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22
"""Weave - storage of related text file versions"""
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# before intset (r923) 2000 versions in 41.5s
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# with intset (r926) 2000 versions in 93s !!!
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# better to just use plain sets.
28
# making _extract build and return a list, rather than being a generator
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# with python -O, r923 does 2000 versions in 36.87s
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# with optimizations to avoid mutating lists - 35.75! I guess copying
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# all the elements every time costs more than the small manipulations.
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# a surprisingly small change.
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# r931, which avoids using a generator for extract, does 36.98s
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# with memoized inclusions, takes 41.49s; not very good
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# with slots, takes 37.35s; without takes 39.16, a bit surprising
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# with the delta calculation mixed in with the add method, rather than
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# separated, takes 36.78s
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# with delta folded in and mutation of the list, 36.13s
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# with all this and simplification of add code, 33s
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# TODO: Perhaps have copy method for Weave instances?
53
25
# XXX: If we do weaves this way, will a merge still behave the same
54
26
# way if it's done in a different order? That's a pretty desirable
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# TODO: Parallel-extract that passes back each line along with a
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# description of which revisions include it. Nice for checking all
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class WeaveError(Exception):
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"""Exception in processing weave"""
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class WeaveFormatError(WeaveError):
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"""Weave invariant violated"""
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# shas or calculating stats in parallel.
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# TODO: Using a single _extract routine and then processing the output
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# is probably inefficient. It's simple enough that we can afford to
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# have slight specializations for different ways its used: annotate,
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# basis for add, get, etc.
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# TODO: Probably the API should work only in names to hide the integer
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# indexes from the user.
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# TODO: Is there any potential performance win by having an add()
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# variant that is passed a pre-cooked version of the single basis
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# TODO: Reweave can possibly be made faster by remembering diffs
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# where the basis and destination are unchanged.
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# FIXME: Sometimes we will be given a parents list for a revision
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# that includes some redundant parents (i.e. already a parent of
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# something in the list.) We should eliminate them. This can
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# be done fairly efficiently because the sequence numbers constrain
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# the possible relationships.
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from difflib import SequenceMatcher
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from bzrlib.trace import mutter
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from bzrlib.errors import (WeaveError, WeaveFormatError, WeaveParentMismatch,
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WeaveRevisionNotPresent, WeaveRevisionAlreadyPresent)
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import bzrlib.errors as errors
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from bzrlib.tsort import topo_sort
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81
class Weave(object):
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82
"""weave - versioned text file storage.
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each version; the parent's parents are implied.
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List of hex SHA-1 of each version, or None if not recorded.
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List of hex SHA-1 of each version.
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List of symbolic names for each version. Each should be unique.
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For each name, the version number.
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Descriptive name of this weave; typically the filename if known.
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__slots__ = ['_weave', '_parents', '_sha1s']
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__slots__ = ['_weave', '_parents', '_sha1s', '_names', '_name_map',
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def __init__(self, weave_name=None):
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self._parents = []
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self._weave_name = weave_name
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return "Weave(%r)" % self._weave_name
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"""Return a deep copy of self.
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The copy can be modified without affecting the original weave."""
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other._weave = self._weave[:]
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other._parents = self._parents[:]
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other._sha1s = self._sha1s[:]
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other._names = self._names[:]
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other._name_map = self._name_map.copy()
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other._weave_name = self._weave_name
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def __eq__(self, other):
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199
if not isinstance(other, Weave):
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return self._parents == other._parents \
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and self._weave == other._weave
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and self._weave == other._weave \
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and self._sha1s == other._sha1s
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def __ne__(self, other):
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return not self.__eq__(other)
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def add(self, parents, text):
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def __contains__(self, name):
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return self._name_map.has_key(name)
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def maybe_lookup(self, name_or_index):
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"""Convert possible symbolic name to index, or pass through indexes."""
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if isinstance(name_or_index, (int, long)):
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return self.lookup(name_or_index)
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def lookup(self, name):
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"""Convert symbolic version name to index."""
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return self._name_map[name]
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raise WeaveRevisionNotPresent(name, self)
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return self._names[:]
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def iter_names(self):
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"""Yield a list of all names in this weave."""
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return iter(self._names)
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def idx_to_name(self, version):
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return self._names[version]
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def _check_repeated_add(self, name, parents, text, sha1):
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"""Check that a duplicated add is OK.
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If it is, return the (old) index; otherwise raise an exception.
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idx = self.lookup(name)
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if sorted(self._parents[idx]) != sorted(parents) \
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or sha1 != self._sha1s[idx]:
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raise WeaveRevisionAlreadyPresent(name, self)
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def add(self, name, parents, text, sha1=None):
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"""Add a single text on top of the weave.
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Returns the index number of the newly added version.
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Symbolic name for this version.
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(Typically the revision-id of the revision that added it.)
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List or set of direct parent version numbers.
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Sequence of lines to be added in the new version."""
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Sequence of lines to be added in the new version.
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sha -- SHA-1 of the file, if known. This is trusted to be
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from bzrlib.osutils import sha_strings
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assert isinstance(name, basestring)
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sha1 = sha_strings(text)
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if name in self._name_map:
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return self._check_repeated_add(name, parents, text, sha1)
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parents = map(self.maybe_lookup, parents)
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self._check_versions(parents)
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## self._check_lines(text)
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new_version = len(self._parents)
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# if we abort after here the weave will be corrupt
207
self._parents.append(frozenset(parents))
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# if we abort after here the (in-memory) weave will be corrupt because only
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# some fields are updated
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self._parents.append(parents[:])
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self._sha1s.append(sha1)
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self._names.append(name)
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self._name_map[name] = new_version
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# we don't destroy ourselves
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self._weave[i:i] = ([('{', new_version)]
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+ [('}', new_version)])
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offset += 2 + (j2 - j1)
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return new_version
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def add_identical(self, old_rev_id, new_rev_id, parents):
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"""Add an identical text to old_rev_id as new_rev_id."""
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old_lines = self.get(self.lookup(old_rev_id))
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self.add(new_rev_id, parents, old_lines)
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def inclusions(self, versions):
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"""Return set of all ancestors of given version(s)."""
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i = set(versions)
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# include all its parents
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i.update(self._parents[v])
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raise ValueError("version %d not present in weave" % v)
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for v in xrange(max(versions), 0, -1):
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# include all its parents
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i.update(self._parents[v])
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## except IndexError:
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## raise ValueError("version %d not present in weave" % v)
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def parents(self, version):
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return self._parents[version]
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def parent_names(self, version):
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"""Return version names for parents of a version."""
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return map(self.idx_to_name, self._parents[self.lookup(version)])
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def minimal_parents(self, version):
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result.append((istack[-1], lineno, l))
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raise WFE("unclosed insertion blocks at end of weave",
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raise WeaveFormatError("unclosed insertion blocks "
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"at end of weave: %s" % istack)
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raise WFE("unclosed deletion blocks at end of weave",
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raise WeaveFormatError("unclosed deletion blocks at end of weave: %s"
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def get_iter(self, version):
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def get_iter(self, name_or_index):
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"""Yield lines for the specified version."""
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for origin, lineno, line in self._extract([version]):
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incls = [self.maybe_lookup(name_or_index)]
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# We don't have sha1 sums for multiple entries
564
for origin, lineno, line in self._extract(incls):
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def get(self, index):
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return list(self.get_iter(index))
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expected_sha1 = self._sha1s[index]
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measured_sha1 = cur_sha.hexdigest()
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if measured_sha1 != expected_sha1:
572
raise errors.WeaveInvalidChecksum(
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'file %s, revision %s, expected: %s, measured %s'
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% (self._weave_name, self._names[index],
575
expected_sha1, measured_sha1))
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def get_text(self, name_or_index):
579
return ''.join(self.get_iter(name_or_index))
580
assert isinstance(version, int)
583
def get_lines(self, name_or_index):
584
return list(self.get_iter(name_or_index))
590
def get_sha1(self, name):
591
"""Get the stored sha1 sum for the given revision.
593
:param name: The name of the version to lookup
595
return self._sha1s[self.lookup(name)]
474
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def mash_iter(self, included):
475
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"""Return composed version of multiple included versions."""
599
included = map(self.maybe_lookup, included)
476
600
for origin, lineno, text in self._extract(included):
506
629
raise WeaveFormatError("invalid included version %d for index %d"
507
630
% (inclusions[-1], version))
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# try extracting all versions; this is a bit slow and parallel
510
# extraction could be used
632
# try extracting all versions; parallel extraction is used
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nv = self.numversions()
634
sha1s = [sha.new() for i in range(nv)]
635
texts = [[] for i in range(nv)]
638
# For creating the ancestry, IntSet is much faster (3.7s vs 0.17s)
639
# The problem is that set membership is much more expensive
641
for p in self._parents[i]:
642
new_inc.update(inclusions[p])
644
#assert set(new_inc) == self.inclusions([i]), 'failed %s != %s' % (new_inc, self.inclusions([i]))
645
inclusions.append(new_inc)
647
nlines = len(self._weave)
649
update_text = 'checking weave'
651
short_name = os.path.basename(self._weave_name)
652
update_text = 'checking %s' % (short_name,)
653
update_text = update_text[:25]
655
for lineno, insert, deleteset, line in self._walk():
657
progress_bar.update(update_text, lineno, nlines)
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for j, j_inc in enumerate(inclusions):
660
# The active inclusion must be an ancestor,
661
# and no ancestors must have deleted this line,
662
# because we don't support resurrection.
663
if (insert in j_inc) and not (deleteset & j_inc):
664
sha1s[j].update(line)
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for version in range(nv):
515
progress_bar.update('checking text', version, nv)
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for l in self.get_iter(version):
667
hd = sha1s[version].hexdigest()
520
668
expected = self._sha1s[version]
521
669
if hd != expected:
522
raise WeaveError("mismatched sha1 for version %d; "
523
"got %s, expected %s"
524
% (version, hd, expected))
670
raise errors.WeaveInvalidChecksum(
671
"mismatched sha1 for version %s: "
672
"got %s, expected %s"
673
% (self._names[version], hd, expected))
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675
# TODO: check insertions are properly nested, that there are
527
676
# no lines outside of insertion blocks, that deletions are
528
677
# properly paired, etc.
532
def merge(self, merge_versions):
533
"""Automerge and mark conflicts between versions.
535
This returns a sequence, each entry describing alternatives
536
for a chunk of the file. Each of the alternatives is given as
539
If there is a chunk of the file where there's no diagreement,
540
only one alternative is given.
543
# approach: find the included versions common to all the
545
raise NotImplementedError()
549
679
def _delta(self, included, lines):
550
680
"""Return changes from basis to new revision.
664
798
'killed-both'), \
674
"""Show some text information about the weave."""
675
print '%6s %40s %20s' % ('ver', 'sha1', 'parents')
676
for i in (6, 40, 20):
802
def join(self, other):
804
"""Integrate versions from other into this weave.
806
The resulting weave contains all the history of both weaves;
807
any version you could retrieve from either self or other can be
808
retrieved from self after this call.
810
It is illegal for the two weaves to contain different values
811
or different parents for any version. See also reweave().
813
if other.numversions() == 0:
814
return # nothing to update, easy
815
# two loops so that we do not change ourselves before verifying it
817
# work through in index order to make sure we get all dependencies
818
for other_idx, name in enumerate(other._names):
819
self._check_version_consistent(other, other_idx, name)
824
for other_idx, name in enumerate(other._names):
825
# TODO: If all the parents of the other version are already
826
# present then we can avoid some work by just taking the delta
827
# and adjusting the offsets.
828
new_parents = self._imported_parents(other, other_idx)
829
sha1 = other._sha1s[other_idx]
833
if name in self._names:
834
idx = self.lookup(name)
835
n1 = map(other.idx_to_name, other._parents[other_idx] )
836
n2 = map(self.idx_to_name, self._parents[other_idx] )
837
if sha1 == self._sha1s[idx] and n1 == n2:
841
lines = other.get_lines(other_idx)
842
self.add(name, new_parents, lines, sha1)
844
mutter("merged = %d, processed = %d, file_id=%s; deltat=%d"%(
845
merged,processed,self._weave_name, time.time( )-time0))
850
def _imported_parents(self, other, other_idx):
851
"""Return list of parents in self corresponding to indexes in other."""
853
for parent_idx in other._parents[other_idx]:
854
parent_name = other._names[parent_idx]
855
if parent_name not in self._names:
856
# should not be possible
857
raise WeaveError("missing parent {%s} of {%s} in %r"
858
% (parent_name, other._name_map[other_idx], self))
859
new_parents.append(self._name_map[parent_name])
862
def _check_version_consistent(self, other, other_idx, name):
863
"""Check if a version in consistent in this and other.
865
To be consistent it must have:
868
* the same direct parents (by name, not index, and disregarding
871
If present & correct return True;
872
if not present in self return False;
873
if inconsistent raise error."""
874
this_idx = self._name_map.get(name, -1)
876
if self._sha1s[this_idx] != other._sha1s[other_idx]:
877
raise WeaveError("inconsistent texts for version {%s} "
878
"when joining weaves"
880
self_parents = self._parents[this_idx]
881
other_parents = other._parents[other_idx]
882
n1 = [self._names[i] for i in self_parents]
883
n2 = [other._names[i] for i in other_parents]
887
raise WeaveParentMismatch("inconsistent parents "
888
"for version {%s}: %s vs %s" % (name, n1, n2))
894
def reweave(self, other):
895
"""Reweave self with other."""
896
new_weave = reweave(self, other)
897
for attr in self.__slots__:
898
setattr(self, attr, getattr(new_weave, attr))
902
"""Combine two weaves and return the result.
904
This works even if a revision R has different parents in
905
wa and wb. In the resulting weave all the parents are given.
907
This is done by just building up a new weave, maintaining ordering
908
of the versions in the two inputs. More efficient approaches
909
might be possible but it should only be necessary to do
910
this operation rarely, when a new previously ghost version is
915
queue_a = range(wa.numversions())
916
queue_b = range(wb.numversions())
917
# first determine combined parents of all versions
918
# map from version name -> all parent names
919
combined_parents = _reweave_parent_graphs(wa, wb)
920
mutter("combined parents: %r", combined_parents)
921
order = topo_sort(combined_parents.iteritems())
922
mutter("order to reweave: %r", order)
924
if name in wa._name_map:
925
lines = wa.get_lines(name)
926
if name in wb._name_map:
927
assert lines == wb.get_lines(name)
929
lines = wb.get_lines(name)
930
wr.add(name, combined_parents[name], lines)
934
def _reweave_parent_graphs(wa, wb):
935
"""Return combined parent ancestry for two weaves.
937
Returned as a list of (version_name, set(parent_names))"""
939
for weave in [wa, wb]:
940
for idx, name in enumerate(weave._names):
941
p = combined.setdefault(name, set())
942
p.update(map(weave.idx_to_name, weave._parents[idx]))
947
"""Show the weave's table-of-contents"""
948
print '%6s %50s %10s %10s' % ('ver', 'name', 'sha1', 'parents')
949
for i in (6, 50, 10, 10):
679
952
for i in range(w.numversions()):
680
953
sha1 = w._sha1s[i]
681
print '%6d %40s %s' % (i, sha1, ' '.join(map(str, w._parents[i])))
685
def weave_stats(weave_file):
686
from bzrlib.progress import ProgressBar
955
parent_str = ' '.join(map(str, w._parents[i]))
956
print '%6d %-50.50s %10.10s %s' % (i, name, sha1, parent_str)
960
def weave_stats(weave_file, pb):
687
961
from bzrlib.weavefile import read_weave
691
963
wf = file(weave_file, 'rb')
692
964
w = read_weave(wf)
693
965
# FIXME: doesn't work on pipes
added
removed
bzrlib/weave.py
