DBM Filters (via private mail)

	Message-Id: <199904182009.NAA19152@activestate.com>
	Subject: DBM Filters

p4raw-id: //depot/perl@3317

7 files changed, 1314 insertions, 13 deletions

diff --git a/t/lib/db-btree.t b/t/lib/db-btree.t
index 1ebc64df35..7f982d6fd6 100755
--- a/t/lib/db-btree.t
+++ b/t/lib/db-btree.t
@@ -12,7 +12,7 @@ BEGIN {
 use DB_File; 
 use Fcntl;
 
-print "1..102\n";
+print "1..148\n";
 
 sub ok
 {
@@ -38,7 +38,7 @@ sub lexical
     return @a - @b ;
 }
 
-$Dfile = "dbbtree.tmp";
+my $Dfile = "dbbtree.tmp";
 unlink $Dfile;
 
 umask(0);
@@ -609,4 +609,191 @@ EOM
 
 }
 
+{
+   # DBM Filter tests
+   use strict ;
+   my (%h, $db) ;
+   my ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   unlink $Dfile;
+
+   sub checkOutput
+   {
+       my($fk, $sk, $fv, $sv) = @_ ;
+       return
+           $fetch_key eq $fk && $store_key eq $sk && 
+	   $fetch_value eq $fv && $store_value eq $sv &&
+	   $_ eq 'original' ;
+   }
+   
+   ok(103, $db = tie(%h, 'DB_File', $Dfile, O_RDWR|O_CREAT, 0640, $DB_BTREE ) );
+
+   $db->filter_fetch_key   (sub { $fetch_key = $_ }) ;
+   $db->filter_store_key   (sub { $store_key = $_ }) ;
+   $db->filter_fetch_value (sub { $fetch_value = $_}) ;
+   $db->filter_store_value (sub { $store_value = $_ }) ;
+
+   $_ = "original" ;
+
+   $h{"fred"} = "joe" ;
+   #                   fk   sk     fv   sv
+   ok(104, checkOutput( "", "fred", "", "joe")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(105, $h{"fred"} eq "joe");
+   #                   fk    sk     fv    sv
+   ok(106, checkOutput( "", "fred", "joe", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(107, $db->FIRSTKEY() eq "fred") ;
+   #                    fk     sk  fv  sv
+   ok(108, checkOutput( "fred", "", "", "")) ;
+
+   # replace the filters, but remember the previous set
+   my ($old_fk) = $db->filter_fetch_key   
+   			(sub { $_ = uc $_ ; $fetch_key = $_ }) ;
+   my ($old_sk) = $db->filter_store_key   
+   			(sub { $_ = lc $_ ; $store_key = $_ }) ;
+   my ($old_fv) = $db->filter_fetch_value 
+   			(sub { $_ = "[$_]"; $fetch_value = $_ }) ;
+   my ($old_sv) = $db->filter_store_value 
+   			(sub { s/o/x/g; $store_value = $_ }) ;
+   
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   $h{"Fred"} = "Joe" ;
+   #                   fk   sk     fv    sv
+   ok(109, checkOutput( "", "fred", "", "Jxe")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(110, $h{"Fred"} eq "[Jxe]");
+   #                   fk   sk     fv    sv
+   ok(111, checkOutput( "", "fred", "[Jxe]", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(112, $db->FIRSTKEY() eq "FRED") ;
+   #                   fk   sk     fv    sv
+   ok(113, checkOutput( "FRED", "", "", "")) ;
+
+   # put the original filters back
+   $db->filter_fetch_key   ($old_fk);
+   $db->filter_store_key   ($old_sk);
+   $db->filter_fetch_value ($old_fv);
+   $db->filter_store_value ($old_sv);
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   $h{"fred"} = "joe" ;
+   ok(114, checkOutput( "", "fred", "", "joe")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(115, $h{"fred"} eq "joe");
+   ok(116, checkOutput( "", "fred", "joe", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(117, $db->FIRSTKEY() eq "fred") ;
+   ok(118, checkOutput( "fred", "", "", "")) ;
+
+   # delete the filters
+   $db->filter_fetch_key   (undef);
+   $db->filter_store_key   (undef);
+   $db->filter_fetch_value (undef);
+   $db->filter_store_value (undef);
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   $h{"fred"} = "joe" ;
+   ok(119, checkOutput( "", "", "", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(120, $h{"fred"} eq "joe");
+   ok(121, checkOutput( "", "", "", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(122, $db->FIRSTKEY() eq "fred") ;
+   ok(123, checkOutput( "", "", "", "")) ;
+
+   undef $db ;
+   untie %h;
+   unlink $Dfile;
+}
+
+{    
+    # DBM Filter with a closure
+
+    use strict ;
+    my (%h, $db) ;
+
+    unlink $Dfile;
+    ok(124, $db = tie(%h, 'DB_File', $Dfile, O_RDWR|O_CREAT, 0640, $DB_BTREE ) );
+
+    my %result = () ;
+
+    sub Closure
+    {
+        my ($name) = @_ ;
+	my $count = 0 ;
+	my @kept = () ;
+
+	return sub { ++$count ; 
+		     push @kept, $_ ; 
+		     $result{$name} = "$name - $count: [@kept]" ;
+		   }
+    }
+
+    $db->filter_store_key(Closure("store key")) ;
+    $db->filter_store_value(Closure("store value")) ;
+    $db->filter_fetch_key(Closure("fetch key")) ;
+    $db->filter_fetch_value(Closure("fetch value")) ;
+
+    $_ = "original" ;
+
+    $h{"fred"} = "joe" ;
+    ok(125, $result{"store key"} eq "store key - 1: [fred]");
+    ok(126, $result{"store value"} eq "store value - 1: [joe]");
+    ok(127, ! defined $result{"fetch key"} );
+    ok(128, ! defined $result{"fetch value"} );
+    ok(129, $_ eq "original") ;
+
+    ok(130, $db->FIRSTKEY() eq "fred") ;
+    ok(131, $result{"store key"} eq "store key - 1: [fred]");
+    ok(132, $result{"store value"} eq "store value - 1: [joe]");
+    ok(133, $result{"fetch key"} eq "fetch key - 1: [fred]");
+    ok(134, ! defined $result{"fetch value"} );
+    ok(135, $_ eq "original") ;
+
+    $h{"jim"}  = "john" ;
+    ok(136, $result{"store key"} eq "store key - 2: [fred jim]");
+    ok(137, $result{"store value"} eq "store value - 2: [joe john]");
+    ok(138, $result{"fetch key"} eq "fetch key - 1: [fred]");
+    ok(139, ! defined $result{"fetch value"} );
+    ok(140, $_ eq "original") ;
+
+    ok(141, $h{"fred"} eq "joe");
+    ok(142, $result{"store key"} eq "store key - 3: [fred jim fred]");
+    ok(143, $result{"store value"} eq "store value - 2: [joe john]");
+    ok(144, $result{"fetch key"} eq "fetch key - 1: [fred]");
+    ok(145, $result{"fetch value"} eq "fetch value - 1: [joe]");
+    ok(146, $_ eq "original") ;
+
+    undef $db ;
+    untie %h;
+    unlink $Dfile;
+}		
+
+{
+   # DBM Filter recursion detection
+   use strict ;
+   my (%h, $db) ;
+   unlink $Dfile;
+
+   ok(147, $db = tie(%h, 'DB_File', $Dfile, O_RDWR|O_CREAT, 0640, $DB_BTREE ) );
+
+   $db->filter_store_key (sub { $_ = $h{$_} }) ;
+
+   eval '$h{1} = 1234' ;
+   ok(148, $@ =~ /^recursion detected in filter_store_key at/ );
+   
+   undef $db ;
+   untie %h;
+   unlink $Dfile;
+}
+
+
 exit ;
diff --git a/t/lib/db-hash.t b/t/lib/db-hash.t
index 9f2456f7bb..21f2aadada 100755
--- a/t/lib/db-hash.t
+++ b/t/lib/db-hash.t
@@ -12,7 +12,7 @@ BEGIN {
 use DB_File; 
 use Fcntl;
 
-print "1..62\n";
+print "1..108\n";
 
 sub ok
 {
@@ -23,7 +23,7 @@ sub ok
     print "ok $no\n" ;
 }
 
-$Dfile = "dbhash.tmp";
+my $Dfile = "dbhash.tmp";
 unlink $Dfile;
 
 umask(0);
@@ -413,4 +413,191 @@ EOM
     unlink "SubDB.pm", "dbhash.tmp" ;
 
 }
+
+{
+   # DBM Filter tests
+   use strict ;
+   my (%h, $db) ;
+   my ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   unlink $Dfile;
+
+   sub checkOutput
+   {
+       my($fk, $sk, $fv, $sv) = @_ ;
+       return
+           $fetch_key eq $fk && $store_key eq $sk && 
+	   $fetch_value eq $fv && $store_value eq $sv &&
+	   $_ eq 'original' ;
+   }
+   
+   ok(63, $db = tie(%h, 'DB_File', $Dfile, O_RDWR|O_CREAT, 0640, $DB_HASH ) );
+
+   $db->filter_fetch_key   (sub { $fetch_key = $_ }) ;
+   $db->filter_store_key   (sub { $store_key = $_ }) ;
+   $db->filter_fetch_value (sub { $fetch_value = $_}) ;
+   $db->filter_store_value (sub { $store_value = $_ }) ;
+
+   $_ = "original" ;
+
+   $h{"fred"} = "joe" ;
+   #                   fk   sk     fv   sv
+   ok(64, checkOutput( "", "fred", "", "joe")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(65, $h{"fred"} eq "joe");
+   #                   fk    sk     fv    sv
+   ok(66, checkOutput( "", "fred", "joe", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(67, $db->FIRSTKEY() eq "fred") ;
+   #                    fk     sk  fv  sv
+   ok(68, checkOutput( "fred", "", "", "")) ;
+
+   # replace the filters, but remember the previous set
+   my ($old_fk) = $db->filter_fetch_key   
+   			(sub { $_ = uc $_ ; $fetch_key = $_ }) ;
+   my ($old_sk) = $db->filter_store_key   
+   			(sub { $_ = lc $_ ; $store_key = $_ }) ;
+   my ($old_fv) = $db->filter_fetch_value 
+   			(sub { $_ = "[$_]"; $fetch_value = $_ }) ;
+   my ($old_sv) = $db->filter_store_value 
+   			(sub { s/o/x/g; $store_value = $_ }) ;
+   
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   $h{"Fred"} = "Joe" ;
+   #                   fk   sk     fv    sv
+   ok(69, checkOutput( "", "fred", "", "Jxe")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(70, $h{"Fred"} eq "[Jxe]");
+   #                   fk   sk     fv    sv
+   ok(71, checkOutput( "", "fred", "[Jxe]", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(72, $db->FIRSTKEY() eq "FRED") ;
+   #                   fk   sk     fv    sv
+   ok(73, checkOutput( "FRED", "", "", "")) ;
+
+   # put the original filters back
+   $db->filter_fetch_key   ($old_fk);
+   $db->filter_store_key   ($old_sk);
+   $db->filter_fetch_value ($old_fv);
+   $db->filter_store_value ($old_sv);
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   $h{"fred"} = "joe" ;
+   ok(74, checkOutput( "", "fred", "", "joe")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(75, $h{"fred"} eq "joe");
+   ok(76, checkOutput( "", "fred", "joe", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(77, $db->FIRSTKEY() eq "fred") ;
+   ok(78, checkOutput( "fred", "", "", "")) ;
+
+   # delete the filters
+   $db->filter_fetch_key   (undef);
+   $db->filter_store_key   (undef);
+   $db->filter_fetch_value (undef);
+   $db->filter_store_value (undef);
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   $h{"fred"} = "joe" ;
+   ok(79, checkOutput( "", "", "", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(80, $h{"fred"} eq "joe");
+   ok(81, checkOutput( "", "", "", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(82, $db->FIRSTKEY() eq "fred") ;
+   ok(83, checkOutput( "", "", "", "")) ;
+
+   undef $db ;
+   untie %h;
+   unlink $Dfile;
+}
+
+{    
+    # DBM Filter with a closure
+
+    use strict ;
+    my (%h, $db) ;
+
+    unlink $Dfile;
+    ok(84, $db = tie(%h, 'DB_File', $Dfile, O_RDWR|O_CREAT, 0640, $DB_HASH ) );
+
+    my %result = () ;
+
+    sub Closure
+    {
+        my ($name) = @_ ;
+	my $count = 0 ;
+	my @kept = () ;
+
+	return sub { ++$count ; 
+		     push @kept, $_ ; 
+		     $result{$name} = "$name - $count: [@kept]" ;
+		   }
+    }
+
+    $db->filter_store_key(Closure("store key")) ;
+    $db->filter_store_value(Closure("store value")) ;
+    $db->filter_fetch_key(Closure("fetch key")) ;
+    $db->filter_fetch_value(Closure("fetch value")) ;
+
+    $_ = "original" ;
+
+    $h{"fred"} = "joe" ;
+    ok(85, $result{"store key"} eq "store key - 1: [fred]");
+    ok(86, $result{"store value"} eq "store value - 1: [joe]");
+    ok(87, ! defined $result{"fetch key"} );
+    ok(88, ! defined $result{"fetch value"} );
+    ok(89, $_ eq "original") ;
+
+    ok(90, $db->FIRSTKEY() eq "fred") ;
+    ok(91, $result{"store key"} eq "store key - 1: [fred]");
+    ok(92, $result{"store value"} eq "store value - 1: [joe]");
+    ok(93, $result{"fetch key"} eq "fetch key - 1: [fred]");
+    ok(94, ! defined $result{"fetch value"} );
+    ok(95, $_ eq "original") ;
+
+    $h{"jim"}  = "john" ;
+    ok(96, $result{"store key"} eq "store key - 2: [fred jim]");
+    ok(97, $result{"store value"} eq "store value - 2: [joe john]");
+    ok(98, $result{"fetch key"} eq "fetch key - 1: [fred]");
+    ok(99, ! defined $result{"fetch value"} );
+    ok(100, $_ eq "original") ;
+
+    ok(101, $h{"fred"} eq "joe");
+    ok(102, $result{"store key"} eq "store key - 3: [fred jim fred]");
+    ok(103, $result{"store value"} eq "store value - 2: [joe john]");
+    ok(104, $result{"fetch key"} eq "fetch key - 1: [fred]");
+    ok(105, $result{"fetch value"} eq "fetch value - 1: [joe]");
+    ok(106, $_ eq "original") ;
+
+    undef $db ;
+    untie %h;
+    unlink $Dfile;
+}		
+
+{
+   # DBM Filter recursion detection
+   use strict ;
+   my (%h, $db) ;
+   unlink $Dfile;
+
+   ok(107, $db = tie(%h, 'DB_File', $Dfile, O_RDWR|O_CREAT, 0640, $DB_HASH ) );
+
+   $db->filter_store_key (sub { $_ = $h{$_} }) ;
+
+   eval '$h{1} = 1234' ;
+   ok(108, $@ =~ /^recursion detected in filter_store_key at/ );
+   
+   undef $db ;
+   untie %h;
+   unlink $Dfile;
+}
+
 exit ;
diff --git a/t/lib/db-recno.t b/t/lib/db-recno.t
index d5afeb0e0d..cb223b1bc8 100755
--- a/t/lib/db-recno.t
+++ b/t/lib/db-recno.t
@@ -56,7 +56,7 @@ sub bad_one
 EOM
 }
 
-print "1..78\n";
+print "1..124\n";
 
 my $Dfile = "recno.tmp";
 unlink $Dfile ;
@@ -452,4 +452,190 @@ EOM
 
 }
 
+{
+   # DBM Filter tests
+   use strict ;
+   my (@h, $db) ;
+   my ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   unlink $Dfile;
+
+   sub checkOutput
+   {
+       my($fk, $sk, $fv, $sv) = @_ ;
+       return
+           $fetch_key eq $fk && $store_key eq $sk && 
+	   $fetch_value eq $fv && $store_value eq $sv &&
+	   $_ eq 'original' ;
+   }
+   
+   ok(79, $db = tie(@h, 'DB_File', $Dfile, O_RDWR|O_CREAT, 0640, $DB_RECNO ) );
+
+   $db->filter_fetch_key   (sub { $fetch_key = $_ }) ;
+   $db->filter_store_key   (sub { $store_key = $_ }) ;
+   $db->filter_fetch_value (sub { $fetch_value = $_}) ;
+   $db->filter_store_value (sub { $store_value = $_ }) ;
+
+   $_ = "original" ;
+
+   $h[0] = "joe" ;
+   #                   fk   sk     fv   sv
+   ok(80, checkOutput( "", 0, "", "joe")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(81, $h[0] eq "joe");
+   #                   fk  sk  fv    sv
+   ok(82, checkOutput( "", 0, "joe", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(83, $db->FIRSTKEY() == 0) ;
+   #                    fk     sk  fv  sv
+   ok(84, checkOutput( 0, "", "", "")) ;
+
+   # replace the filters, but remember the previous set
+   my ($old_fk) = $db->filter_fetch_key   
+   			(sub { ++ $_ ; $fetch_key = $_ }) ;
+   my ($old_sk) = $db->filter_store_key   
+   			(sub { $_ *= 2 ; $store_key = $_ }) ;
+   my ($old_fv) = $db->filter_fetch_value 
+   			(sub { $_ = "[$_]"; $fetch_value = $_ }) ;
+   my ($old_sv) = $db->filter_store_value 
+   			(sub { s/o/x/g; $store_value = $_ }) ;
+   
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   $h[1] = "Joe" ;
+   #                   fk   sk     fv    sv
+   ok(85, checkOutput( "", 2, "", "Jxe")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(86, $h[1] eq "[Jxe]");
+   #                   fk   sk     fv    sv
+   ok(87, checkOutput( "", 2, "[Jxe]", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(88, $db->FIRSTKEY() == 1) ;
+   #                   fk   sk     fv    sv
+   ok(89, checkOutput( 1, "", "", "")) ;
+   
+   # put the original filters back
+   $db->filter_fetch_key   ($old_fk);
+   $db->filter_store_key   ($old_sk);
+   $db->filter_fetch_value ($old_fv);
+   $db->filter_store_value ($old_sv);
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   $h[0] = "joe" ;
+   ok(90, checkOutput( "", 0, "", "joe")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(91, $h[0] eq "joe");
+   ok(92, checkOutput( "", 0, "joe", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(93, $db->FIRSTKEY() == 0) ;
+   ok(94, checkOutput( 0, "", "", "")) ;
+
+   # delete the filters
+   $db->filter_fetch_key   (undef);
+   $db->filter_store_key   (undef);
+   $db->filter_fetch_value (undef);
+   $db->filter_store_value (undef);
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   $h[0] = "joe" ;
+   ok(95, checkOutput( "", "", "", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(96, $h[0] eq "joe");
+   ok(97, checkOutput( "", "", "", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(98, $db->FIRSTKEY() == 0) ;
+   ok(99, checkOutput( "", "", "", "")) ;
+
+   undef $db ;
+   untie @h;
+   unlink $Dfile;
+}
+
+{    
+    # DBM Filter with a closure
+
+    use strict ;
+    my (@h, $db) ;
+
+    unlink $Dfile;
+    ok(100, $db = tie(@h, 'DB_File', $Dfile, O_RDWR|O_CREAT, 0640, $DB_RECNO ) );
+
+    my %result = () ;
+
+    sub Closure
+    {
+        my ($name) = @_ ;
+	my $count = 0 ;
+	my @kept = () ;
+
+	return sub { ++$count ; 
+		     push @kept, $_ ; 
+		     $result{$name} = "$name - $count: [@kept]" ;
+		   }
+    }
+
+    $db->filter_store_key(Closure("store key")) ;
+    $db->filter_store_value(Closure("store value")) ;
+    $db->filter_fetch_key(Closure("fetch key")) ;
+    $db->filter_fetch_value(Closure("fetch value")) ;
+
+    $_ = "original" ;
+
+    $h[0] = "joe" ;
+    ok(101, $result{"store key"} eq "store key - 1: [0]");
+    ok(102, $result{"store value"} eq "store value - 1: [joe]");
+    ok(103, ! defined $result{"fetch key"} );
+    ok(104, ! defined $result{"fetch value"} );
+    ok(105, $_ eq "original") ;
+
+    ok(106, $db->FIRSTKEY() == 0 ) ;
+    ok(107, $result{"store key"} eq "store key - 1: [0]");
+    ok(108, $result{"store value"} eq "store value - 1: [joe]");
+    ok(109, $result{"fetch key"} eq "fetch key - 1: [0]");
+    ok(110, ! defined $result{"fetch value"} );
+    ok(111, $_ eq "original") ;
+
+    $h[7]  = "john" ;
+    ok(112, $result{"store key"} eq "store key - 2: [0 7]");
+    ok(113, $result{"store value"} eq "store value - 2: [joe john]");
+    ok(114, $result{"fetch key"} eq "fetch key - 1: [0]");
+    ok(115, ! defined $result{"fetch value"} );
+    ok(116, $_ eq "original") ;
+
+    ok(117, $h[0] eq "joe");
+    ok(118, $result{"store key"} eq "store key - 3: [0 7 0]");
+    ok(119, $result{"store value"} eq "store value - 2: [joe john]");
+    ok(120, $result{"fetch key"} eq "fetch key - 1: [0]");
+    ok(121, $result{"fetch value"} eq "fetch value - 1: [joe]");
+    ok(122, $_ eq "original") ;
+
+    undef $db ;
+    untie @h;
+    unlink $Dfile;
+}		
+
+{
+   # DBM Filter recursion detection
+   use strict ;
+   my (@h, $db) ;
+   unlink $Dfile;
+
+   ok(123, $db = tie(@h, 'DB_File', $Dfile, O_RDWR|O_CREAT, 0640, $DB_RECNO ) );
+
+   $db->filter_store_key (sub { $_ = $h[0] }) ;
+
+   eval '$h[1] = 1234' ;
+   ok(124, $@ =~ /^recursion detected in filter_store_key at/ );
+   
+   undef $db ;
+   untie @h;
+   unlink $Dfile;
+}
+
 exit ;
diff --git a/t/lib/gdbm.t b/t/lib/gdbm.t
index f88d4708bb..d8c0ed29c3 100755
--- a/t/lib/gdbm.t
+++ b/t/lib/gdbm.t
@@ -13,7 +13,7 @@ BEGIN {
 
 use GDBM_File;
 
-print "1..20\n";
+print "1..66\n";
 
 unlink <Op.dbmx*>;
 
@@ -206,3 +206,189 @@ EOM
     unlink "SubDB.pm", <dbhash.tmp*> ;
 
 }
+
+{
+   # DBM Filter tests
+   use strict ;
+   my (%h, $db) ;
+   my ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+
+   sub checkOutput
+   {
+       my($fk, $sk, $fv, $sv) = @_ ;
+       return
+           $fetch_key eq $fk && $store_key eq $sk && 
+	   $fetch_value eq $fv && $store_value eq $sv &&
+	   $_ eq 'original' ;
+   }
+   
+   unlink <Op.dbmx*>;
+   ok(21, $db = tie(%h, 'GDBM_File','Op.dbmx', &GDBM_WRCREAT, 0640)) ;
+
+   $db->filter_fetch_key   (sub { $fetch_key = $_ }) ;
+   $db->filter_store_key   (sub { $store_key = $_ }) ;
+   $db->filter_fetch_value (sub { $fetch_value = $_}) ;
+   $db->filter_store_value (sub { $store_value = $_ }) ;
+
+   $_ = "original" ;
+
+   $h{"fred"} = "joe" ;
+   #                   fk   sk     fv   sv
+   ok(22, checkOutput( "", "fred", "", "joe")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(23, $h{"fred"} eq "joe");
+   #                   fk    sk     fv    sv
+   ok(24, checkOutput( "", "fred", "joe", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(25, $db->FIRSTKEY() eq "fred") ;
+   #                    fk     sk  fv  sv
+   ok(26, checkOutput( "fred", "", "", "")) ;
+
+   # replace the filters, but remember the previous set
+   my ($old_fk) = $db->filter_fetch_key   
+   			(sub { $_ = uc $_ ; $fetch_key = $_ }) ;
+   my ($old_sk) = $db->filter_store_key   
+   			(sub { $_ = lc $_ ; $store_key = $_ }) ;
+   my ($old_fv) = $db->filter_fetch_value 
+   			(sub { $_ = "[$_]"; $fetch_value = $_ }) ;
+   my ($old_sv) = $db->filter_store_value 
+   			(sub { s/o/x/g; $store_value = $_ }) ;
+   
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   $h{"Fred"} = "Joe" ;
+   #                   fk   sk     fv    sv
+   ok(27, checkOutput( "", "fred", "", "Jxe")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(28, $h{"Fred"} eq "[Jxe]");
+   #                   fk   sk     fv    sv
+   ok(29, checkOutput( "", "fred", "[Jxe]", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(30, $db->FIRSTKEY() eq "FRED") ;
+   #                   fk   sk     fv    sv
+   ok(31, checkOutput( "FRED", "", "", "")) ;
+
+   # put the original filters back
+   $db->filter_fetch_key   ($old_fk);
+   $db->filter_store_key   ($old_sk);
+   $db->filter_fetch_value ($old_fv);
+   $db->filter_store_value ($old_sv);
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   $h{"fred"} = "joe" ;
+   ok(32, checkOutput( "", "fred", "", "joe")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(33, $h{"fred"} eq "joe");
+   ok(34, checkOutput( "", "fred", "joe", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(35, $db->FIRSTKEY() eq "fred") ;
+   ok(36, checkOutput( "fred", "", "", "")) ;
+
+   # delete the filters
+   $db->filter_fetch_key   (undef);
+   $db->filter_store_key   (undef);
+   $db->filter_fetch_value (undef);
+   $db->filter_store_value (undef);
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   $h{"fred"} = "joe" ;
+   ok(37, checkOutput( "", "", "", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(38, $h{"fred"} eq "joe");
+   ok(39, checkOutput( "", "", "", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(40, $db->FIRSTKEY() eq "fred") ;
+   ok(41, checkOutput( "", "", "", "")) ;
+
+   undef $db ;
+   untie %h;
+   unlink <Op.dbmx*>;
+}
+
+{    
+    # DBM Filter with a closure
+
+    use strict ;
+    my (%h, $db) ;
+
+    unlink <Op.dbmx*>;
+    ok(42, $db = tie(%h, 'GDBM_File','Op.dbmx', &GDBM_WRCREAT, 0640)) ;
+
+    my %result = () ;
+
+    sub Closure
+    {
+        my ($name) = @_ ;
+	my $count = 0 ;
+	my @kept = () ;
+
+	return sub { ++$count ; 
+		     push @kept, $_ ; 
+		     $result{$name} = "$name - $count: [@kept]" ;
+		   }
+    }
+
+    $db->filter_store_key(Closure("store key")) ;
+    $db->filter_store_value(Closure("store value")) ;
+    $db->filter_fetch_key(Closure("fetch key")) ;
+    $db->filter_fetch_value(Closure("fetch value")) ;
+
+    $_ = "original" ;
+
+    $h{"fred"} = "joe" ;
+    ok(43, $result{"store key"} eq "store key - 1: [fred]");
+    ok(44, $result{"store value"} eq "store value - 1: [joe]");
+    ok(45, !defined $result{"fetch key"} );
+    ok(46, !defined $result{"fetch value"} );
+    ok(47, $_ eq "original") ;
+
+    ok(48, $db->FIRSTKEY() eq "fred") ;
+    ok(49, $result{"store key"} eq "store key - 1: [fred]");
+    ok(50, $result{"store value"} eq "store value - 1: [joe]");
+    ok(51, $result{"fetch key"} eq "fetch key - 1: [fred]");
+    ok(52, ! defined $result{"fetch value"} );
+    ok(53, $_ eq "original") ;
+
+    $h{"jim"}  = "john" ;
+    ok(54, $result{"store key"} eq "store key - 2: [fred jim]");
+    ok(55, $result{"store value"} eq "store value - 2: [joe john]");
+    ok(56, $result{"fetch key"} eq "fetch key - 1: [fred]");
+    ok(57, $result{"fetch value"} eq "");
+    ok(58, $_ eq "original") ;
+
+    ok(59, $h{"fred"} eq "joe");
+    ok(60, $result{"store key"} eq "store key - 3: [fred jim fred]");
+    ok(61, $result{"store value"} eq "store value - 2: [joe john]");
+    ok(62, $result{"fetch key"} eq "fetch key - 1: [fred]");
+    ok(63, $result{"fetch value"} eq "fetch value - 1: [joe]");
+    ok(64, $_ eq "original") ;
+
+    undef $db ;
+    untie %h;
+    unlink <Op.dbmx*>;
+}
+
+{
+   # DBM Filter recursion detection
+   use strict ;
+   my (%h, $db) ;
+   unlink <Op.dbmx*>;
+
+   ok(65, $db = tie(%h, 'GDBM_File','Op.dbmx', &GDBM_WRCREAT, 0640)) ;
+
+   $db->filter_store_key (sub { $_ = $h{$_} }) ;
+
+   eval '$h{1} = 1234' ;
+   ok(66, $@ =~ /^recursion detected in filter_store_key at/ );
+   
+   undef $db ;
+   untie %h;
+   unlink <Op.dbmx*>;
+}
diff --git a/t/lib/ndbm.t b/t/lib/ndbm.t
index be122ff687..de42c0d990 100755
--- a/t/lib/ndbm.t
+++ b/t/lib/ndbm.t
@@ -16,7 +16,7 @@ require NDBM_File;
 #If Fcntl is not available, try 0x202 or 0x102 for O_RDWR|O_CREAT
 use Fcntl;
 
-print "1..18\n";
+print "1..64\n";
 
 unlink <Op.dbmx*>;
 
@@ -205,3 +205,189 @@ EOM
     unlink "SubDB.pm", <dbhash.tmp*> ;
 
 }
+
+{
+   # DBM Filter tests
+   use strict ;
+   my (%h, $db) ;
+   my ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+
+   sub checkOutput
+   {
+       my($fk, $sk, $fv, $sv) = @_ ;
+       return
+           $fetch_key eq $fk && $store_key eq $sk && 
+	   $fetch_value eq $fv && $store_value eq $sv &&
+	   $_ eq 'original' ;
+   }
+   
+   unlink <Op.dbmx*>;
+   ok(19, $db = tie(%h, 'NDBM_File','Op.dbmx', O_RDWR|O_CREAT, 0640)) ;
+
+   $db->filter_fetch_key   (sub { $fetch_key = $_ }) ;
+   $db->filter_store_key   (sub { $store_key = $_ }) ;
+   $db->filter_fetch_value (sub { $fetch_value = $_}) ;
+   $db->filter_store_value (sub { $store_value = $_ }) ;
+
+   $_ = "original" ;
+
+   $h{"fred"} = "joe" ;
+   #                   fk   sk     fv   sv
+   ok(20, checkOutput( "", "fred", "", "joe")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(21, $h{"fred"} eq "joe");
+   #                   fk    sk     fv    sv
+   ok(22, checkOutput( "", "fred", "joe", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(23, $db->FIRSTKEY() eq "fred") ;
+   #                    fk     sk  fv  sv
+   ok(24, checkOutput( "fred", "", "", "")) ;
+
+   # replace the filters, but remember the previous set
+   my ($old_fk) = $db->filter_fetch_key   
+   			(sub { $_ = uc $_ ; $fetch_key = $_ }) ;
+   my ($old_sk) = $db->filter_store_key   
+   			(sub { $_ = lc $_ ; $store_key = $_ }) ;
+   my ($old_fv) = $db->filter_fetch_value 
+   			(sub { $_ = "[$_]"; $fetch_value = $_ }) ;
+   my ($old_sv) = $db->filter_store_value 
+   			(sub { s/o/x/g; $store_value = $_ }) ;
+   
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   $h{"Fred"} = "Joe" ;
+   #                   fk   sk     fv    sv
+   ok(25, checkOutput( "", "fred", "", "Jxe")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(26, $h{"Fred"} eq "[Jxe]");
+   #                   fk   sk     fv    sv
+   ok(27, checkOutput( "", "fred", "[Jxe]", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(28, $db->FIRSTKEY() eq "FRED") ;
+   #                   fk   sk     fv    sv
+   ok(29, checkOutput( "FRED", "", "", "")) ;
+
+   # put the original filters back
+   $db->filter_fetch_key   ($old_fk);
+   $db->filter_store_key   ($old_sk);
+   $db->filter_fetch_value ($old_fv);
+   $db->filter_store_value ($old_sv);
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   $h{"fred"} = "joe" ;
+   ok(30, checkOutput( "", "fred", "", "joe")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(31, $h{"fred"} eq "joe");
+   ok(32, checkOutput( "", "fred", "joe", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(33, $db->FIRSTKEY() eq "fred") ;
+   ok(34, checkOutput( "fred", "", "", "")) ;
+
+   # delete the filters
+   $db->filter_fetch_key   (undef);
+   $db->filter_store_key   (undef);
+   $db->filter_fetch_value (undef);
+   $db->filter_store_value (undef);
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   $h{"fred"} = "joe" ;
+   ok(35, checkOutput( "", "", "", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(36, $h{"fred"} eq "joe");
+   ok(37, checkOutput( "", "", "", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(38, $db->FIRSTKEY() eq "fred") ;
+   ok(39, checkOutput( "", "", "", "")) ;
+
+   undef $db ;
+   untie %h;
+   unlink <Op.dbmx*>;
+}
+
+{    
+    # DBM Filter with a closure
+
+    use strict ;
+    my (%h, $db) ;
+
+    unlink <Op.dbmx*>;
+    ok(40, $db = tie(%h, 'NDBM_File','Op.dbmx', O_RDWR|O_CREAT, 0640)) ;
+
+    my %result = () ;
+
+    sub Closure
+    {
+        my ($name) = @_ ;
+	my $count = 0 ;
+	my @kept = () ;
+
+	return sub { ++$count ; 
+		     push @kept, $_ ; 
+		     $result{$name} = "$name - $count: [@kept]" ;
+		   }
+    }
+
+    $db->filter_store_key(Closure("store key")) ;
+    $db->filter_store_value(Closure("store value")) ;
+    $db->filter_fetch_key(Closure("fetch key")) ;
+    $db->filter_fetch_value(Closure("fetch value")) ;
+
+    $_ = "original" ;
+
+    $h{"fred"} = "joe" ;
+    ok(41, $result{"store key"} eq "store key - 1: [fred]");
+    ok(42, $result{"store value"} eq "store value - 1: [joe]");
+    ok(43, !defined $result{"fetch key"} );
+    ok(44, !defined $result{"fetch value"} );
+    ok(45, $_ eq "original") ;
+
+    ok(46, $db->FIRSTKEY() eq "fred") ;
+    ok(47, $result{"store key"} eq "store key - 1: [fred]");
+    ok(48, $result{"store value"} eq "store value - 1: [joe]");
+    ok(49, $result{"fetch key"} eq "fetch key - 1: [fred]");
+    ok(50, ! defined $result{"fetch value"} );
+    ok(51, $_ eq "original") ;
+
+    $h{"jim"}  = "john" ;
+    ok(52, $result{"store key"} eq "store key - 2: [fred jim]");
+    ok(53, $result{"store value"} eq "store value - 2: [joe john]");
+    ok(54, $result{"fetch key"} eq "fetch key - 1: [fred]");
+    ok(55, $result{"fetch value"} eq "");
+    ok(56, $_ eq "original") ;
+
+    ok(57, $h{"fred"} eq "joe");
+    ok(58, $result{"store key"} eq "store key - 3: [fred jim fred]");
+    ok(59, $result{"store value"} eq "store value - 2: [joe john]");
+    ok(60, $result{"fetch key"} eq "fetch key - 1: [fred]");
+    ok(61, $result{"fetch value"} eq "fetch value - 1: [joe]");
+    ok(62, $_ eq "original") ;
+
+    undef $db ;
+    untie %h;
+    unlink <Op.dbmx*>;
+}		
+
+{
+   # DBM Filter recursion detection
+   use strict ;
+   my (%h, $db) ;
+   unlink <Op.dbmx*>;
+
+   ok(63, $db = tie(%h, 'NDBM_File','Op.dbmx', O_RDWR|O_CREAT, 0640)) ;
+
+   $db->filter_store_key (sub { $_ = $h{$_} }) ;
+
+   eval '$h{1} = 1234' ;
+   ok(64, $@ =~ /^recursion detected in filter_store_key at/ );
+   
+   undef $db ;
+   untie %h;
+   unlink <Op.dbmx*>;
+}
diff --git a/t/lib/odbm.t b/t/lib/odbm.t
index 78d8593319..c5458d5e19 100755
--- a/t/lib/odbm.t
+++ b/t/lib/odbm.t
@@ -16,7 +16,7 @@ require ODBM_File;
 #If Fcntl is not available, try 0x202 or 0x102 for O_RDWR|O_CREAT
 use Fcntl;
 
-print "1..18\n";
+print "1..64\n";
 
 unlink <Op.dbmx*>;
 
@@ -205,3 +205,189 @@ EOM
     unlink "SubDB.pm", <dbhash.tmp*> ;
 
 }
+
+{
+   # DBM Filter tests
+   use strict ;
+   my (%h, $db) ;
+   my ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+
+   sub checkOutput
+   {
+       my($fk, $sk, $fv, $sv) = @_ ;
+       return
+           $fetch_key eq $fk && $store_key eq $sk && 
+	   $fetch_value eq $fv && $store_value eq $sv &&
+	   $_ eq 'original' ;
+   }
+   
+   unlink <Op.dbmx*>;
+   ok(19, $db = tie(%h, 'ODBM_File','Op.dbmx', O_RDWR|O_CREAT, 0640)) ;
+
+   $db->filter_fetch_key   (sub { $fetch_key = $_ }) ;
+   $db->filter_store_key   (sub { $store_key = $_ }) ;
+   $db->filter_fetch_value (sub { $fetch_value = $_}) ;
+   $db->filter_store_value (sub { $store_value = $_ }) ;
+
+   $_ = "original" ;
+
+   $h{"fred"} = "joe" ;
+   #                   fk   sk     fv   sv
+   ok(20, checkOutput( "", "fred", "", "joe")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(21, $h{"fred"} eq "joe");
+   #                   fk    sk     fv    sv
+   ok(22, checkOutput( "", "fred", "joe", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(23, $db->FIRSTKEY() eq "fred") ;
+   #                    fk     sk  fv  sv
+   ok(24, checkOutput( "fred", "", "", "")) ;
+
+   # replace the filters, but remember the previous set
+   my ($old_fk) = $db->filter_fetch_key   
+   			(sub { $_ = uc $_ ; $fetch_key = $_ }) ;
+   my ($old_sk) = $db->filter_store_key   
+   			(sub { $_ = lc $_ ; $store_key = $_ }) ;
+   my ($old_fv) = $db->filter_fetch_value 
+   			(sub { $_ = "[$_]"; $fetch_value = $_ }) ;
+   my ($old_sv) = $db->filter_store_value 
+   			(sub { s/o/x/g; $store_value = $_ }) ;
+   
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   $h{"Fred"} = "Joe" ;
+   #                   fk   sk     fv    sv
+   ok(25, checkOutput( "", "fred", "", "Jxe")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(26, $h{"Fred"} eq "[Jxe]");
+   #                   fk   sk     fv    sv
+   ok(27, checkOutput( "", "fred", "[Jxe]", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(28, $db->FIRSTKEY() eq "FRED") ;
+   #                   fk   sk     fv    sv
+   ok(29, checkOutput( "FRED", "", "", "")) ;
+
+   # put the original filters back
+   $db->filter_fetch_key   ($old_fk);
+   $db->filter_store_key   ($old_sk);
+   $db->filter_fetch_value ($old_fv);
+   $db->filter_store_value ($old_sv);
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   $h{"fred"} = "joe" ;
+   ok(30, checkOutput( "", "fred", "", "joe")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(31, $h{"fred"} eq "joe");
+   ok(32, checkOutput( "", "fred", "joe", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(33, $db->FIRSTKEY() eq "fred") ;
+   ok(34, checkOutput( "fred", "", "", "")) ;
+
+   # delete the filters
+   $db->filter_fetch_key   (undef);
+   $db->filter_store_key   (undef);
+   $db->filter_fetch_value (undef);
+   $db->filter_store_value (undef);
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   $h{"fred"} = "joe" ;
+   ok(35, checkOutput( "", "", "", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(36, $h{"fred"} eq "joe");
+   ok(37, checkOutput( "", "", "", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(38, $db->FIRSTKEY() eq "fred") ;
+   ok(39, checkOutput( "", "", "", "")) ;
+
+   undef $db ;
+   untie %h;
+   unlink <Op.dbmx*>;
+}
+
+{    
+    # DBM Filter with a closure
+
+    use strict ;
+    my (%h, $db) ;
+
+    unlink <Op.dbmx*>;
+    ok(40, $db = tie(%h, 'ODBM_File','Op.dbmx', O_RDWR|O_CREAT, 0640)) ;
+
+    my %result = () ;
+
+    sub Closure
+    {
+        my ($name) = @_ ;
+	my $count = 0 ;
+	my @kept = () ;
+
+	return sub { ++$count ; 
+		     push @kept, $_ ; 
+		     $result{$name} = "$name - $count: [@kept]" ;
+		   }
+    }
+
+    $db->filter_store_key(Closure("store key")) ;
+    $db->filter_store_value(Closure("store value")) ;
+    $db->filter_fetch_key(Closure("fetch key")) ;
+    $db->filter_fetch_value(Closure("fetch value")) ;
+
+    $_ = "original" ;
+
+    $h{"fred"} = "joe" ;
+    ok(41, $result{"store key"} eq "store key - 1: [fred]");
+    ok(42, $result{"store value"} eq "store value - 1: [joe]");
+    ok(43, !defined $result{"fetch key"} );
+    ok(44, !defined $result{"fetch value"} );
+    ok(45, $_ eq "original") ;
+
+    ok(46, $db->FIRSTKEY() eq "fred") ;
+    ok(47, $result{"store key"} eq "store key - 1: [fred]");
+    ok(48, $result{"store value"} eq "store value - 1: [joe]");
+    ok(49, $result{"fetch key"} eq "fetch key - 1: [fred]");
+    ok(50, ! defined $result{"fetch value"} );
+    ok(51, $_ eq "original") ;
+
+    $h{"jim"}  = "john" ;
+    ok(52, $result{"store key"} eq "store key - 2: [fred jim]");
+    ok(53, $result{"store value"} eq "store value - 2: [joe john]");
+    ok(54, $result{"fetch key"} eq "fetch key - 1: [fred]");
+    ok(55, $result{"fetch value"} eq "");
+    ok(56, $_ eq "original") ;
+
+    ok(57, $h{"fred"} eq "joe");
+    ok(58, $result{"store key"} eq "store key - 3: [fred jim fred]");
+    ok(59, $result{"store value"} eq "store value - 2: [joe john]");
+    ok(60, $result{"fetch key"} eq "fetch key - 1: [fred]");
+    ok(61, $result{"fetch value"} eq "fetch value - 1: [joe]");
+    ok(62, $_ eq "original") ;
+
+    undef $db ;
+    untie %h;
+    unlink <Op.dbmx*>;
+}		
+
+{
+   # DBM Filter recursion detection
+   use strict ;
+   my (%h, $db) ;
+   unlink <Op.dbmx*>;
+
+   ok(63, $db = tie(%h, 'ODBM_File','Op.dbmx', O_RDWR|O_CREAT, 0640)) ;
+
+   $db->filter_store_key (sub { $_ = $h{$_} }) ;
+
+   eval '$h{1} = 1234' ;
+   ok(64, $@ =~ /^recursion detected in filter_store_key at/ );
+   
+   undef $db ;
+   untie %h;
+   unlink <Op.dbmx*>;
+}
diff --git a/t/lib/sdbm.t b/t/lib/sdbm.t
index af796c1b31..2689d1962e 100755
--- a/t/lib/sdbm.t
+++ b/t/lib/sdbm.t
@@ -15,7 +15,7 @@ require SDBM_File;
 #If Fcntl is not available, try 0x202 or 0x102 for O_RDWR|O_CREAT
 use Fcntl;
 
-print "1..20\n";
+print "1..66\n";
 
 unlink <Op_dbmx.*>;
 
@@ -208,8 +208,191 @@ ok(19, !exists $h{'goner1'});
 ok(20, exists $h{'foo'});
 
 untie %h;
-if ($^O eq 'VMS') {
-  unlink 'Op_dbmx.sdbm_dir', $Dfile;
-} else {
-  unlink 'Op_dbmx.dir', $Dfile;
+unlink <Op_dbmx*>, $Dfile;
+
+{
+   # DBM Filter tests
+   use strict ;
+   my (%h, $db) ;
+   my ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+
+   sub checkOutput
+   {
+       my($fk, $sk, $fv, $sv) = @_ ;
+       return
+           $fetch_key eq $fk && $store_key eq $sk && 
+	   $fetch_value eq $fv && $store_value eq $sv &&
+	   $_ eq 'original' ;
+   }
+   
+   unlink <Op_dbmx*>;
+   ok(21, $db = tie(%h, 'SDBM_File','Op_dbmx', O_RDWR|O_CREAT, 0640)) ;
+
+   $db->filter_fetch_key   (sub { $fetch_key = $_ }) ;
+   $db->filter_store_key   (sub { $store_key = $_ }) ;
+   $db->filter_fetch_value (sub { $fetch_value = $_}) ;
+   $db->filter_store_value (sub { $store_value = $_ }) ;
+
+   $_ = "original" ;
+
+   $h{"fred"} = "joe" ;
+   #                   fk   sk     fv   sv
+   ok(22, checkOutput( "", "fred", "", "joe")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(23, $h{"fred"} eq "joe");
+   #                   fk    sk     fv    sv
+   ok(24, checkOutput( "", "fred", "joe", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(25, $db->FIRSTKEY() eq "fred") ;
+   #                    fk     sk  fv  sv
+   ok(26, checkOutput( "fred", "", "", "")) ;
+
+   # replace the filters, but remember the previous set
+   my ($old_fk) = $db->filter_fetch_key   
+   			(sub { $_ = uc $_ ; $fetch_key = $_ }) ;
+   my ($old_sk) = $db->filter_store_key   
+   			(sub { $_ = lc $_ ; $store_key = $_ }) ;
+   my ($old_fv) = $db->filter_fetch_value 
+   			(sub { $_ = "[$_]"; $fetch_value = $_ }) ;
+   my ($old_sv) = $db->filter_store_value 
+   			(sub { s/o/x/g; $store_value = $_ }) ;
+   
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   $h{"Fred"} = "Joe" ;
+   #                   fk   sk     fv    sv
+   ok(27, checkOutput( "", "fred", "", "Jxe")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(28, $h{"Fred"} eq "[Jxe]");
+   #                   fk   sk     fv    sv
+   ok(29, checkOutput( "", "fred", "[Jxe]", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(30, $db->FIRSTKEY() eq "FRED") ;
+   #                   fk   sk     fv    sv
+   ok(31, checkOutput( "FRED", "", "", "")) ;
+
+   # put the original filters back
+   $db->filter_fetch_key   ($old_fk);
+   $db->filter_store_key   ($old_sk);
+   $db->filter_fetch_value ($old_fv);
+   $db->filter_store_value ($old_sv);
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   $h{"fred"} = "joe" ;
+   ok(32, checkOutput( "", "fred", "", "joe")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(33, $h{"fred"} eq "joe");
+   ok(34, checkOutput( "", "fred", "joe", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(35, $db->FIRSTKEY() eq "fred") ;
+   ok(36, checkOutput( "fred", "", "", "")) ;
+
+   # delete the filters
+   $db->filter_fetch_key   (undef);
+   $db->filter_store_key   (undef);
+   $db->filter_fetch_value (undef);
+   $db->filter_store_value (undef);
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   $h{"fred"} = "joe" ;
+   ok(37, checkOutput( "", "", "", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(38, $h{"fred"} eq "joe");
+   ok(39, checkOutput( "", "", "", "")) ;
+
+   ($fetch_key, $store_key, $fetch_value, $store_value) = ("") x 4 ;
+   ok(40, $db->FIRSTKEY() eq "fred") ;
+   ok(41, checkOutput( "", "", "", "")) ;
+
+   undef $db ;
+   untie %h;
+   unlink <Op_dbmx*>;
+}
+
+{    
+    # DBM Filter with a closure
+
+    use strict ;
+    my (%h, $db) ;
+
+    unlink <Op_dbmx*>;
+    ok(42, $db = tie(%h, 'SDBM_File','Op_dbmx', O_RDWR|O_CREAT, 0640)) ;
+
+    my %result = () ;
+
+    sub Closure
+    {
+        my ($name) = @_ ;
+	my $count = 0 ;
+	my @kept = () ;
+
+	return sub { ++$count ; 
+		     push @kept, $_ ; 
+		     $result{$name} = "$name - $count: [@kept]" ;
+		   }
+    }
+
+    $db->filter_store_key(Closure("store key")) ;
+    $db->filter_store_value(Closure("store value")) ;
+    $db->filter_fetch_key(Closure("fetch key")) ;
+    $db->filter_fetch_value(Closure("fetch value")) ;
+
+    $_ = "original" ;
+
+    $h{"fred"} = "joe" ;
+    ok(43, $result{"store key"} eq "store key - 1: [fred]");
+    ok(44, $result{"store value"} eq "store value - 1: [joe]");
+    ok(45, !defined $result{"fetch key"} );
+    ok(46, !defined $result{"fetch value"} );
+    ok(47, $_ eq "original") ;
+
+    ok(48, $db->FIRSTKEY() eq "fred") ;
+    ok(49, $result{"store key"} eq "store key - 1: [fred]");
+    ok(50, $result{"store value"} eq "store value - 1: [joe]");
+    ok(51, $result{"fetch key"} eq "fetch key - 1: [fred]");
+    ok(52, ! defined $result{"fetch value"} );
+    ok(53, $_ eq "original") ;
+
+    $h{"jim"}  = "john" ;
+    ok(54, $result{"store key"} eq "store key - 2: [fred jim]");
+    ok(55, $result{"store value"} eq "store value - 2: [joe john]");
+    ok(56, $result{"fetch key"} eq "fetch key - 1: [fred]");
+    ok(57, $result{"fetch value"} eq "");
+    ok(58, $_ eq "original") ;
+
+    ok(59, $h{"fred"} eq "joe");
+    ok(60, $result{"store key"} eq "store key - 3: [fred jim fred]");
+    ok(61, $result{"store value"} eq "store value - 2: [joe john]");
+    ok(62, $result{"fetch key"} eq "fetch key - 1: [fred]");
+    ok(63, $result{"fetch value"} eq "fetch value - 1: [joe]");
+    ok(64, $_ eq "original") ;
+
+    undef $db ;
+    untie %h;
+    unlink <Op_dbmx*>;
+}		
+
+{
+   # DBM Filter recursion detection
+   use strict ;
+   my (%h, $db) ;
+   unlink <Op_dbmx*>;
+
+   ok(65, $db = tie(%h, 'SDBM_File','Op_dbmx', O_RDWR|O_CREAT, 0640)) ;
+
+   $db->filter_store_key (sub { $_ = $h{$_} }) ;
+
+   eval '$h{1} = 1234' ;
+   ok(66, $@ =~ /^recursion detected in filter_store_key at/ );
+   
+   undef $db ;
+   untie %h;
+   unlink <Op_dbmx*>;
 }
+