perf: use storage API for resolving manifest node
lookup() isn't part of the storage API. And this code shouldn't
be accessing manifestlog._revlog directly for the modern code base.
So let's port it to the modern API.
Note that the previous code was busted for cases where we needed
to call lookup() because lookup() isn't exposed by manifestrevlog
any more.
This change is strictly BC breaking because we no longer support
resolving partial nodes. But it is a perf* command and I don't
think we should flag the change as such.
Differential Revision: https://phab.mercurial-scm.org/D4390
# revlog.py - storage back-end for mercurial
#
# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""Storage back-end for Mercurial.
This provides efficient delta storage with O(1) retrieve and append
and O(changes) merge between branches.
"""
from __future__ import absolute_import
import collections
import contextlib
import errno
import hashlib
import heapq
import os
import re
import struct
import zlib
# import stuff from node for others to import from revlog
from .node import (
bin,
hex,
nullhex,
nullid,
nullrev,
wdirfilenodeids,
wdirhex,
wdirid,
wdirrev,
)
from .i18n import _
from .thirdparty import (
attr,
)
from . import (
ancestor,
error,
mdiff,
policy,
pycompat,
repository,
templatefilters,
util,
)
from .utils import (
interfaceutil,
stringutil,
)
parsers = policy.importmod(r'parsers')
# Aliased for performance.
_zlibdecompress = zlib.decompress
# revlog header flags
REVLOGV0 = 0
REVLOGV1 = 1
# Dummy value until file format is finalized.
# Reminder: change the bounds check in revlog.__init__ when this is changed.
REVLOGV2 = 0xDEAD
FLAG_INLINE_DATA = (1 << 16)
FLAG_GENERALDELTA = (1 << 17)
REVLOG_DEFAULT_FLAGS = FLAG_INLINE_DATA
REVLOG_DEFAULT_FORMAT = REVLOGV1
REVLOG_DEFAULT_VERSION = REVLOG_DEFAULT_FORMAT | REVLOG_DEFAULT_FLAGS
REVLOGV1_FLAGS = FLAG_INLINE_DATA | FLAG_GENERALDELTA
REVLOGV2_FLAGS = REVLOGV1_FLAGS
# revlog index flags
REVIDX_ISCENSORED = (1 << 15) # revision has censor metadata, must be verified
REVIDX_ELLIPSIS = (1 << 14) # revision hash does not match data (narrowhg)
REVIDX_EXTSTORED = (1 << 13) # revision data is stored externally
REVIDX_DEFAULT_FLAGS = 0
# stable order in which flags need to be processed and their processors applied
REVIDX_FLAGS_ORDER = [
REVIDX_ISCENSORED,
REVIDX_ELLIPSIS,
REVIDX_EXTSTORED,
]
REVIDX_KNOWN_FLAGS = util.bitsfrom(REVIDX_FLAGS_ORDER)
# bitmark for flags that could cause rawdata content change
REVIDX_RAWTEXT_CHANGING_FLAGS = REVIDX_ISCENSORED | REVIDX_EXTSTORED
# max size of revlog with inline data
_maxinline = 131072
_chunksize = 1048576
RevlogError = error.RevlogError
LookupError = error.LookupError
AmbiguousPrefixLookupError = error.AmbiguousPrefixLookupError
CensoredNodeError = error.CensoredNodeError
ProgrammingError = error.ProgrammingError
# Store flag processors (cf. 'addflagprocessor()' to register)
_flagprocessors = {
REVIDX_ISCENSORED: None,
}
_mdre = re.compile('\1\n')
def parsemeta(text):
"""return (metadatadict, metadatasize)"""
# text can be buffer, so we can't use .startswith or .index
if text[:2] != '\1\n':
return None, None
s = _mdre.search(text, 2).start()
mtext = text[2:s]
meta = {}
for l in mtext.splitlines():
k, v = l.split(": ", 1)
meta[k] = v
return meta, (s + 2)
def packmeta(meta, text):
keys = sorted(meta)
metatext = "".join("%s: %s\n" % (k, meta[k]) for k in keys)
return "\1\n%s\1\n%s" % (metatext, text)
def _censoredtext(text):
m, offs = parsemeta(text)
return m and "censored" in m
def addflagprocessor(flag, processor):
"""Register a flag processor on a revision data flag.
Invariant:
- Flags need to be defined in REVIDX_KNOWN_FLAGS and REVIDX_FLAGS_ORDER,
and REVIDX_RAWTEXT_CHANGING_FLAGS if they can alter rawtext.
- Only one flag processor can be registered on a specific flag.
- flagprocessors must be 3-tuples of functions (read, write, raw) with the
following signatures:
- (read) f(self, rawtext) -> text, bool
- (write) f(self, text) -> rawtext, bool
- (raw) f(self, rawtext) -> bool
"text" is presented to the user. "rawtext" is stored in revlog data, not
directly visible to the user.
The boolean returned by these transforms is used to determine whether
the returned text can be used for hash integrity checking. For example,
if "write" returns False, then "text" is used to generate hash. If
"write" returns True, that basically means "rawtext" returned by "write"
should be used to generate hash. Usually, "write" and "read" return
different booleans. And "raw" returns a same boolean as "write".
Note: The 'raw' transform is used for changegroup generation and in some
debug commands. In this case the transform only indicates whether the
contents can be used for hash integrity checks.
"""
if not flag & REVIDX_KNOWN_FLAGS:
msg = _("cannot register processor on unknown flag '%#x'.") % (flag)
raise ProgrammingError(msg)
if flag not in REVIDX_FLAGS_ORDER:
msg = _("flag '%#x' undefined in REVIDX_FLAGS_ORDER.") % (flag)
raise ProgrammingError(msg)
if flag in _flagprocessors:
msg = _("cannot register multiple processors on flag '%#x'.") % (flag)
raise error.Abort(msg)
_flagprocessors[flag] = processor
def getoffset(q):
return int(q >> 16)
def gettype(q):
return int(q & 0xFFFF)
def offset_type(offset, type):
if (type & ~REVIDX_KNOWN_FLAGS) != 0:
raise ValueError('unknown revlog index flags')
return int(int(offset) << 16 | type)
_nullhash = hashlib.sha1(nullid)
def hash(text, p1, p2):
"""generate a hash from the given text and its parent hashes
This hash combines both the current file contents and its history
in a manner that makes it easy to distinguish nodes with the same
content in the revision graph.
"""
# As of now, if one of the parent node is null, p2 is null
if p2 == nullid:
# deep copy of a hash is faster than creating one
s = _nullhash.copy()
s.update(p1)
else:
# none of the parent nodes are nullid
if p1 < p2:
a = p1
b = p2
else:
a = p2
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
p1, p2: parent revs of the revision
btext: built text cache consisting of a one-element list
cachedelta: (baserev, uncompressed_delta) or None
flags: flags associated to the revision storage
One of btext[0] or cachedelta must be set.
"""
node = attr.ib()
p1 = attr.ib()
p2 = attr.ib()
btext = attr.ib()
textlen = attr.ib()
cachedelta = attr.ib()
flags = attr.ib()
@interfaceutil.implementer(repository.irevisiondelta)
@attr.s(slots=True, frozen=True)
class revlogrevisiondelta(object):
node = attr.ib()
p1node = attr.ib()
p2node = attr.ib()
basenode = attr.ib()
linknode = attr.ib()
flags = attr.ib()
baserevisionsize = attr.ib()
revision = attr.ib()
delta = attr.ib()
# index v0:
# 4 bytes: offset
# 4 bytes: compressed length
# 4 bytes: base rev
# 4 bytes: link rev
# 20 bytes: parent 1 nodeid
# 20 bytes: parent 2 nodeid
# 20 bytes: nodeid
indexformatv0 = struct.Struct(">4l20s20s20s")
indexformatv0_pack = indexformatv0.pack
indexformatv0_unpack = indexformatv0.unpack
class revlogoldindex(list):
def __getitem__(self, i):
if i == -1:
return (0, 0, 0, -1, -1, -1, -1, nullid)
return list.__getitem__(self, i)
# maximum <delta-chain-data>/<revision-text-length> ratio
LIMIT_DELTA2TEXT = 2
class revlogoldio(object):
def __init__(self):
self.size = indexformatv0.size
def parseindex(self, data, inline):
s = self.size
index = []
nodemap = {nullid: nullrev}
n = off = 0
l = len(data)
while off + s <= l:
cur = data[off:off + s]
off += s
e = indexformatv0_unpack(cur)
# transform to revlogv1 format
e2 = (offset_type(e[0], 0), e[1], -1, e[2], e[3],
nodemap.get(e[4], nullrev), nodemap.get(e[5], nullrev), e[6])
index.append(e2)
nodemap[e[6]] = n
n += 1
return revlogoldindex(index), nodemap, None
def packentry(self, entry, node, version, rev):
if gettype(entry[0]):
raise RevlogError(_('index entry flags need revlog version 1'))
e2 = (getoffset(entry[0]), entry[1], entry[3], entry[4],
node(entry[5]), node(entry[6]), entry[7])
return indexformatv0_pack(*e2)
# index ng:
# 6 bytes: offset
# 2 bytes: flags
# 4 bytes: compressed length
# 4 bytes: uncompressed length
# 4 bytes: base rev
# 4 bytes: link rev
# 4 bytes: parent 1 rev
# 4 bytes: parent 2 rev
# 32 bytes: nodeid
indexformatng = struct.Struct(">Qiiiiii20s12x")
indexformatng_pack = indexformatng.pack
versionformat = struct.Struct(">I")
versionformat_pack = versionformat.pack
versionformat_unpack = versionformat.unpack
# corresponds to uncompressed length of indexformatng (2 gigs, 4-byte
# signed integer)
_maxentrysize = 0x7fffffff
class revlogio(object):
def __init__(self):
self.size = indexformatng.size
def parseindex(self, data, inline):
# call the C implementation to parse the index data
index, cache = parsers.parse_index2(data, inline)
return index, getattr(index, 'nodemap', None), cache
def packentry(self, entry, node, version, rev):
p = indexformatng_pack(*entry)
if rev == 0:
p = versionformat_pack(version) + p[4:]
return p
class revlog(object):
"""
the underlying revision storage object
A revlog consists of two parts, an index and the revision data.
The index is a file with a fixed record size containing
information on each revision, including its nodeid (hash), the
nodeids of its parents, the position and offset of its data within
the data file, and the revision it's based on. Finally, each entry
contains a linkrev entry that can serve as a pointer to external
data.
The revision data itself is a linear collection of data chunks.
Each chunk represents a revision and is usually represented as a
delta against the previous chunk. To bound lookup time, runs of
deltas are limited to about 2 times the length of the original
version data. This makes retrieval of a version proportional to
its size, or O(1) relative to the number of revisions.
Both pieces of the revlog are written to in an append-only
fashion, which means we never need to rewrite a file to insert or
remove data, and can use some simple techniques to avoid the need
for locking while reading.
If checkambig, indexfile is opened with checkambig=True at
writing, to avoid file stat ambiguity.
If mmaplargeindex is True, and an mmapindexthreshold is set, the
index will be mmapped rather than read if it is larger than the
configured threshold.
If censorable is True, the revlog can have censored revisions.
"""
def __init__(self, opener, indexfile, datafile=None, checkambig=False,
mmaplargeindex=False, censorable=False):
"""
create a revlog object
opener is a function that abstracts the file opening operation
and can be used to implement COW semantics or the like.
"""
self.indexfile = indexfile
self.datafile = datafile or (indexfile[:-2] + ".d")
self.opener = opener
# When True, indexfile is opened with checkambig=True at writing, to
# avoid file stat ambiguity.
self._checkambig = checkambig
self._censorable = censorable
# 3-tuple of (node, rev, text) for a raw revision.
self._cache = None
# Maps rev to chain base rev.
self._chainbasecache = util.lrucachedict(100)
# 2-tuple of (offset, data) of raw data from the revlog at an offset.
self._chunkcache = (0, '')
# How much data to read and cache into the raw revlog data cache.
self._chunkcachesize = 65536
self._maxchainlen = None
self._deltabothparents = True
self.index = []
# Mapping of partial identifiers to full nodes.
self._pcache = {}
# Mapping of revision integer to full node.
self._nodecache = {nullid: nullrev}
self._nodepos = None
self._compengine = 'zlib'
self._maxdeltachainspan = -1
self._withsparseread = False
self._sparserevlog = False
self._srdensitythreshold = 0.50
self._srmingapsize = 262144
mmapindexthreshold = None
v = REVLOG_DEFAULT_VERSION
opts = getattr(opener, 'options', None)
if opts is not None:
if 'revlogv2' in opts:
# version 2 revlogs always use generaldelta.
v = REVLOGV2 | FLAG_GENERALDELTA | FLAG_INLINE_DATA
elif 'revlogv1' in opts:
if 'generaldelta' in opts:
v |= FLAG_GENERALDELTA
else:
v = 0
if 'chunkcachesize' in opts:
self._chunkcachesize = opts['chunkcachesize']
if 'maxchainlen' in opts:
self._maxchainlen = opts['maxchainlen']
if 'deltabothparents' in opts:
self._deltabothparents = opts['deltabothparents']
self._lazydeltabase = bool(opts.get('lazydeltabase', False))
if 'compengine' in opts:
self._compengine = opts['compengine']
if 'maxdeltachainspan' in opts:
self._maxdeltachainspan = opts['maxdeltachainspan']
if mmaplargeindex and 'mmapindexthreshold' in opts:
mmapindexthreshold = opts['mmapindexthreshold']
self._sparserevlog = bool(opts.get('sparse-revlog', False))
withsparseread = bool(opts.get('with-sparse-read', False))
# sparse-revlog forces sparse-read
self._withsparseread = self._sparserevlog or withsparseread
if 'sparse-read-density-threshold' in opts:
self._srdensitythreshold = opts['sparse-read-density-threshold']
if 'sparse-read-min-gap-size' in opts:
self._srmingapsize = opts['sparse-read-min-gap-size']
if self._chunkcachesize <= 0:
raise RevlogError(_('revlog chunk cache size %r is not greater '
'than 0') % self._chunkcachesize)
elif self._chunkcachesize & (self._chunkcachesize - 1):
raise RevlogError(_('revlog chunk cache size %r is not a power '
'of 2') % self._chunkcachesize)
indexdata = ''
self._initempty = True
try:
with self._indexfp() as f:
if (mmapindexthreshold is not None and
self.opener.fstat(f).st_size >= mmapindexthreshold):
indexdata = util.buffer(util.mmapread(f))
else:
indexdata = f.read()
if len(indexdata) > 0:
v = versionformat_unpack(indexdata[:4])[0]
self._initempty = False
except IOError as inst:
if inst.errno != errno.ENOENT:
raise
self.version = v
self._inline = v & FLAG_INLINE_DATA
self._generaldelta = v & FLAG_GENERALDELTA
flags = v & ~0xFFFF
fmt = v & 0xFFFF
if fmt == REVLOGV0:
if flags:
raise RevlogError(_('unknown flags (%#04x) in version %d '
'revlog %s') %
(flags >> 16, fmt, self.indexfile))
elif fmt == REVLOGV1:
if flags & ~REVLOGV1_FLAGS:
raise RevlogError(_('unknown flags (%#04x) in version %d '
'revlog %s') %
(flags >> 16, fmt, self.indexfile))
elif fmt == REVLOGV2:
if flags & ~REVLOGV2_FLAGS:
raise RevlogError(_('unknown flags (%#04x) in version %d '
'revlog %s') %
(flags >> 16, fmt, self.indexfile))
else:
raise RevlogError(_('unknown version (%d) in revlog %s') %
(fmt, self.indexfile))
self._storedeltachains = True
self._io = revlogio()
if self.version == REVLOGV0:
self._io = revlogoldio()
try:
d = self._io.parseindex(indexdata, self._inline)
except (ValueError, IndexError):
raise RevlogError(_("index %s is corrupted") % (self.indexfile))
self.index, nodemap, self._chunkcache = d
if nodemap is not None:
self.nodemap = self._nodecache = nodemap
if not self._chunkcache:
self._chunkclear()
# revnum -> (chain-length, sum-delta-length)
self._chaininfocache = {}
# revlog header -> revlog compressor
self._decompressors = {}
@util.propertycache
def _compressor(self):
return util.compengines[self._compengine].revlogcompressor()
def _indexfp(self, mode='r'):
"""file object for the revlog's index file"""
args = {r'mode': mode}
if mode != 'r':
args[r'checkambig'] = self._checkambig
if mode == 'w':
args[r'atomictemp'] = True
return self.opener(self.indexfile, **args)
def _datafp(self, mode='r'):
"""file object for the revlog's data file"""
return self.opener(self.datafile, mode=mode)
@contextlib.contextmanager
def _datareadfp(self, existingfp=None):
"""file object suitable to read data"""
if existingfp is not None:
yield existingfp
else:
if self._inline:
func = self._indexfp
else:
func = self._datafp
with func() as fp:
yield fp
def tip(self):
return self.node(len(self.index) - 1)
def __contains__(self, rev):
return 0 <= rev < len(self)
def __len__(self):
return len(self.index)
def __iter__(self):
return iter(pycompat.xrange(len(self)))
def revs(self, start=0, stop=None):
"""iterate over all rev in this revlog (from start to stop)"""
step = 1
length = len(self)
if stop is not None:
if start > stop:
step = -1
stop += step
if stop > length:
stop = length
else:
stop = length
return pycompat.xrange(start, stop, step)
@util.propertycache
def nodemap(self):
if self.index:
# populate mapping down to the initial node
node0 = self.index[0][7] # get around changelog filtering
self.rev(node0)
return self._nodecache
def hasnode(self, node):
try:
self.rev(node)
return True
except KeyError:
return False
def candelta(self, baserev, rev):
"""whether two revisions (baserev, rev) can be delta-ed or not"""
# Disable delta if either rev requires a content-changing flag
# processor (ex. LFS). This is because such flag processor can alter
# the rawtext content that the delta will be based on, and two clients
# could have a same revlog node with different flags (i.e. different
# rawtext contents) and the delta could be incompatible.
if ((self.flags(baserev) & REVIDX_RAWTEXT_CHANGING_FLAGS)
or (self.flags(rev) & REVIDX_RAWTEXT_CHANGING_FLAGS)):
return False
return True
def clearcaches(self):
self._cache = None
self._chainbasecache.clear()
self._chunkcache = (0, '')
self._pcache = {}
try:
self._nodecache.clearcaches()
except AttributeError:
self._nodecache = {nullid: nullrev}
self._nodepos = None
def rev(self, node):
try:
return self._nodecache[node]
except TypeError:
raise
except RevlogError:
# parsers.c radix tree lookup failed
if node == wdirid or node in wdirfilenodeids:
raise error.WdirUnsupported
raise LookupError(node, self.indexfile, _('no node'))
except KeyError:
# pure python cache lookup failed
n = self._nodecache
i = self.index
p = self._nodepos
if p is None:
p = len(i) - 1
else:
assert p < len(i)
for r in pycompat.xrange(p, -1, -1):
v = i[r][7]
n[v] = r
if v == node:
self._nodepos = r - 1
return r
if node == wdirid or node in wdirfilenodeids:
raise error.WdirUnsupported
raise LookupError(node, self.indexfile, _('no node'))
# Accessors for index entries.
# First tuple entry is 8 bytes. First 6 bytes are offset. Last 2 bytes
# are flags.
def start(self, rev):
return int(self.index[rev][0] >> 16)
def flags(self, rev):
return self.index[rev][0] & 0xFFFF
def length(self, rev):
return self.index[rev][1]
def rawsize(self, rev):
"""return the length of the uncompressed text for a given revision"""
l = self.index[rev][2]
if l >= 0:
return l
t = self.revision(rev, raw=True)
return len(t)
def size(self, rev):
"""length of non-raw text (processed by a "read" flag processor)"""
# fast path: if no "read" flag processor could change the content,
# size is rawsize. note: ELLIPSIS is known to not change the content.
flags = self.flags(rev)
if flags & (REVIDX_KNOWN_FLAGS ^ REVIDX_ELLIPSIS) == 0:
return self.rawsize(rev)
return len(self.revision(rev, raw=False))
def chainbase(self, rev):
base = self._chainbasecache.get(rev)
if base is not None:
return base
index = self.index
iterrev = rev
base = index[iterrev][3]
while base != iterrev:
iterrev = base
base = index[iterrev][3]
self._chainbasecache[rev] = base
return base
def linkrev(self, rev):
return self.index[rev][4]
def parentrevs(self, rev):
try:
entry = self.index[rev]
except IndexError:
if rev == wdirrev:
raise error.WdirUnsupported
raise
return entry[5], entry[6]
def node(self, rev):
try:
return self.index[rev][7]
except IndexError:
if rev == wdirrev:
raise error.WdirUnsupported
raise
# Derived from index values.
def end(self, rev):
return self.start(rev) + self.length(rev)
def parents(self, node):
i = self.index
d = i[self.rev(node)]
return i[d[5]][7], i[d[6]][7] # map revisions to nodes inline
def chainlen(self, rev):
return self._chaininfo(rev)[0]
def _chaininfo(self, rev):
chaininfocache = self._chaininfocache
if rev in chaininfocache:
return chaininfocache[rev]
index = self.index
generaldelta = self._generaldelta
iterrev = rev
e = index[iterrev]
clen = 0
compresseddeltalen = 0
while iterrev != e[3]:
clen += 1
compresseddeltalen += e[1]
if generaldelta:
iterrev = e[3]
else:
iterrev -= 1
if iterrev in chaininfocache:
t = chaininfocache[iterrev]
clen += t[0]
compresseddeltalen += t[1]
break
e = index[iterrev]
else:
# Add text length of base since decompressing that also takes
# work. For cache hits the length is already included.
compresseddeltalen += e[1]
r = (clen, compresseddeltalen)
chaininfocache[rev] = r
return r
def _deltachain(self, rev, stoprev=None):
"""Obtain the delta chain for a revision.
``stoprev`` specifies a revision to stop at. If not specified, we
stop at the base of the chain.
Returns a 2-tuple of (chain, stopped) where ``chain`` is a list of
revs in ascending order and ``stopped`` is a bool indicating whether
``stoprev`` was hit.
"""
# Try C implementation.
try:
return self.index.deltachain(rev, stoprev, self._generaldelta)
except AttributeError:
pass
chain = []
# Alias to prevent attribute lookup in tight loop.
index = self.index
generaldelta = self._generaldelta
iterrev = rev
e = index[iterrev]
while iterrev != e[3] and iterrev != stoprev:
chain.append(iterrev)
if generaldelta:
iterrev = e[3]
else:
iterrev -= 1
e = index[iterrev]
if iterrev == stoprev:
stopped = True
else:
chain.append(iterrev)
stopped = False
chain.reverse()
return chain, stopped
def ancestors(self, revs, stoprev=0, inclusive=False):
"""Generate the ancestors of 'revs' in reverse topological order.
Does not generate revs lower than stoprev.
See the documentation for ancestor.lazyancestors for more details."""
return ancestor.lazyancestors(self.parentrevs, revs, stoprev=stoprev,
inclusive=inclusive)
def descendants(self, revs):
"""Generate the descendants of 'revs' in revision order.
Yield a sequence of revision numbers starting with a child of
some rev in revs, i.e., each revision is *not* considered a
descendant of itself. Results are ordered by revision number (a
topological sort)."""
first = min(revs)
if first == nullrev:
for i in self:
yield i
return
seen = set(revs)
for i in self.revs(start=first + 1):
for x in self.parentrevs(i):
if x != nullrev and x in seen:
seen.add(i)
yield i
break
def findcommonmissing(self, common=None, heads=None):
"""Return a tuple of the ancestors of common and the ancestors of heads
that are not ancestors of common. In revset terminology, we return the
tuple:
::common, (::heads) - (::common)
The list is sorted by revision number, meaning it is
topologically sorted.
'heads' and 'common' are both lists of node IDs. If heads is
not supplied, uses all of the revlog's heads. If common is not
supplied, uses nullid."""
if common is None:
common = [nullid]
if heads is None:
heads = self.heads()
common = [self.rev(n) for n in common]
heads = [self.rev(n) for n in heads]
# we want the ancestors, but inclusive
class lazyset(object):
def __init__(self, lazyvalues):
self.addedvalues = set()
self.lazyvalues = lazyvalues
def __contains__(self, value):
return value in self.addedvalues or value in self.lazyvalues
def __iter__(self):
added = self.addedvalues
for r in added:
yield r
for r in self.lazyvalues:
if not r in added:
yield r
def add(self, value):
self.addedvalues.add(value)
def update(self, values):
self.addedvalues.update(values)
has = lazyset(self.ancestors(common))
has.add(nullrev)
has.update(common)
# take all ancestors from heads that aren't in has
missing = set()
visit = collections.deque(r for r in heads if r not in has)
while visit:
r = visit.popleft()
if r in missing:
continue
else:
missing.add(r)
for p in self.parentrevs(r):
if p not in has:
visit.append(p)
missing = list(missing)
missing.sort()
return has, [self.node(miss) for miss in missing]
def incrementalmissingrevs(self, common=None):
"""Return an object that can be used to incrementally compute the
revision numbers of the ancestors of arbitrary sets that are not
ancestors of common. This is an ancestor.incrementalmissingancestors
object.
'common' is a list of revision numbers. If common is not supplied, uses
nullrev.
"""
if common is None:
common = [nullrev]
return ancestor.incrementalmissingancestors(self.parentrevs, common)
def findmissingrevs(self, common=None, heads=None):
"""Return the revision numbers of the ancestors of heads that
are not ancestors of common.
More specifically, return a list of revision numbers corresponding to
nodes N such that every N satisfies the following constraints:
1. N is an ancestor of some node in 'heads'
2. N is not an ancestor of any node in 'common'
The list is sorted by revision number, meaning it is
topologically sorted.
'heads' and 'common' are both lists of revision numbers. If heads is
not supplied, uses all of the revlog's heads. If common is not
supplied, uses nullid."""
if common is None:
common = [nullrev]
if heads is None:
heads = self.headrevs()
inc = self.incrementalmissingrevs(common=common)
return inc.missingancestors(heads)
def findmissing(self, common=None, heads=None):
"""Return the ancestors of heads that are not ancestors of common.
More specifically, return a list of nodes N such that every N
satisfies the following constraints:
1. N is an ancestor of some node in 'heads'
2. N is not an ancestor of any node in 'common'
The list is sorted by revision number, meaning it is
topologically sorted.
'heads' and 'common' are both lists of node IDs. If heads is
not supplied, uses all of the revlog's heads. If common is not
supplied, uses nullid."""
if common is None:
common = [nullid]
if heads is None:
heads = self.heads()
common = [self.rev(n) for n in common]
heads = [self.rev(n) for n in heads]
inc = self.incrementalmissingrevs(common=common)
return [self.node(r) for r in inc.missingancestors(heads)]
def nodesbetween(self, roots=None, heads=None):
"""Return a topological path from 'roots' to 'heads'.
Return a tuple (nodes, outroots, outheads) where 'nodes' is a
topologically sorted list of all nodes N that satisfy both of
these constraints:
1. N is a descendant of some node in 'roots'
2. N is an ancestor of some node in 'heads'
Every node is considered to be both a descendant and an ancestor
of itself, so every reachable node in 'roots' and 'heads' will be
included in 'nodes'.
'outroots' is the list of reachable nodes in 'roots', i.e., the
subset of 'roots' that is returned in 'nodes'. Likewise,
'outheads' is the subset of 'heads' that is also in 'nodes'.
'roots' and 'heads' are both lists of node IDs. If 'roots' is
unspecified, uses nullid as the only root. If 'heads' is
unspecified, uses list of all of the revlog's heads."""
nonodes = ([], [], [])
if roots is not None:
roots = list(roots)
if not roots:
return nonodes
lowestrev = min([self.rev(n) for n in roots])
else:
roots = [nullid] # Everybody's a descendant of nullid
lowestrev = nullrev
if (lowestrev == nullrev) and (heads is None):
# We want _all_ the nodes!
return ([self.node(r) for r in self], [nullid], list(self.heads()))
if heads is None:
# All nodes are ancestors, so the latest ancestor is the last
# node.
highestrev = len(self) - 1
# Set ancestors to None to signal that every node is an ancestor.
ancestors = None
# Set heads to an empty dictionary for later discovery of heads
heads = {}
else:
heads = list(heads)
if not heads:
return nonodes
ancestors = set()
# Turn heads into a dictionary so we can remove 'fake' heads.
# Also, later we will be using it to filter out the heads we can't
# find from roots.
heads = dict.fromkeys(heads, False)
# Start at the top and keep marking parents until we're done.
nodestotag = set(heads)
# Remember where the top was so we can use it as a limit later.
highestrev = max([self.rev(n) for n in nodestotag])
while nodestotag:
# grab a node to tag
n = nodestotag.pop()
# Never tag nullid
if n == nullid:
continue
# A node's revision number represents its place in a
# topologically sorted list of nodes.
r = self.rev(n)
if r >= lowestrev:
if n not in ancestors:
# If we are possibly a descendant of one of the roots
# and we haven't already been marked as an ancestor
ancestors.add(n) # Mark as ancestor
# Add non-nullid parents to list of nodes to tag.
nodestotag.update([p for p in self.parents(n) if
p != nullid])
elif n in heads: # We've seen it before, is it a fake head?
# So it is, real heads should not be the ancestors of
# any other heads.
heads.pop(n)
if not ancestors:
return nonodes
# Now that we have our set of ancestors, we want to remove any
# roots that are not ancestors.
# If one of the roots was nullid, everything is included anyway.
if lowestrev > nullrev:
# But, since we weren't, let's recompute the lowest rev to not
# include roots that aren't ancestors.
# Filter out roots that aren't ancestors of heads
roots = [root for root in roots if root in ancestors]
# Recompute the lowest revision
if roots:
lowestrev = min([self.rev(root) for root in roots])
else:
# No more roots? Return empty list
return nonodes
else:
# We are descending from nullid, and don't need to care about
# any other roots.
lowestrev = nullrev
roots = [nullid]
# Transform our roots list into a set.
descendants = set(roots)
# Also, keep the original roots so we can filter out roots that aren't
# 'real' roots (i.e. are descended from other roots).
roots = descendants.copy()
# Our topologically sorted list of output nodes.
orderedout = []
# Don't start at nullid since we don't want nullid in our output list,
# and if nullid shows up in descendants, empty parents will look like
# they're descendants.
for r in self.revs(start=max(lowestrev, 0), stop=highestrev + 1):
n = self.node(r)
isdescendant = False
if lowestrev == nullrev: # Everybody is a descendant of nullid
isdescendant = True
elif n in descendants:
# n is already a descendant
isdescendant = True
# This check only needs to be done here because all the roots
# will start being marked is descendants before the loop.
if n in roots:
# If n was a root, check if it's a 'real' root.
p = tuple(self.parents(n))
# If any of its parents are descendants, it's not a root.
if (p[0] in descendants) or (p[1] in descendants):
roots.remove(n)
else:
p = tuple(self.parents(n))
# A node is a descendant if either of its parents are
# descendants. (We seeded the dependents list with the roots
# up there, remember?)
if (p[0] in descendants) or (p[1] in descendants):
descendants.add(n)
isdescendant = True
if isdescendant and ((ancestors is None) or (n in ancestors)):
# Only include nodes that are both descendants and ancestors.
orderedout.append(n)
if (ancestors is not None) and (n in heads):
# We're trying to figure out which heads are reachable
# from roots.
# Mark this head as having been reached
heads[n] = True
elif ancestors is None:
# Otherwise, we're trying to discover the heads.
# Assume this is a head because if it isn't, the next step
# will eventually remove it.
heads[n] = True
# But, obviously its parents aren't.
for p in self.parents(n):
heads.pop(p, None)
heads = [head for head, flag in heads.iteritems() if flag]
roots = list(roots)
assert orderedout
assert roots
assert heads
return (orderedout, roots, heads)
def headrevs(self):
try:
return self.index.headrevs()
except AttributeError:
return self._headrevs()
def computephases(self, roots):
return self.index.computephasesmapsets(roots)
def _headrevs(self):
count = len(self)
if not count:
return [nullrev]
# we won't iter over filtered rev so nobody is a head at start
ishead = [0] * (count + 1)
index = self.index
for r in self:
ishead[r] = 1 # I may be an head
e = index[r]
ishead[e[5]] = ishead[e[6]] = 0 # my parent are not
return [r for r, val in enumerate(ishead) if val]
def heads(self, start=None, stop=None):
"""return the list of all nodes that have no children
if start is specified, only heads that are descendants of
start will be returned
if stop is specified, it will consider all the revs from stop
as if they had no children
"""
if start is None and stop is None:
if not len(self):
return [nullid]
return [self.node(r) for r in self.headrevs()]
if start is None:
start = nullid
if stop is None:
stop = []
stoprevs = set([self.rev(n) for n in stop])
startrev = self.rev(start)
reachable = {startrev}
heads = {startrev}
parentrevs = self.parentrevs
for r in self.revs(start=startrev + 1):
for p in parentrevs(r):
if p in reachable:
if r not in stoprevs:
reachable.add(r)
heads.add(r)
if p in heads and p not in stoprevs:
heads.remove(p)
return [self.node(r) for r in heads]
def children(self, node):
"""find the children of a given node"""
c = []
p = self.rev(node)
for r in self.revs(start=p + 1):
prevs = [pr for pr in self.parentrevs(r) if pr != nullrev]
if prevs:
for pr in prevs:
if pr == p:
c.append(self.node(r))
elif p == nullrev:
c.append(self.node(r))
return c
def commonancestorsheads(self, a, b):
"""calculate all the heads of the common ancestors of nodes a and b"""
a, b = self.rev(a), self.rev(b)
ancs = self._commonancestorsheads(a, b)
return pycompat.maplist(self.node, ancs)
def _commonancestorsheads(self, *revs):
"""calculate all the heads of the common ancestors of revs"""
try:
ancs = self.index.commonancestorsheads(*revs)
except (AttributeError, OverflowError): # C implementation failed
ancs = ancestor.commonancestorsheads(self.parentrevs, *revs)
return ancs
def isancestor(self, a, b):
"""return True if node a is an ancestor of node b
A revision is considered an ancestor of itself."""
a, b = self.rev(a), self.rev(b)
return self.isancestorrev(a, b)
def isancestorrev(self, a, b):
"""return True if revision a is an ancestor of revision b
A revision is considered an ancestor of itself.
The implementation of this is trivial but the use of
commonancestorsheads is not."""
if a == nullrev:
return True
elif a == b:
return True
elif a > b:
return False
return a in self._commonancestorsheads(a, b)
def ancestor(self, a, b):
"""calculate the "best" common ancestor of nodes a and b"""
a, b = self.rev(a), self.rev(b)
try:
ancs = self.index.ancestors(a, b)
except (AttributeError, OverflowError):
ancs = ancestor.ancestors(self.parentrevs, a, b)
if ancs:
# choose a consistent winner when there's a tie
return min(map(self.node, ancs))
return nullid
def _match(self, id):
if isinstance(id, int):
# rev
return self.node(id)
if len(id) == 20:
# possibly a binary node
# odds of a binary node being all hex in ASCII are 1 in 10**25
try:
node = id
self.rev(node) # quick search the index
return node
except LookupError:
pass # may be partial hex id
try:
# str(rev)
rev = int(id)
if "%d" % rev != id:
raise ValueError
if rev < 0:
rev = len(self) + rev
if rev < 0 or rev >= len(self):
raise ValueError
return self.node(rev)
except (ValueError, OverflowError):
pass
if len(id) == 40:
try:
# a full hex nodeid?
node = bin(id)
self.rev(node)
return node
except (TypeError, LookupError):
pass
def _partialmatch(self, id):
# we don't care wdirfilenodeids as they should be always full hash
maybewdir = wdirhex.startswith(id)
try:
partial = self.index.partialmatch(id)
if partial and self.hasnode(partial):
if maybewdir:
# single 'ff...' match in radix tree, ambiguous with wdir
raise RevlogError
return partial
if maybewdir:
# no 'ff...' match in radix tree, wdir identified
raise error.WdirUnsupported
return None
except RevlogError:
# parsers.c radix tree lookup gave multiple matches
# fast path: for unfiltered changelog, radix tree is accurate
if not getattr(self, 'filteredrevs', None):
raise AmbiguousPrefixLookupError(id, self.indexfile,
_('ambiguous identifier'))
# fall through to slow path that filters hidden revisions
except (AttributeError, ValueError):
# we are pure python, or key was too short to search radix tree
pass
if id in self._pcache:
return self._pcache[id]
if len(id) <= 40:
try:
# hex(node)[:...]
l = len(id) // 2 # grab an even number of digits
prefix = bin(id[:l * 2])
nl = [e[7] for e in self.index if e[7].startswith(prefix)]
nl = [n for n in nl if hex(n).startswith(id) and
self.hasnode(n)]
if nullhex.startswith(id):
nl.append(nullid)
if len(nl) > 0:
if len(nl) == 1 and not maybewdir:
self._pcache[id] = nl[0]
return nl[0]
raise AmbiguousPrefixLookupError(id, self.indexfile,
_('ambiguous identifier'))
if maybewdir:
raise error.WdirUnsupported
return None
except TypeError:
pass
def lookup(self, id):
"""locate a node based on:
- revision number or str(revision number)
- nodeid or subset of hex nodeid
"""
n = self._match(id)
if n is not None:
return n
n = self._partialmatch(id)
if n:
return n
raise LookupError(id, self.indexfile, _('no match found'))
def shortest(self, node, minlength=1):
"""Find the shortest unambiguous prefix that matches node."""
def isvalid(prefix):
try:
node = self._partialmatch(prefix)
except error.RevlogError:
return False
except error.WdirUnsupported:
# single 'ff...' match
return True
if node is None:
raise LookupError(node, self.indexfile, _('no node'))
return True
def maybewdir(prefix):
return all(c == 'f' for c in prefix)
hexnode = hex(node)
def disambiguate(hexnode, minlength):
"""Disambiguate against wdirid."""
for length in range(minlength, 41):
prefix = hexnode[:length]
if not maybewdir(prefix):
return prefix
if not getattr(self, 'filteredrevs', None):
try:
length = max(self.index.shortest(node), minlength)
return disambiguate(hexnode, length)
except RevlogError:
if node != wdirid:
raise LookupError(node, self.indexfile, _('no node'))
except AttributeError:
# Fall through to pure code
pass
if node == wdirid:
for length in range(minlength, 41):
prefix = hexnode[:length]
if isvalid(prefix):
return prefix
for length in range(minlength, 41):
prefix = hexnode[:length]
if isvalid(prefix):
return disambiguate(hexnode, length)
def cmp(self, node, text):
"""compare text with a given file revision
returns True if text is different than what is stored.
"""
p1, p2 = self.parents(node)
return hash(text, p1, p2) != node
def _cachesegment(self, offset, data):
"""Add a segment to the revlog cache.
Accepts an absolute offset and the data that is at that location.
"""
o, d = self._chunkcache
# try to add to existing cache
if o + len(d) == offset and len(d) + len(data) < _chunksize:
self._chunkcache = o, d + data
else:
self._chunkcache = offset, data
def _readsegment(self, offset, length, df=None):
"""Load a segment of raw data from the revlog.
Accepts an absolute offset, length to read, and an optional existing
file handle to read from.
If an existing file handle is passed, it will be seeked and the
original seek position will NOT be restored.
Returns a str or buffer of raw byte data.
"""
# Cache data both forward and backward around the requested
# data, in a fixed size window. This helps speed up operations
# involving reading the revlog backwards.
cachesize = self._chunkcachesize
realoffset = offset & ~(cachesize - 1)
reallength = (((offset + length + cachesize) & ~(cachesize - 1))
- realoffset)
with self._datareadfp(df) as df:
df.seek(realoffset)
d = df.read(reallength)
self._cachesegment(realoffset, d)
if offset != realoffset or reallength != length:
return util.buffer(d, offset - realoffset, length)
return d
def _getsegment(self, offset, length, df=None):
"""Obtain a segment of raw data from the revlog.
Accepts an absolute offset, length of bytes to obtain, and an
optional file handle to the already-opened revlog. If the file
handle is used, it's original seek position will not be preserved.
Requests for data may be returned from a cache.
Returns a str or a buffer instance of raw byte data.
"""
o, d = self._chunkcache
l = len(d)
# is it in the cache?
cachestart = offset - o
cacheend = cachestart + length
if cachestart >= 0 and cacheend <= l:
if cachestart == 0 and cacheend == l:
return d # avoid a copy
return util.buffer(d, cachestart, cacheend - cachestart)
return self._readsegment(offset, length, df=df)
def _getsegmentforrevs(self, startrev, endrev, df=None):
"""Obtain a segment of raw data corresponding to a range of revisions.
Accepts the start and end revisions and an optional already-open
file handle to be used for reading. If the file handle is read, its
seek position will not be preserved.
Requests for data may be satisfied by a cache.
Returns a 2-tuple of (offset, data) for the requested range of
revisions. Offset is the integer offset from the beginning of the
revlog and data is a str or buffer of the raw byte data.
Callers will need to call ``self.start(rev)`` and ``self.length(rev)``
to determine where each revision's data begins and ends.
"""
# Inlined self.start(startrev) & self.end(endrev) for perf reasons
# (functions are expensive).
index = self.index
istart = index[startrev]
start = int(istart[0] >> 16)
if startrev == endrev:
end = start + istart[1]
else:
iend = index[endrev]
end = int(iend[0] >> 16) + iend[1]
if self._inline:
start += (startrev + 1) * self._io.size
end += (endrev + 1) * self._io.size
length = end - start
return start, self._getsegment(start, length, df=df)
def _chunk(self, rev, df=None):
"""Obtain a single decompressed chunk for a revision.
Accepts an integer revision and an optional already-open file handle
to be used for reading. If used, the seek position of the file will not
be preserved.
Returns a str holding uncompressed data for the requested revision.
"""
return self.decompress(self._getsegmentforrevs(rev, rev, df=df)[1])
def _chunks(self, revs, df=None, targetsize=None):
"""Obtain decompressed chunks for the specified revisions.
Accepts an iterable of numeric revisions that are assumed to be in
ascending order. Also accepts an optional already-open file handle
to be used for reading. If used, the seek position of the file will
not be preserved.
This function is similar to calling ``self._chunk()`` multiple times,
but is faster.
Returns a list with decompressed data for each requested revision.
"""
if not revs:
return []
start = self.start
length = self.length
inline = self._inline
iosize = self._io.size
buffer = util.buffer
l = []
ladd = l.append
if not self._withsparseread:
slicedchunks = (revs,)
else:
slicedchunks = _slicechunk(self, revs, targetsize=targetsize)
for revschunk in slicedchunks:
firstrev = revschunk[0]
# Skip trailing revisions with empty diff
for lastrev in revschunk[::-1]:
if length(lastrev) != 0:
break
try:
offset, data = self._getsegmentforrevs(firstrev, lastrev, df=df)
except OverflowError:
# issue4215 - we can't cache a run of chunks greater than
# 2G on Windows
return [self._chunk(rev, df=df) for rev in revschunk]
decomp = self.decompress
for rev in revschunk:
chunkstart = start(rev)
if inline:
chunkstart += (rev + 1) * iosize
chunklength = length(rev)
ladd(decomp(buffer(data, chunkstart - offset, chunklength)))
return l
def _chunkclear(self):
"""Clear the raw chunk cache."""
self._chunkcache = (0, '')
def deltaparent(self, rev):
"""return deltaparent of the given revision"""
base = self.index[rev][3]
if base == rev:
return nullrev
elif self._generaldelta:
return base
else:
return rev - 1
def issnapshot(self, rev):
"""tells whether rev is a snapshot
"""
if rev == nullrev:
return True
deltap = self.deltaparent(rev)
if deltap == nullrev:
return True
p1, p2 = self.parentrevs(rev)
if deltap in (p1, p2):
return False
return self.issnapshot(deltap)
def snapshotdepth(self, rev):
"""number of snapshot in the chain before this one"""
if not self.issnapshot(rev):
raise ProgrammingError('revision %d not a snapshot')
return len(self._deltachain(rev)[0]) - 1
def revdiff(self, rev1, rev2):
"""return or calculate a delta between two revisions
The delta calculated is in binary form and is intended to be written to
revlog data directly. So this function needs raw revision data.
"""
if rev1 != nullrev and self.deltaparent(rev2) == rev1:
return bytes(self._chunk(rev2))
return mdiff.textdiff(self.revision(rev1, raw=True),
self.revision(rev2, raw=True))
def revision(self, nodeorrev, _df=None, raw=False):
"""return an uncompressed revision of a given node or revision
number.
_df - an existing file handle to read from. (internal-only)
raw - an optional argument specifying if the revision data is to be
treated as raw data when applying flag transforms. 'raw' should be set
to True when generating changegroups or in debug commands.
"""
if isinstance(nodeorrev, int):
rev = nodeorrev
node = self.node(rev)
else:
node = nodeorrev
rev = None
cachedrev = None
flags = None
rawtext = None
if node == nullid:
return ""
if self._cache:
if self._cache[0] == node:
# _cache only stores rawtext
if raw:
return self._cache[2]
# duplicated, but good for perf
if rev is None:
rev = self.rev(node)
if flags is None:
flags = self.flags(rev)
# no extra flags set, no flag processor runs, text = rawtext
if flags == REVIDX_DEFAULT_FLAGS:
return self._cache[2]
# rawtext is reusable. need to run flag processor
rawtext = self._cache[2]
cachedrev = self._cache[1]
# look up what we need to read
if rawtext is None:
if rev is None:
rev = self.rev(node)
chain, stopped = self._deltachain(rev, stoprev=cachedrev)
if stopped:
rawtext = self._cache[2]
# drop cache to save memory
self._cache = None
targetsize = None
rawsize = self.index[rev][2]
if 0 <= rawsize:
targetsize = 4 * rawsize
bins = self._chunks(chain, df=_df, targetsize=targetsize)
if rawtext is None:
rawtext = bytes(bins[0])
bins = bins[1:]
rawtext = mdiff.patches(rawtext, bins)
self._cache = (node, rev, rawtext)
if flags is None:
if rev is None:
rev = self.rev(node)
flags = self.flags(rev)
text, validatehash = self._processflags(rawtext, flags, 'read', raw=raw)
if validatehash:
self.checkhash(text, node, rev=rev)
return text
def hash(self, text, p1, p2):
"""Compute a node hash.
Available as a function so that subclasses can replace the hash
as needed.
"""
return hash(text, p1, p2)
def _processflags(self, text, flags, operation, raw=False):
"""Inspect revision data flags and applies transforms defined by
registered flag processors.
``text`` - the revision data to process
``flags`` - the revision flags
``operation`` - the operation being performed (read or write)
``raw`` - an optional argument describing if the raw transform should be
applied.
This method processes the flags in the order (or reverse order if
``operation`` is 'write') defined by REVIDX_FLAGS_ORDER, applying the
flag processors registered for present flags. The order of flags defined
in REVIDX_FLAGS_ORDER needs to be stable to allow non-commutativity.
Returns a 2-tuple of ``(text, validatehash)`` where ``text`` is the
processed text and ``validatehash`` is a bool indicating whether the
returned text should be checked for hash integrity.
Note: If the ``raw`` argument is set, it has precedence over the
operation and will only update the value of ``validatehash``.
"""
# fast path: no flag processors will run
if flags == 0:
return text, True
if not operation in ('read', 'write'):
raise ProgrammingError(_("invalid '%s' operation ") % (operation))
# Check all flags are known.
if flags & ~REVIDX_KNOWN_FLAGS:
raise RevlogError(_("incompatible revision flag '%#x'") %
(flags & ~REVIDX_KNOWN_FLAGS))
validatehash = True
# Depending on the operation (read or write), the order might be
# reversed due to non-commutative transforms.
orderedflags = REVIDX_FLAGS_ORDER
if operation == 'write':
orderedflags = reversed(orderedflags)
for flag in orderedflags:
# If a flagprocessor has been registered for a known flag, apply the
# related operation transform and update result tuple.
if flag & flags:
vhash = True
if flag not in _flagprocessors:
message = _("missing processor for flag '%#x'") % (flag)
raise RevlogError(message)
processor = _flagprocessors[flag]
if processor is not None:
readtransform, writetransform, rawtransform = processor
if raw:
vhash = rawtransform(self, text)
elif operation == 'read':
text, vhash = readtransform(self, text)
else: # write operation
text, vhash = writetransform(self, text)
validatehash = validatehash and vhash
return text, validatehash
def checkhash(self, text, node, p1=None, p2=None, rev=None):
"""Check node hash integrity.
Available as a function so that subclasses can extend hash mismatch
behaviors as needed.
"""
try:
if p1 is None and p2 is None:
p1, p2 = self.parents(node)
if node != self.hash(text, p1, p2):
revornode = rev
if revornode is None:
revornode = templatefilters.short(hex(node))
raise RevlogError(_("integrity check failed on %s:%s")
% (self.indexfile, pycompat.bytestr(revornode)))
except RevlogError:
if self._censorable and _censoredtext(text):
raise error.CensoredNodeError(self.indexfile, node, text)
raise
def _enforceinlinesize(self, tr, fp=None):
"""Check if the revlog is too big for inline and convert if so.
This should be called after revisions are added to the revlog. If the
revlog has grown too large to be an inline revlog, it will convert it
to use multiple index and data files.
"""
tiprev = len(self) - 1
if (not self._inline or
(self.start(tiprev) + self.length(tiprev)) < _maxinline):
return
trinfo = tr.find(self.indexfile)
if trinfo is None:
raise RevlogError(_("%s not found in the transaction")
% self.indexfile)
trindex = trinfo[2]
if trindex is not None:
dataoff = self.start(trindex)
else:
# revlog was stripped at start of transaction, use all leftover data
trindex = len(self) - 1
dataoff = self.end(tiprev)
tr.add(self.datafile, dataoff)
if fp:
fp.flush()
fp.close()
with self._datafp('w') as df:
for r in self:
df.write(self._getsegmentforrevs(r, r)[1])
with self._indexfp('w') as fp:
self.version &= ~FLAG_INLINE_DATA
self._inline = False
io = self._io
for i in self:
e = io.packentry(self.index[i], self.node, self.version, i)
fp.write(e)
# the temp file replace the real index when we exit the context
# manager
tr.replace(self.indexfile, trindex * self._io.size)
self._chunkclear()
def addrevision(self, text, transaction, link, p1, p2, cachedelta=None,
node=None, flags=REVIDX_DEFAULT_FLAGS, deltacomputer=None):
"""add a revision to the log
text - the revision data to add
transaction - the transaction object used for rollback
link - the linkrev data to add
p1, p2 - the parent nodeids of the revision
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
multiple calls
"""
if link == nullrev:
raise RevlogError(_("attempted to add linkrev -1 to %s")
% self.indexfile)
if flags:
node = node or self.hash(text, p1, p2)
rawtext, validatehash = self._processflags(text, flags, 'write')
# If the flag processor modifies the revision data, ignore any provided
# cachedelta.
if rawtext != text:
cachedelta = None
if len(rawtext) > _maxentrysize:
raise RevlogError(
_("%s: size of %d bytes exceeds maximum revlog storage of 2GiB")
% (self.indexfile, len(rawtext)))
node = node or self.hash(rawtext, p1, p2)
if node in self.nodemap:
return node
if validatehash:
self.checkhash(rawtext, node, p1=p1, p2=p2)
return self.addrawrevision(rawtext, transaction, link, p1, p2, node,
flags, cachedelta=cachedelta,
deltacomputer=deltacomputer)
def addrawrevision(self, rawtext, transaction, link, p1, p2, node, flags,
cachedelta=None, deltacomputer=None):
"""add a raw revision with known flags, node and parents
useful when reusing a revision not stored in this revlog (ex: received
over wire, or read from an external bundle).
"""
dfh = None
if not self._inline:
dfh = self._datafp("a+")
ifh = self._indexfp("a+")
try:
return self._addrevision(node, rawtext, transaction, link, p1, p2,
flags, cachedelta, ifh, dfh,
deltacomputer=deltacomputer)
finally:
if dfh:
dfh.close()
ifh.close()
def compress(self, data):
"""Generate a possibly-compressed representation of data."""
if not data:
return '', data
compressed = self._compressor.compress(data)
if compressed:
# The revlog compressor added the header in the returned data.
return '', compressed
if data[0:1] == '\0':
return '', data
return 'u', data
def decompress(self, data):
"""Decompress a revlog chunk.
The chunk is expected to begin with a header identifying the
format type so it can be routed to an appropriate decompressor.
"""
if not data:
return data
# Revlogs are read much more frequently than they are written and many
# chunks only take microseconds to decompress, so performance is
# important here.
#
# We can make a few assumptions about revlogs:
#
# 1) the majority of chunks will be compressed (as opposed to inline
# raw data).
# 2) decompressing *any* data will likely by at least 10x slower than
# returning raw inline data.
# 3) we want to prioritize common and officially supported compression
# engines
#
# It follows that we want to optimize for "decompress compressed data
# when encoded with common and officially supported compression engines"
# case over "raw data" and "data encoded by less common or non-official
# compression engines." That is why we have the inline lookup first
# followed by the compengines lookup.
#
# According to `hg perfrevlogchunks`, this is ~0.5% faster for zlib
# compressed chunks. And this matters for changelog and manifest reads.
t = data[0:1]
if t == 'x':
try:
return _zlibdecompress(data)
except zlib.error as e:
raise RevlogError(_('revlog decompress error: %s') %
stringutil.forcebytestr(e))
# '\0' is more common than 'u' so it goes first.
elif t == '\0':
return data
elif t == 'u':
return util.buffer(data, 1)
try:
compressor = self._decompressors[t]
except KeyError:
try:
engine = util.compengines.forrevlogheader(t)
compressor = engine.revlogcompressor()
self._decompressors[t] = compressor
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
see addrevision for argument descriptions.
note: "addrevision" takes non-raw text, "_addrevision" takes raw text.
if "deltacomputer" is not provided or None, a defaultdeltacomputer will
be used.
invariants:
- rawtext is optional (can be None); if not set, cachedelta must be set.
if both are set, they must correspond to each other.
"""
if node == nullid:
raise RevlogError(_("%s: attempt to add null revision") %
(self.indexfile))
if node == wdirid or node in wdirfilenodeids:
raise RevlogError(_("%s: attempt to add wdir revision") %
(self.indexfile))
if self._inline:
fh = ifh
else:
fh = dfh
btext = [rawtext]
curr = len(self)
prev = curr - 1
offset = self.end(prev)
p1r, p2r = self.rev(p1), self.rev(p2)
# full versions are inserted when the needed deltas
# become comparable to the uncompressed text
if rawtext is None:
# need rawtext size, before changed by flag processors, which is
# the non-raw size. use revlog explicitly to avoid filelog's extra
# logic that might remove metadata size.
textlen = mdiff.patchedsize(revlog.size(self, cachedelta[0]),
cachedelta[1])
else:
textlen = len(rawtext)
if deltacomputer is None:
deltacomputer = _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
# avoid overhead fetching flags again.
if flags & REVIDX_RAWTEXT_CHANGING_FLAGS:
deltainfo = None
else:
deltainfo = deltacomputer.finddeltainfo(revinfo, fh)
if deltainfo is not None:
base = deltainfo.base
chainbase = deltainfo.chainbase
data = deltainfo.data
l = deltainfo.deltalen
else:
rawtext = deltacomputer.buildtext(revinfo, fh)
data = self.compress(rawtext)
l = len(data[1]) + len(data[0])
base = chainbase = curr
e = (offset_type(offset, flags), l, textlen,
base, link, p1r, p2r, node)
self.index.append(e)
self.nodemap[node] = curr
entry = self._io.packentry(e, self.node, self.version, curr)
self._writeentry(transaction, ifh, dfh, entry, data, link, offset)
if alwayscache and rawtext is None:
rawtext = deltacomputer.buildtext(revinfo, fh)
if type(rawtext) == bytes: # only accept immutable objects
self._cache = (node, curr, rawtext)
self._chainbasecache[curr] = chainbase
return node
def _writeentry(self, transaction, ifh, dfh, entry, data, link, offset):
# Files opened in a+ mode have inconsistent behavior on various
# platforms. Windows requires that a file positioning call be made
# when the file handle transitions between reads and writes. See
# 3686fa2b8eee and the mixedfilemodewrapper in windows.py. On other
# platforms, Python or the platform itself can be buggy. Some versions
# of Solaris have been observed to not append at the end of the file
# if the file was seeked to before the end. See issue4943 for more.
#
# We work around this issue by inserting a seek() before writing.
# Note: This is likely not necessary on Python 3.
ifh.seek(0, os.SEEK_END)
if dfh:
dfh.seek(0, os.SEEK_END)
curr = len(self) - 1
if not self._inline:
transaction.add(self.datafile, offset)
transaction.add(self.indexfile, curr * len(entry))
if data[0]:
dfh.write(data[0])
dfh.write(data[1])
ifh.write(entry)
else:
offset += curr * self._io.size
transaction.add(self.indexfile, offset, curr)
ifh.write(entry)
ifh.write(data[0])
ifh.write(data[1])
self._enforceinlinesize(transaction, ifh)
def addgroup(self, deltas, linkmapper, transaction, addrevisioncb=None):
"""
add a delta group
given a set of deltas, add them to the revision log. the
first delta is against its parent, which should be in our
log, the rest are against the previous delta.
If ``addrevisioncb`` is defined, it will be called with arguments of
this revlog and the node that was added.
"""
nodes = []
r = len(self)
end = 0
if r:
end = self.end(r - 1)
ifh = self._indexfp("a+")
isize = r * self._io.size
if self._inline:
transaction.add(self.indexfile, end + isize, r)
dfh = None
else:
transaction.add(self.indexfile, isize, r)
transaction.add(self.datafile, end)
dfh = self._datafp("a+")
def flush():
if dfh:
dfh.flush()
ifh.flush()
try:
deltacomputer = _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
nodes.append(node)
if node in self.nodemap:
# this can happen if two branches make the same change
continue
for p in (p1, p2):
if p not in self.nodemap:
raise LookupError(p, self.indexfile,
_('unknown parent'))
if deltabase not in self.nodemap:
raise LookupError(deltabase, self.indexfile,
_('unknown delta base'))
baserev = self.rev(deltabase)
if baserev != nullrev and self.iscensored(baserev):
# if base is censored, delta must be full replacement in a
# single patch operation
hlen = struct.calcsize(">lll")
oldlen = self.rawsize(baserev)
newlen = len(delta) - hlen
if delta[:hlen] != mdiff.replacediffheader(oldlen, newlen):
raise error.CensoredBaseError(self.indexfile,
self.node(baserev))
if not flags and self._peek_iscensored(baserev, delta, flush):
flags |= REVIDX_ISCENSORED
# We assume consumers of addrevisioncb will want to retrieve
# the added revision, which will require a call to
# revision(). revision() will fast path if there is a cache
# hit. So, we tell _addrevision() to always cache in this case.
# We're only using addgroup() in the context of changegroup
# generation so the revision data can always be handled as raw
# by the flagprocessor.
self._addrevision(node, None, transaction, link,
p1, p2, flags, (baserev, delta),
ifh, dfh,
alwayscache=bool(addrevisioncb),
deltacomputer=deltacomputer)
if addrevisioncb:
addrevisioncb(self, node)
if not dfh and not self._inline:
# addrevision switched from inline to conventional
# reopen the index
ifh.close()
dfh = self._datafp("a+")
ifh = self._indexfp("a+")
finally:
if dfh:
dfh.close()
ifh.close()
return nodes
def iscensored(self, rev):
"""Check if a file revision is censored."""
if not self._censorable:
return False
return self.flags(rev) & REVIDX_ISCENSORED
def _peek_iscensored(self, baserev, delta, flush):
"""Quickly check if a delta produces a censored revision."""
if not self._censorable:
return False
# Fragile heuristic: unless new file meta keys are added alphabetically
# preceding "censored", all censored revisions are prefixed by
# "\1\ncensored:". A delta producing such a censored revision must be a
# full-replacement delta, so we inspect the first and only patch in the
# delta for this prefix.
hlen = struct.calcsize(">lll")
if len(delta) <= hlen:
return False
oldlen = self.rawsize(baserev)
newlen = len(delta) - hlen
if delta[:hlen] != mdiff.replacediffheader(oldlen, newlen):
return False
add = "\1\ncensored:"
addlen = len(add)
return newlen >= addlen and delta[hlen:hlen + addlen] == add
def getstrippoint(self, minlink):
"""find the minimum rev that must be stripped to strip the linkrev
Returns a tuple containing the minimum rev and a set of all revs that
have linkrevs that will be broken by this strip.
"""
brokenrevs = set()
strippoint = len(self)
heads = {}
futurelargelinkrevs = set()
for head in self.headrevs():
headlinkrev = self.linkrev(head)
heads[head] = headlinkrev
if headlinkrev >= minlink:
futurelargelinkrevs.add(headlinkrev)
# This algorithm involves walking down the rev graph, starting at the
# heads. Since the revs are topologically sorted according to linkrev,
# once all head linkrevs are below the minlink, we know there are
# no more revs that could have a linkrev greater than minlink.
# So we can stop walking.
while futurelargelinkrevs:
strippoint -= 1
linkrev = heads.pop(strippoint)
if linkrev < minlink:
brokenrevs.add(strippoint)
else:
futurelargelinkrevs.remove(linkrev)
for p in self.parentrevs(strippoint):
if p != nullrev:
plinkrev = self.linkrev(p)
heads[p] = plinkrev
if plinkrev >= minlink:
futurelargelinkrevs.add(plinkrev)
return strippoint, brokenrevs
def strip(self, minlink, transaction):
"""truncate the revlog on the first revision with a linkrev >= minlink
This function is called when we're stripping revision minlink and
its descendants from the repository.
We have to remove all revisions with linkrev >= minlink, because
the equivalent changelog revisions will be renumbered after the
strip.
So we truncate the revlog on the first of these revisions, and
trust that the caller has saved the revisions that shouldn't be
removed and that it'll re-add them after this truncation.
"""
if len(self) == 0:
return
rev, _ = self.getstrippoint(minlink)
if rev == len(self):
return
# first truncate the files on disk
end = self.start(rev)
if not self._inline:
transaction.add(self.datafile, end)
end = rev * self._io.size
else:
end += rev * self._io.size
transaction.add(self.indexfile, end)
# then reset internal state in memory to forget those revisions
self._cache = None
self._chaininfocache = {}
self._chunkclear()
for x in pycompat.xrange(rev, len(self)):
del self.nodemap[self.node(x)]
del self.index[rev:-1]
self._nodepos = None
def checksize(self):
expected = 0
if len(self):
expected = max(0, self.end(len(self) - 1))
try:
with self._datafp() as f:
f.seek(0, 2)
actual = f.tell()
dd = actual - expected
except IOError as inst:
if inst.errno != errno.ENOENT:
raise
dd = 0
try:
f = self.opener(self.indexfile)
f.seek(0, 2)
actual = f.tell()
f.close()
s = self._io.size
i = max(0, actual // s)
di = actual - (i * s)
if self._inline:
databytes = 0
for r in self:
databytes += max(0, self.length(r))
dd = 0
di = actual - len(self) * s - databytes
except IOError as inst:
if inst.errno != errno.ENOENT:
raise
di = 0
return (dd, di)
def files(self):
res = [self.indexfile]
if not self._inline:
res.append(self.datafile)
return res
def emitrevisiondeltas(self, requests):
frev = self.rev
prevrev = None
for request in requests:
node = request.node
rev = frev(node)
if prevrev is None:
prevrev = self.index[rev][5]
# Requesting a full revision.
if request.basenode == nullid:
baserev = nullrev
# Requesting an explicit revision.
elif request.basenode is not None:
baserev = frev(request.basenode)
# Allowing us to choose.
else:
p1rev, p2rev = self.parentrevs(rev)
deltaparentrev = self.deltaparent(rev)
# Avoid sending full revisions when delta parent is null. Pick
# prev in that case. It's tempting to pick p1 in this case, as
# p1 will be smaller in the common case. However, computing a
# delta against p1 may require resolving the raw text of p1,
# which could be expensive. The revlog caches should have prev
# cached, meaning less CPU for delta generation. There is
# likely room to add a flag and/or config option to control this
# behavior.
if deltaparentrev == nullrev and self._storedeltachains:
baserev = prevrev
# Revlog is configured to use full snapshot for a reason.
# Stick to full snapshot.
elif deltaparentrev == nullrev:
baserev = nullrev
# Pick previous when we can't be sure the base is available
# on consumer.
elif deltaparentrev not in (p1rev, p2rev, prevrev):
baserev = prevrev
else:
baserev = deltaparentrev
if baserev != nullrev and not self.candelta(baserev, rev):
baserev = nullrev
revision = None
delta = None
baserevisionsize = None
if self.iscensored(baserev) or self.iscensored(rev):
try:
revision = self.revision(node, raw=True)
except error.CensoredNodeError as e:
revision = e.tombstone
if baserev != nullrev:
baserevisionsize = self.rawsize(baserev)
elif baserev == nullrev:
revision = self.revision(node, raw=True)
else:
delta = self.revdiff(baserev, rev)
extraflags = REVIDX_ELLIPSIS if request.ellipsis else 0
yield revlogrevisiondelta(
node=node,
p1node=request.p1node,
p2node=request.p2node,
linknode=request.linknode,
basenode=self.node(baserev),
flags=self.flags(rev) | extraflags,
baserevisionsize=baserevisionsize,
revision=revision,
delta=delta)
prevrev = rev
DELTAREUSEALWAYS = 'always'
DELTAREUSESAMEREVS = 'samerevs'
DELTAREUSENEVER = 'never'
DELTAREUSEFULLADD = 'fulladd'
DELTAREUSEALL = {'always', 'samerevs', 'never', 'fulladd'}
def clone(self, tr, destrevlog, addrevisioncb=None,
deltareuse=DELTAREUSESAMEREVS, deltabothparents=None):
"""Copy this revlog to another, possibly with format changes.
The destination revlog will contain the same revisions and nodes.
However, it may not be bit-for-bit identical due to e.g. delta encoding
differences.
The ``deltareuse`` argument control how deltas from the existing revlog
are preserved in the destination revlog. The argument can have the
following values:
DELTAREUSEALWAYS
Deltas will always be reused (if possible), even if the destination
revlog would not select the same revisions for the delta. This is the
fastest mode of operation.
DELTAREUSESAMEREVS
Deltas will be reused if the destination revlog would pick the same
revisions for the delta. This mode strikes a balance between speed
and optimization.
DELTAREUSENEVER
Deltas will never be reused. This is the slowest mode of execution.
This mode can be used to recompute deltas (e.g. if the diff/delta
algorithm changes).
Delta computation can be slow, so the choice of delta reuse policy can
significantly affect run time.
The default policy (``DELTAREUSESAMEREVS``) strikes a balance between
two extremes. Deltas will be reused if they are appropriate. But if the
delta could choose a better revision, it will do so. This means if you
are converting a non-generaldelta revlog to a generaldelta revlog,
deltas will be recomputed if the delta's parent isn't a parent of the
revision.
In addition to the delta policy, the ``deltabothparents`` argument
controls whether to compute deltas against both parents for merges.
By default, the current default is used.
"""
if deltareuse not in self.DELTAREUSEALL:
raise ValueError(_('value for deltareuse invalid: %s') % deltareuse)
if len(destrevlog):
raise ValueError(_('destination revlog is not empty'))
if getattr(self, 'filteredrevs', None):
raise ValueError(_('source revlog has filtered revisions'))
if getattr(destrevlog, 'filteredrevs', None):
raise ValueError(_('destination revlog has filtered revisions'))
# lazydeltabase controls whether to reuse a cached delta, if possible.
oldlazydeltabase = destrevlog._lazydeltabase
oldamd = destrevlog._deltabothparents
try:
if deltareuse == self.DELTAREUSEALWAYS:
destrevlog._lazydeltabase = True
elif deltareuse == self.DELTAREUSESAMEREVS:
destrevlog._lazydeltabase = False
destrevlog._deltabothparents = deltabothparents or oldamd
populatecachedelta = deltareuse in (self.DELTAREUSEALWAYS,
self.DELTAREUSESAMEREVS)
deltacomputer = _deltacomputer(destrevlog)
index = self.index
for rev in self:
entry = index[rev]
# Some classes override linkrev to take filtered revs into
# account. Use raw entry from index.
flags = entry[0] & 0xffff
linkrev = entry[4]
p1 = index[entry[5]][7]
p2 = index[entry[6]][7]
node = entry[7]
# (Possibly) reuse the delta from the revlog if allowed and
# the revlog chunk is a delta.
cachedelta = None
rawtext = None
if populatecachedelta:
dp = self.deltaparent(rev)
if dp != nullrev:
cachedelta = (dp, bytes(self._chunk(rev)))
if not cachedelta:
rawtext = self.revision(rev, raw=True)
if deltareuse == self.DELTAREUSEFULLADD:
destrevlog.addrevision(rawtext, tr, linkrev, p1, p2,
cachedelta=cachedelta,
node=node, flags=flags,
deltacomputer=deltacomputer)
else:
ifh = destrevlog.opener(destrevlog.indexfile, 'a+',
checkambig=False)
dfh = None
if not destrevlog._inline:
dfh = destrevlog.opener(destrevlog.datafile, 'a+')
try:
destrevlog._addrevision(node, rawtext, tr, linkrev, p1,
p2, flags, cachedelta, ifh, dfh,
deltacomputer=deltacomputer)
finally:
if dfh:
dfh.close()
ifh.close()
if addrevisioncb:
addrevisioncb(self, rev, node)
finally:
destrevlog._lazydeltabase = oldlazydeltabase
destrevlog._deltabothparents = oldamd