Adapted everything to new exploded format

git-svn-id: http://svn.savannah.nongnu.org/svn/rdiff-backup/trunk@130 2b77aa54-bcbc-44c9-a7ec-4f6cf2b41109

1 files changed, 262 insertions, 0 deletions

diff --git a/rdiff-backup/rdiff_backup/Hardlink.py b/rdiff-backup/rdiff_backup/Hardlink.py
new file mode 100644
index 0000000..9389b6f
--- /dev/null
+++ b/rdiff-backup/rdiff_backup/Hardlink.py
@@ -0,0 +1,262 @@
+from __future__ import generators
+import cPickle
+
+#######################################################################
+#
+# hardlink - code for preserving and restoring hardlinks
+#
+# If the preserve_hardlinks option is selected, linked files in the
+# source directory will be linked in the mirror directory.  Linked
+# files are treated like any other with respect to incrementing, but a
+# database of all links will be recorded at each session, so linked
+# files can still be restored from the increments.
+#
+
+"""Hardlink class methods and data
+
+All these functions are meant to be executed on the destination
+side.  The source side should only transmit inode information.
+
+"""
+
+# In all of these lists of indicies are the values.  The keys in
+# _inode_ ones are (inode, devloc) pairs.
+_src_inode_indicies = {}
+_dest_inode_indicies = {}
+
+# The keys for these two are just indicies.  They share values
+# with the earlier dictionaries.
+_src_index_indicies = {}
+_dest_index_indicies = {}
+
+# When a linked file is restored, its path is added to this dict,
+# so it can be found when later paths being restored are linked to
+# it.
+_restore_index_path = {}
+
+def get_inode_key(rorp):
+	"""Return rorp's key for _inode_ dictionaries"""
+	return (rorp.getinode(), rorp.getdevloc())
+
+def get_indicies(rorp, source):
+	"""Return a list of similarly linked indicies, using rorp's index"""
+	if source: dict = _src_index_indicies
+	else: dict = _dest_index_indicies
+	try: return dict[rorp.index]
+	except KeyError: return []
+
+def add_rorp(rorp, source):
+	"""Process new rorp and update hard link dictionaries
+
+	First enter it into src_inode_indicies.  If we have already
+	seen all the hard links, then we can delete the entry.
+	Everything must stay recorded in src_index_indicies though.
+
+	"""
+	if not rorp.isreg() or rorp.getnumlinks() < 2: return
+
+	if source:
+		inode_dict, index_dict = _src_inode_indicies, _src_index_indicies
+	else: inode_dict, index_dict = _dest_inode_indicies, _dest_index_indicies
+
+	rp_inode_key = get_inode_key(rorp)
+	if inode_dict.has_key(rp_inode_key):
+		index_list = inode_dict[rp_inode_key]
+		index_list.append(rorp.index)
+		if len(index_list) == rorp.getnumlinks():
+			del inode_dict[rp_inode_key]
+	else: # make new entry in both src dicts
+		index_list = [rorp.index]
+		inode_dict[rp_inode_key] = index_list
+	index_dict[rorp.index] = index_list
+
+def add_rorp_iter(iter, source):
+	"""Return new rorp iterator like iter that add_rorp's first"""
+	for rorp in iter:
+		add_rorp(rorp, source)
+		yield rorp
+
+def rorp_eq(src_rorp, dest_rorp):
+	"""Compare hardlinked for equality
+
+	Two files may otherwise seem equal but be hardlinked in
+	different ways.  This function considers them equal enough if
+	they have been hardlinked correctly to the previously seen
+	indicies.
+
+	"""
+	assert src_rorp.index == dest_rorp.index
+	if (not src_rorp.isreg() or not dest_rorp.isreg() or
+		src_rorp.getnumlinks() == dest_rorp.getnumlinks() == 1):
+		return 1 # Hard links don't apply
+
+	src_index_list = get_indicies(src_rorp, 1)
+	dest_index_list = get_indicies(dest_rorp, None)
+
+	# If a list only has one element, then it is only hardlinked
+	# to itself so far, so that is not a genuine difference yet.
+	if not src_index_list or len(src_index_list) == 1:
+		return not dest_index_list or len(dest_index_list) == 1
+	if not dest_index_list or len(dest_index_list) == 1: return None
+
+	# Both index lists exist and are non-empty
+	return src_index_list == dest_index_list # they are always sorted
+
+def islinked(rorp):
+	"""True if rorp's index is already linked to something on src side"""
+	return len(get_indicies(rorp, 1)) >= 2
+
+def restore_link(index, rpath):
+	"""Restores a linked file by linking it
+
+	When restoring, all the hardlink data is already present, and
+	we can only link to something already written.  In either
+	case, add to the _restore_index_path dict, so we know later
+	that the file is available for hard
+	linking.
+
+	Returns true if succeeded in creating rpath, false if must
+	restore rpath normally.
+
+	"""
+	if index not in _src_index_indicies: return None
+	for linked_index in _src_index_indicies[index]:
+		if linked_index in _restore_index_path:
+			srcpath = _restore_index_path[linked_index]
+			Log("Restoring %s by hard linking to %s" %
+				(rpath.path, srcpath), 6)
+			rpath.hardlink(srcpath)
+			return 1
+	_restore_index_path[index] = rpath.path
+	return None
+
+def link_rp(src_rorp, dest_rpath, dest_root = None):
+	"""Make dest_rpath into a link analogous to that of src_rorp"""
+	if not dest_root: dest_root = dest_rpath # use base of dest_rpath
+	dest_link_rpath = RPath(dest_root.conn, dest_root.base,
+							get_indicies(src_rorp, 1)[0])
+	dest_rpath.hardlink(dest_link_rpath.path)
+
+def write_linkdict(rpath, dict, compress = None):
+	"""Write link data to the rbdata dir
+
+	It is stored as the a big pickled dictionary dated to match
+	the current hardlinks.
+
+	"""
+	assert (Globals.isbackup_writer and
+			rpath.conn is Globals.local_connection)
+	tf = TempFileManager.new(rpath)
+	def init():
+		fp = tf.open("wb", compress)
+		cPickle.dump(dict, fp)
+		assert not fp.close()
+		tf.setdata()
+	Robust.make_tf_robustaction(init, (tf,), (rpath,)).execute()
+
+def get_linkrp(data_rpath, time, prefix):
+	"""Return RPath of linkdata, or None if cannot find"""
+	for rp in map(data_rpath.append, data_rpath.listdir()):
+		if (rp.isincfile() and rp.getincbase_str() == prefix and
+			(rp.getinctype() == 'snapshot' or rp.getinctype() == 'data')
+			and Time.stringtotime(rp.getinctime()) == time):
+			return rp
+	return None
+
+def get_linkdata(data_rpath, time, prefix = 'hardlink_data'):
+	"""Return index dictionary written by write_linkdata at time"""
+	rp = get_linkrp(data_rpath, time, prefix)
+	if not rp: return None
+	fp = rp.open("rb", rp.isinccompressed())
+	index_dict = cPickle.load(fp)
+	assert not fp.close()
+	return index_dict
+
+def final_writedata():
+	"""Write final checkpoint data to rbdir after successful backup"""
+	global final_inc
+	if _src_index_indicies:
+		Log("Writing hard link data", 6)
+		if Globals.compression:
+			final_inc = Globals.rbdir.append("hardlink_data.%s.data.gz" %
+											 Time.curtimestr)
+		else: final_inc = Globals.rbdir.append("hardlink_data.%s.data" %
+											   Time.curtimestr)
+		write_linkdict(final_inc, _src_index_indicies, Globals.compression)
+	else: # no hardlinks, so writing unnecessary
+		final_inc = None
+
+def retrieve_final(time):
+	"""Set source index dictionary from hardlink_data file if avail"""
+	global _src_index_indicies
+	hd = get_linkdata(Globals.rbdir, time)
+	if hd is None: return None
+	_src_index_indicies = hd
+	return 1
+
+def final_checkpoint(data_rpath):
+	"""Write contents of the four dictionaries to the data dir
+
+	If rdiff-backup receives a fatal error, it may still be able
+	to save the contents of the four hard link dictionaries.
+	Because these dictionaries may be big, they are not saved
+	after every 20 seconds or whatever, but just at the end.
+
+	"""
+	Log("Writing intermediate hard link data to disk", 2)
+	src_inode_rp = data_rpath.append("hardlink_source_inode_checkpoint."
+									 "%s.data" % Time.curtimestr)
+	src_index_rp = data_rpath.append("hardlink_source_index_checkpoint."
+									 "%s.data" % Time.curtimestr)
+	dest_inode_rp = data_rpath.append("hardlink_dest_inode_checkpoint."
+									  "%s.data" % Time.curtimestr)
+	dest_index_rp = data_rpath.append("hardlink_dest_index_checkpoint."
+									  "%s.data" % Time.curtimestr)
+	for (rp, dict) in ((src_inode_rp, _src_inode_indicies),
+					   (src_index_rp, _src_index_indicies),
+					   (dest_inode_rp, _dest_inode_indicies),
+					   (dest_index_rp, _dest_index_indicies)):
+		write_linkdict(rp, dict)
+
+def retrieve_checkpoint(data_rpath, time):
+	"""Retrieve hardlink data from final checkpoint
+
+	Return true if the retrieval worked, false otherwise.
+
+	"""
+	global _src_inode_indicies, _src_index_indicies
+	global _dest_inode_indicies, _dest_index_indicies
+	try:
+		src_inode = get_linkdata(data_rpath, time,
+								 "hardlink_source_inode_checkpoint")
+		src_index = get_linkdata(data_rpath, time,
+								 "hardlink_source_index_checkpoint")
+		dest_inode = get_linkdata(data_rpath, time,
+								  "hardlink_dest_inode_checkpoint")
+		dest_index = get_linkdata(data_rpath, time,
+								  "hardlink_dest_index_checkpoint")
+	except cPickle.UnpicklingError:
+		Log("Unpickling Error", 2)
+		return None
+	if (src_inode is None or src_index is None or
+		dest_inode is None or dest_index is None): return None
+	_src_inode_indicies, _src_index_indicies = src_inode, src_index
+	_dest_inode_indicies, _dest_index_indicies = dest_inode, dest_index
+	return 1
+
+def remove_all_checkpoints():
+	"""Remove all hardlink checkpoint information from directory"""
+	prefix_list = ["hardlink_source_inode_checkpoint",
+				   "hardlink_source_index_checkpoint",
+				   "hardlink_dest_inode_checkpoint",
+				   "hardlink_dest_index_checkpoint"]
+	for rp in map(Globals.rbdir.append, Globals.rbdir.listdir()):
+		if (rp.isincfile() and rp.getincbase_str() in prefix_list and
+			(rp.getinctype() == 'snapshot' or rp.getinctype() == 'data')):
+			rp.delete()
+
+
+from log import *
+from robust import *
+from rpath import *
+import Globals, Time