retrieve_fd {
+	my ($file) = @_;
+	my $fd = fileno($file);
+	logcroak "not a valid file descriptor" unless defined $fd;
+	my $self;
+	my $da = $@;							# Could be from exception handler
+	eval { $self = pretrieve($file) };		# Call C routine
+	logcroak $@ if $@ =~ s/\.?\n$/,/;
+	$@ = $da;
+	return $self;
+}
+
+#
+# thaw
+#
+# Recreate objects in memory from an existing frozen image created
+# by freeze.  If the frozen image passed is undef, return undef.
+#
+sub thaw {
+	my ($frozen) = @_;
+	return undef unless defined $frozen;
+	my $self;
+	my $da = $@;							# Could be from exception handler
+	eval { $self = mretrieve($frozen) };	# Call C routine
+	logcroak $@ if $@ =~ s/\.?\n$/,/;
+	$@ = $da;
+	return $self;
+}
+
+=head1 NAME
+
+Storable - persistency for perl data structures
+
+=head1 SYNOPSIS
+
+ use Storable;
+ store \%table, 'file';
+ $hashref = retrieve('file');
+
+ use Storable qw(nstore store_fd nstore_fd freeze thaw dclone);
+
+ # Network order
+ nstore \%table, 'file';
+ $hashref = retrieve('file');	# There is NO nretrieve()
+
+ # Storing to and retrieving from an already opened file
+ store_fd \@array, \*STDOUT;
+ nstore_fd \%table, \*STDOUT;
+ $aryref = retrieve_fd(\*SOCKET);
+ $hashref = retrieve_fd(\*SOCKET);
+
+ # Serializing to memory
+ $serialized = freeze \%table;
+ %table_clone = %{ thaw($serialized) };
+
+ # Deep (recursive) cloning
+ $cloneref = dclone($ref);
+
+=head1 DESCRIPTION
+
+The Storable package brings persistency to your perl data structures
+containing SCALAR, ARRAY, HASH or REF objects, i.e. anything that can be
+convenientely stored to disk and retrieved at a later time.
+
+It can be used in the regular procedural way by calling C<store> with
+a reference to the object to be stored, along with the file name where
+the image should be written.
+The routine returns C<undef> for I/O problems or other internal error,
+a true value otherwise. Serious errors are propagated as a C<die> exception.
+
+To retrieve data stored to disk, use C<retrieve> with a file name,
+and the objects stored into that file are recreated into memory for you,
+a I<reference> to the root object being returned. In case an I/O error
+occurs while reading, C<undef> is returned instead. Other serious
+errors are propagated via C<die>.
+
+Since storage is performed recursively, you might want to stuff references
+to objects that share a lot of common data into a single array or hash
+table, and then store that object. That way, when you retrieve back the
+whole thing, the objects will continue to share what they originally shared.
+
+At the cost of a slight header overhead, you may store to an already
+opened file descriptor using the C<store_fd> routine, and retrieve
+from a file via C<retrieve_fd>. Those names aren't imported by default,
+so you will have to do that explicitely if you need those routines.
+The file descriptor you supply must be already opened, for read
+if you're going to retrieve and for write if you wish to store.
+
+	store_fd(\%table, *STDOUT) || die "can't store to stdout\n";
+	$hashref = retrieve_fd(*STDIN);
+
+You can also store data in network order to allow easy sharing across
+multiple platforms, or when storing on a socket known to be remotely
+connected. The routines to call have an initial C<n> prefix for I<network>,
+as in C<nstore> and C<nstore_fd>. At retrieval time, your data will be
+correctly restored so you don't have to know whether you're restoring
+from native or network ordered data.
+
+When using C<retrieve_fd>, objects are retrieved in sequence, one
+object (i.e. one recursive tree) per associated C<store_fd>.
+
+If you're more from the object-oriented camp, you can inherit from
+Storable and directly store your objects by invoking C<store> as
+a method. The fact that the root of the to-be-stored tree is a
+blessed reference (i.e. an object) is special-cased so that the
+retrieve does not provide a reference to that object but rather the
+blessed object reference itself. (Otherwise, you'd get a reference
+to that blessed object).
+
+=head1 MEMORY STORE
+
+The Storable engine can also store data into a Perl scalar instead, to
+later retrieve them. This is mainly used to freeze a complex structure in
+some safe compact memory place (where it can possibly be sent to another
+process via some IPC, since freezing the structure also serializes it in
+effect). Later on, and maybe somewhere else, you can thaw the Perl scalar
+out and recreate the original complex structure in memory.
+
+Surprisingly, the routines to be called are named C<freeze> and C<thaw>.
+If you wish to send out the frozen scalar to another machine, use
+C<nfreeze> instead to get a portable image.
+
+Note that freezing an object structure and immediately thawing it
+actually achieves a deep cloning of that structure:
+
+    dclone(.) = thaw(freeze(.))
+
+Storable provides you with a C<dclone> interface which does not create
+that intermediary scalar but instead freezes the structure in some
+internal memory space and then immediatly thaws it out.
+
+=head1 SPEED
+
+The heart of Storable is written in C for decent speed. Extra low-level
+optimization have been made when manipulating perl internals, to
+sacrifice encapsulation for the benefit of a greater speed.
+
+=head1 CANONICAL REPRESENTATION
+
+Normally Storable stores elements of hashes in the order they are
+stored internally by Perl, i.e. pseudo-randomly.  If you set
+C<$Storable::canonical> to some C<TRUE> value, Storable will store
+hashes with the elements sorted by their key.  This allows you to
+compare data structures by comparing their frozen representations (or
+even the compressed frozen representations), which can be useful for
+creating lookup tables for complicated queries.
+
+Canonical order does not imply network order, those are two orthogonal
+settings.
+
+=head1 ERROR REPORTING
+
+Storable uses the "exception" paradigm, in that it does not try to workaround
+failures: if something bad happens, an exception is generated from the
+caller's perspective (see L<Carp> and C<croak()>).  Use eval {} to trap
+those exceptions.
+
+When Storable croaks, it tries to report the error via the C<logcroak()>
+routine from the C<Log::Agent> package, if it is available.
+
+=head1 WIZARDS ONLY
+
+=head2 Hooks
+
+Any class may define hooks that will be called during the serialization
+and deserialization process on objects that are instances of that class.
+Those hooks can redefine the way serialization is performed (and therefore,
+how the symetrical deserialization should be conducted).
+
+Since we said earlier:
+
+    dclone(.) = thaw(freeze(.))
+
+everything we say about hooks should also hold for deep cloning. However,
+hooks get to know whether the operation is a mere serialization, or a cloning.
+
+Therefore, when serializing hooks are involved,
+
+    dclone(.) <> thaw(freeze(.))
+
+Well, you could keep them in sync, but there's no guarantee it will always
+hold on classes somebody else wrote.  Besides, there is little to gain in
+doing so: a serializing hook could only keep one attribute of an object,
+which is probably not what should happen during a deep cloning of that
+same object.
+
+Here is the hooking interface:
+
+=over
+
+=item C<STORABLE_freeze> I<obj>, I<cloning>
+
+The serializing hook, called on the object during serialization.  It can be
+inherited, or defined in the class itself, like any other method.
+
+Arguments: I<obj> is the object to serialize, I<cloning> is a flag indicating
+whether we're in a dclone() or a regular serialization via store() or freeze().
+
+Returned value: A LIST C<($serialized, $ref1, $ref2, ...)> where $serialized
+is the serialized form to be used, and the optional $ref1, $ref2, etc... are
+extra references that you wish to let the Storable engine serialize.
+
+At deserialization time, you will be given back the same LIST, but all the
+extra references will be pointing into the deserialized structure.
+
+The B<first time> the hook is hit in a serialization flow, you may have it
+return an empty list.  That will signal the Storable engine to further
+discard that hook for this class and to therefore revert to the default
+serialization of the underlying Perl data.  The hook will again be normally
+processed in the next serialization.
+
+Unless you know better, serializing hook should always say:
+
+    sub STORABLE_freeze {
+        my ($self, $cloning) = @_;
+        return if $cloning;         # Regular default serialization
+        ....
+    }
+
+in order to keep reasonable dclone() semantics.
+
+=item C<STORABLE_thaw> I<obj>, I<cloning>, I<serialized>, ...
+
+The deserializing hook called on the object during deserialization.
+But wait. If we're deserializing, there's no object yet... right?
+
+Wrong: the Storable engine creates an empty one for you.  If you know Eiffel,
+you can view C<STORABLE_thaw> as an alternate creation routine.
+
+This means the hook can be inherited like any other method, and that
+I<obj> is your blessed reference for this particular instance.
+
+The other arguments should look familiar if you know C<STORABLE_freeze>:
+I<cloning> is true when we're part of a deep clone operation, I<serialized>
+is the serialized string you returned to the engine in C<STORABLE_freeze>,
+and there may be an optional list of references, in the same order you gave
+them at serialization time, pointing to the deserialized objects (which
+have been processed courtesy of the Storable engine).
+
+It is up to you to use these information to populate I<obj> the way you want.
+
+Returned value: none.
+
+=back
+
+=head2 Predicates
+
+Predicates are not exportable.  They must be called by explicitely prefixing
+them with the Storable package name.
+
+=over
+
+=item C<Storable::last_op_in_netorder>
+
+The C<Storable::last_op_in_netorder()> predicate will tell you whether
+network order was used in the last store or retrieve operation.  If you
+don't know how to use this, just forget about it.
+
+=item C<Storable::is_storing>
+
+Returns true if within a store operation (via STORABLE_freeze hook).
+
+=item C<Storable::is_retrieving>
+
+Returns true if within a retrieve operation, (via STORABLE_thaw hook).
+
+=back
+
+=head2 Recursion
+
+With hooks comes the ability to recurse back to the Storable engine.  Indeed,
+hooks are regular Perl code, and Storable is convenient when it comes to
+serialize and deserialize things, so why not use it to handle the
+serialization string?
+
+There are a few things you need to know however:
+
+=over
+
+=item *
+
+You can create endless loops if the things you serialize via freeze()
+(for instance) point back to the object we're trying to serialize in the hook.
+
+=item *
+
+Shared references among objects will not stay shared: if we're serializing
+the list of object [A, C] where both object A and C refer to the SAME object
+B, and if there is a serializing hook in A that says freeze(B), then when
+deserializing, we'll get [A', C'] where A' refers to B', but C' refers to D,
+a deep clone of B'.  The topology was not preserved.
+
+=back
+
+That's why C<STORABLE_freeze> lets you provide a list of references
+to serialize.  The engine guarantees that those will be serialized in the
+same context as the other objects, and therefore that shared objects will
+stay shared.
+
+In the above [A, C] example, the C<STORABLE_freeze> hook could return:
+
+	("something", $self->{B})
+
+and the B part would be serialized by the engine.  In C<STORABLE_thaw>, you
+would get back the reference to the B' object, deserialized for you.
+
+Therefore, recursion should normally be avoided, but is nonetheless supported.
+
+=head2 Deep Cloning
+
+There is a new Clone module available on CPAN which implements deep cloning
+natively, i.e. without freezing to memory and thawing the result.  It is
+aimed to replace Storable's dclone() some day.  However, it does not currently
+support Storable hooks to redefine the way deep cloning is performed.
+
+=head1 EXAMPLES
+
+Here are some code samples showing a possible usage of Storable:
+
+	use Storable qw(store retrieve freeze thaw dclone);
+
+	%color = ('Blue' => 0.1, 'Red' => 0.8, 'Black' => 0, 'White' => 1);
+
+	store(\%color, '/tmp/colors') or die "Can't store %a in /tmp/colors!\n";
+
+	$colref = retrieve('/tmp/colors');
+	die "Unable to retrieve from /tmp/colors!\n" unless defined $colref;
+	printf "Blue is still %lf\n", $colref->{'Blue'};
+
+	$colref2 = dclone(\%color);
+
+	$str = freeze(\%color);
+	printf "Serialization of %%color is %d bytes long.\n", length($str);
+	$colref3 = thaw($str);
+
+which prints (on my machine):
+
+	Blue is still 0.100000
+	Serialization of %color is 102 bytes long.
+
+=head1 WARNING
+
+If you're using references as keys within your hash tables, you're bound
+to disapointment when retrieving your data. Indeed, Perl stringifies
+references used as hash table keys. If you later wish to access the
+items via another reference stringification (i.e. using the same
+reference that was used for the key originally to record the value into
+the hash table), it will work because both references stringify to the
+same string.
+
+It won't work across a C<store> and C<retrieve> operations however, because
+the addresses in the retrieved objects, which are part of the stringified
+references, will probably differ from the original addresses. The
+topology of your structure is preserved, but not hidden semantics
+like those.
+
+On platforms where it matters, be sure to call C<binmode()> on the
+descriptors that you pass to Storable functions.
+
+Storing data canonically that contains large hashes can be
+significantly slower than storing the same data normally, as
+temprorary arrays to hold the keys for each hash have to be allocated,
+populated, sorted and freed.  Some tests have shown a halving of the
+speed of storing -- the exact penalty will depend on the complexity of
+your data.  There is no slowdown on retrieval.
+
+=head1 BUGS
+
+You can't store GLOB, CODE, FORMLINE, etc... If you can define
+semantics for those operations, feel free to enhance Storable so that
+it can deal with them.
+
+The store functions will C<croak> if they run into such references
+unless you set C<$Storable::forgive_me> to some C<TRUE> value. In that
+case, the fatal message is turned in a warning and some
+meaningless string is stored instead.
+
+Setting C<$Storable::canonical> may not yield frozen strings that
+compare equal due to possible stringification of numbers. When the
+string version of a scalar exists, it is the form stored, therefore
+if you happen to use your numbers as strings between two freezing
+operations on the same data structures, you will get different
+results.
+
+Due to the aforementionned optimizations, Storable is at the mercy
+of perl's internal redesign or structure changes. If that bothers
+you, you can try convincing Larry that what is used in Storable
+should be documented and consistently kept in future revisions.
+
+=head1 CREDITS
+
+Thank you to (in chronological order):
+
+	Jarkko Hietaniemi <jhi@iki.fi>
+	Ulrich Pfeifer <pfeifer@charly.informatik.uni-dortmund.de>
+	Benjamin A. Holzman <bah@ecnvantage.com>
+	Andrew Ford <A.Ford@ford-mason.co.uk>
+	Gisle Aas <gisle@aas.no>
+	Jeff Gresham <gresham_jeffrey@jpmorgan.com>
+	Murray Nesbitt <murray@activestate.com>
+	Marc Lehmann <pcg@opengroup.org>
+
+for their bug reports, suggestions and contributions.
+
+Benjamin Holzman contributed the tied variable support, Andrew Ford
+contributed the canonical order for hashes, and Gisle Aas fixed
+a few misunderstandings of mine regarding the Perl internals,
+and optimized the emission of "tags" in the output streams by
+simply counting the objects instead of tagging them (leading to
+a binary incompatibility for the Storable image starting at version
+0.6--older images are of course still properly understood).
+Murray Nesbitt made Storable thread-safe.  Marc Lehmann added overloading
+and reference to tied items support.
+
+=head1 TRANSLATIONS
+
+There is a Japanese translation of this man page available at
+http://member.nifty.ne.jp/hippo2000/perltips/storable.htm ,
+courtesy of Kawai, Takanori <kawai@nippon-rad.co.jp>.
+
+=head1 AUTHOR
+
+Raphael Manfredi F<E<lt>Raphael_Manfredi@pobox.comE<gt>>
+
+=head1 SEE ALSO
+
+Clone(3).
+
+=cut
+
diff --git a/ext/Storable/Storable.xs b/ext/Storable/Storable.xs
new file mode 100644
index 0000000000..3de5891d1c
--- /dev/null
+++ b/ext/Storable/Storable.xs
@@ -0,0 +1,4510 @@
+/*
+ * Store and retrieve mechanism.
+ */
+
+/*
+ * $Id: Storable.xs,v 0.7.1.2 2000/08/14 07:19:27 ram Exp $
+ *
+ *  Copyright (c) 1995-2000, Raphael Manfredi
+ *  
+ *  You may redistribute only under the terms of the Artistic License,
+ *  as specified in the README file that comes with the distribution.
+ *
+ * $Log: Storable.xs,v $
+ * Revision 0.7.1.2  2000/08/14 07:19:27  ram
+ * patch2: added a refcnt dec in retrieve_tied_key()
+ *
+ * Revision 0.7.1.1  2000/08/13 20:10:06  ram
+ * patch1: was wrongly optimizing for "undef" values in hashes
+ * patch1: added support for ref to tied items in hash/array
+ * patch1: added overloading support
+ *
+ * Revision 0.7  2000/08/03 22:04:44  ram
+ * Baseline for second beta release.
+ *
+ */
+
+#include <EXTERN.h>
+#include <perl.h>
+#include <patchlevel.h>		/* Perl's one, needed since 5.6 */
+#include <XSUB.h>
+
+/*#define DEBUGME /* Debug mode, turns assertions on as well */
+/*#define DASSERT /* Assertion mode */
+
+/*
+ * Pre PerlIO time when none of USE_PERLIO and PERLIO_IS_STDIO is defined
+ * Provide them with the necessary defines so they can build with pre-5.004.
+ */
+#ifndef USE_PERLIO
+#ifndef PERLIO_IS_STDIO
+#define PerlIO FILE
+#define PerlIO_getc(x) getc(x)
+#define PerlIO_putc(f,x) putc(x,f)
+#define PerlIO_read(x,y,z) fread(y,1,z,x)
+#define PerlIO_write(x,y,z) fwrite(y,1,z,x)
+#define PerlIO_stdoutf printf
+#endif	/* PERLIO_IS_STDIO */
+#endif	/* USE_PERLIO */
+
+/*
+ * Earlier versions of perl might be used, we can't assume they have the latest!
+ */
+#ifndef newRV_noinc
+#define newRV_noinc(sv)		((Sv = newRV(sv)), --SvREFCNT(SvRV(Sv)), Sv)
+#endif
+#if (PATCHLEVEL <= 4)		/* Older perls (<= 5.004) lack PL_ namespace */
+#define PL_sv_yes	sv_yes
+#define PL_sv_no	sv_no
+#define PL_sv_undef	sv_undef
+#endif
+#ifndef HvSHAREKEYS_off
+#define HvSHAREKEYS_off(hv)	/* Ignore */
+#endif
+
+#ifdef DEBUGME
+#ifndef DASSERT
+#define DASSERT
+#endif
+#define TRACEME(x)	do { PerlIO_stdoutf x; PerlIO_stdoutf("\n"); } while (0)
+#else
+#define TRACEME(x)
+#endif
+
+#ifdef DASSERT
+#define ASSERT(x,y)	do {									\
+	if (!(x)) {												\
+		PerlIO_stdoutf("ASSERT FAILED (\"%s\", line %d): ",	\
+			__FILE__, __LINE__);							\
+		PerlIO_stdoutf y; PerlIO_stdoutf("\n");				\
+	}														\
+} while (0)
+#else
+#define ASSERT(x,y)
+#endif
+
+/*
+ * Type markers.
+ */
+
+#define C(x) ((char) (x))	/* For markers with dynamic retrieval handling */
+
+#define SX_OBJECT	C(0)	/* Already stored object */
+#define SX_LSCALAR	C(1)	/* Scalar (string) forthcoming (length, data) */
+#define SX_ARRAY	C(2)	/* Array forthcominng (size, item list) */
+#define SX_HASH		C(3)	/* Hash forthcoming (size, key/value pair list) */
+#define SX_REF		C(4)	/* Reference to object forthcoming */
+#define SX_UNDEF	C(5)	/* Undefined scalar */
+#define SX_INTEGER	C(6)	/* Integer forthcoming */
+#define SX_DOUBLE	C(7)	/* Double forthcoming */
+#define SX_BYTE		C(8)	/* (signed) byte forthcoming */
+#define SX_NETINT	C(9)	/* Integer in network order forthcoming */
+#define SX_SCALAR	C(10)	/* Scalar (small) forthcoming (length, data) */
+#define SX_TIED_ARRAY  C(11)  /* Tied array forthcoming */
+#define SX_TIED_HASH   C(12)  /* Tied hash forthcoming */
+#define SX_TIED_SCALAR C(13)  /* Tied scalar forthcoming */
+#define SX_SV_UNDEF	C(14)	/* Perl's immortal PL_sv_undef */
+#define SX_SV_YES	C(15)	/* Perl's immortal PL_sv_yes */
+#define SX_SV_NO	C(16)	/* Perl's immortal PL_sv_no */
+#define SX_BLESS	C(17)	/* Object is blessed */
+#define SX_IX_BLESS	C(18)	/* Object is blessed, classname given by index */
+#define SX_HOOK		C(19)	/* Stored via hook, user-defined */
+#define SX_OVERLOAD	C(20)	/* Overloaded reference */
+#define SX_TIED_KEY C(21)   /* Tied magic key forthcoming */
+#define SX_TIED_IDX C(22)   /* Tied magic index forthcoming */
+#define SX_ERROR	C(23)	/* Error */
+
+/*
+ * Those are only used to retrieve "old" pre-0.6 binary images.
+ */
+#define SX_ITEM		'i'		/* An array item introducer */
+#define SX_IT_UNDEF	'I'		/* Undefined array item */
+#define SX_KEY		'k'		/* An hash key introducer */
+#define SX_VALUE	'v'		/* An hash value introducer */
+#define SX_VL_UNDEF	'V'		/* Undefined hash value */
+
+/*
+ * Those are only used to retrieve "old" pre-0.7 binary images
+ */
+
+#define SX_CLASS	'b'		/* Object is blessed, class name length <255 */
+#define SX_LG_CLASS 'B'		/* Object is blessed, class name length >255 */
+#define SX_STORED	'X'		/* End of object */
+
+/*
+ * Limits between short/long length representation.
+ */
+
+#define LG_SCALAR	255		/* Large scalar length limit */
+#define LG_BLESS	127		/* Large classname bless limit */
+
+/*
+ * Operation types
+ */
+
+#define ST_STORE	0x1		/* Store operation */
+#define ST_RETRIEVE	0x2		/* Retrieval operation */
+#define ST_CLONE	0x4		/* Deep cloning operation */
+
+/*
+ * The following structure is used for hash table key retrieval. Since, when
+ * retrieving objects, we'll be facing blessed hash references, it's best
+ * to pre-allocate that buffer once and resize it as the need arises, never
+ * freeing it (keys will be saved away someplace else anyway, so even large
+ * keys are not enough a motivation to reclaim that space).
+ *
+ * This structure is also used for memory store/retrieve operations which
+ * happen in a fixed place before being malloc'ed elsewhere if persistency
+ * is required. Hence the aptr pointer.
+ */
+struct extendable {
+	char *arena;		/* Will hold hash key strings, resized as needed */
+	STRLEN asiz;		/* Size of aforementionned buffer */
+	char *aptr;			/* Arena pointer, for in-place read/write ops */
+	char *aend;			/* First invalid address */
+};
+
+/*
+ * At store time:
+ * An hash table records the objects which have already been stored.
+ * Those are referred to as SX_OBJECT in the file, and their "tag" (i.e.
+ * an arbitrary sequence number) is used to identify them.
+ *
+ * At retrieve time:
+ * An array table records the objects which have already been retrieved,
+ * as seen by the tag determind by counting the objects themselves. The
+ * reference to that retrieved object is kept in the table, and is returned
+ * when an SX_OBJECT is found bearing that same tag.
+ *
+ * The same processing is used to record "classname" for blessed objects:
+ * indexing by a hash at store time, and via an array at retrieve time.
+ */
+
+typedef unsigned long stag_t;	/* Used by pre-0.6 binary format */
+
+/*
+ * The following "thread-safe" related defines were contributed by
+ * Murray Nesbitt <murray@activestate.com> and integrated by RAM, who
+ * only renamed things a little bit to ensure consistency with surrounding
+ * code.	-- RAM, 14/09/1999
+ *
+ * The original patch suffered from the fact that the stcxt_t structure
+ * was global.  Murray tried to minimize the impact on the code as much as
+ * possible.
+ *
+ * Starting with 0.7, Storable can be re-entrant, via the STORABLE_xxx hooks
+ * on objects.  Therefore, the notion of context needs to be generalized,
+ * threading or not.
+ */
+
+#define MY_VERSION "Storable(" XS_VERSION ")"
+
+typedef struct stcxt {
+	int entry;			/* flags recursion */
+	int optype;			/* type of traversal operation */
+    HV *hseen;			/* which objects have been seen, store time */
+    AV *aseen;			/* which objects have been seen, retrieve time */
+    HV *hclass;			/* which classnames have been seen, store time */
+    AV *aclass;			/* which classnames have been seen, retrieve time */
+    HV *hook;			/* cache for hook methods per class name */
+    I32 tagnum;			/* incremented at store time for each seen object */
+    I32 classnum;		/* incremented at store time for each seen classname */
+    int netorder;		/* true if network order used */
+    int forgive_me;		/* whether to be forgiving... */
+    int canonical;		/* whether to store hashes sorted by key */
+	int dirty;			/* context is dirty due to CROAK() -- can be cleaned */
+    struct extendable keybuf;	/* for hash key retrieval */
+    struct extendable membuf;	/* for memory store/retrieve operations */
+	PerlIO *fio;		/* where I/O are performed, NULL for memory */
+	int ver_major;		/* major of version for retrieved object */
+	int ver_minor;		/* minor of version for retrieved object */
+	SV *(**retrieve_vtbl)();	/* retrieve dispatch table */
+	struct stcxt *prev;	/* contexts chained backwards in real recursion */
+} stcxt_t;
+
+#if defined(MULTIPLICITY) || defined(PERL_OBJECT) || defined(PERL_CAPI)
+
+#if (PATCHLEVEL <= 4) && (SUBVERSION < 68)
+#define dSTCXT_SV 									\
+	SV *perinterp_sv = perl_get_sv(MY_VERSION, FALSE)
+#else	/* >= perl5.004_68 */
+#define dSTCXT_SV									\
+	SV *perinterp_sv = *hv_fetch(PL_modglobal,		\
+		MY_VERSION, sizeof(MY_VERSION)-1, TRUE)
+#endif	/* < perl5.004_68 */
+
+#define dSTCXT_PTR(T,name)							\
+	T name = (T)(perinterp_sv && SvIOK(perinterp_sv)\
+				? SvIVX(perinterp_sv) : NULL)
+#define dSTCXT										\
+	dSTCXT_SV;										\
+	dSTCXT_PTR(stcxt_t *, cxt)
+
+#define INIT_STCXT									\
+      dSTCXT;										\
+      Newz(0, cxt, 1, stcxt_t);						\
+      sv_setiv(perinterp_sv, (IV) cxt)
+
+#define SET_STCXT(x) do {							\
+	dSTCXT_SV;										\
+	sv_setiv(perinterp_sv, (IV) (x));				\
+} while (0)
+
+#else /* !MULTIPLICITY && !PERL_OBJECT && !PERL_CAPI */
+
+static stcxt_t Context;
+static stcxt_t *Context_ptr = &Context;
+#define dSTCXT			stcxt_t *cxt = Context_ptr
+#define INIT_STCXT		dSTCXT
+#define SET_STCXT(x)	Context_ptr = x
+
+#endif /* MULTIPLICITY || PERL_OBJECT || PERL_CAPI */
+
+/*
+ * KNOWN BUG:
+ *   Croaking implies a memory leak, since we don't use setjmp/longjmp
+ *   to catch the exit and free memory used during store or retrieve
+ *   operations.  This is not too difficult to fix, but I need to understand
+ *   how Perl does it, and croaking is exceptional anyway, so I lack the
+ *   motivation to do it.
+ *
+ * The current workaround is to mark the context as dirty when croaking,
+ * so that data structures can be freed whenever we renter Storable code
+ * (but only *then*: it's a workaround, not a fix).
+ *
+ * This is also imperfect, because we don't really know how far they trapped
+ * the croak(), and when we were recursing, we won't be able to clean anything
+ * but the topmost context stacked.
+ */
+
+#define CROAK(x)	do { cxt->dirty = 1; croak x; } while (0)
+
+/*
+ * End of "thread-safe" related definitions.
+ */
+
+/*
+ * key buffer handling
+ */
+#define kbuf	(cxt->keybuf).arena
+#define ksiz	(cxt->keybuf).asiz
+#define KBUFINIT() do {					\
+	if (!kbuf) {						\
+		TRACEME(("** allocating kbuf of 128 bytes")); \
+		New(10003, kbuf, 128, char);	\
+		ksiz = 128;						\
+	}									\
+} while (0)
+#define KBUFCHK(x) do {			\
+	if (x >= ksiz) {			\
+		TRACEME(("** extending kbuf to %d bytes", x+1)); \
+		Renew(kbuf, x+1, char);	\
+		ksiz = x+1;				\
+	}							\
+} while (0)
+
+/*
+ * memory buffer handling
+ */
+#define mbase	(cxt->membuf).arena
+#define msiz	(cxt->membuf).asiz
+#define mptr	(cxt->membuf).aptr
+#define mend	(cxt->membuf).aend
+
+#define MGROW	(1 << 13)
+#define MMASK	(MGROW - 1)
+
+#define round_mgrow(x)	\
+	((unsigned long) (((unsigned long) (x) + MMASK) & ~MMASK))
+#define trunc_int(x)	\
+	((unsigned long) ((unsigned long) (x) & ~(sizeof(int)-1)))
+#define int_aligned(x)	\
+	((unsigned long) (x) == trunc_int(x))
+
+#define MBUF_INIT(x) do {				\
+	if (!mbase) {						\
+		TRACEME(("** allocating mbase of %d bytes", MGROW)); \
+		New(10003, mbase, MGROW, char);	\
+		msiz = MGROW;					\
+	}									\
+	mptr = mbase;						\
+	if (x)								\
+		mend = mbase + x;				\
+	else								\
+		mend = mbase + msiz;			\
+} while (0)
+
+#define MBUF_TRUNC(x)	mptr = mbase + x
+#define MBUF_SIZE()		(mptr - mbase)
+
+/*
+ * Use SvPOKp(), because SvPOK() fails on tainted scalars.
+ * See store_scalar() for other usage of this workaround.
+ */
+#define MBUF_LOAD(v) do {				\
+	if (!SvPOKp(v))						\
+		CROAK(("Not a scalar string"));	\
+	mptr = mbase = SvPV(v, msiz);		\
+	mend = mbase + msiz;				\
+} while (0)
+
+#define MBUF_XTEND(x) do {			\
+	int nsz = (int) round_mgrow((x)+msiz);	\
+	int offset = mptr - mbase;		\
+	TRACEME(("** extending mbase to %d bytes", nsz));	\
+	Renew(mbase, nsz, char);		\
+	msiz = nsz;						\
+	mptr = mbase + offset;			\
+	mend = mbase + nsz;				\
+} while (0)
+
+#define MBUF_CHK(x) do {			\
+	if ((mptr + (x)) > mend)		\
+		MBUF_XTEND(x);				\
+} while (0)
+
+#define MBUF_GETC(x) do {			\
+	if (mptr < mend)				\
+		x = (int) (unsigned char) *mptr++;	\
+	else							\
+		return (SV *) 0;			\
+} while (0)
+
+#define MBUF_GETINT(x) do {				\
+	if ((mptr + sizeof(int)) <= mend) {	\
+		if (int_aligned(mptr))			\
+			x = *(int *) mptr;			\
+		else							\
+			memcpy(&x, mptr, sizeof(int));	\
+		mptr += sizeof(int);			\
+	} else								\
+		return (SV *) 0;				\
+} while (0)
+
+#define MBUF_READ(x,s) do {			\
+	if ((mptr + (s)) <= mend) {		\
+		memcpy(x, mptr, s);			\
+		mptr += s;					\
+	} else							\
+		return (SV *) 0;			\
+} while (0)
+
+#define MBUF_SAFEREAD(x,s,z) do {	\
+	if ((mptr + (s)) <= mend) {		\
+		memcpy(x, mptr, s);			\
+		mptr += s;					\
+	} else {						\
+		sv_free(z);					\
+		return (SV *) 0;			\
+	}								\
+} while (0)
+
+#define MBUF_PUTC(c) do {			\
+	if (mptr < mend)				\
+		*mptr++ = (char) c;			\
+	else {							\
+		MBUF_XTEND(1);				\
+		*mptr++ = (char) c;			\
+	}								\
+} while (0)
+
+#define MBUF_PUTINT(i) do {			\
+	MBUF_CHK(sizeof(int));			\
+	if (int_aligned(mptr))			\
+		*(int *) mptr = i;			\
+	else							\
+		memcpy(mptr, &i, sizeof(int));	\
+	mptr += sizeof(int);			\
+} while (0)
+
+#define MBUF_WRITE(x,s) do {		\
+	MBUF_CHK(s);					\
+	memcpy(mptr, x, s);				\
+	mptr += s;						\
+} while (0)
+
+/*
+ * LOW_32BITS
+ *
+ * Keep only the low 32 bits of a pointer (used for tags, which are not
+ * really pointers).
+ */
+
+#if PTRSIZE <= 4
+#define LOW_32BITS(x)	((I32) (x))
+#else
+#if BYTEORDER == 0x87654321
+#define LOW_32BITS(x)	((I32) ((unsigned long) (x) & 0xffffffff00000000UL))
+#else       /* BYTEORDER == 0x12345678 */
+#define LOW_32BITS(x)	((I32) ((unsigned long) (x) & 0xffffffffUL))
+#endif
+#endif
+
+/*
+ * Possible return values for sv_type().
+ */
+
+#define svis_REF		0
+#define svis_SCALAR		1
+#define svis_ARRAY		2
+#define svis_HASH		3
+#define svis_TIED		4
+#define svis_TIED_ITEM	5
+#define svis_OTHER		6
+
+/*
+ * Flags for SX_HOOK.
+ */
+
+#define SHF_TYPE_MASK		0x03
+#define SHF_LARGE_CLASSLEN	0x04
+#define SHF_LARGE_STRLEN	0x08
+#define SHF_LARGE_LISTLEN	0x10
+#define SHF_IDX_CLASSNAME	0x20
+#define SHF_NEED_RECURSE	0x40
+#define SHF_HAS_LIST		0x80
+
+/*
+ * Types for SX_HOOK (2 bits).
+ */
+
+#define SHT_SCALAR			0
+#define SHT_ARRAY			1
+#define SHT_HASH			2
+
+/*
+ * Before 0.6, the magic string was "perl-store" (binary version number 0).
+ *
+ * Since 0.6 introduced many binary incompatibilities, the magic string has
+ * been changed to "pst0" to allow an old image to be properly retrieved by
+ * a newer Storable, but ensure a newer image cannot be retrieved with an
+ * older version.
+ *
+ * At 0.7, objects are given the ability to serialize themselves, and the
+ * set of markers is extended, backward compatibility is not jeopardized,
+ * so the binary version number could have remained unchanged.  To correctly
+ * spot errors if a file making use of 0.7-specific extensions is given to
+ * 0.6 for retrieval, the binary version was moved to "2".  And I'm introducing
+ * a "minor" version, to better track this kind of evolution from now on.
+ * 
+ */
+static char old_magicstr[] = "perl-store";	/* Magic number before 0.6 */
+static char magicstr[] = "pst0";			/* Used as a magic number */
+
+#define STORABLE_BIN_MAJOR	2				/* Binary major "version" */
+#define STORABLE_BIN_MINOR	1				/* Binary minor "version" */
+
+/*
+ * Useful store shortcuts...
+ */
+
+#define PUTMARK(x) do {						\
+	if (!cxt->fio)							\
+		MBUF_PUTC(x);						\
+	else if (PerlIO_putc(cxt->fio, x) == EOF)	\
+		return -1;							\
+} while (0)
+
+#ifdef HAS_HTONL
+#define WLEN(x)	do {				\
+	if (cxt->netorder) {			\
+		int y = (int) htonl(x);		\
+		if (!cxt->fio)				\
+			MBUF_PUTINT(y);			\
+		else if (PerlIO_write(cxt->fio, &y, sizeof(y)) != sizeof(y))	\
+			return -1;				\
+	} else {						\
+		if (!cxt->fio)				\
+			MBUF_PUTINT(x);			\
+		else if (PerlIO_write(cxt->fio, &x, sizeof(x)) != sizeof(x))	\
+			return -1;				\
+	}								\
+} while (0)
+#else
+#define WLEN(x)	do {				\
+	if (!cxt->fio)					\
+		MBUF_PUTINT(x);				\
+	else if (PerlIO_write(cxt->fio, &x, sizeof(x)) != sizeof(x))	\
+		return -1;					\
+	} while (0)
+#endif
+
+#define WRITE(x,y) do {						\
+	if (!cxt->fio)							\
+		MBUF_WRITE(x,y);					\
+	else if (PerlIO_write(cxt->fio, x, y) != y)	\
+		return -1;							\
+	} while (0)
+
+#define STORE_SCALAR(pv, len) do {		\
+	if (len <= LG_SCALAR) {				\
+		unsigned char clen = (unsigned char) len;	\
+		PUTMARK(SX_SCALAR);				\
+		PUTMARK(clen);					\
+		if (len)						\
+			WRITE(pv, len);				\
+	} else {							\
+		PUTMARK(SX_LSCALAR);			\
+		WLEN(len);						\
+		WRITE(pv, len);					\
+	}									\
+} while (0)
+
+/*
+ * Store undef in arrays and hashes without recursing through store().
+ */
+#define STORE_UNDEF() do {				\
+	cxt->tagnum++;						\
+	PUTMARK(SX_UNDEF);					\
+} while (0)
+
+/*
+ * Useful retrieve shortcuts...
+ */
+
+#define GETCHAR() \
+	(cxt->fio ? PerlIO_getc(cxt->fio) : (mptr >= mend ? EOF : (int) *mptr++))
+
+#define GETMARK(x) do {							\
+	if (!cxt->fio)								\
+		MBUF_GETC(x);							\
+	else if ((x = PerlIO_getc(cxt->fio)) == EOF)	\
+		return (SV *) 0;						\
+} while (0)
+
+#ifdef HAS_NTOHL
+#define RLEN(x)	do {					\
+	if (!cxt->fio)						\
+		MBUF_GETINT(x);					\
+	else if (PerlIO_read(cxt->fio, &x, sizeof(x)) != sizeof(x))	\
+		return (SV *) 0;				\
+	if (cxt->netorder)					\
+		x = (int) ntohl(x);				\
+} while (0)
+#else
+#define RLEN(x)	do {					\
+	if (!cxt->fio)						\
+		MBUF_GETINT(x);					\
+	else if (PerlIO_read(cxt->fio, &x, sizeof(x)) != sizeof(x))	\
+		return (SV *) 0;				\
+} while (0)
+#endif
+
+#define READ(x,y) do {						\
+	if (!cxt->fio)							\
+		MBUF_READ(x, y);					\
+	else if (PerlIO_read(cxt->fio, x, y) != y)	\
+		return (SV *) 0;					\
+} while (0)
+
+#define SAFEREAD(x,y,z) do { 					\
+	if (!cxt->fio)								\
+		MBUF_SAFEREAD(x,y,z);					\
+	else if (PerlIO_read(cxt->fio, x, y) != y)	 {	\
+		sv_free(z);								\
+		return (SV *) 0;						\
+	}											\
+} while (0)
+
+/*
+ * This macro is used at retrieve time, to remember where object 'y', bearing a
+ * given tag 'tagnum', has been retrieved. Next time we see an SX_OBJECT marker,
+ * we'll therefore know where it has been retrieved and will be able to
+ * share the same reference, as in the original stored memory image.
+ */
+#define SEEN(y) do {						\
+	if (!y)									\
+		return (SV *) 0;					\
+	if (av_store(cxt->aseen, cxt->tagnum++, SvREFCNT_inc(y)) == 0) \
+		return (SV *) 0;					\
+	TRACEME(("aseen(#%d) = 0x%lx (refcnt=%d)", cxt->tagnum-1, \
+		(unsigned long) y, SvREFCNT(y)-1)); \
+} while (0)
+
+/*
+ * Bless `s' in `p', via a temporary reference, required by sv_bless().
+ */
+#define BLESS(s,p) do {					\
+	SV *ref;								\
+	HV *stash;								\
+	TRACEME(("blessing 0x%lx in %s", (unsigned long) (s), (p))); \
+	stash = gv_stashpv((p), TRUE);			\
+	ref = newRV_noinc(s);					\
+	(void) sv_bless(ref, stash);			\
+	SvRV(ref) = 0;							\
+	SvREFCNT_dec(ref);						\
+} while (0)
+
+static int store();
+static SV *retrieve();
+
+/*
+ * Dynamic dispatching table for SV store.
+ */
+
+static int store_ref(stcxt_t *cxt, SV *sv);
+static int store_scalar(stcxt_t *cxt, SV *sv);
+static int store_array(stcxt_t *cxt, AV *av);
+static int store_hash(stcxt_t *cxt, HV *hv);
+static int store_tied(stcxt_t *cxt, SV *sv);
+static int store_tied_item(stcxt_t *cxt, SV *sv);
+static int store_other(stcxt_t *cxt, SV *sv);
+
+static int (*sv_store[])() = {
+	store_ref,			/* svis_REF */
+	store_scalar,		/* svis_SCALAR */
+	store_array,		/* svis_ARRAY */
+	store_hash,			/* svis_HASH */
+	store_tied,			/* svis_TIED */
+	store_tied_item,	/* svis_TIED_ITEM */
+	store_other,		/* svis_OTHER */
+};
+
+#define SV_STORE(x)	(*sv_store[x])
+
+/*
+ * Dynamic dispatching tables for SV retrieval.
+ */
+
+static SV *retrieve_lscalar(stcxt_t *cxt);
+static SV *old_retrieve_array(stcxt_t *cxt);
+static SV *old_retrieve_hash(stcxt_t *cxt);
+static SV *retrieve_ref(stcxt_t *cxt);
+static SV *retrieve_undef(stcxt_t *cxt);
+static SV *retrieve_integer(stcxt_t *cxt);
+static SV *retrieve_double(stcxt_t *cxt);
+static SV *retrieve_byte(stcxt_t *cxt);
+static SV *retrieve_netint(stcxt_t *cxt);
+static SV *retrieve_scalar(stcxt_t *cxt);
+static SV *retrieve_tied_array(stcxt_t *cxt);
+static SV *retrieve_tied_hash(stcxt_t *cxt);
+static SV *retrieve_tied_scalar(stcxt_t *cxt);
+static SV *retrieve_other(stcxt_t *cxt);
+
+static SV *(*sv_old_retrieve[])() = {
+	0,			/* SX_OBJECT -- entry unused dynamically */
+	retrieve_lscalar,		/* SX_LSCALAR */
+	old_retrieve_array,		/* SX_ARRAY -- for pre-0.6 binaries */
+	old_retrieve_hash,		/* SX_HASH -- for pre-0.6 binaries */
+	retrieve_ref,			/* SX_REF */
+	retrieve_undef,			/* SX_UNDEF */
+	retrieve_integer,		/* SX_INTEGER */
+	retrieve_double,		/* SX_DOUBLE */
+	retrieve_byte,			/* SX_BYTE */
+	retrieve_netint,		/* SX_NETINT */
+	retrieve_scalar,		/* SX_SCALAR */
+	retrieve_tied_array,	/* SX_ARRAY */
+	retrieve_tied_hash,		/* SX_HASH */
+	retrieve_tied_scalar,	/* SX_SCALAR */
+	retrieve_other,			/* SX_SV_UNDEF not supported */
+	retrieve_other,			/* SX_SV_YES not supported */
+	retrieve_other,			/* SX_SV_NO not supported */
+	retrieve_other,			/* SX_BLESS not supported */
+	retrieve_other,			/* SX_IX_BLESS not supported */
+	retrieve_other,			/* SX_HOOK not supported */
+	retrieve_other,			/* SX_OVERLOADED not supported */
+	retrieve_other,			/* SX_TIED_KEY not supported */
+	retrieve_other,			/* SX_TIED_IDX not supported */
+	retrieve_other,			/* SX_ERROR */
+};
+
+static SV *retrieve_array(stcxt_t *cxt);
+static SV *retrieve_hash(stcxt_t *cxt);
+static SV *retrieve_sv_undef(stcxt_t *cxt);
+static SV *retrieve_sv_yes(stcxt_t *cxt);
+static SV *retrieve_sv_no(stcxt_t *cxt);
+static SV *retrieve_blessed(stcxt_t *cxt);
+static SV *retrieve_idx_blessed(stcxt_t *cxt);
+static SV *retrieve_hook(stcxt_t *cxt);
+static SV *retrieve_overloaded(stcxt_t *cxt);
+static SV *retrieve_tied_key(stcxt_t *cxt);
+static SV *retrieve_tied_idx(stcxt_t *cxt);
+
+static SV *(*sv_retrieve[])() = {
+	0,			/* SX_OBJECT -- entry unused dynamically */
+	retrieve_lscalar,		/* SX_LSCALAR */
+	retrieve_array,			/* SX_ARRAY */
+	retrieve_hash,			/* SX_HASH */
+	retrieve_ref,			/* SX_REF */
+	retrieve_undef,			/* SX_UNDEF */
+	retrieve_integer,		/* SX_INTEGER */
+	retrieve_double,		/* SX_DOUBLE */
+	retrieve_byte,			/* SX_BYTE */
+	retrieve_netint,		/* SX_NETINT */
+	retrieve_scalar,		/* SX_SCALAR */
+	retrieve_tied_array,	/* SX_ARRAY */
+	retrieve_tied_hash,		/* SX_HASH */
+	retrieve_tied_scalar,	/* SX_SCALAR */
+	retrieve_sv_undef,		/* SX_SV_UNDEF */
+	retrieve_sv_yes,		/* SX_SV_YES */
+	retrieve_sv_no,			/* SX_SV_NO */
+	retrieve_blessed,		/* SX_BLESS */
+	retrieve_idx_blessed,	/* SX_IX_BLESS */
+	retrieve_hook,			/* SX_HOOK */
+	retrieve_overloaded,	/* SX_OVERLOAD */
+	retrieve_tied_key,		/* SX_TIED_KEY */
+	retrieve_tied_idx,		/* SX_TIED_IDX */
+	retrieve_other,			/* SX_ERROR */
+};
+
+#define RETRIEVE(c,x) (*(c)->retrieve_vtbl[(x) >= SX_ERROR ? SX_ERROR : (x)])
+
+static SV *mbuf2sv();
+static int store_blessed();
+
+/***
+ *** Context management.
+ ***/
+
+/*
+ * init_perinterp
+ *
+ * Called once per "thread" (interpreter) to initialize some global context.
+ */
+static void init_perinterp() {
+    INIT_STCXT;
+
+    cxt->netorder = 0;		/* true if network order used */
+    cxt->forgive_me = -1;	/* whether to be forgiving... */
+}
+
+/*
+ * init_store_context
+ *
+ * Initialize a new store context for real recursion.
+ */
+static void init_store_context(cxt, f, optype, network_order)
+stcxt_t *cxt;
+PerlIO *f;
+int optype;
+int network_order;
+{
+	TRACEME(("init_store_context"));
+
+	cxt->netorder = network_order;
+	cxt->forgive_me = -1;			/* Fetched from perl if needed */
+	cxt->canonical = -1;			/* Idem */
+	cxt->tagnum = -1;				/* Reset tag numbers */
+	cxt->classnum = -1;				/* Reset class numbers */
+	cxt->fio = f;					/* Where I/O are performed */
+	cxt->optype = optype;			/* A store, or a deep clone */
+	cxt->entry = 1;					/* No recursion yet */
+
+	/*
+	 * The `hseen' table is used to keep track of each SV stored and their
+	 * associated tag numbers is special. It is "abused" because the
+	 * values stored are not real SV, just integers cast to (SV *),
+	 * which explains the freeing below.
+	 *
+	 * It is also one possible bottlneck to achieve good storing speed,
+	 * so the "shared keys" optimization is turned off (unlikely to be
+	 * of any use here), and the hash table is "pre-extended". Together,
+	 * those optimizations increase the throughput by 12%.
+	 */
+
+	cxt->hseen = newHV();			/* Table where seen objects are stored */
+	HvSHAREKEYS_off(cxt->hseen);
+
+	/*
+	 * The following does not work well with perl5.004_04, and causes
+	 * a core dump later on, in a completely unrelated spot, which
+	 * makes me think there is a memory corruption going on.
+	 *
+	 * Calling hv_ksplit(hseen, HBUCKETS) instead of manually hacking
+	 * it below does not make any difference. It seems to work fine
+	 * with perl5.004_68 but given the probable nature of the bug,
+	 * that does not prove anything.
+	 *
+	 * It's a shame because increasing the amount of buckets raises
+	 * store() throughput by 5%, but until I figure this out, I can't
+	 * allow for this to go into production.
+	 *
+	 * It is reported fixed in 5.005, hence the #if.
+	 */
+#if PATCHLEVEL < 5
+#define HBUCKETS	4096				/* Buckets for %hseen */
+	HvMAX(cxt->hseen) = HBUCKETS - 1;	/* keys %hseen = $HBUCKETS; */
+#endif
+
+	/*
+	 * The `hclass' hash uses the same settings as `hseen' above, but it is
+	 * used to assign sequential tags (numbers) to class names for blessed
+	 * objects.
+	 *
+	 * We turn the shared key optimization on.
+	 */
+
+	cxt->hclass = newHV();			/* Where seen classnames are stored */
+
+#if PATCHLEVEL < 5
+	HvMAX(cxt->hclass) = HBUCKETS - 1;	/* keys %hclass = $HBUCKETS; */
+#endif
+
+	/*
+	 * The `hook' hash table is used to keep track of the references on
+	 * the STORABLE_freeze hook routines, when found in some class name.
+	 *
+	 * It is assumed that the inheritance tree will not be changed during
+	 * storing, and that no new method will be dynamically created by the
+	 * hooks.
+	 */
+
+	cxt->hook = newHV();			/* Table where hooks are cached */
+}
+
+/*
+ * clean_store_context
+ *
+ * Clean store context by
+ */
+static void clean_store_context(cxt)
+stcxt_t *cxt;
+{
+	HE *he;
+
+	TRACEME(("clean_store_context"));
+
+	ASSERT(cxt->optype & ST_STORE, ("was performing a store()"));
+
+	/*
+	 * Insert real values into hashes where we stored faked pointers.
+	 */
+
+	hv_iterinit(cxt->hseen);
+	while (he = hv_iternext(cxt->hseen))
+		HeVAL(he) = &PL_sv_undef;
+
+	hv_iterinit(cxt->hclass);
+	while (he = hv_iternext(cxt->hclass))
+		HeVAL(he) = &PL_sv_undef;
+
+	/*
+	 * And now dispose of them...
+	 */
+
+	hv_undef(cxt->hseen);
+	sv_free((SV *) cxt->hseen);
+
+	hv_undef(cxt->hclass);
+	sv_free((SV *) cxt->hclass);
+
+	hv_undef(cxt->hook);
+	sv_free((SV *) cxt->hook);
+
+	cxt->entry = 0;
+	cxt->dirty = 0;
+}
+
+/*
+ * init_retrieve_context
+ *
+ * Initialize a new retrieve context for real recursion.
+ */
+static void init_retrieve_context(cxt, optype)
+stcxt_t *cxt;
+int optype;
+{
+	TRACEME(("init_retrieve_context"));
+
+	/*
+	 * The hook hash table is used to keep track of the references on
+	 * the STORABLE_thaw hook routines, when found in some class name.
+	 *
+	 * It is assumed that the inheritance tree will not be changed during
+	 * storing, and that no new method will be dynamically created by the
+	 * hooks.
+	 */
+
+	cxt->hook  = newHV();			/* Caches STORABLE_thaw */
+
+	/*
+	 * If retrieving an old binary version, the cxt->retrieve_vtbl variable
+	 * was set to sv_old_retrieve. We'll need a hash table to keep track of
+	 * the correspondance between the tags and the tag number used by the
+	 * new retrieve routines.
+	 */
+
+	cxt->hseen = (cxt->retrieve_vtbl == sv_old_retrieve) ? newHV() : 0;
+
+	cxt->aseen = newAV();			/* Where retrieved objects are kept */
+	cxt->aclass = newAV();			/* Where seen classnames are kept */
+	cxt->tagnum = 0;				/* Have to count objects... */
+	cxt->classnum = 0;				/* ...and class names as well */
+	cxt->optype = optype;
+	cxt->entry = 1;					/* No recursion yet */
+}
+
+/*
+ * clean_retrieve_context
+ *
+ * Clean retrieve context by
+ */
+static void clean_retrieve_context(cxt)
+stcxt_t *cxt;
+{
+	TRACEME(("clean_retrieve_context"));
+
+	ASSERT(cxt->optype & ST_RETRIEVE, ("was performing a retrieve()"));
+
+	av_undef(cxt->aseen);
+	sv_free((SV *) cxt->aseen);
+
+	av_undef(cxt->aclass);
+	sv_free((SV *) cxt->aclass);
+
+	hv_undef(cxt->hook);
+	sv_free((SV *) cxt->hook);
+
+	if (cxt->hseen)
+		sv_free((SV *) cxt->hseen);		/* optional HV, for backward compat. */
+
+	cxt->entry = 0;
+	cxt->dirty = 0;
+}
+
+/*
+ * clean_context
+ *
+ * A workaround for the CROAK bug: cleanup the last context.
+ */
+static void clean_context(cxt)
+stcxt_t *cxt;
+{
+	TRACEME(("clean_context"));
+
+	ASSERT(cxt->dirty, ("dirty context"));
+
+	if (cxt->optype & ST_RETRIEVE)
+		clean_retrieve_context(cxt);
+	else
+		clean_store_context(cxt);
+}
+
+/*
+ * allocate_context
+ *
+ * Allocate a new context and push it on top of the parent one.
+ * This new context is made globally visible via SET_STCXT().
+ */
+static stcxt_t *allocate_context(parent_cxt)
+stcxt_t *parent_cxt;
+{
+	stcxt_t *cxt;
+
+	TRACEME(("allocate_context"));
+
+	ASSERT(!parent_cxt->dirty, ("parent context clean"));
+
+	Newz(0, cxt, 1, stcxt_t);
+	cxt->prev = parent_cxt;
+	SET_STCXT(cxt);
+
+	return cxt;
+}
+
+/*
+ * free_context
+ *
+ * Free current context, which cannot be the "root" one.
+ * Make the context underneath globally visible via SET_STCXT().
+ */
+static void free_context(cxt)
+stcxt_t *cxt;
+{
+	stcxt_t *prev = cxt->prev;
+
+	TRACEME(("free_context"));
+
+	ASSERT(!cxt->dirty, ("clean context"));
+	ASSERT(prev, ("not freeing root context"));
+
+	if (kbuf)
+		Safefree(kbuf);
+	if (mbase)
+		Safefree(mbase);
+
+	Safefree(cxt);
+	SET_STCXT(prev);
+}
+
+/***
+ *** Predicates.
+ ***/
+
+/*
+ * is_storing
+ *
+ * Tells whether we're in the middle of a store operation.
+ */
+int is_storing()
+{
+	dSTCXT;
+
+	return cxt->entry && (cxt->optype & ST_STORE);
+}
+
+/*
+ * is_retrieving
+ *
+ * Tells whether we're in the middle of a retrieve operation.
+ */
+int is_retrieving()
+{
+	dSTCXT;
+
+	return cxt->entry && (cxt->optype & ST_RETRIEVE);
+}
+
+/*
+ * last_op_in_netorder
+ *
+ * Returns whether last operation was made using network order.
+ *
+ * This is typically out-of-band information that might prove useful
+ * to people wishing to convert native to network order data when used.
+ */
+int last_op_in_netorder()
+{
+	dSTCXT;
+
+	return cxt->netorder;
+}
+
+/***
+ *** Hook lookup and calling routines.
+ ***/
+
+/*
+ * pkg_fetchmeth
+ *
+ * A wrapper on gv_fetchmethod_autoload() which caches results.
+ *
+ * Returns the routine reference as an SV*, or null if neither the package
+ * nor its ancestors know about the method.
+ */
+static SV *pkg_fetchmeth(cache, pkg, method)
+HV *cache;
+HV *pkg;
+char *method;
+{
+	GV *gv;
+	SV *sv;
+	SV **svh;
+
+	/*
+	 * The following code is the same as the one performed by UNIVERSAL::can
+	 * in the Perl core.
+	 */
+
+	gv = gv_fetchmethod_autoload(pkg, method, FALSE);
+	if (gv && isGV(gv)) {
+		sv = newRV((SV*) GvCV(gv));
+		TRACEME(("%s->%s: 0x%lx", HvNAME(pkg), method, (unsigned long) sv));
+	} else {
+		sv = newSVsv(&PL_sv_undef);
+		TRACEME(("%s->%s: not found", HvNAME(pkg), method));
+	}
+
+	/*
+	 * Cache the result, ignoring failure: if we can't store the value,
+	 * it just won't be cached.
+	 */
+
+	(void) hv_store(cache, HvNAME(pkg), strlen(HvNAME(pkg)), sv, 0);
+
+	return SvOK(sv) ? sv : (SV *) 0;
+}
+
+/*
+ * pkg_hide
+ *
+ * Force cached value to be undef: hook ignored even if present.
+ */
+static void pkg_hide(cache, pkg, method)
+HV *cache;
+HV *pkg;
+char *method;
+{
+	(void) hv_store(cache,
+		HvNAME(pkg), strlen(HvNAME(pkg)), newSVsv(&PL_sv_undef), 0);
+}
+
+/*
+ * pkg_can
+ *
+ * Our own "UNIVERSAL::can", which caches results.
+ *
+ * Returns the routine reference as an SV*, or null if the object does not
+ * know about the method.
+ */
+static SV *pkg_can(cache, pkg, method)
+HV *cache;
+HV *pkg;
+char *method;
+{
+	SV **svh;
+	SV *sv;
+
+	TRACEME(("pkg_can for %s->%s", HvNAME(pkg), method));
+
+	/*
+	 * Look into the cache to see whether we already have determined
+	 * where the routine was, if any.
+	 *
+	 * NOTA BENE: we don't use `method' at all in our lookup, since we know
+	 * that only one hook (i.e. always the same) is cached in a given cache.
+	 */
+
+	svh = hv_fetch(cache, HvNAME(pkg), strlen(HvNAME(pkg)), FALSE);
+	if (svh) {
+		sv = *svh;
+		if (!SvOK(sv)) {
+			TRACEME(("cached %s->%s: not found", HvNAME(pkg), method));
+			return (SV *) 0;
+		} else {
+			TRACEME(("cached %s->%s: 0x%lx", HvNAME(pkg), method,
+				(unsigned long) sv));
+			return sv;
+		}
+	}
+
+	TRACEME(("not cached yet"));
+	return pkg_fetchmeth(cache, pkg, method);		/* Fetch and cache */
+}
+
+/*
+ * scalar_call
+ *
+ * Call routine as obj->hook(av) in scalar context.
+ * Propagates the single returned value if not called in void context.
+ */
+static SV *scalar_call(obj, hook, cloning, av, flags)
+SV *obj;
+SV *hook;
+int cloning;
+AV *av;
+I32 flags;
+{
+	dSP;
+	int count;
+	SV *sv = 0;
+
+	TRACEME(("scalar_call (cloning=%d)", cloning));
+
+	ENTER;
+	SAVETMPS;
+
+	PUSHMARK(sp);
+	XPUSHs(obj);
+	XPUSHs(sv_2mortal(newSViv(cloning)));		/* Cloning flag */
+	if (av) {
+		SV **ary = AvARRAY(av);
+		int cnt = AvFILLp(av) + 1;
+		int i;
+		XPUSHs(ary[0]);							/* Frozen string */
+		for (i = 1; i < cnt; i++) {
+			TRACEME(("pushing arg #%d (0x%lx)...", i, (unsigned long) ary[i]));
+			XPUSHs(sv_2mortal(newRV(ary[i])));
+		}
+	}
+	PUTBACK;
+
+	TRACEME(("calling..."));
+	count = perl_call_sv(hook, flags);		/* Go back to Perl code */
+	TRACEME(("count = %d", count));
+
+	SPAGAIN;
+
+	if (count) {
+		sv = POPs;
+		SvREFCNT_inc(sv);		/* We're returning it, must stay alive! */
+	}
+
+	PUTBACK;
+	FREETMPS;
+	LEAVE;
+
+	return sv;
+}
+
+/*
+ * array_call
+ *
+ * Call routine obj->hook(cloning) in array context.
+ * Returns the list of returned values in an array.
+ */
+static AV *array_call(obj, hook, cloning)
+SV *obj;
+SV *hook;
+int cloning;
+{
+	dSP;
+	int count;
+	AV *av;
+	int i;
+
+	TRACEME(("arrary_call (cloning=%d), cloning"));
+
+	ENTER;
+	SAVETMPS;
+
+	PUSHMARK(sp);
+	XPUSHs(obj);								/* Target object */
+	XPUSHs(sv_2mortal(newSViv(cloning)));		/* Cloning flag */
+	PUTBACK;
+
+	count = perl_call_sv(hook, G_ARRAY);		/* Go back to Perl code */
+
+	SPAGAIN;
+
+	av = newAV();
+	for (i = count - 1; i >= 0; i--) {
+		SV *sv = POPs;
+		av_store(av, i, SvREFCNT_inc(sv));
+	}
+
+	PUTBACK;
+	FREETMPS;
+	LEAVE;
+
+	return av;
+}
+
+/*
+ * known_class
+ *
+ * Lookup the class name in the `hclass' table and either assign it a new ID
+ * or return the existing one, by filling in `classnum'.
+ *
+ * Return true if the class was known, false if the ID was just generated.
+ */
+static int known_class(cxt, name, len, classnum)
+stcxt_t *cxt;
+char *name;		/* Class name */
+int len;		/* Name length */
+I32 *classnum;
+{
+	SV **svh;
+	HV *hclass = cxt->hclass;
+
+	TRACEME(("known_class (%s)", name));
+
+	/*
+	 * Recall that we don't store pointers in this hash table, but tags.
+	 * Therefore, we need LOW_32BITS() to extract the relevant parts.
+	 */
+
+	svh = hv_fetch(hclass, name, len, FALSE);
+	if (svh) {
+		*classnum = LOW_32BITS(*svh);
+		return TRUE;
+	}
+
+	/*
+	 * Unknown classname, we need to record it.
+	 * The (IV) cast below is for 64-bit machines, to avoid compiler warnings.
+	 */
+
+	cxt->classnum++;
+	if (!hv_store(hclass, name, len, (SV*)(IV) cxt->classnum, 0))
+		CROAK(("Unable to record new classname"));
+
+	*classnum = cxt->classnum;
+	return FALSE;
+}
+
+/***
+ *** Sepcific store routines.
+ ***/
+
+/*
+ * store_ref
+ *
+ * Store a reference.
+ * Layout is SX_REF <object> or SX_OVERLOAD <object>.
+ */
+static int store_ref(cxt, sv)
+stcxt_t *cxt;
+SV *sv;
+{
+	TRACEME(("store_ref (0x%lx)", (unsigned long) sv));
+
+	/*
+	 * Follow reference, and check if target is overloaded.
+	 */
+
+	sv = SvRV(sv);
+
+	if (SvOBJECT(sv)) {
+		HV *stash = (HV *) SvSTASH(sv);
+		if (stash && Gv_AMG(stash)) {
+			TRACEME(("ref (0x%lx) is overloaded", (unsigned long) sv));
+			PUTMARK(SX_OVERLOAD);
+		} else
+			PUTMARK(SX_REF);
+	} else
+		PUTMARK(SX_REF);
+
+	return store(cxt, sv);
+}
+
+/*
+ * store_scalar
+ *
+ * Store a scalar.
+ *
+ * Layout is SX_LSCALAR <length> <data>, SX_SCALAR <lenght> <data> or SX_UNDEF.
+ * The <data> section is omitted if <length> is 0.
+ *
+ * If integer or double, the layout is SX_INTEGER <data> or SX_DOUBLE <data>.
+ * Small integers (within [-127, +127]) are stored as SX_BYTE <byte>.
+ */
+static int store_scalar(cxt, sv)
+stcxt_t *cxt;
+SV *sv;
+{
+	IV iv;
+	char *pv;
+	STRLEN len;
+	U32 flags = SvFLAGS(sv);			/* "cc -O" may put it in register */
+
+	TRACEME(("store_scalar (0x%lx)", (unsigned long) sv));
+
+	/*
+	 * For efficiency, break the SV encapsulation by peaking at the flags
+	 * directly without using the Perl macros to avoid dereferencing
+	 * sv->sv_flags each time we wish to check the flags.
+	 */
+
+	if (!(flags & SVf_OK)) {			/* !SvOK(sv) */
+		if (sv == &PL_sv_undef) {
+			TRACEME(("immortal undef"));
+			PUTMARK(SX_SV_UNDEF);
+		} else {
+			TRACEME(("undef at 0x%x", sv));
+			PUTMARK(SX_UNDEF);
+		}
+		return 0;
+	}
+
+	/*
+	 * Always store the string representation of a scalar if it exists.
+	 * Gisle Aas provided me with this test case, better than a long speach:
+	 *
+	 *  perl -MDevel::Peek -le '$a="abc"; $a+0; Dump($a)'
+	 *  SV = PVNV(0x80c8520)
+	 *       REFCNT = 1
+	 *       FLAGS = (NOK,POK,pNOK,pPOK)
+	 *       IV = 0
+	 *       NV = 0
+	 *       PV = 0x80c83d0 "abc"\0
+	 *       CUR = 3
+	 *       LEN = 4
+	 *
+	 * Write SX_SCALAR, length, followed by the actual data.
+	 *
+	 * Otherwise, write an SX_BYTE, SX_INTEGER or an SX_DOUBLE as
+	 * appropriate, followed by the actual (binary) data. A double
+	 * is written as a string if network order, for portability.
+	 *
+	 * NOTE: instead of using SvNOK(sv), we test for SvNOKp(sv).
+	 * The reason is that when the scalar value is tainted, the SvNOK(sv)
+	 * value is false.
+	 *
+	 * The test for a read-only scalar with both POK and NOK set is meant
+	 * to quickly detect &PL_sv_yes and &PL_sv_no without having to pay the
+	 * address comparison for each scalar we store.
+	 */
+
+#define SV_MAYBE_IMMORTAL (SVf_READONLY|SVf_POK|SVf_NOK)
+
+	if ((flags & SV_MAYBE_IMMORTAL) == SV_MAYBE_IMMORTAL) {
+		if (sv == &PL_sv_yes) {
+			TRACEME(("immortal yes"));
+			PUTMARK(SX_SV_YES);
+		} else if (sv == &PL_sv_no) {
+			TRACEME(("immortal no"));
+			PUTMARK(SX_SV_NO);
+		} else {
+			pv = SvPV(sv, len);			/* We know it's SvPOK */
+			goto string;				/* Share code below */
+		}
+	} else if (flags & SVp_POK) {		/* SvPOKp(sv) => string */
+		pv = SvPV(sv, len);
+
+		/*
+		 * Will come here from below with pv and len set if double & netorder,
+		 * or from above if it was readonly, POK and NOK but neither &PL_sv_yes
+		 * nor &PL_sv_no.
+		 */
+	string:
+
+		STORE_SCALAR(pv, len);
+		TRACEME(("ok (scalar 0x%lx '%s', length = %d)",
+			(unsigned long) sv, SvPVX(sv), len));
+
+	} else if (flags & SVp_NOK) {		/* SvNOKp(sv) => double */
+		double nv = SvNV(sv);
+
+		/*
+		 * Watch for number being an integer in disguise.
+		 */
+		if (nv == (double) (iv = I_V(nv))) {
+			TRACEME(("double %lf is actually integer %ld", nv, iv));
+			goto integer;		/* Share code below */
+		}
+
+		if (cxt->netorder) {
+			TRACEME(("double %lf stored as string", nv));
+			pv = SvPV(sv, len);
+			goto string;		/* Share code above */
+		}
+
+		PUTMARK(SX_DOUBLE);
+		WRITE(&nv, sizeof(nv));
+
+		TRACEME(("ok (double 0x%lx, value = %lf)", (unsigned long) sv, nv));
+
+	} else if (flags & SVp_IOK) {		/* SvIOKp(sv) => integer */
+		iv = SvIV(sv);
+
+		/*
+		 * Will come here from above with iv set if double is an integer.
+		 */
+	integer:
+
+		/*
+		 * Optimize small integers into a single byte, otherwise store as
+		 * a real integer (converted into network order if they asked).
+		 */
+
+		if (iv >= -128 && iv <= 127) {
+			unsigned char siv = (unsigned char) (iv + 128);	/* [0,255] */
+			PUTMARK(SX_BYTE);
+			PUTMARK(siv);
+			TRACEME(("small integer stored as %d", siv));
+		} else if (cxt->netorder) {
+			int niv;
+#ifdef HAS_HTONL
+			niv = (int) htonl(iv);
+			TRACEME(("using network order"));
+#else
+			niv = (int) iv;
+			TRACEME(("as-is for network order"));
+#endif
+			PUTMARK(SX_NETINT);
+			WRITE(&niv, sizeof(niv));
+		} else {
+			PUTMARK(SX_INTEGER);
+			WRITE(&iv, sizeof(iv));
+		}
+
+		TRACEME(("ok (integer 0x%lx, value = %d)", (unsigned long) sv, iv));
+
+	} else
+		CROAK(("Can't determine type of %s(0x%lx)", sv_reftype(sv, FALSE),
+			(unsigned long) sv));
+
+	return 0;		/* Ok, no recursion on scalars */
+}
+
+/*
+ * store_array
+ *
+ * Store an array.
+ *
+ * Layout is SX_ARRAY <size> followed by each item, in increading index order.
+ * Each item is stored as <object>.
+ */
+static int store_array(cxt, av)
+stcxt_t *cxt;
+AV *av;
+{
+	SV **sav;
+	I32 len = av_len(av) + 1;
+	I32 i;
+	int ret;
+
+	TRACEME(("store_array (0x%lx)", (unsigned long) av));
+
+	/* 
+	 * Signal array by emitting SX_ARRAY, followed by the array length.
+	 */
+
+	PUTMARK(SX_ARRAY);
+	WLEN(len);
+	TRACEME(("size = %d", len));
+
+	/*
+	 * Now store each item recursively.
+	 */
+
+	for (i = 0; i < len; i++) {
+		sav = av_fetch(av, i, 0);
+		if (!sav) {
+			TRACEME(("(#%d) undef item", i));
+			STORE_UNDEF();
+			continue;
+		}
+		TRACEME(("(#%d) item", i));
+		if (ret = store(cxt, *sav))
+			return ret;
+	}
+
+	TRACEME(("ok (array)"));
+
+	return 0;
+}
+
+/*
+ * sortcmp
+ *
+ * Sort two SVs
+ * Borrowed from perl source file pp_ctl.c, where it is used by pp_sort.
+ */
+static int
+sortcmp(a, b)
+const void *a;
+const void *b;
+{
+	return sv_cmp(*(SV * const *) a, *(SV * const *) b);
+}
+
+
+/*
+ * store_hash
+ *
+ * Store an hash table.
+ *
+ * Layout is SX_HASH <size> followed by each key/value pair, in random order.
+ * Values are stored as <object>.
+ * Keys are stored as <length> <data>, the <data> section being omitted
+ * if length is 0.
+ */
+static int store_hash(cxt, hv)
+stcxt_t *cxt;
+HV *hv;
+{
+	I32 len = HvKEYS(hv);
+	I32 i;
+	int ret = 0;
+	I32 riter;
+	HE *eiter;
+
+	TRACEME(("store_hash (0x%lx)", (unsigned long) hv));
+
+	/* 
+	 * Signal hash by emitting SX_HASH, followed by the table length.
+	 */
+
+	PUTMARK(SX_HASH);
+	WLEN(len);
+	TRACEME(("size = %d", len));
+
+	/*
+	 * Save possible iteration state via each() on that table.
+	 */
+
+	riter = HvRITER(hv);
+	eiter = HvEITER(hv);
+	hv_iterinit(hv);
+
+	/*
+	 * Now store each item recursively.
+	 *
+     * If canonical is defined to some true value then store each
+     * key/value pair in sorted order otherwise the order is random.
+	 * Canonical order is irrelevant when a deep clone operation is performed.
+	 *
+	 * Fetch the value from perl only once per store() operation, and only
+	 * when needed.
+	 */
+
+	if (
+		!(cxt->optype & ST_CLONE) && (cxt->canonical == 1 ||
+		(cxt->canonical < 0 && (cxt->canonical =
+			SvTRUE(perl_get_sv("Storable::canonical", TRUE)) ? 1 : 0)))
+	) {
+		/*
+		 * Storing in order, sorted by key.
+		 * Run through the hash, building up an array of keys in a
+		 * mortal array, sort the array and then run through the
+		 * array.  
+		 */
+
+		AV *av = newAV();
+
+		TRACEME(("using canonical order"));
+
+		for (i = 0; i < len; i++) {
+			HE *he = hv_iternext(hv);
+			SV *key = hv_iterkeysv(he);
+			av_store(av, AvFILLp(av)+1, key);	/* av_push(), really */
+		}
+			
+		qsort((char *) AvARRAY(av), len, sizeof(SV *), sortcmp);
+
+		for (i = 0; i < len; i++) {
+			char *keyval;
+			I32 keylen;
+			SV *key = av_shift(av);
+			HE *he  = hv_fetch_ent(hv, key, 0, 0);
+			SV *val = HeVAL(he);
+			if (val == 0)
+				return 1;		/* Internal error, not I/O error */
+			
+			/*
+			 * Store value first.
+			 */
+			
+			TRACEME(("(#%d) value 0x%lx", i, (unsigned long) val));
+
+			if (ret = store(cxt, val))
+				goto out;
+
+			/*
+			 * Write key string.
+			 * Keys are written after values to make sure retrieval
+			 * can be optimal in terms of memory usage, where keys are
+			 * read into a fixed unique buffer called kbuf.
+			 * See retrieve_hash() for details.
+			 */
+			 
+			keyval = hv_iterkey(he, &keylen);
+			TRACEME(("(#%d) key '%s'", i, keyval));
+			WLEN(keylen);
+			if (keylen)
+				WRITE(keyval, keylen);
+		}
+
+		/* 
+		 * Free up the temporary array
+		 */
+
+		av_undef(av);
+		sv_free((SV *) av);
+
+	} else {
+
+		/*
+		 * Storing in "random" order (in the order the keys are stored
+		 * within the the hash).  This is the default and will be faster!
+		 */
+  
+		for (i = 0; i < len; i++) {
+			char *key;
+			I32 len;
+			SV *val = hv_iternextsv(hv, &key, &len);
+
+			if (val == 0)
+				return 1;		/* Internal error, not I/O error */
+
+			/*
+			 * Store value first.
+			 */
+
+			TRACEME(("(#%d) value 0x%lx", i, (unsigned long) val));
+
+			if (ret = store(cxt, val))
+				goto out;
+
+			/*
+			 * Write key string.
+			 * Keys are written after values to make sure retrieval
+			 * can be optimal in terms of memory usage, where keys are
+			 * read into a fixed unique buffer called kbuf.
+			 * See retrieve_hash() for details.
+			 */
+
+			TRACEME(("(#%d) key '%s'", i, key));
+			WLEN(len);
+			if (len)
+				WRITE(key, len);
+		}
+    }
+
+	TRACEME(("ok (hash 0x%lx)", (unsigned long) hv));
+
+out:
+	HvRITER(hv) = riter;		/* Restore hash iterator state */
+	HvEITER(hv) = eiter;
+
+	return ret;
+}
+
+/*
+ * store_tied
+ *
+ * When storing a tied object (be it a tied scalar, array or hash), we lay out
+ * a special mark, followed by the underlying tied object. For instance, when
+ * dealing with a tied hash, we store SX_TIED_HASH <hash object>, where
+ * <hash object> stands for the serialization of the tied hash.
+ */
+static int store_tied(cxt, sv)
+stcxt_t *cxt;
+SV *sv;
+{
+	MAGIC *mg;
+	int ret = 0;
+	int svt = SvTYPE(sv);
+	char mtype = 'P';
+
+	TRACEME(("store_tied (0x%lx)", (unsigned long) sv));
+
+	/*
+	 * We have a small run-time penalty here because we chose to factorise
+	 * all tieds objects into the same routine, and not have a store_tied_hash,
+	 * a store_tied_array, etc...
+	 *
+	 * Don't use a switch() statement, as most compilers don't optimize that
+	 * well for 2/3 values. An if() else if() cascade is just fine. We put
+	 * tied hashes first, as they are the most likely beasts.
+	 */
+
+	if (svt == SVt_PVHV) {
+		TRACEME(("tied hash"));
+		PUTMARK(SX_TIED_HASH);			/* Introduces tied hash */
+	} else if (svt == SVt_PVAV) {
+		TRACEME(("tied array"));
+		PUTMARK(SX_TIED_ARRAY);			/* Introduces tied array */
+	} else {
+		TRACEME(("tied scalar"));
+		PUTMARK(SX_TIED_SCALAR);		/* Introduces tied scalar */
+		mtype = 'q';
+	}
+
+	if (!(mg = mg_find(sv, mtype)))
+		CROAK(("No magic '%c' found while storing tied %s", mtype,
+			(svt == SVt_PVHV) ? "hash" :
+				(svt == SVt_PVAV) ? "array" : "scalar"));
+
+	/*
+	 * The mg->mg_obj found by mg_find() above actually points to the
+	 * underlying tied Perl object implementation. For instance, if the
+	 * original SV was that of a tied array, then mg->mg_obj is an AV.
+	 *
+	 * Note that we store the Perl object as-is. We don't call its FETCH
+	 * method along the way. At retrieval time, we won't call its STORE
+	 * method either, but the tieing magic will be re-installed. In itself,
+	 * that ensures that the tieing semantics are preserved since futher
+	 * accesses on the retrieved object will indeed call the magic methods...
+	 */
+
+	if (ret = store(cxt, mg->mg_obj))
+		return ret;
+
+	TRACEME(("ok (tied)"));
+
+	return 0;
+}
+
+/*
+ * store_tied_item
+ *
+ * Stores a reference to an item within a tied structure:
+ *
+ *  . \$h{key}, stores both the (tied %h) object and 'key'.
+ *  . \$a[idx], stores both the (tied @a) object and 'idx'.
+ *
+ * Layout is therefore either:
+ *     SX_TIED_KEY <object> <key>
+ *     SX_TIED_IDX <object> <index>
+ */
+static int store_tied_item(cxt, sv)
+stcxt_t *cxt;
+SV *sv;
+{
+	MAGIC *mg;
+	int ret;
+
+	TRACEME(("store_tied_item (0x%lx)", (unsigned long) sv));
+
+	if (!(mg = mg_find(sv, 'p')))
+		CROAK(("No magic 'p' found while storing reference to tied item"));
+
+	/*
+	 * We discriminate between \$h{key} and \$a[idx] via mg_ptr.
+	 */
+
+	if (mg->mg_ptr) {
+		TRACEME(("store_tied_item: storing a ref to a tied hash item"));
+		PUTMARK(SX_TIED_KEY);
+		TRACEME(("store_tied_item: storing OBJ 0x%lx",
+			(unsigned long) mg->mg_obj));
+
+		if (ret = store(cxt, mg->mg_obj))
+			return ret;
+
+		TRACEME(("store_tied_item: storing PTR 0x%lx",
+			(unsigned long) mg->mg_ptr));
+
+		if (ret = store(cxt, (SV *) mg->mg_ptr))
+			return ret;
+	} else {
+		I32 idx = mg->mg_len;
+
+		TRACEME(("store_tied_item: storing a ref to a tied array item "));
+		PUTMARK(SX_TIED_IDX);
+		TRACEME(("store_tied_item: storing OBJ 0x%lx",
+			(unsigned long) mg->mg_obj));
+
+		if (ret = store(cxt, mg->mg_obj))
+			return ret;
+
+		TRACEME(("store_tied_item: storing IDX %d", idx));
+
+		WLEN(idx);
+	}
+
+	TRACEME(("ok (tied item)"));
+
+	return 0;
+}
+
+/*
+ * store_hook		-- dispatched manually, not via sv_store[]
+ *
+ * The blessed SV is serialized by a hook.
+ *
+ * Simple Layout is:
+ *
+ *     SX_HOOK <flags> <len> <classname> <len2> <str> [<len3> <object-IDs>]
+ *
+ * where <flags> indicates how long <len>, <len2> and <len3> are, whether
+ * the trailing part [] is present, the type of object (scalar, array or hash).
+ * There is also a bit which says how the classname is stored between:
+ *
+ *     <len> <classname>
+ *     <index>
+ *
+ * and when the <index> form is used (classname already seen), the "large
+ * classname" bit in <flags> indicates how large the <index> is.
+ * 
+ * The serialized string returned by the hook is of length <len2> and comes
+ * next.  It is an opaque string for us.
+ *
+ * Those <len3> object IDs which are listed last represent the extra references
+ * not directly serialized by the hook, but which are linked to the object.
+ *
+ * When recursion is mandated to resolve object-IDs not yet seen, we have
+ * instead, with <header> being flags with bits set to indicate the object type
+ * and that recursion was indeed needed:
+ *
+ *     SX_HOOK <header> <object> <header> <object> <flags>
+ *
+ * that same header being repeated between serialized objects obtained through
+ * recursion, until we reach flags indicating no recursion, at which point
+ * we know we've resynchronized with a single layout, after <flags>.
+ */
+static int store_hook(cxt, sv, type, pkg, hook)
+stcxt_t *cxt;
+SV *sv;
+HV *pkg;
+SV *hook;
+{
+	I32 len;
+	char *class;
+	STRLEN len2;
+	SV *ref;
+	AV *av;
+	SV **ary;
+	int count;				/* really len3 + 1 */
+	unsigned char flags;
+	char *pv;
+	int i;
+	int recursed = 0;		/* counts recursion */
+	int obj_type;			/* object type, on 2 bits */
+	I32 classnum;
+	int ret;
+	int clone = cxt->optype & ST_CLONE;
+
+	TRACEME(("store_hook, class \"%s\", tagged #%d", HvNAME(pkg), cxt->tagnum));
+
+	/*
+	 * Determine object type on 2 bits.
+	 */
+
+	switch (type) {
+	case svis_SCALAR:
+		obj_type = SHT_SCALAR;
+		break;
+	case svis_ARRAY:
+		obj_type = SHT_ARRAY;
+		break;
+	case svis_HASH:
+		obj_type = SHT_HASH;
+		break;
+	default:
+		CROAK(("Unexpected object type (%d) in store_hook()", type));
+	}
+	flags = SHF_NEED_RECURSE | obj_type;
+
+	class = HvNAME(pkg);
+	len = strlen(class);
+
+	/*
+	 * To call the hook, we need to fake a call like:
+	 *
+	 *    $object->STORABLE_freeze($cloning);
+	 *
+	 * but we don't have the $object here.  For instance, if $object is
+	 * a blessed array, what we have in `sv' is the array, and we can't
+	 * call a method on those.
+	 *
+	 * Therefore, we need to create a temporary reference to the object and
+	 * make the call on that reference.
+	 */
+
+	TRACEME(("about to call STORABLE_freeze on class %s", class));
+
+	ref = newRV_noinc(sv);				/* Temporary reference */
+	av = array_call(ref, hook, clone);	/* @a = $object->STORABLE_freeze($c) */
+	SvRV(ref) = 0;
+	SvREFCNT_dec(ref);					/* Reclaim temporary reference */
+
+	count = AvFILLp(av) + 1;
+	TRACEME(("store_hook, array holds %d items", count));
+
+	/*
+	 * If they return an empty list, it means they wish to ignore the
+	 * hook for this class (and not just this instance -- that's for them
+	 * to handle if they so wish).
+	 *
+	 * Simply disable the cached entry for the hook (it won't be recomputed
+	 * since it's present in the cache) and recurse to store_blessed().
+	 */
+
+	if (!count) {
+		/*
+		 * They must not change their mind in the middle of a serialization.
+		 */
+
+		if (hv_fetch(cxt->hclass, class, len, FALSE))
+			CROAK(("Too late to ignore hooks for %s class \"%s\"",
+				(cxt->optype & ST_CLONE) ? "cloning" : "storing", class));
+	
+		pkg_hide(cxt->hook, pkg, "STORABLE_freeze");
+
+		ASSERT(!pkg_can(cxt->hook, pkg, "STORABLE_freeze"), ("hook invisible"));
+		TRACEME(("Ignoring STORABLE_freeze in class \"%s\"", class));
+
+		return store_blessed(cxt, sv, type, pkg);
+	}
+
+	/*
+	 * Get frozen string.
+	 */
+
+	ary = AvARRAY(av);
+	pv = SvPV(ary[0], len2);
+
+	/*
+	 * Allocate a class ID if not already done.
+	 */
+
+	if (!known_class(cxt, class, len, &classnum)) {
+		TRACEME(("first time we see class %s, ID = %d", class, classnum));
+		classnum = -1;				/* Mark: we must store classname */
+	} else {
+		TRACEME(("already seen class %s, ID = %d", class, classnum));
+	}
+
+	/*
+	 * If they returned more than one item, we need to serialize some
+	 * extra references if not already done.
+	 *
+	 * Loop over the array, starting at postion #1, and for each item,
+	 * ensure it is a reference, serialize it if not already done, and
+	 * replace the entry with the tag ID of the corresponding serialized
+	 * object.
+	 *
+	 * We CHEAT by not calling av_fetch() and read directly within the
+	 * array, for speed.
+	 */
+
+	for (i = 1; i < count; i++) {
+		SV **svh;
+		SV *xsv = ary[i];
+
+		if (!SvROK(xsv))
+			CROAK(("Item #%d from hook in %s is not a reference", i, class));
+		xsv = SvRV(xsv);		/* Follow ref to know what to look for */
+
+		/*
+		 * Look in hseen and see if we have a tag already.
+		 * Serialize entry if not done already, and get its tag.
+		 */
+
+		if (svh = hv_fetch(cxt->hseen, (char *) &xsv, sizeof(xsv), FALSE))
+			goto sv_seen;		/* Avoid moving code too far to the right */
+
+		TRACEME(("listed object %d at 0x%lx is unknown",
+			i-1, (unsigned long) xsv));
+
+		/*
+		 * We need to recurse to store that object and get it to be known
+		 * so that we can resolve the list of object-IDs at retrieve time.
+		 *
+		 * The first time we do this, we need to emit the proper header
+		 * indicating that we recursed, and what the type of object is (the
+		 * object we're storing via a user-hook).  Indeed, during retrieval,
+		 * we'll have to create the object before recursing to retrieve the
+		 * others, in case those would point back at that object.
+		 */
+
+		/* [SX_HOOK] <flags> <object>*/
+		if (!recursed++)
+			PUTMARK(SX_HOOK);
+		PUTMARK(flags);
+
+		if (ret = store(cxt, xsv))		/* Given by hook for us to store */
+			return ret;
+
+		svh = hv_fetch(cxt->hseen, (char *) &xsv, sizeof(xsv), FALSE);
+		if (!svh)
+			CROAK(("Could not serialize item #%d from hook in %s", i, class));
+
+		/*
+		 * Replace entry with its tag (not a real SV, so no refcnt increment)
+		 */
+
+	sv_seen:
+		SvREFCNT_dec(xsv);
+		ary[i] = *svh;
+		TRACEME(("listed object %d at 0x%lx is tag #%d",
+			i-1, (unsigned long) xsv, (I32) *svh));
+	}
+
+	/*
+	 * Compute leading flags.
+	 */
+
+	flags = obj_type;
+	if (((classnum == -1) ? len : classnum) > LG_SCALAR)
+		flags |= SHF_LARGE_CLASSLEN;
+	if (classnum != -1)
+		flags |= SHF_IDX_CLASSNAME;
+	if (len2 > LG_SCALAR)
+		flags |= SHF_LARGE_STRLEN;
+	if (count > 1)
+		flags |= SHF_HAS_LIST;
+	if (count > (LG_SCALAR + 1))
+		flags |= SHF_LARGE_LISTLEN;
+
+	/* 
+	 * We're ready to emit either serialized form:
+	 *
+	 *   SX_HOOK <flags> <len> <classname> <len2> <str> [<len3> <object-IDs>]
+	 *   SX_HOOK <flags> <index>           <len2> <str> [<len3> <object-IDs>]
+	 *
+	 * If we recursed, the SX_HOOK has already been emitted.
+	 */
+
+	TRACEME(("SX_HOOK (recursed=%d) flags=0x%x class=%d len=%d len2=%d len3=%d",
+		recursed, flags, classnum, len, len2, count-1));
+
+	/* SX_HOOK <flags> */
+	if (!recursed)
+		PUTMARK(SX_HOOK);
+	PUTMARK(flags);
+
+	/* <len> <classname> or <index> */
+	if (flags & SHF_IDX_CLASSNAME) {
+		if (flags & SHF_LARGE_CLASSLEN)
+			WLEN(classnum);
+		else {
+			unsigned char cnum = (unsigned char) classnum;
+			PUTMARK(cnum);
+		}
+	} else {
+		if (flags & SHF_LARGE_CLASSLEN)
+			WLEN(len);
+		else {
+			unsigned char clen = (unsigned char) len;
+			PUTMARK(clen);
+		}
+		WRITE(class, len);		/* Final \0 is omitted */
+	}
+
+	/* <len2> <frozen-str> */
+	if (flags & SHF_LARGE_STRLEN)
+		WLEN(len2);
+	else {
+		unsigned char clen = (unsigned char) len2;
+		PUTMARK(clen);
+	}
+	if (len2)
+		WRITE(pv, len2);	/* Final \0 is omitted */
+
+	/* [<len3> <object-IDs>] */
+	if (flags & SHF_HAS_LIST) {
+		int len3 = count - 1;
+		if (flags & SHF_LARGE_LISTLEN)
+			WLEN(len3);
+		else {
+			unsigned char clen = (unsigned char) len3;
+			PUTMARK(clen);
+		}
+
+		/*
+		 * NOTA BENE, for 64-bit machines: the ary[i] below does not yield a
+		 * real pointer, rather a tag number, well under the 32-bit limit.
+		 */
+
+		for (i = 1; i < count; i++) {
+			I32 tagval = htonl(LOW_32BITS(ary[i]));
+			WRITE(&tagval, sizeof(I32));
+			TRACEME(("object %d, tag #%d", i-1, ntohl(tagval)));
+		}
+	}
+
+	/*
+	 * Free the array.  We need extra care for indices after 0, since they
+	 * don't hold real SVs but integers cast.
+	 */
+
+	if (count > 1)
+		AvFILLp(av) = 0;	/* Cheat, nothing after 0 interests us */
+	av_undef(av);
+	sv_free((SV *) av);
+
+	return 0;
+}
+
+/*
+ * store_blessed	-- dispatched manually, not via sv_store[]
+ *
+ * Check whether there is a STORABLE_xxx hook defined in the class or in one
+ * of its ancestors.  If there is, then redispatch to store_hook();
+ *
+ * Otherwise, the blessed SV is stored using the following layout:
+ *
+ *    SX_BLESS <flag> <len> <classname> <object>
+ *
+ * where <flag> indicates whether <len> is stored on 0 or 4 bytes, depending
+ * on the high-order bit in flag: if 1, then length follows on 4 bytes.
+ * Otherwise, the low order bits give the length, thereby giving a compact
+ * representation for class names less than 127 chars long.
+ *
+ * Each <classname> seen is remembered and indexed, so that the next time
+ * an object in the blessed in the same <classname> is stored, the following
+ * will be emitted:
+ *
+ *    SX_IX_BLESS <flag> <index> <object>
+ *
+ * where <index> is the classname index, stored on 0 or 4 bytes depending
+ * on the high-order bit in flag (same encoding as above for <len>).
+ */
+static int store_blessed(cxt, sv, type, pkg)
+stcxt_t *cxt;
+SV *sv;
+int type;
+HV *pkg;
+{
+	SV *hook;
+	I32 len;
+	char *class;
+	I32 classnum;
+
+	TRACEME(("store_blessed, type %d, class \"%s\"", type, HvNAME(pkg)));
+
+	/*
+	 * Look for a hook for this blessed SV and redirect to store_hook()
+	 * if needed.
+	 */
+
+	hook = pkg_can(cxt->hook, pkg, "STORABLE_freeze");
+	if (hook)
+		return store_hook(cxt, sv, type, pkg, hook);
+
+	/*
+	 * This is a blessed SV without any serialization hook.
+	 */
+
+	class = HvNAME(pkg);
+	len = strlen(class);
+
+	TRACEME(("blessed 0x%lx in %s, no hook: tagged #%d",
+		(unsigned long) sv, class, cxt->tagnum));
+
+	/*
+	 * Determine whether it is the first time we see that class name (in which
+	 * case it will be stored in the SX_BLESS form), or whether we already
+	 * saw that class name before (in which case the SX_IX_BLESS form will be
+	 * used).
+	 */
+
+	if (known_class(cxt, class, len, &classnum)) {
+		TRACEME(("already seen class %s, ID = %d", class, classnum));
+		PUTMARK(SX_IX_BLESS);
+		if (classnum <= LG_BLESS) {
+			unsigned char cnum = (unsigned char) classnum;
+			PUTMARK(cnum);
+		} else {
+			unsigned char flag = (unsigned char) 0x80;
+			PUTMARK(flag);
+			WLEN(classnum);
+		}
+	} else {
+		TRACEME(("first time we see class %s, ID = %d", class, classnum));
+		PUTMARK(SX_BLESS);
+		if (len <= LG_BLESS) {
+			unsigned char clen = (unsigned char) len;
+			PUTMARK(clen);
+		} else {
+			unsigned char flag = (unsigned char) 0x80;
+			PUTMARK(flag);
+			WLEN(len);					/* Don't BER-encode, this should be rare */
+		}
+		WRITE(class, len);				/* Final \0 is omitted */
+	}
+
+	/*
+	 * Now emit the <object> part.
+	 */
+
+	return SV_STORE(type)(cxt, sv);
+}
+
+/*
+ * store_other
+ *
+ * We don't know how to store the item we reached, so return an error condition.
+ * (it's probably a GLOB, some CODE reference, etc...)
+ *
+ * If they defined the `forgive_me' variable at the Perl level to some
+ * true value, then don't croak, just warn, and store a placeholder string
+ * instead.
+ */
+static int store_other(cxt, sv)
+stcxt_t *cxt;
+SV *sv;
+{
+	STRLEN len;
+	static char buf[80];
+
+	TRACEME(("store_other"));
+
+	/*
+	 * Fetch the value from perl only once per store() operation.
+	 */
+
+	if (
+		cxt->forgive_me == 0 ||
+		(cxt->forgive_me < 0 && !(cxt->forgive_me =
+			SvTRUE(perl_get_sv("Storable::forgive_me", TRUE)) ? 1 : 0))
+	)
+		CROAK(("Can't store %s items", sv_reftype(sv, FALSE)));
+
+	warn("Can't store item %s(0x%lx)",
+		sv_reftype(sv, FALSE), (unsigned long) sv);
+
+	/*
+	 * Store placeholder string as a scalar instead...
+	 */
+
+	(void) sprintf(buf, "You lost %s(0x%lx)\0", sv_reftype(sv, FALSE),
+		(unsigned long) sv);
+
+	len = strlen(buf);
+	STORE_SCALAR(buf, len);
+	TRACEME(("ok (dummy \"%s\", length = %d)", buf, len));
+
+	return 0;
+}
+
+/***
+ *** Store driving routines
+ ***/
+
+/*
+ * sv_type
+ *
+ * WARNING: partially duplicates Perl's sv_reftype for speed.
+ *
+ * Returns the type of the SV, identified by an integer. That integer
+ * may then be used to index the dynamic routine dispatch table.
+ */
+static int sv_type(sv)
+SV *sv;
+{
+	switch (SvTYPE(sv)) {
+	case SVt_NULL:
+	case SVt_IV:
+	case SVt_NV:
+		/*
+		 * No need to check for ROK, that can't be set here since there
+		 * is no field capable of hodling the xrv_rv reference.
+		 */
+		return svis_SCALAR;
+	case SVt_PV:
+	case SVt_RV:
+	case SVt_PVIV:
+	case SVt_PVNV:
+		/*
+		 * Starting from SVt_PV, it is possible to have the ROK flag
+		 * set, the pointer to the other SV being either stored in
+		 * the xrv_rv (in the case of a pure SVt_RV), or as the
+		 * xpv_pv field of an SVt_PV and its heirs.
+		 *
+		 * However, those SV cannot be magical or they would be an
+		 * SVt_PVMG at least.
+		 */
+		return SvROK(sv) ? svis_REF : svis_SCALAR;
+	case SVt_PVMG:
+	case SVt_PVLV:		/* Workaround for perl5.004_04 "LVALUE" bug */
+		if (SvRMAGICAL(sv) && (mg_find(sv, 'p')))
+			return svis_TIED_ITEM;
+		/* FALL THROUGH */
+	case SVt_PVBM:
+		if (SvRMAGICAL(sv) && (mg_find(sv, 'q')))
+			return svis_TIED;
+		return SvROK(sv) ? svis_REF : svis_SCALAR;
+	case SVt_PVAV:
+		if (SvRMAGICAL(sv) && (mg_find(sv, 'P')))
+			return svis_TIED;
+		return svis_ARRAY;
+	case SVt_PVHV:
+		if (SvRMAGICAL(sv) && (mg_find(sv, 'P')))
+			return svis_TIED;
+		return svis_HASH;
+	default:
+		break;
+	}
+
+	return svis_OTHER;
+}
+
+/*
+ * store
+ *
+ * Recursively store objects pointed to by the sv to the specified file.
+ *
+ * Layout is <content> or SX_OBJECT <tagnum> if we reach an already stored
+ * object (one for which storage has started -- it may not be over if we have
+ * a self-referenced structure). This data set forms a stored <object>.
+ */
+static int store(cxt, sv)
+stcxt_t *cxt;
+SV *sv;
+{
+	SV **svh;
+	int ret;
+	SV *tag;
+	int type;
+    HV *hseen = cxt->hseen;
+
+	TRACEME(("store (0x%lx)", (unsigned long) sv));
+
+	/*
+	 * If object has already been stored, do not duplicate data.
+	 * Simply emit the SX_OBJECT marker followed by its tag data.
+	 * The tag is always written in network order.
+	 *
+	 * NOTA BENE, for 64-bit machines: the "*svh" below does not yield a
+	 * real pointer, rather a tag number (watch the insertion code below).
+	 * That means it pobably safe to assume it is well under the 32-bit limit,
+	 * and makes the truncation safe.
+	 *		-- RAM, 14/09/1999
+	 */
+
+	svh = hv_fetch(hseen, (char *) &sv, sizeof(sv), FALSE);
+	if (svh) {
+		I32 tagval = htonl(LOW_32BITS(*svh));
+
+		TRACEME(("object 0x%lx seen as #%d",
+			(unsigned long) sv, ntohl(tagval)));
+
+		PUTMARK(SX_OBJECT);
+		WRITE(&tagval, sizeof(I32));
+		return 0;
+	}
+
+	/*
+	 * Allocate a new tag and associate it with the address of the sv being
+	 * stored, before recursing...
+	 *
+	 * In order to avoid creating new SvIVs to hold the tagnum we just
+	 * cast the tagnum to a SV pointer and store that in the hash.  This
+	 * means that we must clean up the hash manually afterwards, but gives
+	 * us a 15% throughput increase.
+	 *
+	 * The (IV) cast below is for 64-bit machines, to avoid warnings from
+	 * the compiler. Please, let me know if it does not work.
+	 *		-- RAM, 14/09/1999
+	 */
+
+	cxt->tagnum++;
+	if (!hv_store(hseen,
+			(char *) &sv, sizeof(sv), (SV*)(IV) cxt->tagnum, 0))
+		return -1;
+
+	/*
+	 * Store `sv' and everything beneath it, using appropriate routine.
+	 * Abort immediately if we get a non-zero status back.
+	 */
+
+	type = sv_type(sv);
+
+	TRACEME(("storing 0x%lx tag #%d, type %d...",
+		(unsigned long) sv, cxt->tagnum, type));
+
+	if (SvOBJECT(sv)) {
+		HV *pkg = SvSTASH(sv);
+		ret = store_blessed(cxt, sv, type, pkg);
+	} else
+		ret = SV_STORE(type)(cxt, sv);
+
+	TRACEME(("%s (stored 0x%lx, refcnt=%d, %s)",
+		ret ? "FAILED" : "ok", (unsigned long) sv,
+		SvREFCNT(sv), sv_reftype(sv, FALSE)));
+
+	return ret;
+}
+
+/*
+ * magic_write
+ *
+ * Write magic number and system information into the file.
+ * Layout is <magic> <network> [<len> <byteorder> <sizeof int> <sizeof long>
+ * <sizeof ptr>] where <len> is the length of the byteorder hexa string.
+ * All size and lenghts are written as single characters here.
+ *
+ * Note that no byte ordering info is emitted when <network> is true, since
+ * integers will be emitted in network order in that case.
+ */
+static int magic_write(cxt)
+stcxt_t *cxt;
+{
+	char buf[256];	/* Enough room for 256 hexa digits */
+	unsigned char c;
+	int use_network_order = cxt->netorder;
+
+	TRACEME(("magic_write on fd=%d", cxt->fio ? fileno(cxt->fio) : -1));
+
+	if (cxt->fio)
+		WRITE(magicstr, strlen(magicstr));	/* Don't write final \0 */
+
+	/*
+	 * Starting with 0.6, the "use_network_order" byte flag is also used to
+	 * indicate the version number of the binary image, encoded in the upper
+	 * bits. The bit 0 is always used to indicate network order.
+	 */
+
+	c = (unsigned char)
+		((use_network_order ? 0x1 : 0x0) | (STORABLE_BIN_MAJOR << 1));
+	PUTMARK(c);
+
+	/*
+	 * Starting with 0.7, a full byte is dedicated to the minor version of
+	 * the binary format, which is incremented only when new markers are
+	 * introduced, for instance, but when backward compatibility is preserved.
+	 */
+
+	PUTMARK((unsigned char) STORABLE_BIN_MINOR);
+
+	if (use_network_order)
+		return 0;						/* Don't bother with byte ordering */
+
+	sprintf(buf, "%lx", (unsigned long) BYTEORDER);
+	c = (unsigned char) strlen(buf);
+	PUTMARK(c);
+	WRITE(buf, (unsigned int) c);		/* Don't write final \0 */
+	PUTMARK((unsigned char) sizeof(int));
+	PUTMARK((unsigned char) sizeof(long));
+	PUTMARK((unsigned char) sizeof(char *));
+
+	TRACEME(("ok (magic_write byteorder = 0x%lx [%d], I%d L%d P%d)",
+		(unsigned long) BYTEORDER, (int) c,
+		sizeof(int), sizeof(long), sizeof(char *)));
+
+	return 0;
+}
+
+/*
+ * do_store
+ *
+ * Common code for store operations.
+ *
+ * When memory store is requested (f = NULL) and a non null SV* is given in
+ * `res', it is filled with a new SV created out of the memory buffer.
+ *
+ * It is required to provide a non-null `res' when the operation type is not
+ * dclone() and store() is performed to memory.
+ */
+static int do_store(f, sv, optype, network_order, res)
+PerlIO *f;
+SV *sv;
+int optype;
+int network_order;
+SV **res;
+{
+	dSTCXT;
+	int status;
+
+	ASSERT(!(f == 0 && !(optype & ST_CLONE)) || res,
+		("must supply result SV pointer for real recursion to memory"));
+
+	TRACEME(("do_store (optype=%d, netorder=%d)",
+		optype, network_order));
+
+	optype |= ST_STORE;
+
+	/*
+	 * Workaround for CROAK leak: if they enter with a "dirty" context,
+	 * free up memory for them now.
+	 */
+
+	if (cxt->dirty)
+		clean_context(cxt);
+
+	/*
+	 * Now that STORABLE_xxx hooks exist, it is possible that they try to
+	 * re-enter store() via the hooks.  We need to stack contexts.
+	 */
+
+	if (cxt->entry)
+		cxt = allocate_context(cxt);
+
+	cxt->entry++;
+
+	ASSERT(cxt->entry == 1, ("starting new recursion"));
+	ASSERT(!cxt->dirty, ("clean context"));
+
+	/*
+	 * Ensure sv is actually a reference. From perl, we called something
+	 * like:
+	 *       pstore(FILE, \@array);
+	 * so we must get the scalar value behing that reference.
+	 */
+
+	if (!SvROK(sv))
+		CROAK(("Not a reference"));
+	sv = SvRV(sv);			/* So follow it to know what to store */
+
+	/* 
+	 * If we're going to store to memory, reset the buffer.
+	 */
+
+	if (!f)
+		MBUF_INIT(0);
+
+	/*
+	 * Prepare context and emit headers.
+	 */
+
+	init_store_context(cxt, f, optype, network_order);
+
+	if (-1 == magic_write(cxt))		/* Emit magic and ILP info */
+		return 0;					/* Error */
+
+	/*
+	 * Recursively store object...
+	 */
+
+	ASSERT(is_storing(), ("within store operation"));
+
+	status = store(cxt, sv);		/* Just do it! */
+
+	/*
+	 * If they asked for a memory store and they provided an SV pointer,
+	 * make an SV string out of the buffer and fill their pointer.
+	 *
+	 * When asking for ST_REAL, it's MANDATORY for the caller to provide
+	 * an SV, since context cleanup might free the buffer if we did recurse.
+	 * (unless caller is dclone(), which is aware of that).
+	 */
+
+	if (!cxt->fio && res)
+		*res = mbuf2sv();
+
+	/*
+	 * Final cleanup.
+	 *
+	 * The "root" context is never freed, since it is meant to be always
+	 * handy for the common case where no recursion occurs at all (i.e.
+	 * we enter store() outside of any Storable code and leave it, period).
+	 * We know it's the "root" context because there's nothing stacked
+	 * underneath it.
+	 *
+	 * OPTIMIZATION:
+	 *
+	 * When deep cloning, we don't free the context: doing so would force
+	 * us to copy the data in the memory buffer.  Sicne we know we're
+	 * about to enter do_retrieve...
+	 */
+
+	clean_store_context(cxt);
+	if (cxt->prev && !(cxt->optype & ST_CLONE))
+		free_context(cxt);
+
+	TRACEME(("do_store returns %d", status));
+
+	return status == 0;
+}
+
+/*
+ * pstore
+ *
+ * Store the transitive data closure of given object to disk.
+ * Returns 0 on error, a true value otherwise.
+ */
+int pstore(f, sv)
+PerlIO *f;
+SV *sv;
+{
+	TRACEME(("pstore"));
+	return do_store(f, sv, 0, FALSE, Nullsv);
+
+}
+
+/*
+ * net_pstore
+ *
+ * Same as pstore(), but network order is used for integers and doubles are
+ * emitted as strings.
+ */
+int net_pstore(f, sv)
+PerlIO *f;
+SV *sv;
+{
+	TRACEME(("net_pstore"));
+	return do_store(f, sv, 0, TRUE, Nullsv);
+}
+
+/***
+ *** Memory stores.
+ ***/
+
+/*
+ * mbuf2sv
+ *
+ * Build a new SV out of the content of the internal memory buffer.
+ */
+static SV *mbuf2sv()
+{
+	dSTCXT;
+
+	return newSVpv(mbase, MBUF_SIZE());
+}
+
+/*
+ * mstore
+ *
+ * Store the transitive data closure of given object to memory.
+ * Returns undef on error, a scalar value containing the data otherwise.
+ */
+SV *mstore(sv)
+SV *sv;
+{
+	dSTCXT;
+	SV *out;
+
+	TRACEME(("mstore"));
+
+	if (!do_store(0, sv, 0, FALSE, &out))
+		return &PL_sv_undef;
+
+	return out;
+}
+
+/*
+ * net_mstore
+ *
+ * Same as mstore(), but network order is used for integers and doubles are
+ * emitted as strings.
+ */
+SV *net_mstore(sv)
+SV *sv;
+{
+	dSTCXT;
+	SV *out;
+
+	TRACEME(("net_mstore"));
+
+	if (!do_store(0, sv, 0, TRUE, &out))
+		return &PL_sv_undef;
+
+	return out;
+}
+
+/***
+ *** Specific retrieve callbacks.
+ ***/
+
+/*
+ * retrieve_other
+ *
+ * Return an error via croak, since it is not possible that we get here
+ * under normal conditions, when facing a file produced via pstore().
+ */
+static SV *retrieve_other(cxt)
+stcxt_t *cxt;
+{
+	if (
+		cxt->ver_major != STORABLE_BIN_MAJOR &&
+		cxt->ver_minor != STORABLE_BIN_MINOR
+	) {
+		CROAK(("Corrupted storable %s (binary v%d.%d), current is v%d.%d",
+			cxt->fio ? "file" : "string",
+			cxt->ver_major, cxt->ver_minor,
+			STORABLE_BIN_MAJOR, STORABLE_BIN_MINOR));
+	} else {
+		CROAK(("Corrupted storable %s (binary v%d.%d)",
+			cxt->fio ? "file" : "string",
+			cxt->ver_major, cxt->ver_minor));
+	}
+
+	return (SV *) 0;		/* Just in case */
+}
+
+/*
+ * retrieve_idx_blessed
+ *
+ * Layout is SX_IX_BLESS <index> <object> with SX_IX_BLESS already read.
+ * <index> can be coded on either 1 or 5 bytes.
+ */
+static SV *retrieve_idx_blessed(cxt)
+stcxt_t *cxt;
+{
+	I32 idx;
+	char *class;
+	SV **sva;
+	SV *sv;
+
+	TRACEME(("retrieve_idx_blessed (#%d)", cxt->tagnum));
+
+	GETMARK(idx);			/* Index coded on a single char? */
+	if (idx & 0x80)
+		RLEN(idx);
+
+	/*
+	 * Fetch classname in `aclass'
+	 */
+
+	sva = av_fetch(cxt->aclass, idx, FALSE);
+	if (!sva)
+		CROAK(("Class name #%d should have been seen already", idx));
+
+	class = SvPVX(*sva);	/* We know it's a PV, by construction */
+
+	TRACEME(("class ID %d => %s", idx, class));
+
+	/*
+	 * Retrieve object and bless it.
+	 */
+
+	sv = retrieve(cxt);
+	if (sv)
+		BLESS(sv, class);
+
+	return sv;
+}
+
+/*
+ * retrieve_blessed
+ *
+ * Layout is SX_BLESS <len> <classname> <object> with SX_BLESS already read.
+ * <len> can be coded on either 1 or 5 bytes.
+ */
+static SV *retrieve_blessed(cxt)
+stcxt_t *cxt;
+{
+	I32 len;
+	SV *sv;
+	char buf[LG_BLESS + 1];		/* Avoid malloc() if possible */
+	char *class = buf;
+
+	TRACEME(("retrieve_blessed (#%d)", cxt->tagnum));
+
+	/*
+	 * Decode class name length and read that name.
+	 *
+	 * Short classnames have two advantages: their length is stored on one
+	 * single byte, and the string can be read on the stack.
+	 */
+
+	GETMARK(len);			/* Length coded on a single char? */
+	if (len & 0x80) {
+		RLEN(len);
+		TRACEME(("** allocating %d bytes for class name", len+1));
+		New(10003, class, len+1, char);
+	}
+	READ(class, len);
+	class[len] = '\0';		/* Mark string end */
+
+	/*
+	 * It's a new classname, otherwise it would have been an SX_IX_BLESS.
+	 */
+
+	if (!av_store(cxt->aclass, cxt->classnum++, newSVpvn(class, len)))
+		return (SV *) 0;
+
+	/*
+	 * Retrieve object and bless it.
+	 */
+
+	sv = retrieve(cxt);
+	if (sv) {
+		BLESS(sv, class);
+		if (class != buf)
+			Safefree(class);
+	}
+
+	return sv;
+}
+
+/*
+ * retrieve_hook
+ *
+ * Layout: SX_HOOK <flags> <len> <classname> <len2> <str> [<len3> <object-IDs>]
+ * with leading mark already read, as usual.
+ *
+ * When recursion was involved during serialization of the object, there
+ * is an unknown amount of serialized objects after the SX_HOOK mark.  Until
+ * we reach a <flags> marker with the recursion bit cleared.
+ */
+static SV *retrieve_hook(cxt)
+stcxt_t *cxt;
+{
+	I32 len;
+	char buf[LG_BLESS + 1];		/* Avoid malloc() if possible */
+	char *class = buf;
+	unsigned int flags;
+	I32 len2;
+	SV *frozen;
+	I32 len3 = 0;
+	AV *av = 0;
+	SV *hook;
+	SV *sv;
+	SV *rv;
+	int obj_type;
+	I32 classname;
+	int clone = cxt->optype & ST_CLONE;
+
+	TRACEME(("retrieve_hook (#%d)", cxt->tagnum));
+
+	/*
+	 * Read flags, which tell us about the type, and whether we need to recurse.
+	 */
+
+	GETMARK(flags);
+
+	/*
+	 * Create the (empty) object, and mark it as seen.
+	 *
+	 * This must be done now, because tags are incremented, and during
+	 * serialization, the object tag was affected before recursion could
+	 * take place.
+	 */
+
+	obj_type = flags & SHF_TYPE_MASK;
+	switch (obj_type) {
+	case SHT_SCALAR:
+		sv = newSV(0);
+		break;
+	case SHT_ARRAY:
+		sv = (SV *) newAV();
+		break;
+	case SHT_HASH:
+		sv = (SV *) newHV();
+		break;
+	default:
+		return retrieve_other(cxt);		/* Let it croak */
+	}
+	SEEN(sv);
+
+	/*
+	 * Whilst flags tell us to recurse, do so.
+	 *
+	 * We don't need to remember the addresses returned by retrieval, because
+	 * all the references will be obtained through indirection via the object
+	 * tags in the object-ID list.
+	 */
+
+	while (flags & SHF_NEED_RECURSE) {
+		TRACEME(("retrieve_hook recursing..."));
+		rv = retrieve(cxt);
+		if (!rv)
+			return (SV *) 0;
+		TRACEME(("retrieve_hook back with rv=0x%lx", (unsigned long) rv));
+		GETMARK(flags);
+	}
+
+	if (flags & SHF_IDX_CLASSNAME) {
+		SV **sva;
+		I32 idx;
+
+		/*
+		 * Fetch index from `aclass'
+		 */
+
+		if (flags & SHF_LARGE_CLASSLEN)
+			RLEN(idx);
+		else
+			GETMARK(idx);
+
+		sva = av_fetch(cxt->aclass, idx, FALSE);
+		if (!sva)
+			CROAK(("Class name #%d should have been seen already", idx));
+
+		class = SvPVX(*sva);	/* We know it's a PV, by construction */
+		TRACEME(("class ID %d => %s", idx, class));
+
+	} else {
+		/*
+		 * Decode class name length and read that name.
+		 *
+		 * NOTA BENE: even if the length is stored on one byte, we don't read
+		 * on the stack.  Just like retrieve_blessed(), we limit the name to
+		 * LG_BLESS bytes.  This is an arbitrary decision.
+		 */
+
+		if (flags & SHF_LARGE_CLASSLEN)
+			RLEN(len);
+		else
+			GETMARK(len);
+
+		if (len > LG_BLESS) {
+			TRACEME(("** allocating %d bytes for class name", len+1));
+			New(10003, class, len+1, char);
+		}
+
+		READ(class, len);
+		class[len] = '\0';		/* Mark string end */
+
+		/*
+		 * Record new classname.
+		 */
+
+		if (!av_store(cxt->aclass, cxt->classnum++, newSVpvn(class, len)))
+			return (SV *) 0;
+	}
+
+	TRACEME(("class name: %s", class));
+
+	/*
+	 * Decode user-frozen string length and read it in a SV.
+	 *
+	 * For efficiency reasons, we read data directly into the SV buffer.
+	 * To understand that code, read retrieve_scalar()
+	 */
+
+	if (flags & SHF_LARGE_STRLEN)
+		RLEN(len2);
+	else
+		GETMARK(len2);
+
+	frozen = NEWSV(10002, len2);
+	if (len2) {
+		SAFEREAD(SvPVX(frozen), len2, frozen);
+		SvCUR_set(frozen, len2);
+		*SvEND(frozen) = '\0';
+	}
+	(void) SvPOK_only(frozen);		/* Validates string pointer */
+	SvTAINT(frozen);
+
+	TRACEME(("frozen string: %d bytes", len2));
+
+	/*
+	 * Decode object-ID list length, if present.
+	 */
+
+	if (flags & SHF_HAS_LIST) {
+		if (flags & SHF_LARGE_LISTLEN)
+			RLEN(len3);
+		else
+			GETMARK(len3);
+		if (len3) {
+			av = newAV();
+			av_extend(av, len3 + 1);	/* Leave room for [0] */
+			AvFILLp(av) = len3;			/* About to be filled anyway */
+		}
+	}
+
+	TRACEME(("has %d object IDs to link", len3));
+
+	/*
+	 * Read object-ID list into array.
+	 * Because we pre-extended it, we can cheat and fill it manually.
+	 *
+	 * We read object tags and we can convert them into SV* on the fly
+	 * because we know all the references listed in there (as tags)
+	 * have been already serialized, hence we have a valid correspondance
+	 * between each of those tags and the recreated SV.
+	 */
+
+	if (av) {
+		SV **ary = AvARRAY(av);
+		int i;
+		for (i = 1; i <= len3; i++) {	/* We leave [0] alone */
+			I32 tag;
+			SV **svh;
+			SV *xsv;
+
+			READ(&tag, sizeof(I32));
+			tag = ntohl(tag);
+			svh = av_fetch(cxt->aseen, tag, FALSE);
+			if (!svh)
+				CROAK(("Object #%d should have been retrieved already", tag));
+			xsv = *svh;
+			ary[i] = SvREFCNT_inc(xsv);
+		}
+	}
+
+	/*
+	 * Bless the object and look up the STORABLE_thaw hook.
+	 */
+
+	BLESS(sv, class);
+	hook = pkg_can(cxt->hook, SvSTASH(sv), "STORABLE_thaw");
+	if (!hook)
+		CROAK(("No STORABLE_thaw defined for objects of class %s", class));
+
+	/*
+	 * If we don't have an `av' yet, prepare one.
+	 * Then insert the frozen string as item [0].
+	 */
+
+	if (!av) {
+		av = newAV();
+		av_extend(av, 1);
+		AvFILLp(av) = 0;
+	}
+	AvARRAY(av)[0] = SvREFCNT_inc(frozen);
+
+	/*
+	 * Call the hook as:
+	 *
+	 *   $object->STORABLE_thaw($cloning, $frozen, @refs);
+	 * 
+	 * where $object is our blessed (empty) object, $cloning is a boolean
+	 * telling whether we're running a deep clone, $frozen is the frozen
+	 * string the user gave us in his serializing hook, and @refs, which may
+	 * be empty, is the list of extra references he returned along for us
+	 * to serialize.
+	 *
+	 * In effect, the hook is an alternate creation routine for the class,
+	 * the object itself being already created by the runtime.
+	 */
+
+	TRACEME(("calling STORABLE_thaw on %s at 0x%lx (%d args)",
+		class, (unsigned long) sv, AvFILLp(av) + 1));
+
+	rv = newRV(sv);
+	(void) scalar_call(rv, hook, clone, av, G_SCALAR|G_DISCARD);
+	SvREFCNT_dec(rv);
+
+	/*
+	 * Final cleanup.
+	 */
+
+	SvREFCNT_dec(frozen);
+	av_undef(av);
+	sv_free((SV *) av);
+	if (!(flags & SHF_IDX_CLASSNAME) && class != buf)
+		Safefree(class);
+
+	return sv;
+}
+
+/*
+ * retrieve_ref
+ *
+ * Retrieve reference to some other scalar.
+ * Layout is SX_REF <object>, with SX_REF already read.
+ */
+static SV *retrieve_ref(cxt)
+stcxt_t *cxt;
+{
+	SV *rv;
+	SV *sv;
+
+	TRACEME(("retrieve_ref (#%d)", cxt->tagnum));
+
+	/*
+	 * We need to create the SV that holds the reference to the yet-to-retrieve
+	 * object now, so that we may record the address in the seen table.
+	 * Otherwise, if the object to retrieve references us, we won't be able
+	 * to resolve the SX_OBJECT we'll see at that point! Hence we cannot
+	 * do the retrieve first and use rv = newRV(sv) since it will be too late
+	 * for SEEN() recording.
+	 */
+
+	rv = NEWSV(10002, 0);
+	SEEN(rv);				/* Will return if rv is null */
+	sv = retrieve(cxt);		/* Retrieve <object> */
+	if (!sv)
+		return (SV *) 0;	/* Failed */
+
+	/*
+	 * WARNING: breaks RV encapsulation.
+	 *
+	 * Now for the tricky part. We have to upgrade our existing SV, so that
+	 * it is now an RV on sv... Again, we cheat by duplicating the code
+	 * held in newSVrv(), since we already got our SV from retrieve().
+	 *
+	 * We don't say:
+	 *
+	 *		SvRV(rv) = SvREFCNT_inc(sv);
+	 *
+	 * here because the reference count we got from retrieve() above is
+	 * already correct: if the object was retrieved from the file, then
+	 * its reference count is one. Otherwise, if it was retrieved via
+	 * an SX_OBJECT indication, a ref count increment was done.
+	 */
+
+	sv_upgrade(rv, SVt_RV);
+	SvRV(rv) = sv;				/* $rv = \$sv */
+	SvROK_on(rv);
+
+	TRACEME(("ok (retrieve_ref at 0x%lx)", (unsigned long) rv));
+
+	return rv;
+}
+
+/*
+ * retrieve_overloaded
+ *
+ * Retrieve reference to some other scalar with overloading.
+ * Layout is SX_OVERLOAD <object>, with SX_OVERLOAD already read.
+ */
+static SV *retrieve_overloaded(cxt)
+stcxt_t *cxt;
+{
+	SV *rv;
+	SV *sv;
+	HV *stash;
+
+	TRACEME(("retrieve_overloaded (#%d)", cxt->tagnum));
+
+	/*
+	 * Same code as retrieve_ref(), duplicated to avoid extra call.
+	 */
+
+	rv = NEWSV(10002, 0);
+	SEEN(rv);				/* Will return if rv is null */
+	sv = retrieve(cxt);		/* Retrieve <object> */
+	if (!sv)
+		return (SV *) 0;	/* Failed */
+
+	/*
+	 * WARNING: breaks RV encapsulation.
+	 */
+
+	sv_upgrade(rv, SVt_RV);
+	SvRV(rv) = sv;				/* $rv = \$sv */
+	SvROK_on(rv);
+
+	/*
+	 * Restore overloading magic.
+	 */
+
+	stash = (HV *) SvSTASH (sv);
+	if (!stash || !Gv_AMG(stash))
+		CROAK(("Cannot restore overloading on %s(0x%lx)", sv_reftype(sv, FALSE),
+			(unsigned long) sv));
+
+	SvAMAGIC_on(rv);
+
+	TRACEME(("ok (retrieve_overloaded at 0x%lx)", (unsigned long) rv));
+
+	return rv;
+}
+
+/*
+ * retrieve_tied_array
+ *
+ * Retrieve tied array
+ * Layout is SX_TIED_ARRAY <object>, with SX_TIED_ARRAY already read.
+ */
+static SV *retrieve_tied_array(cxt)
+stcxt_t *cxt;
+{
+	SV *tv;
+	SV *sv;
+
+	TRACEME(("retrieve_tied_array (#%d)", cxt->tagnum));
+
+	tv = NEWSV(10002, 0);
+	SEEN(tv);					/* Will return if tv is null */
+	sv = retrieve(cxt);			/* Retrieve <object> */
+	if (!sv)
+		return (SV *) 0;		/* Failed */
+
+	sv_upgrade(tv, SVt_PVAV);
+	AvREAL_off((AV *)tv);
+	sv_magic(tv, sv, 'P', Nullch, 0);
+	SvREFCNT_dec(sv);			/* Undo refcnt inc from sv_magic() */
+
+	TRACEME(("ok (retrieve_tied_array at 0x%lx)", (unsigned long) tv));
+
+	return tv;
+}
+
+/*
+ * retrieve_tied_hash
+ *
+ * Retrieve tied hash
+ * Layout is SX_TIED_HASH <object>, with SX_TIED_HASH already read.
+ */
+static SV *retrieve_tied_hash(cxt)
+stcxt_t *cxt;
+{
+	SV *tv;
+	SV *sv;
+
+	TRACEME(("retrieve_tied_hash (#%d)", cxt->tagnum));
+
+	tv = NEWSV(10002, 0);
+	SEEN(tv);					/* Will return if tv is null */
+	sv = retrieve(cxt);			/* Retrieve <object> */
+	if (!sv)
+		return (SV *) 0;		/* Failed */
+
+	sv_upgrade(tv, SVt_PVHV);
+	sv_magic(tv, sv, 'P', Nullch, 0);
+	SvREFCNT_dec(sv);			/* Undo refcnt inc from sv_magic() */
+
+	TRACEME(("ok (retrieve_tied_hash at 0x%lx)", (unsigned long) tv));
+
+	return tv;
+}
+
+/*
+ * retrieve_tied_scalar
+ *
+ * Retrieve tied scalar
+ * Layout is SX_TIED_SCALAR <object>, with SX_TIED_SCALAR already read.
+ */
+static SV *retrieve_tied_scalar(cxt)
+stcxt_t *cxt;
+{
+	SV *tv;
+	SV *sv;
+
+	TRACEME(("retrieve_tied_scalar (#%d)", cxt->tagnum));
+
+	tv = NEWSV(10002, 0);
+	SEEN(tv);					/* Will return if rv is null */
+	sv = retrieve(cxt);			/* Retrieve <object> */
+	if (!sv)
+		return (SV *) 0;		/* Failed */
+
+	sv_upgrade(tv, SVt_PVMG);
+	sv_magic(tv, sv, 'q', Nullch, 0);
+	SvREFCNT_dec(sv);			/* Undo refcnt inc from sv_magic() */
+
+	TRACEME(("ok (retrieve_tied_scalar at 0x%lx)", (unsigned long) tv));
+
+	return tv;
+}
+
+/*
+ * retrieve_tied_key
+ *
+ * Retrieve reference to value in a tied hash.
+ * Layout is SX_TIED_KEY <object> <key>, with SX_TIED_KEY already read.
+ */
+static SV *retrieve_tied_key(cxt)
+stcxt_t *cxt;
+{
+	SV *tv;
+	SV *sv;
+	SV *key;
+
+	TRACEME(("retrieve_tied_key (#%d)", cxt->tagnum));
+
+	tv = NEWSV(10002, 0);
+	SEEN(tv);					/* Will return if tv is null */
+	sv = retrieve(cxt);			/* Retrieve <object> */
+	if (!sv)
+		return (SV *) 0;		/* Failed */
+
+	key = retrieve(cxt);		/* Retrieve <key> */
+	if (!key)
+		return (SV *) 0;		/* Failed */
+
+	sv_upgrade(tv, SVt_PVMG);
+	sv_magic(tv, sv, 'p', (char *)key, HEf_SVKEY);
+	SvREFCNT_dec(key);			/* Undo refcnt inc from sv_magic() */
+	SvREFCNT_dec(sv);			/* Undo refcnt inc from sv_magic() */
+
+	return tv;
+}
+
+/*
+ * retrieve_tied_idx
+ *
+ * Retrieve reference to value in a tied array.
+ * Layout is SX_TIED_IDX <object> <idx>, with SX_TIED_IDX already read.
+ */
+static SV *retrieve_tied_idx(cxt)
+stcxt_t *cxt;
+{
+	SV *tv;
+	SV *sv;
+	I32 idx;
+
+	TRACEME(("retrieve_tied_idx (#%d)", cxt->tagnum));
+
+	tv = NEWSV(10002, 0);
+	SEEN(tv);					/* Will return if tv is null */
+	sv = retrieve(cxt);			/* Retrieve <object> */
+	if (!sv)
+		return (SV *) 0;		/* Failed */
+
+	RLEN(idx);					/* Retrieve <idx> */
+
+	sv_upgrade(tv, SVt_PVMG);
+	sv_magic(tv, sv, 'p', Nullch, idx);
+	SvREFCNT_dec(sv);			/* Undo refcnt inc from sv_magic() */
+
+	return tv;
+}
+
+
+/*
+ * retrieve_lscalar
+ *
+ * Retrieve defined long (string) scalar.
+ *
+ * Layout is SX_LSCALAR <length> <data>, with SX_LSCALAR already read.
+ * The scalar is "long" in that <length> is larger than LG_SCALAR so it
+ * was not stored on a single byte.
+ */
+static SV *retrieve_lscalar(cxt)
+stcxt_t *cxt;
+{
+	STRLEN len;
+	SV *sv;
+
+	RLEN(len);
+	TRACEME(("retrieve_lscalar (#%d), len = %d", cxt->tagnum, len));
+
+	/*
+	 * Allocate an empty scalar of the suitable length.
+	 */
+
+	sv = NEWSV(10002, len);
+	SEEN(sv);			/* Associate this new scalar with tag "tagnum" */
+
+	/*
+	 * WARNING: duplicates parts of sv_setpv and breaks SV data encapsulation.
+	 *
+	 * Now, for efficiency reasons, read data directly inside the SV buffer,
+	 * and perform the SV final settings directly by duplicating the final
+	 * work done by sv_setpv. Since we're going to allocate lots of scalars
+	 * this way, it's worth the hassle and risk.
+	 */
+
+	SAFEREAD(SvPVX(sv), len, sv);
+	SvCUR_set(sv, len);				/* Record C string length */
+	*SvEND(sv) = '\0';				/* Ensure it's null terminated anyway */
+	(void) SvPOK_only(sv);			/* Validate string pointer */
+	SvTAINT(sv);					/* External data cannot be trusted */
+
+	TRACEME(("large scalar len %d '%s'", len, SvPVX(sv)));
+	TRACEME(("ok (retrieve_lscalar at 0x%lx)", (unsigned long) sv));
+
+	return sv;
+}
+
+/*
+ * retrieve_scalar
+ *
+ * Retrieve defined short (string) scalar.
+ *
+ * Layout is SX_SCALAR <length> <data>, with SX_SCALAR already read.
+ * The scalar is "short" so <length> is single byte. If it is 0, there
+ * is no <data> section.
+ */
+static SV *retrieve_scalar(cxt)
+stcxt_t *cxt;
+{
+	int len;
+	SV *sv;
+
+	GETMARK(len);
+	TRACEME(("retrieve_scalar (#%d), len = %d", cxt->tagnum, len));
+
+	/*
+	 * Allocate an empty scalar of the suitable length.
+	 */
+
+	sv = NEWSV(10002, len);
+	SEEN(sv);			/* Associate this new scalar with tag "tagnum" */
+
+	/*
+	 * WARNING: duplicates parts of sv_setpv and breaks SV data encapsulation.
+	 */
+
+	if (len == 0) {
+		/*
+		 * newSV did not upgrade to SVt_PV so the scalar is undefined.
+		 * To make it defined with an empty length, upgrade it now...
+		 */
+		sv_upgrade(sv, SVt_PV);
+		SvGROW(sv, 1);
+		*SvEND(sv) = '\0';			/* Ensure it's null terminated anyway */
+		TRACEME(("ok (retrieve_scalar empty at 0x%lx)", (unsigned long) sv));
+	} else {
+		/*
+		 * Now, for efficiency reasons, read data directly inside the SV buffer,
+		 * and perform the SV final settings directly by duplicating the final
+		 * work done by sv_setpv. Since we're going to allocate lots of scalars
+		 * this way, it's worth the hassle and risk.
+		 */
+		SAFEREAD(SvPVX(sv), len, sv);
+		SvCUR_set(sv, len);			/* Record C string length */
+		*SvEND(sv) = '\0';			/* Ensure it's null terminated anyway */
+		TRACEME(("small scalar len %d '%s'", len, SvPVX(sv)));
+	}
+
+	(void) SvPOK_only(sv);			/* Validate string pointer */
+	SvTAINT(sv);					/* External data cannot be trusted */
+
+	TRACEME(("ok (retrieve_scalar at 0x%lx)", (unsigned long) sv));
+	return sv;
+}
+
+/*
+ * retrieve_integer
+ *
+ * Retrieve defined integer.
+ * Layout is SX_INTEGER <data>, whith SX_INTEGER already read.
+ */
+static SV *retrieve_integer(cxt)
+stcxt_t *cxt;
+{
+	SV *sv;
+	IV iv;
+
+	TRACEME(("retrieve_integer (#%d)", cxt->tagnum));
+
+	READ(&iv, sizeof(iv));
+	sv = newSViv(iv);
+	SEEN(sv);			/* Associate this new scalar with tag "tagnum" */
+
+	TRACEME(("integer %d", iv));
+	TRACEME(("ok (retrieve_integer at 0x%lx)", (unsigned long) sv));
+
+	return sv;
+}
+
+/*
+ * retrieve_netint
+ *
+ * Retrieve defined integer in network order.
+ * Layout is SX_NETINT <data>, whith SX_NETINT already read.
+ */
+static SV *retrieve_netint(cxt)
+stcxt_t *cxt;
+{
+	SV *sv;
+	int iv;
+
+	TRACEME(("retrieve_netint (#%d)", cxt->tagnum));
+
+	READ(&iv, sizeof(iv));
+#ifdef HAS_NTOHL
+	sv = newSViv((int) ntohl(iv));
+	TRACEME(("network integer %d", (int) ntohl(iv)));
+#else
+	sv = newSViv(iv);
+	TRACEME(("network integer (as-is) %d", iv));
+#endif
+	SEEN(sv);			/* Associate this new scalar with tag "tagnum" */
+
+	TRACEME(("ok (retrieve_netint at 0x%lx)", (unsigned long) sv));
+
+	return sv;
+}
+
+/*
+ * retrieve_double
+ *
+ * Retrieve defined double.
+ * Layout is SX_DOUBLE <data>, whith SX_DOUBLE already read.
+ */
+static SV *retrieve_double(cxt)
+stcxt_t *cxt;
+{
+	SV *sv;
+	double nv;
+
+	TRACEME(("retrieve_double (#%d)", cxt->tagnum));
+
+	READ(&nv, sizeof(nv));
+	sv = newSVnv(nv);
+	SEEN(sv);			/* Associate this new scalar with tag "tagnum" */
+
+	TRACEME(("double %lf", nv));
+	TRACEME(("ok (retrieve_double at 0x%lx)", (unsigned long) sv));
+
+	return sv;
+}
+
+/*
+ * retrieve_byte
+ *
+ * Retrieve defined byte (small integer within the [-128, +127] range).
+ * Layout is SX_BYTE <data>, whith SX_BYTE already read.
+ */
+static SV *retrieve_byte(cxt)
+stcxt_t *cxt;
+{
+	SV *sv;
+	int siv;
+
+	TRACEME(("retrieve_byte (#%d)", cxt->tagnum));
+
+	GETMARK(siv);
+	TRACEME(("small integer read as %d", (unsigned char) siv));
+	sv = newSViv((unsigned char) siv - 128);
+	SEEN(sv);			/* Associate this new scalar with tag "tagnum" */
+
+	TRACEME(("byte %d", (unsigned char) siv - 128));
+	TRACEME(("ok (retrieve_byte at 0x%lx)", (unsigned long) sv));
+
+	return sv;
+}
+
+/*
+ * retrieve_undef
+ *
+ * Return the undefined value.
+ */
+static SV *retrieve_undef(cxt)
+stcxt_t *cxt;
+{
+	SV* sv;
+
+	TRACEME(("retrieve_undef"));
+
+	sv = newSV(0);
+	SEEN(sv);
+
+	return sv;
+}
+
+/*
+ * retrieve_sv_undef
+ *
+ * Return the immortal undefined value.
+ */
+static SV *retrieve_sv_undef(cxt)
+stcxt_t *cxt;
+{
+	SV *sv = &PL_sv_undef;
+
+	TRACEME(("retrieve_sv_undef"));
+
+	SEEN(sv);
+	return sv;
+}
+
+/*
+ * retrieve_sv_yes
+ *
+ * Return the immortal yes value.
+ */
+static SV *retrieve_sv_yes(cxt)
+stcxt_t *cxt;
+{
+	SV *sv = &PL_sv_yes;
+
+	TRACEME(("retrieve_sv_yes"));
+
+	SEEN(sv);
+	return sv;
+}
+
+/*
+ * retrieve_sv_no
+ *
+ * Return the immortal no value.
+ */
+static SV *retrieve_sv_no(cxt)
+stcxt_t *cxt;
+{
+	SV *sv = &PL_sv_no;
+
+	TRACEME(("retrieve_sv_no"));
+
+	SEEN(sv);
+	return sv;
+}
+
+/*
+ * retrieve_array
+ *
+ * Retrieve a whole array.
+ * Layout is SX_ARRAY <size> followed by each item, in increading index order.
+ * Each item is stored as <object>.
+ *
+ * When we come here, SX_ARRAY has been read already.
+ */
+static SV *retrieve_array(cxt)
+stcxt_t *cxt;
+{
+	I32 len;
+	I32 i;
+	AV *av;
+	SV *sv;
+
+	TRACEME(("retrieve_array (#%d)", cxt->tagnum));
+
+	/*
+	 * Read length, and allocate array, then pre-extend it.
+	 */
+
+	RLEN(len);
+	TRACEME(("size = %d", len));
+	av = newAV();
+	SEEN(av);					/* Will return if array not allocated nicely */
+	if (len)
+		av_extend(av, len);
+	else
+		return (SV *) av;		/* No data follow if array is empty */
+
+	/*
+	 * Now get each item in turn...
+	 */
+
+	for (i = 0; i < len; i++) {
+		TRACEME(("(#%d) item", i));
+		sv = retrieve(cxt);				/* Retrieve item */
+		if (!sv)
+			return (SV *) 0;
+		if (av_store(av, i, sv) == 0)
+			return (SV *) 0;
+	}
+
+	TRACEME(("ok (retrieve_array at 0x%lx)", (unsigned long) av));
+
+	return (SV *) av;
+}
+
+/*
+ * retrieve_hash
+ *
+ * Retrieve a whole hash table.
+ * Layout is SX_HASH <size> followed by each key/value pair, in random order.
+ * Keys are stored as <length> <data>, the <data> section being omitted
+ * if length is 0.
+ * Values are stored as <object>.
+ *
+ * When we come here, SX_HASH has been read already.
+ */
+static SV *retrieve_hash(cxt)
+stcxt_t *cxt;
+{
+	I32 len;
+	I32 size;
+	I32 i;
+	HV *hv;
+	SV *sv;
+	static SV *sv_h_undef = (SV *) 0;		/* hv_store() bug */
+
+	TRACEME(("retrieve_hash (#%d)", cxt->tagnum));
+
+	/*
+	 * Read length, allocate table.
+	 */
+
+	RLEN(len);
+	TRACEME(("size = %d", len));
+	hv = newHV();
+	SEEN(hv);			/* Will return if table not allocated properly */
+	if (len == 0)
+		return (SV *) hv;	/* No data follow if table empty */
+
+	/*
+	 * Now get each key/value pair in turn...
+	 */
+
+	for (i = 0; i < len; i++) {
+		/*
+		 * Get value first.
+		 */
+
+		TRACEME(("(#%d) value", i));
+		sv = retrieve(cxt);
+		if (!sv)
+			return (SV *) 0;
+
+		/*
+		 * Get key.
+		 * Since we're reading into kbuf, we must ensure we're not
+		 * recursing between the read and the hv_store() where it's used.
+		 * Hence the key comes after the value.
+		 */
+
+		RLEN(size);						/* Get key size */
+		KBUFCHK(size);					/* Grow hash key read pool if needed */
+		if (size)
+			READ(kbuf, size);
+		kbuf[size] = '\0';				/* Mark string end, just in case */
+		TRACEME(("(#%d) key '%s'", i, kbuf));
+
+		/*
+		 * Enter key/value pair into hash table.
+		 */
+
+		if (hv_store(hv, kbuf, (U32) size, sv, 0) == 0)
+			return (SV *) 0;
+	}
+
+	TRACEME(("ok (retrieve_hash at 0x%lx)", (unsigned long) hv));
+
+	return (SV *) hv;
+}
+
+/*
+ * old_retrieve_array
+ *
+ * Retrieve a whole array in pre-0.6 binary format.
+ *
+ * Layout is SX_ARRAY <size> followed by each item, in increading index order.
+ * Each item is stored as SX_ITEM <object> or SX_IT_UNDEF for "holes".
+ *
+ * When we come here, SX_ARRAY has been read already.
+ */
+static SV *old_retrieve_array(cxt)
+stcxt_t *cxt;
+{
+	I32 len;
+	I32 i;
+	AV *av;
+	SV *sv;
+	int c;
+
+	TRACEME(("old_retrieve_array (#%d)", cxt->tagnum));
+
+	/*
+	 * Read length, and allocate array, then pre-extend it.
+	 */
+
+	RLEN(len);
+	TRACEME(("size = %d", len));
+	av = newAV();
+	SEEN(av);					/* Will return if array not allocated nicely */
+	if (len)
+		av_extend(av, len);
+	else
+		return (SV *) av;		/* No data follow if array is empty */
+
+	/*
+	 * Now get each item in turn...
+	 */
+
+	for (i = 0; i < len; i++) {
+		GETMARK(c);
+		if (c == SX_IT_UNDEF) {
+			TRACEME(("(#%d) undef item", i));
+			continue;			/* av_extend() already filled us with undef */
+		}
+		if (c != SX_ITEM)
+			(void) retrieve_other(0);	/* Will croak out */
+		TRACEME(("(#%d) item", i));
+		sv = retrieve(cxt);				/* Retrieve item */
+		if (!sv)
+			return (SV *) 0;
+		if (av_store(av, i, sv) == 0)
+			return (SV *) 0;
+	}
+
+	TRACEME(("ok (old_retrieve_array at 0x%lx)", (unsigned long) av));
+
+	return (SV *) av;
+}
+
+/*
+ * old_retrieve_hash
+ *
+ * Retrieve a whole hash table in pre-0.6 binary format.
+ *
+ * Layout is SX_HASH <size> followed by each key/value pair, in random order.
+ * Keys are stored as SX_KEY <length> <data>, the <data> section being omitted
+ * if length is 0.
+ * Values are stored as SX_VALUE <object> or SX_VL_UNDEF for "holes".
+ *
+ * When we come here, SX_HASH has been read already.
+ */
+static SV *old_retrieve_hash(cxt)
+stcxt_t *cxt;
+{
+	I32 len;
+	I32 size;
+	I32 i;
+	HV *hv;
+	SV *sv;
+	int c;
+	static SV *sv_h_undef = (SV *) 0;		/* hv_store() bug */
+
+	TRACEME(("old_retrieve_hash (#%d)", cxt->tagnum));
+
+	/*
+	 * Read length, allocate table.
+	 */
+
+	RLEN(len);
+	TRACEME(("size = %d", len));
+	hv = newHV();
+	SEEN(hv);				/* Will return if table not allocated properly */
+	if (len == 0)
+		return (SV *) hv;	/* No data follow if table empty */
+
+	/*
+	 * Now get each key/value pair in turn...
+	 */
+
+	for (i = 0; i < len; i++) {
+		/*
+		 * Get value first.
+		 */
+
+		GETMARK(c);
+		if (c == SX_VL_UNDEF) {
+			TRACEME(("(#%d) undef value", i));
+			/*
+			 * Due to a bug in hv_store(), it's not possible to pass
+			 * &PL_sv_undef to hv_store() as a value, otherwise the
+			 * associated key will not be creatable any more. -- RAM, 14/01/97
+			 */
+			if (!sv_h_undef)
+				sv_h_undef = newSVsv(&PL_sv_undef);
+			sv = SvREFCNT_inc(sv_h_undef);
+		} else if (c == SX_VALUE) {
+			TRACEME(("(#%d) value", i));
+			sv = retrieve(cxt);
+			if (!sv)
+				return (SV *) 0;
+		} else
+			(void) retrieve_other(0);	/* Will croak out */
+
+		/*
+		 * Get key.
+		 * Since we're reading into kbuf, we must ensure we're not
+		 * recursing between the read and the hv_store() where it's used.
+		 * Hence the key comes after the value.
+		 */
+
+		GETMARK(c);
+		if (c != SX_KEY)
+			(void) retrieve_other(0);	/* Will croak out */
+		RLEN(size);						/* Get key size */
+		KBUFCHK(size);					/* Grow hash key read pool if needed */
+		if (size)
+			READ(kbuf, size);
+		kbuf[size] = '\0';				/* Mark string end, just in case */
+		TRACEME(("(#%d) key '%s'", i, kbuf));
+
+		/*
+		 * Enter key/value pair into hash table.
+		 */
+
+		if (hv_store(hv, kbuf, (U32) size, sv, 0) == 0)
+			return (SV *) 0;
+	}
+
+	TRACEME(("ok (retrieve_hash at 0x%lx)", (unsigned long) hv));
+
+	return (SV *) hv;
+}
+
+/***
+ *** Retrieval engine.
+ ***/
+
+/*
+ * magic_check
+ *
+ * Make sure the stored data we're trying to retrieve has been produced
+ * on an ILP compatible system with the same byteorder. It croaks out in
+ * case an error is detected. [ILP = integer-long-pointer sizes]
+ * Returns null if error is detected, &PL_sv_undef otherwise.
+ *
+ * Note that there's no byte ordering info emitted when network order was
+ * used at store time.
+ */
+static SV *magic_check(cxt)
+stcxt_t *cxt;
+{
+	char buf[256];
+	char byteorder[256];
+	int c;
+	int use_network_order;
+	int version_major;
+	int version_minor = 0;
+
+	TRACEME(("magic_check"));
+
+	/*
+	 * The "magic number" is only for files, not when freezing in memory.
+	 */
+
+	if (cxt->fio) {
+		STRLEN len = sizeof(magicstr) - 1;
+		STRLEN old_len;
+
+		READ(buf, len);					/* Not null-terminated */
+		buf[len] = '\0';				/* Is now */
+
+		if (0 == strcmp(buf, magicstr))
+			goto magic_ok;
+
+		/*
+		 * Try to read more bytes to check for the old magic number, which
+		 * was longer.
+		 */
+
+		old_len = sizeof(old_magicstr) - 1;
+		READ(&buf[len], old_len - len);
+		buf[old_len] = '\0';			/* Is now null-terminated */
+
+		if (strcmp(buf, old_magicstr))
+			CROAK(("File is not a perl storable"));
+	}
+
+magic_ok:
+	/*
+	 * Starting with 0.6, the "use_network_order" byte flag is also used to
+	 * indicate the version number of the binary, and therefore governs the
+	 * setting of sv_retrieve_vtbl. See magic_write().
+	 */
+
+	GETMARK(use_network_order);
+	version_major = use_network_order >> 1;
+	cxt->retrieve_vtbl = version_major ? sv_retrieve : sv_old_retrieve;
+
+	TRACEME(("magic_check: netorder = 0x%x", use_network_order));
+
+
+	/*
+	 * Starting with 0.7 (binary major 2), a full byte is dedicated to the
+	 * minor version of the protocol.  See magic_write().
+	 */
+
+	if (version_major > 1)
+		GETMARK(version_minor);
+
+	cxt->ver_major = version_major;
+	cxt->ver_minor = version_minor;
+
+	TRACEME(("binary image version is %d.%d", version_major, version_minor));
+
+	/*
+	 * Inter-operability sanity check: we can't retrieve something stored
+	 * using a format more recent than ours, because we have no way to
+	 * know what has changed, and letting retrieval go would mean a probable
+	 * failure reporting a "corrupted" storable file.
+	 */
+
+	if (
+		version_major > STORABLE_BIN_MAJOR ||
+			(version_major == STORABLE_BIN_MAJOR &&
+			version_minor > STORABLE_BIN_MINOR)
+	)
+		CROAK(("Storable binary image v%d.%d more recent than I am (v%d.%d)",
+			version_major, version_minor,
+			STORABLE_BIN_MAJOR, STORABLE_BIN_MINOR));
+
+	/*
+	 * If they stored using network order, there's no byte ordering
+	 * information to check.
+	 */
+
+	if (cxt->netorder = (use_network_order & 0x1))
+		return &PL_sv_undef;			/* No byte ordering info */
+
+	sprintf(byteorder, "%lx", (unsigned long) BYTEORDER);
+	GETMARK(c);
+	READ(buf, c);						/* Not null-terminated */
+	buf[c] = '\0';						/* Is now */
+
+	if (strcmp(buf, byteorder))
+		CROAK(("Byte order is not compatible"));
+	
+	GETMARK(c);		/* sizeof(int) */
+	if ((int) c != sizeof(int))
+		CROAK(("Integer size is not compatible"));
+
+	GETMARK(c);		/* sizeof(long) */
+	if ((int) c != sizeof(long))
+		CROAK(("Long integer size is not compatible"));
+
+	GETMARK(c);		/* sizeof(char *) */
+	if ((int) c != sizeof(char *))
+		CROAK(("Pointer integer size is not compatible"));
+
+	return &PL_sv_undef;	/* OK */
+}
+
+/*
+ * retrieve
+ *
+ * Recursively retrieve objects from the specified file and return their
+ * root SV (which may be an AV or an HV for what we care).
+ * Returns null if there is a problem.
+ */
+static SV *retrieve(cxt)
+stcxt_t *cxt;
+{
+	int type;
+	SV **svh;
+	SV *sv;
+
+	TRACEME(("retrieve"));
+
+	/*
+	 * Grab address tag which identifies the object if we are retrieving
+	 * an older format. Since the new binary format counts objects and no
+	 * longer explicitely tags them, we must keep track of the correspondance
+	 * ourselves.
+	 *
+	 * The following section will disappear one day when the old format is
+	 * no longer supported, hence the final "goto" in the "if" block.
+	 */
+
+	if (cxt->hseen) {						/* Retrieving old binary */
+		stag_t tag;
+		if (cxt->netorder) {
+			I32 nettag;
+			READ(&nettag, sizeof(I32));		/* Ordered sequence of I32 */
+			tag = (stag_t) nettag;
+		} else
+			READ(&tag, sizeof(stag_t));		/* Original address of the SV */
+
+		GETMARK(type);
+		if (type == SX_OBJECT) {
+			I32 tagn;
+			svh = hv_fetch(cxt->hseen, (char *) &tag, sizeof(tag), FALSE);
+			if (!svh)
+				CROAK(("Old tag 0x%x should have been mapped already", tag));
+			tagn = SvIV(*svh);	/* Mapped tag number computed earlier below */
+
+			/*
+			 * The following code is common with the SX_OBJECT case below.
+			 */
+
+			svh = av_fetch(cxt->aseen, tagn, FALSE);
+			if (!svh)
+				CROAK(("Object #%d should have been retrieved already", tagn));
+			sv = *svh;
+			TRACEME(("has retrieved #%d at 0x%lx", tagn, (unsigned long) sv));
+			SvREFCNT_inc(sv);	/* One more reference to this same sv */
+			return sv;			/* The SV pointer where object was retrieved */
+		}
+
+		/*
+		 * Map new object, but don't increase tagnum. This will be done
+		 * by each of the retrieve_* functions when they call SEEN().
+		 *
+		 * The mapping associates the "tag" initially present with a unique
+		 * tag number. See test for SX_OBJECT above to see how this is perused.
+		 */
+
+		if (!hv_store(cxt->hseen, (char *) &tag, sizeof(tag),
+				newSViv(cxt->tagnum), 0))
+			return (SV *) 0;
+
+		goto first_time;
+	}
+
+	/*
+	 * Regular post-0.6 binary format.
+	 */
+
+again:
+	GETMARK(type);
+
+	TRACEME(("retrieve type = %d", type));
+
+	/*
+	 * Are we dealing with an object we should have already retrieved?
+	 */
+
+	if (type == SX_OBJECT) {
+		I32 tag;
+		READ(&tag, sizeof(I32));
+		tag = ntohl(tag);
+		svh = av_fetch(cxt->aseen, tag, FALSE);
+		if (!svh)
+			CROAK(("Object #%d should have been retrieved already", tag));
+		sv = *svh;
+		TRACEME(("had retrieved #%d at 0x%lx", tag, (unsigned long) sv));
+		SvREFCNT_inc(sv);	/* One more reference to this same sv */
+		return sv;			/* The SV pointer where object was retrieved */
+	}
+
+first_time:		/* Will disappear when support for old format is dropped */
+
+	/*
+	 * Okay, first time through for this one.
+	 */
+
+	sv = RETRIEVE(cxt, type)(cxt);
+	if (!sv)
+		return (SV *) 0;			/* Failed */
+
+	/*
+	 * Old binary formats (pre-0.7).
+	 *
+	 * Final notifications, ended by SX_STORED may now follow.
+	 * Currently, the only pertinent notification to apply on the
+	 * freshly retrieved object is either:
+	 *    SX_CLASS <char-len> <classname> for short classnames.
+	 *    SX_LG_CLASS <int-len> <classname> for larger one (rare!).
+	 * Class name is then read into the key buffer pool used by
+	 * hash table key retrieval.
+	 */
+
+	if (cxt->ver_major < 2) {
+		while ((type = GETCHAR()) != SX_STORED) {
+			I32 len;
+			switch (type) {
+			case SX_CLASS:
+				GETMARK(len);			/* Length coded on a single char */
+				break;
+			case SX_LG_CLASS:			/* Length coded on a regular integer */
+				RLEN(len);
+				break;
+			case EOF:
+			default:
+				return (SV *) 0;		/* Failed */
+			}
+			KBUFCHK(len);				/* Grow buffer as necessary */
+			if (len)
+				READ(kbuf, len);
+			kbuf[len] = '\0';			/* Mark string end */
+			BLESS(sv, kbuf);
+		}
+	}
+
+	TRACEME(("ok (retrieved 0x%lx, refcnt=%d, %s)", (unsigned long) sv,
+		SvREFCNT(sv) - 1, sv_reftype(sv, FALSE)));
+
+	return sv;	/* Ok */
+}
+
+/*
+ * do_retrieve
+ *
+ * Retrieve data held in file and return the root object.
+ * Common routine for pretrieve and mretrieve.
+ */
+static SV *do_retrieve(f, in, optype)
+PerlIO *f;
+SV *in;
+int optype;
+{
+	dSTCXT;
+	SV *sv;
+	struct extendable msave;	/* Where potentially valid mbuf is saved */
+
+	TRACEME(("do_retrieve (optype = 0x%x)", optype));
+
+	optype |= ST_RETRIEVE;
+
+	/*
+	 * Sanity assertions for retrieve dispatch tables.
+	 */
+
+	ASSERT(sizeof(sv_old_retrieve) == sizeof(sv_retrieve),
+		("old and new retrieve dispatch table have same size"));
+	ASSERT(sv_old_retrieve[SX_ERROR] == retrieve_other,
+		("SX_ERROR entry correctly initialized in old dispatch table"));
+	ASSERT(sv_retrieve[SX_ERROR] == retrieve_other,
+		("SX_ERROR entry correctly initialized in new dispatch table"));
+
+	/*
+	 * Workaround for CROAK leak: if they enter with a "dirty" context,
+	 * free up memory for them now.
+	 */
+
+	if (cxt->dirty)
+		clean_context(cxt);
+
+	/*
+	 * Now that STORABLE_xxx hooks exist, it is possible that they try to
+	 * re-enter retrieve() via the hooks.
+	 */
+
+	if (cxt->entry)
+		cxt = allocate_context(cxt);
+
+	cxt->entry++;
+
+	ASSERT(cxt->entry == 1, ("starting new recursion"));
+	ASSERT(!cxt->dirty, ("clean context"));
+
+	/*
+	 * Prepare context.
+	 *
+	 * Data is loaded into the memory buffer when f is NULL, unless `in' is
+	 * also NULL, in which case we're expecting the data to already lie
+	 * in the buffer (dclone case).
+	 */
+
+	KBUFINIT();			 		/* Allocate hash key reading pool once */
+
+	if (!f && in) {
+		StructCopy(&cxt->membuf, &msave, struct extendable);
+		MBUF_LOAD(in);
+	}
+
+
+	/*
+	 * Magic number verifications.
+	 *
+	 * This needs to be done before calling init_retrieve_context()
+	 * since the format indication in the file are necessary to conduct
+	 * some of the initializations.
+	 */
+
+	cxt->fio = f;				/* Where I/O are performed */
+
+	if (!magic_check(cxt))
+		CROAK(("Magic number checking on storable %s failed",
+			cxt->fio ? "file" : "string"));
+
+	TRACEME(("data stored in %s format",
+		cxt->netorder ? "net order" : "native"));
+
+	init_retrieve_context(cxt, optype);
+
+	ASSERT(is_retrieving(), ("within retrieve operation"));
+
+	sv = retrieve(cxt);		/* Recursively retrieve object, get root SV */
+
+	/*
+	 * Final cleanup.
+	 */
+
+	if (!f && in)
+		StructCopy(&msave, &cxt->membuf, struct extendable);
+
+	/*
+	 * The "root" context is never freed.
+	 */
+
+	clean_retrieve_context(cxt);
+	if (cxt->prev)				/* This context was stacked */
+		free_context(cxt);		/* It was not the "root" context */
+
+	/*
+	 * Prepare returned value.
+	 */
+
+	if (!sv) {
+		TRACEME(("retrieve ERROR"));
+		return &PL_sv_undef;		/* Something went wrong, return undef */
+	}
+
+	TRACEME(("retrieve got %s(0x%lx)",
+		sv_reftype(sv, FALSE), (unsigned long) sv));
+
+	/*
+	 * Backward compatibility with Storable-0.5@9 (which we know we
+	 * are retrieving if hseen is non-null): don't create an extra RV
+	 * for objects since we special-cased it at store time.
+	 *
+	 * Build a reference to the SV returned by pretrieve even if it is
+	 * already one and not a scalar, for consistency reasons.
+	 *
+	 * NB: although context might have been cleaned, the value of `cxt->hseen'
+	 * remains intact, and can be used as a flag.
+	 */
+
+	if (cxt->hseen) {			/* Was not handling overloading by then */
+		SV *rv;
+		if (sv_type(sv) == svis_REF && (rv = SvRV(sv)) && SvOBJECT(rv))
+			return sv;
+	}
+
+	/*
+	 * If reference is overloaded, restore behaviour.
+	 *
+	 * NB: minor glitch here: normally, overloaded refs are stored specially
+	 * so that we can croak when behaviour cannot be re-installed, and also
+	 * avoid testing for overloading magic at each reference retrieval.
+	 *
+	 * Unfortunately, the root reference is implicitely stored, so we must
+	 * check for possible overloading now.  Furthermore, if we don't restore
+	 * overloading, we cannot croak as if the original ref was, because we
+	 * have no way to determine whether it was an overloaded ref or not in
+	 * the first place.
+	 *
+	 * It's a pity that overloading magic is attached to the rv, and not to
+	 * the underlying sv as blessing is.
+	 */
+
+	if (SvOBJECT(sv)) {
+		HV *stash = (HV *) SvSTASH (sv);
+		SV *rv = newRV_noinc(sv);
+		if (stash && Gv_AMG(stash)) {
+			SvAMAGIC_on(rv);
+			TRACEME(("restored overloading on root reference"));
+		}
+		return rv;
+	}
+
+	return newRV_noinc(sv);
+}
+
+/*
+ * pretrieve
+ *
+ * Retrieve data held in file and return the root object, undef on error.
+ */
+SV *pretrieve(f)
+PerlIO *f;
+{
+	TRACEME(("pretrieve"));
+	return do_retrieve(f, Nullsv, 0);
+}
+
+/*
+ * mretrieve
+ *
+ * Retrieve data held in scalar and return the root object, undef on error.
+ */
+SV *mretrieve(sv)
+SV *sv;
+{
+	TRACEME(("mretrieve"));
+	return do_retrieve(0, sv, 0);
+}
+
+/***
+ *** Deep cloning
+ ***/
+
+/*
+ * dclone
+ *
+ * Deep clone: returns a fresh copy of the original referenced SV tree.
+ *
+ * This is achieved by storing the object in memory and restoring from
+ * there. Not that efficient, but it should be faster than doing it from
+ * pure perl anyway.
+ */
+SV *dclone(sv)
+SV *sv;
+{
+	dSTCXT;
+	int size;
+	stcxt_t *real_context;
+	SV *out;
+
+	TRACEME(("dclone"));
+
+	/*
+	 * Workaround for CROAK leak: if they enter with a "dirty" context,
+	 * free up memory for them now.
+	 */
+
+	if (cxt->dirty)
+		clean_context(cxt);
+
+	/*
+	 * do_store() optimizes for dclone by not freeing its context, should
+	 * we need to allocate one because we're deep cloning from a hook.
+	 */
+
+	if (!do_store(0, sv, ST_CLONE, FALSE, Nullsv))
+		return &PL_sv_undef;				/* Error during store */
+
+	/*
+	 * Because of the above optimization, we have to refresh the context,
+	 * since a new one could have been allocated and stacked by do_store().
+	 */
+
+	{ dSTCXT; real_context = cxt; }		/* Sub-block needed for macro */
+	cxt = real_context;					/* And we need this temporary... */
+
+	/*
+	 * Now, `cxt' may refer to a new context.
+	 */
+
+	ASSERT(!cxt->dirty, ("clean context"));
+	ASSERT(!cxt->entry, ("entry will not cause new context allocation"));
+
+	size = MBUF_SIZE();
+	TRACEME(("dclone stored %d bytes", size));
+
+	MBUF_INIT(size);
+	out = do_retrieve(0, Nullsv, ST_CLONE);	/* Will free non-root context */
+
+	TRACEME(("dclone returns 0x%lx", (unsigned long) out));
+
+	return out;
+}
+
+/***
+ *** Glue with perl.
+ ***/
+
+/*
+ * The Perl IO GV object distinguishes between input and output for sockets
+ * but not for plain files. To allow Storable to transparently work on
+ * plain files and sockets transparently, we have to ask xsubpp to fetch the
+ * right object for us. Hence the OutputStream and InputStream declarations.
+ *
+ * Before perl 5.004_05, those entries in the standard typemap are not
+ * defined in perl include files, so we do that here.
+ */
+
+#ifndef OutputStream
+#define OutputStream	PerlIO *
+#define InputStream		PerlIO *
+#endif	/* !OutputStream */
+
+MODULE = Storable	PACKAGE = Storable
+
+PROTOTYPES: ENABLE
+
+BOOT:
+    init_perinterp();
+
+int
+pstore(f,obj)
+OutputStream	f
+SV *	obj
+
+int
+net_pstore(f,obj)
+OutputStream	f
+SV *	obj
+
+SV *
+mstore(obj)
+SV *	obj
+
+SV *
+net_mstore(obj)
+SV *	obj
+
+SV *
+pretrieve(f)
+InputStream	f
+
+SV *
+mretrieve(sv)
+SV *	sv
+
+SV *
+dclone(sv)
+SV *	sv
+
+int
+last_op_in_netorder()
+
+int
+is_storing()
+
+int
+is_retrieving()
+
diff --git a/ext/Storable/patchlevel.h b/ext/Storable/patchlevel.h
new file mode 100644
index 0000000000..e3d7670bc6
--- /dev/null
+++ b/ext/Storable/patchlevel.h
@@ -0,0 +1 @@
+#define PATCHLEVEL 2