mercurial-scm/hg: mercurial/revlog.py comparison

comparison mercurial/revlog.py @ 39330:655b5b465953

revlog: split functionality related to deltas computation in a new module The revlog module is getting big and this logic is getting more and more advanced. Moving it to `mercurial.revlogutils.deltas` split a lot off revlog.py and will help this logic to become less interleaved with revlog. The code is simply moved without modification (but for namespace changes). Refactoring and improvement will be made in later changesets.

author	Boris Feld <boris.feld@octobus.net>
date	Thu, 16 Aug 2018 02:53:42 +0200
parents	729082bb9938
children	6f4b8f607a31

comparison

equal deleted inserted replaced

-:729082bb9938
+:655b5b465953
 import collections
 import contextlib
 import errno
 import hashlib
-import heapq
 import os
 import re
 import struct
 import zlib
 )
 from .i18n import _
 from .revlogutils.constants import (
 FLAG_GENERALDELTA,
 FLAG_INLINE_DATA,
-LIMIT_DELTA2TEXT,
 REVIDX_DEFAULT_FLAGS,
 REVIDX_ELLIPSIS,
 REVIDX_EXTSTORED,
 REVIDX_FLAGS_ORDER,
 REVIDX_ISCENSORED,
 pycompat,
 repository,
 templatefilters,
 util,
 )
+from .revlogutils import (
+deltas as deltautil,
+)
 from .utils import (
 interfaceutil,
 stringutil,
 )
 b = p1
 s = hashlib.sha1(a)
 s.update(b)
 s.update(text)
 return s.digest()
-class _testrevlog(object):
-"""minimalist fake revlog to use in doctests"""
-def __init__(self, data, density=0.5, mingap=0):
-"""data is an list of revision payload boundaries"""
-self._data = data
-self._srdensitythreshold = density
-self._srmingapsize = mingap
-def start(self, rev):
-if rev == 0:
-return 0
-return self._data[rev - 1]
-def end(self, rev):
-return self._data[rev]
-def length(self, rev):
-return self.end(rev) - self.start(rev)
-def __len__(self):
-return len(self._data)
-def _trimchunk(revlog, revs, startidx, endidx=None):
-"""returns revs[startidx:endidx] without empty trailing revs
-Doctest Setup
->>> revlog = _testrevlog([
-...  5,  #0
-...  10, #1
-...  12, #2
-...  12, #3 (empty)
-...  17, #4
-...  21, #5
-...  21, #6 (empty)
-... ])
-Contiguous cases:
->>> _trimchunk(revlog, [0, 1, 2, 3, 4, 5, 6], 0)
-[0, 1, 2, 3, 4, 5]
->>> _trimchunk(revlog, [0, 1, 2, 3, 4, 5, 6], 0, 5)
-[0, 1, 2, 3, 4]
->>> _trimchunk(revlog, [0, 1, 2, 3, 4, 5, 6], 0, 4)
-[0, 1, 2]
->>> _trimchunk(revlog, [0, 1, 2, 3, 4, 5, 6], 2, 4)
-[2]
->>> _trimchunk(revlog, [0, 1, 2, 3, 4, 5, 6], 3)
-[3, 4, 5]
->>> _trimchunk(revlog, [0, 1, 2, 3, 4, 5, 6], 3, 5)
-[3, 4]
-Discontiguous cases:
->>> _trimchunk(revlog, [1, 3, 5, 6], 0)
-[1, 3, 5]
->>> _trimchunk(revlog, [1, 3, 5, 6], 0, 2)
-[1]
->>> _trimchunk(revlog, [1, 3, 5, 6], 1, 3)
-[3, 5]
->>> _trimchunk(revlog, [1, 3, 5, 6], 1)
-[3, 5]
-"""
-length = revlog.length
-if endidx is None:
-endidx = len(revs)
-# If we have a non-emtpy delta candidate, there are nothing to trim
-if revs[endidx - 1] < len(revlog):
-# Trim empty revs at the end, except the very first revision of a chain
-while (endidx > 1
-and endidx > startidx
-and length(revs[endidx - 1]) == 0):
-endidx -= 1
-return revs[startidx:endidx]
-def _segmentspan(revlog, revs, deltainfo=None):
-"""Get the byte span of a segment of revisions
-revs is a sorted array of revision numbers
->>> revlog = _testrevlog([
-...  5,  #0
-...  10, #1
-...  12, #2
-...  12, #3 (empty)
-...  17, #4
-... ])
->>> _segmentspan(revlog, [0, 1, 2, 3, 4])
-17
->>> _segmentspan(revlog, [0, 4])
-17
->>> _segmentspan(revlog, [3, 4])
-5
->>> _segmentspan(revlog, [1, 2, 3,])
-7
->>> _segmentspan(revlog, [1, 3])
-7
-"""
-if not revs:
-return 0
-if deltainfo is not None and len(revlog) <= revs[-1]:
-if len(revs) == 1:
-return deltainfo.deltalen
-offset = revlog.end(len(revlog) - 1)
-end = deltainfo.deltalen + offset
-else:
-end = revlog.end(revs[-1])
-return end - revlog.start(revs[0])
-def _slicechunk(revlog, revs, deltainfo=None, targetsize=None):
-"""slice revs to reduce the amount of unrelated data to be read from disk.
-``revs`` is sliced into groups that should be read in one time.
-Assume that revs are sorted.
-The initial chunk is sliced until the overall density (payload/chunks-span
-ratio) is above `revlog._srdensitythreshold`. No gap smaller than
-`revlog._srmingapsize` is skipped.
-If `targetsize` is set, no chunk larger than `targetsize` will be yield.
-For consistency with other slicing choice, this limit won't go lower than
-`revlog._srmingapsize`.
-If individual revisions chunk are larger than this limit, they will still
-be raised individually.
->>> revlog = _testrevlog([
-...  5,  #00 (5)
-...  10, #01 (5)
-...  12, #02 (2)
-...  12, #03 (empty)
-...  27, #04 (15)
-...  31, #05 (4)
-...  31, #06 (empty)
-...  42, #07 (11)
-...  47, #08 (5)
-...  47, #09 (empty)
-...  48, #10 (1)
-...  51, #11 (3)
-...  74, #12 (23)
-...  85, #13 (11)
-...  86, #14 (1)
-...  91, #15 (5)
-... ])
->>> list(_slicechunk(revlog, list(range(16))))
-[[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]]
->>> list(_slicechunk(revlog, [0, 15]))
-[[0], [15]]
->>> list(_slicechunk(revlog, [0, 11, 15]))
-[[0], [11], [15]]
->>> list(_slicechunk(revlog, [0, 11, 13, 15]))
-[[0], [11, 13, 15]]
->>> list(_slicechunk(revlog, [1, 2, 3, 5, 8, 10, 11, 14]))
-[[1, 2], [5, 8, 10, 11], [14]]
-Slicing with a maximum chunk size
->>> list(_slicechunk(revlog, [0, 11, 13, 15], targetsize=15))
-[[0], [11], [13], [15]]
->>> list(_slicechunk(revlog, [0, 11, 13, 15], targetsize=20))
-[[0], [11], [13, 15]]
-"""
-if targetsize is not None:
-targetsize = max(targetsize, revlog._srmingapsize)
-# targetsize should not be specified when evaluating delta candidates:
-# * targetsize is used to ensure we stay within specification when reading,
-# * deltainfo is used to pick are good delta chain when writing.
-if not (deltainfo is None or targetsize is None):
-msg = 'cannot use `targetsize` with a `deltainfo`'
-raise error.ProgrammingError(msg)
-for chunk in _slicechunktodensity(revlog, revs,
-deltainfo,
-revlog._srdensitythreshold,
-revlog._srmingapsize):
-for subchunk in _slicechunktosize(revlog, chunk, targetsize):
-yield subchunk
-def _slicechunktosize(revlog, revs, targetsize=None):
-"""slice revs to match the target size
-This is intended to be used on chunk that density slicing selected by that
-are still too large compared to the read garantee of revlog. This might
-happens when "minimal gap size" interrupted the slicing or when chain are
-built in a way that create large blocks next to each other.
->>> revlog = _testrevlog([
-...  3,  #0 (3)
-...  5,  #1 (2)
-...  6,  #2 (1)
-...  8,  #3 (2)
-...  8,  #4 (empty)
-...  11, #5 (3)
-...  12, #6 (1)
-...  13, #7 (1)
-...  14, #8 (1)
-... ])
-Cases where chunk is already small enough
->>> list(_slicechunktosize(revlog, [0], 3))
-[[0]]
->>> list(_slicechunktosize(revlog, [6, 7], 3))
-[[6, 7]]
->>> list(_slicechunktosize(revlog, [0], None))
-[[0]]
->>> list(_slicechunktosize(revlog, [6, 7], None))
-[[6, 7]]
-cases where we need actual slicing
->>> list(_slicechunktosize(revlog, [0, 1], 3))
-[[0], [1]]
->>> list(_slicechunktosize(revlog, [1, 3], 3))
-[[1], [3]]
->>> list(_slicechunktosize(revlog, [1, 2, 3], 3))
-[[1, 2], [3]]
->>> list(_slicechunktosize(revlog, [3, 5], 3))
-[[3], [5]]
->>> list(_slicechunktosize(revlog, [3, 4, 5], 3))
-[[3], [5]]
->>> list(_slicechunktosize(revlog, [5, 6, 7, 8], 3))
-[[5], [6, 7, 8]]
->>> list(_slicechunktosize(revlog, [0, 1, 2, 3, 4, 5, 6, 7, 8], 3))
-[[0], [1, 2], [3], [5], [6, 7, 8]]
-Case with too large individual chunk (must return valid chunk)
->>> list(_slicechunktosize(revlog, [0, 1], 2))
-[[0], [1]]
->>> list(_slicechunktosize(revlog, [1, 3], 1))
-[[1], [3]]
->>> list(_slicechunktosize(revlog, [3, 4, 5], 2))
-[[3], [5]]
-"""
-assert targetsize is None or 0 <= targetsize
-if targetsize is None or _segmentspan(revlog, revs) <= targetsize:
-yield revs
-return
-startrevidx = 0
-startdata = revlog.start(revs[0])
-endrevidx = 0
-iterrevs = enumerate(revs)
-next(iterrevs) # skip first rev.
-for idx, r in iterrevs:
-span = revlog.end(r) - startdata
-if span <= targetsize:
-endrevidx = idx
-else:
-chunk = _trimchunk(revlog, revs, startrevidx, endrevidx + 1)
-if chunk:
-yield chunk
-startrevidx = idx
-startdata = revlog.start(r)
-endrevidx = idx
-yield _trimchunk(revlog, revs, startrevidx)
-def _slicechunktodensity(revlog, revs, deltainfo=None, targetdensity=0.5,
-mingapsize=0):
-"""slice revs to reduce the amount of unrelated data to be read from disk.
-``revs`` is sliced into groups that should be read in one time.
-Assume that revs are sorted.
-``deltainfo`` is a _deltainfo instance of a revision that we would append
-to the top of the revlog.
-The initial chunk is sliced until the overall density (payload/chunks-span
-ratio) is above `targetdensity`. No gap smaller than `mingapsize` is
-skipped.
->>> revlog = _testrevlog([
-...  5,  #00 (5)
-...  10, #01 (5)
-...  12, #02 (2)
-...  12, #03 (empty)
-...  27, #04 (15)
-...  31, #05 (4)
-...  31, #06 (empty)
-...  42, #07 (11)
-...  47, #08 (5)
-...  47, #09 (empty)
-...  48, #10 (1)
-...  51, #11 (3)
-...  74, #12 (23)
-...  85, #13 (11)
-...  86, #14 (1)
-...  91, #15 (5)
-... ])
->>> list(_slicechunktodensity(revlog, list(range(16))))
-[[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]]
->>> list(_slicechunktodensity(revlog, [0, 15]))
-[[0], [15]]
->>> list(_slicechunktodensity(revlog, [0, 11, 15]))
-[[0], [11], [15]]
->>> list(_slicechunktodensity(revlog, [0, 11, 13, 15]))
-[[0], [11, 13, 15]]
->>> list(_slicechunktodensity(revlog, [1, 2, 3, 5, 8, 10, 11, 14]))
-[[1, 2], [5, 8, 10, 11], [14]]
->>> list(_slicechunktodensity(revlog, [1, 2, 3, 5, 8, 10, 11, 14],
-...                           mingapsize=20))
-[[1, 2, 3, 5, 8, 10, 11], [14]]
->>> list(_slicechunktodensity(revlog, [1, 2, 3, 5, 8, 10, 11, 14],
-...                           targetdensity=0.95))
-[[1, 2], [5], [8, 10, 11], [14]]
->>> list(_slicechunktodensity(revlog, [1, 2, 3, 5, 8, 10, 11, 14],
-...                           targetdensity=0.95, mingapsize=12))
-[[1, 2], [5, 8, 10, 11], [14]]
-"""
-start = revlog.start
-length = revlog.length
-if len(revs) <= 1:
-yield revs
-return
-nextrev = len(revlog)
-nextoffset = revlog.end(nextrev - 1)
-if deltainfo is None:
-deltachainspan = _segmentspan(revlog, revs)
-chainpayload = sum(length(r) for r in revs)
-else:
-deltachainspan = deltainfo.distance
-chainpayload = deltainfo.compresseddeltalen
-if deltachainspan < mingapsize:
-yield revs
-return
-readdata = deltachainspan
-if deltachainspan:
-density = chainpayload / float(deltachainspan)
-else:
-density = 1.0
-if density >= targetdensity:
-yield revs
-return
-if deltainfo is not None and deltainfo.deltalen:
-revs = list(revs)
-revs.append(nextrev)
-# Store the gaps in a heap to have them sorted by decreasing size
-gapsheap = []
-heapq.heapify(gapsheap)
-prevend = None
-for i, rev in enumerate(revs):
-if rev < nextrev:
-revstart = start(rev)
-revlen = length(rev)
-else:
-revstart = nextoffset
-revlen = deltainfo.deltalen
-# Skip empty revisions to form larger holes
-if revlen == 0:
-continue
-if prevend is not None:
-gapsize = revstart - prevend
-# only consider holes that are large enough
-if gapsize > mingapsize:
-heapq.heappush(gapsheap, (-gapsize, i))
-prevend = revstart + revlen
-# Collect the indices of the largest holes until the density is acceptable
-indicesheap = []
-heapq.heapify(indicesheap)
-while gapsheap and density < targetdensity:
-oppgapsize, gapidx = heapq.heappop(gapsheap)
-heapq.heappush(indicesheap, gapidx)
-# the gap sizes are stored as negatives to be sorted decreasingly
-# by the heap
-readdata -= (-oppgapsize)
-if readdata > 0:
-density = chainpayload / float(readdata)
-else:
-density = 1.0
-# Cut the revs at collected indices
-previdx = 0
-while indicesheap:
-idx = heapq.heappop(indicesheap)
-chunk = _trimchunk(revlog, revs, previdx, idx)
-if chunk:
-yield chunk
-previdx = idx
-chunk = _trimchunk(revlog, revs, previdx)
-if chunk:
-yield chunk
-@attr.s(slots=True, frozen=True)
-class _deltainfo(object):
-distance = attr.ib()
-deltalen = attr.ib()
-data = attr.ib()
-base = attr.ib()
-chainbase = attr.ib()
-chainlen = attr.ib()
-compresseddeltalen = attr.ib()
-snapshotdepth = attr.ib()
-class _deltacomputer(object):
-def __init__(self, revlog):
-self.revlog = revlog
-def _getcandidaterevs(self, p1, p2, cachedelta):
-"""
-Provides revisions that present an interest to be diffed against,
-grouped by level of easiness.
-"""
-revlog = self.revlog
-gdelta = revlog._generaldelta
-curr = len(revlog)
-prev = curr - 1
-p1r, p2r = revlog.rev(p1), revlog.rev(p2)
-# should we try to build a delta?
-if prev != nullrev and revlog._storedeltachains:
-tested = set()
-# This condition is true most of the time when processing
-# changegroup data into a generaldelta repo. The only time it
-# isn't true is if this is the first revision in a delta chain
-# or if ``format.generaldelta=true`` disabled ``lazydeltabase``.
-if cachedelta and gdelta and revlog._lazydeltabase:
-# Assume what we received from the server is a good choice
-# build delta will reuse the cache
-yield (cachedelta[0],)
-tested.add(cachedelta[0])
-if gdelta:
-# exclude already lazy tested base if any
-parents = [p for p in (p1r, p2r)
-if p != nullrev and p not in tested]
-if not revlog._deltabothparents and len(parents) == 2:
-parents.sort()
-# To minimize the chance of having to build a fulltext,
-# pick first whichever parent is closest to us (max rev)
-yield (parents[1],)
-# then the other one (min rev) if the first did not fit
-yield (parents[0],)
-tested.update(parents)
-elif len(parents) > 0:
-# Test all parents (1 or 2), and keep the best candidate
-yield parents
-tested.update(parents)
-if prev not in tested:
-# other approach failed try against prev to hopefully save us a
-# fulltext.
-yield (prev,)
-tested.add(prev)
-def buildtext(self, revinfo, fh):
-"""Builds a fulltext version of a revision
-revinfo: _revisioninfo instance that contains all needed info
-fh:      file handle to either the .i or the .d revlog file,
-depending on whether it is inlined or not
-"""
-btext = revinfo.btext
-if btext[0] is not None:
-return btext[0]
-revlog = self.revlog
-cachedelta = revinfo.cachedelta
-flags = revinfo.flags
-node = revinfo.node
-baserev = cachedelta[0]
-delta = cachedelta[1]
-# special case deltas which replace entire base; no need to decode
-# base revision. this neatly avoids censored bases, which throw when
-# they're decoded.
-hlen = struct.calcsize(">lll")
-if delta[:hlen] == mdiff.replacediffheader(revlog.rawsize(baserev),
-len(delta) - hlen):
-btext[0] = delta[hlen:]
-else:
-# deltabase is rawtext before changed by flag processors, which is
-# equivalent to non-raw text
-basetext = revlog.revision(baserev, _df=fh, raw=False)
-btext[0] = mdiff.patch(basetext, delta)
-try:
-res = revlog._processflags(btext[0], flags, 'read', raw=True)
-btext[0], validatehash = res
-if validatehash:
-revlog.checkhash(btext[0], node, p1=revinfo.p1, p2=revinfo.p2)
-if flags & REVIDX_ISCENSORED:
-raise RevlogError(_('node %s is not censored') % node)
-except CensoredNodeError:
-# must pass the censored index flag to add censored revisions
-if not flags & REVIDX_ISCENSORED:
-raise
-return btext[0]
-def _builddeltadiff(self, base, revinfo, fh):
-revlog = self.revlog
-t = self.buildtext(revinfo, fh)
-if revlog.iscensored(base):
-# deltas based on a censored revision must replace the
-# full content in one patch, so delta works everywhere
-header = mdiff.replacediffheader(revlog.rawsize(base), len(t))
-delta = header + t
-else:
-ptext = revlog.revision(base, _df=fh, raw=True)
-delta = mdiff.textdiff(ptext, t)
-return delta
-def _builddeltainfo(self, revinfo, base, fh):
-# can we use the cached delta?
-if revinfo.cachedelta and revinfo.cachedelta[0] == base:
-delta = revinfo.cachedelta[1]
-else:
-delta = self._builddeltadiff(base, revinfo, fh)
-revlog = self.revlog
-header, data = revlog.compress(delta)
-deltalen = len(header) + len(data)
-chainbase = revlog.chainbase(base)
-offset = revlog.end(len(revlog) - 1)
-dist = deltalen + offset - revlog.start(chainbase)
-if revlog._generaldelta:
-deltabase = base
-else:
-deltabase = chainbase
-chainlen, compresseddeltalen = revlog._chaininfo(base)
-chainlen += 1
-compresseddeltalen += deltalen
-revlog = self.revlog
-snapshotdepth = None
-if deltabase == nullrev:
-snapshotdepth = 0
-elif revlog._sparserevlog and revlog.issnapshot(deltabase):
-# A delta chain should always be one full snapshot,
-# zero or more semi-snapshots, and zero or more deltas
-p1, p2 = revlog.rev(revinfo.p1), revlog.rev(revinfo.p2)
-if deltabase not in (p1, p2) and revlog.issnapshot(deltabase):
-snapshotdepth = len(revlog._deltachain(deltabase)[0])
-return _deltainfo(dist, deltalen, (header, data), deltabase,
-chainbase, chainlen, compresseddeltalen,
-snapshotdepth)
-def finddeltainfo(self, revinfo, fh):
-"""Find an acceptable delta against a candidate revision
-revinfo: information about the revision (instance of _revisioninfo)
-fh:      file handle to either the .i or the .d revlog file,
-depending on whether it is inlined or not
-Returns the first acceptable candidate revision, as ordered by
-_getcandidaterevs
-"""
-if not revinfo.textlen:
-return None # empty file do not need delta
-cachedelta = revinfo.cachedelta
-p1 = revinfo.p1
-p2 = revinfo.p2
-revlog = self.revlog
-deltalength = self.revlog.length
-deltaparent = self.revlog.deltaparent
-deltainfo = None
-deltas_limit = revinfo.textlen * LIMIT_DELTA2TEXT
-for candidaterevs in self._getcandidaterevs(p1, p2, cachedelta):
-# filter out delta base that will never produce good delta
-candidaterevs = [r for r in candidaterevs
-if self.revlog.length(r) <= deltas_limit]
-nominateddeltas = []
-for candidaterev in candidaterevs:
-# skip over empty delta (no need to include them in a chain)
-while candidaterev != nullrev and not deltalength(candidaterev):
-candidaterev = deltaparent(candidaterev)
-# no need to try a delta against nullid, this will be handled
-# by fulltext later.
-if candidaterev == nullrev:
-continue
-# no delta for rawtext-changing revs (see "candelta" for why)
-if revlog.flags(candidaterev) & REVIDX_RAWTEXT_CHANGING_FLAGS:
-continue
-candidatedelta = self._builddeltainfo(revinfo, candidaterev, fh)
-if revlog._isgooddeltainfo(candidatedelta, revinfo):
-nominateddeltas.append(candidatedelta)
-if nominateddeltas:
-deltainfo = min(nominateddeltas, key=lambda x: x.deltalen)
-break
-return deltainfo
 @attr.s(slots=True, frozen=True)
 class _revisioninfo(object):
 """Information about a revision that allows building its fulltext
 node:       expected hash of the revision
 ladd = l.append
 if not self._withsparseread:
 slicedchunks = (revs,)
 else:
-slicedchunks = _slicechunk(self, revs, targetsize=targetsize)
+slicedchunks = deltautil.slicechunk(self, revs,
+targetsize=targetsize)
 for revschunk in slicedchunks:
 firstrev = revschunk[0]
 # Skip trailing revisions with empty diff
 for lastrev in revschunk[::-1]:
 cachedelta - an optional precomputed delta
 node - nodeid of revision; typically node is not specified, and it is
 computed by default as hash(text, p1, p2), however subclasses might
 use different hashing method (and override checkhash() in such case)
 flags - the known flags to set on the revision
-deltacomputer - an optional _deltacomputer instance shared between
+deltacomputer - an optional deltacomputer instance shared between
 multiple calls
 """
 if link == nullrev:
 raise RevlogError(_("attempted to add linkrev -1 to %s")
 % self.indexfile)
 except KeyError:
 raise RevlogError(_('unknown compression type %r') % t)
 return compressor.decompress(data)
-def _isgooddeltainfo(self, deltainfo, revinfo):
-"""Returns True if the given delta is good. Good means that it is within
-the disk span, disk size, and chain length bounds that we know to be
-performant."""
-if deltainfo is None:
-return False
-# - 'deltainfo.distance' is the distance from the base revision --
-#   bounding it limits the amount of I/O we need to do.
-# - 'deltainfo.compresseddeltalen' is the sum of the total size of
-#   deltas we need to apply -- bounding it limits the amount of CPU
-#   we consume.
-if self._sparserevlog:
-# As sparse-read will be used, we can consider that the distance,
-# instead of being the span of the whole chunk,
-# is the span of the largest read chunk
-base = deltainfo.base
-if base != nullrev:
-deltachain = self._deltachain(base)[0]
-else:
-deltachain = []
-# search for the first non-snapshot revision
-for idx, r in enumerate(deltachain):
-if not self.issnapshot(r):
-break
-deltachain = deltachain[idx:]
-chunks = _slicechunk(self, deltachain, deltainfo)
-all_span = [_segmentspan(self, revs, deltainfo) for revs in chunks]
-distance = max(all_span)
-else:
-distance = deltainfo.distance
-textlen = revinfo.textlen
-defaultmax = textlen * 4
-maxdist = self._maxdeltachainspan
-if not maxdist:
-maxdist = distance # ensure the conditional pass
-maxdist = max(maxdist, defaultmax)
-if self._sparserevlog and maxdist < self._srmingapsize:
-# In multiple place, we are ignoring irrelevant data range below a
-# certain size. Be also apply this tradeoff here and relax span
-# constraint for small enought content.
-maxdist = self._srmingapsize
-# Bad delta from read span:
-#
-#   If the span of data read is larger than the maximum allowed.
-if maxdist < distance:
-return False
-# Bad delta from new delta size:
-#
-#   If the delta size is larger than the target text, storing the
-#   delta will be inefficient.
-if textlen < deltainfo.deltalen:
-return False
-# Bad delta from cumulated payload size:
-#
-#   If the sum of delta get larger than K * target text length.
-if textlen * LIMIT_DELTA2TEXT < deltainfo.compresseddeltalen:
-return False
-# Bad delta from chain length:
-#
-#   If the number of delta in the chain gets too high.
-if self._maxchainlen and  self._maxchainlen < deltainfo.chainlen:
-return False
-# bad delta from intermediate snapshot size limit
-#
-#   If an intermediate snapshot size is higher than the limit.  The
-#   limit exist to prevent endless chain of intermediate delta to be
-#   created.
-if (deltainfo.snapshotdepth is not None and
-(textlen >> deltainfo.snapshotdepth) < deltainfo.deltalen):
-return False
-# bad delta if new intermediate snapshot is larger than the previous
-# snapshot
-if (deltainfo.snapshotdepth
-and self.length(deltainfo.base) < deltainfo.deltalen):
-return False
-return True
 def _addrevision(self, node, rawtext, transaction, link, p1, p2, flags,
 cachedelta, ifh, dfh, alwayscache=False,
 deltacomputer=None):
 """internal function to add revisions to the log
 cachedelta[1])
 else:
 textlen = len(rawtext)
 if deltacomputer is None:
-deltacomputer = _deltacomputer(self)
+deltacomputer = deltautil.deltacomputer(self)
 revinfo = _revisioninfo(node, p1, p2, btext, textlen, cachedelta, flags)
 # no delta for flag processor revision (see "candelta" for why)
 # not calling candelta since only one revision needs test, also to
 def flush():
 if dfh:
 dfh.flush()
 ifh.flush()
 try:
-deltacomputer = _deltacomputer(self)
+deltacomputer = deltautil.deltacomputer(self)
 # loop through our set of deltas
 for data in deltas:
 node, p1, p2, linknode, deltabase, delta, flags = data
 link = linkmapper(linknode)
 flags = flags or REVIDX_DEFAULT_FLAGS
 destrevlog._deltabothparents = deltabothparents or oldamd
 populatecachedelta = deltareuse in (self.DELTAREUSEALWAYS,
 self.DELTAREUSESAMEREVS)
-deltacomputer = _deltacomputer(destrevlog)
+deltacomputer = deltautil.deltacomputer(destrevlog)
 index = self.index
 for rev in self:
 entry = index[rev]
 # Some classes override linkrev to take filtered revs into

Mercurial > public > mercurial-scm > hg

comparison mercurial/revlog.py @ 39330:655b5b465953