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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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# variant that is passed a pre-cooked version of the single basis
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# TODO: Have a way to go back and insert a revision V1 that is a parent
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# of an already-stored revision V2. This means some lines previously
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# counted as new in V2 will be discovered to have actually come from V1.
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# It is probably necessary to insert V1, then compute a whole new diff
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# from the mashed ancestors to V2. This must be repeated for every
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# direct child of V1. The deltas from V2 to its descendents won't change,
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# although their location within the weave may change. It may be possible
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# to just adjust the location of those instructions rather than
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# re-weaving the whole thing. This is expected to be a fairly rare
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# operation, only used when inserting data that was previously a ghost.
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from difflib import SequenceMatcher
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from bzrlib.osutils import sha_strings
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class WeaveError(Exception):
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self._weave_name = 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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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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def join(self, other):
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"""Integrate versions from other into this weave.
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The resulting weave contains all the history of both weaves;
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any version you could retrieve from either self or other can be
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retrieved from self after this call.
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It is illegal for the two weaves to contain different values
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if other.numversions() == 0:
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return # nothing to update, easy
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# work through in index order to make sure we get all dependencies
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for other_idx, name in enumerate(other._names):
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# TODO: If all the parents of the other version are already
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# present then we can avoid some work by just taking the delta
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# and adjusting the offsets.
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if self._check_version_consistent(other, other_idx, name):
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new_parents = self._imported_parents(other, other_idx)
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lines = other.get_lines(other_idx)
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sha1 = other._sha1s[other_idx]
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self.add(name, new_parents, lines, sha1)
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def _imported_parents(self, other, other_idx):
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"""Return list of parents in self corresponding to indexes in other."""
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for parent_idx in other._parents[other_idx]:
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parent_name = other._names[parent_idx]
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if parent_name not in self._names:
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# should not be possible
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raise WeaveError("missing parent {%s} of {%s} in %r"
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% (parent_name, other._name_map[other_idx], self))
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new_parents.append(self._name_map[parent_name])
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def _check_version_consistent(self, other, other_idx, name):
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"""Check if a version in consistent in this and other.
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To be consistent it must have:
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* the same direct parents (by name, not index, and disregarding
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If present & correct return True;
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if not present in self return False;
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if inconsistent raise error."""
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this_idx = self._name_map.get(name, -1)
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if self._sha1s[this_idx] != other._sha1s[other_idx]:
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raise WeaveError("inconsistent texts for version {%s} "
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"when joining weaves"
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self_parents = self._parents[this_idx]
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other_parents = other._parents[other_idx]
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n1 = [self._names[i] for i in self_parents]
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n2 = [other._names[i] for i in other_parents]
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raise WeaveError("inconsistent parents for version {%s}: "
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def weave_toc(w):
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def weave_stats(weave_file, pb):
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def weave_stats(weave_file):
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from bzrlib.progress import ProgressBar
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from bzrlib.weavefile import read_weave
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wf = file(weave_file, 'rb')
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w = read_weave(wf)
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# FIXME: doesn't work on pipes
added
removed
bzrlib/weave.py
