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"""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.
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# 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?
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# XXX: If we do weaves this way, will a merge still behave the same
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# 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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# 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: Perhaps the API should work only in names to hide the integer
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# indexes from the user?
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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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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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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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class Weave(object):
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"""weave - versioned text file storage.
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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', '_names', '_name_map']
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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._name_map = {}
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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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if not isinstance(other, Weave):
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def __ne__(self, other):
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return not self.__eq__(other)
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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 WeaveError("name %s not present in weave" % 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):
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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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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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raise WeaveError("name %r already present in weave" % name)
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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 (in-memory) weave will be corrupt because only
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# some fields are updated
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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
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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],
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expected_sha1, measured_sha1))
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def get_text(self, name_or_index):
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return ''.join(self.get_iter(name_or_index))
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assert isinstance(version, int)
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def get_lines(self, name_or_index):
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return list(self.get_iter(name_or_index))
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def get_sha1(self, name):
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"""Get the stored sha1 sum for the given revision.
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:param name: The name of the version to lookup
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return self._sha1s[self.lookup(name)]
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def mash_iter(self, included):
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"""Return composed version of multiple included versions."""
599
included = map(self.maybe_lookup, included)
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for origin, lineno, text in self._extract(included):
546
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raise WeaveFormatError("invalid included version %d for index %d"
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% (inclusions[-1], version))
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# try extracting all versions; this is a bit slow and parallel
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# extraction could be used
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# try extracting all versions; parallel extraction is used
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nv = self.numversions()
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sha1s = [sha.new() for i in range(nv)]
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texts = [[] for i in range(nv)]
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# For creating the ancestry, IntSet is much faster (3.7s vs 0.17s)
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# The problem is that set membership is much more expensive
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for p in self._parents[i]:
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new_inc.update(inclusions[p])
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#assert set(new_inc) == self.inclusions([i]), 'failed %s != %s' % (new_inc, self.inclusions([i]))
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inclusions.append(new_inc)
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nlines = len(self._weave)
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update_text = 'checking weave'
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short_name = os.path.basename(self._weave_name)
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update_text = 'checking %s' % (short_name,)
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update_text = update_text[:25]
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for lineno, insert, deleteset, line in self._walk():
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progress_bar.update(update_text, lineno, nlines)
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for j, j_inc in enumerate(inclusions):
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# The active inclusion must be an ancestor,
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# and no ancestors must have deleted this line,
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# because we don't support resurrection.
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if (insert in j_inc) and not (deleteset & j_inc):
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sha1s[j].update(line)
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for version in range(nv):
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progress_bar.update('checking text', version, nv)
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for l in self.get_iter(version):
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hd = sha1s[version].hexdigest()
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expected = self._sha1s[version]
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if hd != expected:
561
raise WeaveError("mismatched sha1 for version %d; "
562
"got %s, expected %s"
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% (version, hd, expected))
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raise errors.WeaveInvalidChecksum(
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"mismatched sha1 for version %s: "
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"got %s, expected %s"
673
% (self._names[version], hd, expected))
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# TODO: check insertions are properly nested, that there are
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# no lines outside of insertion blocks, that deletions are
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# properly paired, etc.
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def merge(self, merge_versions):
572
"""Automerge and mark conflicts between versions.
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This returns a sequence, each entry describing alternatives
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for a chunk of the file. Each of the alternatives is given as
578
If there is a chunk of the file where there's no diagreement,
579
only one alternative is given.
582
# approach: find the included versions common to all the
584
raise NotImplementedError()
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def _delta(self, included, lines):
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"""Return changes from basis to new revision.
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'killed-both'), \
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]))
712
946
def weave_toc(w):
added
removed
bzrlib/weave.py
