ref: 986886f2b8ab4a7e1b3d66e99934d8fdab537be9
dir: /sys/src/cmd/hg/mercurial/revlog.py/
# 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, incorporated herein by reference.
"""Storage back-end for Mercurial.
This provides efficient delta storage with O(1) retrieve and append
and O(changes) merge between branches.
"""
# import stuff from node for others to import from revlog
from node import bin, hex, nullid, nullrev, short #@UnusedImport
from i18n import _
import changegroup, ancestor, mdiff, parsers, error, util
import struct, zlib, errno
_pack = struct.pack
_unpack = struct.unpack
_compress = zlib.compress
_decompress = zlib.decompress
_sha = util.sha1
# revlog flags
REVLOGV0 = 0
REVLOGNG = 1
REVLOGNGINLINEDATA = (1 << 16)
REVLOG_DEFAULT_FLAGS = REVLOGNGINLINEDATA
REVLOG_DEFAULT_FORMAT = REVLOGNG
REVLOG_DEFAULT_VERSION = REVLOG_DEFAULT_FORMAT | REVLOG_DEFAULT_FLAGS
_prereadsize = 1048576
RevlogError = error.RevlogError
LookupError = error.LookupError
def getoffset(q):
return int(q >> 16)
def gettype(q):
return int(q & 0xFFFF)
def offset_type(offset, type):
return long(long(offset) << 16 | type)
nullhash = _sha(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
l = [p1, p2]
l.sort()
s = _sha(l[0])
s.update(l[1])
s.update(text)
return s.digest()
def compress(text):
""" generate a possibly-compressed representation of text """
if not text:
return ("", text)
l = len(text)
bin = None
if l < 44:
pass
elif l > 1000000:
# zlib makes an internal copy, thus doubling memory usage for
# large files, so lets do this in pieces
z = zlib.compressobj()
p = []
pos = 0
while pos < l:
pos2 = pos + 2**20
p.append(z.compress(text[pos:pos2]))
pos = pos2
p.append(z.flush())
if sum(map(len, p)) < l:
bin = "".join(p)
else:
bin = _compress(text)
if bin is None or len(bin) > l:
if text[0] == '\0':
return ("", text)
return ('u', text)
return ("", bin)
def decompress(bin):
""" decompress the given input """
if not bin:
return bin
t = bin[0]
if t == '\0':
return bin
if t == 'x':
return _decompress(bin)
if t == 'u':
return bin[1:]
raise RevlogError(_("unknown compression type %r") % t)
class lazyparser(object):
"""
this class avoids the need to parse the entirety of large indices
"""
# lazyparser is not safe to use on windows if win32 extensions not
# available. it keeps file handle open, which make it not possible
# to break hardlinks on local cloned repos.
def __init__(self, dataf):
try:
size = util.fstat(dataf).st_size
except AttributeError:
size = 0
self.dataf = dataf
self.s = struct.calcsize(indexformatng)
self.datasize = size
self.l = size/self.s
self.index = [None] * self.l
self.map = {nullid: nullrev}
self.allmap = 0
self.all = 0
self.mapfind_count = 0
def loadmap(self):
"""
during a commit, we need to make sure the rev being added is
not a duplicate. This requires loading the entire index,
which is fairly slow. loadmap can load up just the node map,
which takes much less time.
"""
if self.allmap:
return
end = self.datasize
self.allmap = 1
cur = 0
count = 0
blocksize = self.s * 256
self.dataf.seek(0)
while cur < end:
data = self.dataf.read(blocksize)
off = 0
for x in xrange(256):
n = data[off + ngshaoffset:off + ngshaoffset + 20]
self.map[n] = count
count += 1
if count >= self.l:
break
off += self.s
cur += blocksize
def loadblock(self, blockstart, blocksize, data=None):
if self.all:
return
if data is None:
self.dataf.seek(blockstart)
if blockstart + blocksize > self.datasize:
# the revlog may have grown since we've started running,
# but we don't have space in self.index for more entries.
# limit blocksize so that we don't get too much data.
blocksize = max(self.datasize - blockstart, 0)
data = self.dataf.read(blocksize)
lend = len(data) / self.s
i = blockstart / self.s
off = 0
# lazyindex supports __delitem__
if lend > len(self.index) - i:
lend = len(self.index) - i
for x in xrange(lend):
if self.index[i + x] is None:
b = data[off : off + self.s]
self.index[i + x] = b
n = b[ngshaoffset:ngshaoffset + 20]
self.map[n] = i + x
off += self.s
def findnode(self, node):
"""search backwards through the index file for a specific node"""
if self.allmap:
return None
# hg log will cause many many searches for the manifest
# nodes. After we get called a few times, just load the whole
# thing.
if self.mapfind_count > 8:
self.loadmap()
if node in self.map:
return node
return None
self.mapfind_count += 1
last = self.l - 1
while self.index[last] != None:
if last == 0:
self.all = 1
self.allmap = 1
return None
last -= 1
end = (last + 1) * self.s
blocksize = self.s * 256
while end >= 0:
start = max(end - blocksize, 0)
self.dataf.seek(start)
data = self.dataf.read(end - start)
findend = end - start
while True:
# we're searching backwards, so we have to make sure
# we don't find a changeset where this node is a parent
off = data.find(node, 0, findend)
findend = off
if off >= 0:
i = off / self.s
off = i * self.s
n = data[off + ngshaoffset:off + ngshaoffset + 20]
if n == node:
self.map[n] = i + start / self.s
return node
else:
break
end -= blocksize
return None
def loadindex(self, i=None, end=None):
if self.all:
return
all = False
if i is None:
blockstart = 0
blocksize = (65536 / self.s) * self.s
end = self.datasize
all = True
else:
if end:
blockstart = i * self.s
end = end * self.s
blocksize = end - blockstart
else:
blockstart = (i & ~1023) * self.s
blocksize = self.s * 1024
end = blockstart + blocksize
while blockstart < end:
self.loadblock(blockstart, blocksize)
blockstart += blocksize
if all:
self.all = True
class lazyindex(object):
"""a lazy version of the index array"""
def __init__(self, parser):
self.p = parser
def __len__(self):
return len(self.p.index)
def load(self, pos):
if pos < 0:
pos += len(self.p.index)
self.p.loadindex(pos)
return self.p.index[pos]
def __getitem__(self, pos):
return _unpack(indexformatng, self.p.index[pos] or self.load(pos))
def __setitem__(self, pos, item):
self.p.index[pos] = _pack(indexformatng, *item)
def __delitem__(self, pos):
del self.p.index[pos]
def insert(self, pos, e):
self.p.index.insert(pos, _pack(indexformatng, *e))
def append(self, e):
self.p.index.append(_pack(indexformatng, *e))
class lazymap(object):
"""a lazy version of the node map"""
def __init__(self, parser):
self.p = parser
def load(self, key):
n = self.p.findnode(key)
if n is None:
raise KeyError(key)
def __contains__(self, key):
if key in self.p.map:
return True
self.p.loadmap()
return key in self.p.map
def __iter__(self):
yield nullid
for i in xrange(self.p.l):
ret = self.p.index[i]
if not ret:
self.p.loadindex(i)
ret = self.p.index[i]
if isinstance(ret, str):
ret = _unpack(indexformatng, ret)
yield ret[7]
def __getitem__(self, key):
try:
return self.p.map[key]
except KeyError:
try:
self.load(key)
return self.p.map[key]
except KeyError:
raise KeyError("node " + hex(key))
def __setitem__(self, key, val):
self.p.map[key] = val
def __delitem__(self, key):
del self.p.map[key]
indexformatv0 = ">4l20s20s20s"
v0shaoffset = 56
class revlogoldio(object):
def __init__(self):
self.size = struct.calcsize(indexformatv0)
def parseindex(self, fp, data, inline):
s = self.size
index = []
nodemap = {nullid: nullrev}
n = off = 0
if len(data) == _prereadsize:
data += fp.read() # read the rest
l = len(data)
while off + s <= l:
cur = data[off:off + s]
off += s
e = _unpack(indexformatv0, 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 index, nodemap, None
def packentry(self, entry, node, version, rev):
e2 = (getoffset(entry[0]), entry[1], entry[3], entry[4],
node(entry[5]), node(entry[6]), entry[7])
return _pack(indexformatv0, *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 = ">Qiiiiii20s12x"
ngshaoffset = 32
versionformat = ">I"
class revlogio(object):
def __init__(self):
self.size = struct.calcsize(indexformatng)
def parseindex(self, fp, data, inline):
if len(data) == _prereadsize:
if util.openhardlinks() and not inline:
# big index, let's parse it on demand
parser = lazyparser(fp)
index = lazyindex(parser)
nodemap = lazymap(parser)
e = list(index[0])
type = gettype(e[0])
e[0] = offset_type(0, type)
index[0] = e
return index, nodemap, None
else:
data += fp.read()
# call the C implementation to parse the index data
index, nodemap, cache = parsers.parse_index(data, inline)
return index, nodemap, cache
def packentry(self, entry, node, version, rev):
p = _pack(indexformatng, *entry)
if rev == 0:
p = _pack(versionformat, 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.
"""
def __init__(self, opener, indexfile):
"""
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 = indexfile[:-2] + ".d"
self.opener = opener
self._cache = None
self._chunkcache = (0, '')
self.nodemap = {nullid: nullrev}
self.index = []
v = REVLOG_DEFAULT_VERSION
if hasattr(opener, "defversion"):
v = opener.defversion
if v & REVLOGNG:
v |= REVLOGNGINLINEDATA
i = ''
try:
f = self.opener(self.indexfile)
i = f.read(_prereadsize)
if len(i) > 0:
v = struct.unpack(versionformat, i[:4])[0]
except IOError, inst:
if inst.errno != errno.ENOENT:
raise
self.version = v
self._inline = v & REVLOGNGINLINEDATA
flags = v & ~0xFFFF
fmt = v & 0xFFFF
if fmt == REVLOGV0 and flags:
raise RevlogError(_("index %s unknown flags %#04x for format v0")
% (self.indexfile, flags >> 16))
elif fmt == REVLOGNG and flags & ~REVLOGNGINLINEDATA:
raise RevlogError(_("index %s unknown flags %#04x for revlogng")
% (self.indexfile, flags >> 16))
elif fmt > REVLOGNG:
raise RevlogError(_("index %s unknown format %d")
% (self.indexfile, fmt))
self._io = revlogio()
if self.version == REVLOGV0:
self._io = revlogoldio()
if i:
try:
d = self._io.parseindex(f, i, self._inline)
except (ValueError, IndexError), e:
raise RevlogError(_("index %s is corrupted") % (self.indexfile))
self.index, self.nodemap, self._chunkcache = d
if not self._chunkcache:
self._chunkclear()
# add the magic null revision at -1 (if it hasn't been done already)
if (self.index == [] or isinstance(self.index, lazyindex) or
self.index[-1][7] != nullid) :
self.index.append((0, 0, 0, -1, -1, -1, -1, nullid))
def _loadindex(self, start, end):
"""load a block of indexes all at once from the lazy parser"""
if isinstance(self.index, lazyindex):
self.index.p.loadindex(start, end)
def _loadindexmap(self):
"""loads both the map and the index from the lazy parser"""
if isinstance(self.index, lazyindex):
p = self.index.p
p.loadindex()
self.nodemap = p.map
def _loadmap(self):
"""loads the map from the lazy parser"""
if isinstance(self.nodemap, lazymap):
self.nodemap.p.loadmap()
self.nodemap = self.nodemap.p.map
def tip(self):
return self.node(len(self.index) - 2)
def __len__(self):
return len(self.index) - 1
def __iter__(self):
for i in xrange(len(self)):
yield i
def rev(self, node):
try:
return self.nodemap[node]
except KeyError:
raise LookupError(node, self.indexfile, _('no node'))
def node(self, rev):
return self.index[rev][7]
def linkrev(self, rev):
return self.index[rev][4]
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 parentrevs(self, rev):
return self.index[rev][5:7]
def start(self, rev):
return int(self.index[rev][0] >> 16)
def end(self, rev):
return self.start(rev) + self.length(rev)
def length(self, rev):
return self.index[rev][1]
def base(self, rev):
return self.index[rev][3]
def size(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(self.node(rev))
return len(t)
# Alternate implementation. The advantage to this code is it
# will be faster for a single revision. However, the results
# are not cached, so finding the size of every revision will
# be slower.
#
# if self.cache and self.cache[1] == rev:
# return len(self.cache[2])
#
# base = self.base(rev)
# if self.cache and self.cache[1] >= base and self.cache[1] < rev:
# base = self.cache[1]
# text = self.cache[2]
# else:
# text = self.revision(self.node(base))
#
# l = len(text)
# for x in xrange(base + 1, rev + 1):
# l = mdiff.patchedsize(l, self._chunk(x))
# return l
def reachable(self, node, stop=None):
"""return the set of all nodes ancestral to a given node, including
the node itself, stopping when stop is matched"""
reachable = set((node,))
visit = [node]
if stop:
stopn = self.rev(stop)
else:
stopn = 0
while visit:
n = visit.pop(0)
if n == stop:
continue
if n == nullid:
continue
for p in self.parents(n):
if self.rev(p) < stopn:
continue
if p not in reachable:
reachable.add(p)
visit.append(p)
return reachable
def ancestors(self, *revs):
'Generate the ancestors of revs using a breadth-first visit'
visit = list(revs)
seen = set([nullrev])
while visit:
for parent in self.parentrevs(visit.pop(0)):
if parent not in seen:
visit.append(parent)
seen.add(parent)
yield parent
def descendants(self, *revs):
'Generate the descendants of revs in topological order'
seen = set(revs)
for i in xrange(min(revs) + 1, len(self)):
for x in self.parentrevs(i):
if x != nullrev and x in seen:
seen.add(i)
yield i
break
def findmissing(self, common=None, heads=None):
'''
returns the topologically sorted list of nodes from the set:
missing = (ancestors(heads) \ ancestors(common))
where ancestors() is the set of ancestors from heads, heads included
if heads is None, the heads of the revlog are used
if common is None, nullid is assumed to be a common node
'''
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
has = set(self.ancestors(*common))
has.add(nullrev)
has.update(common)
# take all ancestors from heads that aren't in has
missing = set()
visit = [r for r in heads if r not in has]
while visit:
r = visit.pop(0)
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 [self.node(r) for r in missing]
def nodesbetween(self, roots=None, heads=None):
"""Return a tuple containing three elements. Elements 1 and 2 contain
a final list bases and heads after all the unreachable ones have been
pruned. Element 0 contains a topologically sorted list of all
nodes that satisfy these constraints:
1. All nodes must be descended from a node in roots (the nodes on
roots are considered descended from themselves).
2. All nodes must also be ancestors of a node in heads (the nodes in
heads are considered to be their own ancestors).
If roots is unspecified, nullid is assumed as the only root.
If heads is unspecified, it is taken to be the output of the
heads method (i.e. a list of all nodes in the repository that
have no children)."""
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 descendent 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, 0)
# 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 descendent 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 = [n for n in roots if n in ancestors]
# Recompute the lowest revision
if roots:
lowestrev = min([self.rev(n) for n 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.
descendents = 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 = descendents.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 descedents, empty parents will look like
# they're descendents.
for r in xrange(max(lowestrev, 0), highestrev + 1):
n = self.node(r)
isdescendent = False
if lowestrev == nullrev: # Everybody is a descendent of nullid
isdescendent = True
elif n in descendents:
# n is already a descendent
isdescendent = True
# This check only needs to be done here because all the roots
# will start being marked is descendents 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 descendents, it's not a root.
if (p[0] in descendents) or (p[1] in descendents):
roots.remove(n)
else:
p = tuple(self.parents(n))
# A node is a descendent if either of its parents are
# descendents. (We seeded the dependents list with the roots
# up there, remember?)
if (p[0] in descendents) or (p[1] in descendents):
descendents.add(n)
isdescendent = True
if isdescendent and ((ancestors is None) or (n in ancestors)):
# Only include nodes that are both descendents 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] = 1
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] = 1
# But, obviously its parents aren't.
for p in self.parents(n):
heads.pop(p, None)
heads = [n for n in heads.iterkeys() if heads[n] != 0]
roots = list(roots)
assert orderedout
assert roots
assert heads
return (orderedout, roots, heads)
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:
count = len(self)
if not count:
return [nullid]
ishead = [1] * (count + 1)
index = self.index
for r in xrange(count):
e = index[r]
ishead[e[5]] = ishead[e[6]] = 0
return [self.node(r) for r in xrange(count) if ishead[r]]
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 = set((startrev,))
heads = set((startrev,))
parentrevs = self.parentrevs
for r in xrange(startrev + 1, len(self)):
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 range(p + 1, len(self)):
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 _match(self, id):
if isinstance(id, (long, 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 str(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):
if len(id) < 40:
try:
# hex(node)[:...]
l = len(id) // 2 # grab an even number of digits
bin_id = bin(id[:l*2])
nl = [n for n in self.nodemap if n[:l] == bin_id]
nl = [n for n in nl if hex(n).startswith(id)]
if len(nl) > 0:
if len(nl) == 1:
return nl[0]
raise LookupError(id, self.indexfile,
_('ambiguous identifier'))
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 cmp(self, node, text):
"""compare text with a given file revision"""
p1, p2 = self.parents(node)
return hash(text, p1, p2) != node
def _addchunk(self, offset, data):
o, d = self._chunkcache
# try to add to existing cache
if o + len(d) == offset and len(d) + len(data) < _prereadsize:
self._chunkcache = o, d + data
else:
self._chunkcache = offset, data
def _loadchunk(self, offset, length):
if self._inline:
df = self.opener(self.indexfile)
else:
df = self.opener(self.datafile)
readahead = max(65536, length)
df.seek(offset)
d = df.read(readahead)
self._addchunk(offset, d)
if readahead > length:
return d[:length]
return d
def _getchunk(self, offset, length):
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 d[cachestart:cacheend]
return self._loadchunk(offset, length)
def _chunkraw(self, startrev, endrev):
start = self.start(startrev)
length = self.end(endrev) - start
if self._inline:
start += (startrev + 1) * self._io.size
return self._getchunk(start, length)
def _chunk(self, rev):
return decompress(self._chunkraw(rev, rev))
def _chunkclear(self):
self._chunkcache = (0, '')
def revdiff(self, rev1, rev2):
"""return or calculate a delta between two revisions"""
if rev1 + 1 == rev2 and self.base(rev1) == self.base(rev2):
return self._chunk(rev2)
return mdiff.textdiff(self.revision(self.node(rev1)),
self.revision(self.node(rev2)))
def revision(self, node):
"""return an uncompressed revision of a given node"""
if node == nullid:
return ""
if self._cache and self._cache[0] == node:
return str(self._cache[2])
# look up what we need to read
text = None
rev = self.rev(node)
base = self.base(rev)
# check rev flags
if self.index[rev][0] & 0xFFFF:
raise RevlogError(_('incompatible revision flag %x') %
(self.index[rev][0] & 0xFFFF))
# do we have useful data cached?
if self._cache and self._cache[1] >= base and self._cache[1] < rev:
base = self._cache[1]
text = str(self._cache[2])
self._loadindex(base, rev + 1)
self._chunkraw(base, rev)
if text is None:
text = self._chunk(base)
bins = [self._chunk(r) for r in xrange(base + 1, rev + 1)]
text = mdiff.patches(text, bins)
p1, p2 = self.parents(node)
if node != hash(text, p1, p2):
raise RevlogError(_("integrity check failed on %s:%d")
% (self.indexfile, rev))
self._cache = (node, rev, text)
return text
def checkinlinesize(self, tr, fp=None):
if not self._inline or (self.start(-2) + self.length(-2)) < 131072:
return
trinfo = tr.find(self.indexfile)
if trinfo is None:
raise RevlogError(_("%s not found in the transaction")
% self.indexfile)
trindex = trinfo[2]
dataoff = self.start(trindex)
tr.add(self.datafile, dataoff)
if fp:
fp.flush()
fp.close()
df = self.opener(self.datafile, 'w')
try:
for r in self:
df.write(self._chunkraw(r, r))
finally:
df.close()
fp = self.opener(self.indexfile, 'w', atomictemp=True)
self.version &= ~(REVLOGNGINLINEDATA)
self._inline = False
for i in self:
e = self._io.packentry(self.index[i], self.node, self.version, i)
fp.write(e)
# if we don't call rename, the temp file will never replace the
# real index
fp.rename()
tr.replace(self.indexfile, trindex * self._io.size)
self._chunkclear()
def addrevision(self, text, transaction, link, p1, p2, d=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
d - an optional precomputed delta
"""
dfh = None
if not self._inline:
dfh = self.opener(self.datafile, "a")
ifh = self.opener(self.indexfile, "a+")
try:
return self._addrevision(text, transaction, link, p1, p2, d, ifh, dfh)
finally:
if dfh:
dfh.close()
ifh.close()
def _addrevision(self, text, transaction, link, p1, p2, d, ifh, dfh):
node = hash(text, p1, p2)
if node in self.nodemap:
return node
curr = len(self)
prev = curr - 1
base = self.base(prev)
offset = self.end(prev)
if curr:
if not d:
ptext = self.revision(self.node(prev))
d = mdiff.textdiff(ptext, text)
data = compress(d)
l = len(data[1]) + len(data[0])
dist = l + offset - self.start(base)
# full versions are inserted when the needed deltas
# become comparable to the uncompressed text
if not curr or dist > len(text) * 2:
data = compress(text)
l = len(data[1]) + len(data[0])
base = curr
e = (offset_type(offset, 0), l, len(text),
base, link, self.rev(p1), self.rev(p2), node)
self.index.insert(-1, e)
self.nodemap[node] = curr
entry = self._io.packentry(e, self.node, self.version, curr)
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])
dfh.flush()
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.checkinlinesize(transaction, ifh)
self._cache = (node, curr, text)
return node
def ancestor(self, a, b):
"""calculate the least common ancestor of nodes a and b"""
def parents(rev):
return [p for p in self.parentrevs(rev) if p != nullrev]
c = ancestor.ancestor(self.rev(a), self.rev(b), parents)
if c is None:
return nullid
return self.node(c)
def group(self, nodelist, lookup, infocollect=None):
"""calculate a delta group
Given a list of changeset revs, return a set of deltas and
metadata corresponding to nodes. the first delta is
parent(nodes[0]) -> nodes[0] the receiver is guaranteed to
have this parent as it has all history before these
changesets. parent is parent[0]
"""
revs = [self.rev(n) for n in nodelist]
# if we don't have any revisions touched by these changesets, bail
if not revs:
yield changegroup.closechunk()
return
# add the parent of the first rev
p = self.parentrevs(revs[0])[0]
revs.insert(0, p)
# build deltas
for d in xrange(len(revs) - 1):
a, b = revs[d], revs[d + 1]
nb = self.node(b)
if infocollect is not None:
infocollect(nb)
p = self.parents(nb)
meta = nb + p[0] + p[1] + lookup(nb)
if a == -1:
d = self.revision(nb)
meta += mdiff.trivialdiffheader(len(d))
else:
d = self.revdiff(a, b)
yield changegroup.chunkheader(len(meta) + len(d))
yield meta
if len(d) > 2**20:
pos = 0
while pos < len(d):
pos2 = pos + 2 ** 18
yield d[pos:pos2]
pos = pos2
else:
yield d
yield changegroup.closechunk()
def addgroup(self, revs, linkmapper, transaction):
"""
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.
"""
#track the base of the current delta log
r = len(self)
t = r - 1
node = None
base = prev = nullrev
start = end = textlen = 0
if r:
end = self.end(t)
ifh = self.opener(self.indexfile, "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.opener(self.datafile, "a")
try:
# loop through our set of deltas
chain = None
for chunk in revs:
node, p1, p2, cs = struct.unpack("20s20s20s20s", chunk[:80])
link = linkmapper(cs)
if node in self.nodemap:
# this can happen if two branches make the same change
chain = node
continue
delta = buffer(chunk, 80)
del chunk
for p in (p1, p2):
if not p in self.nodemap:
raise LookupError(p, self.indexfile, _('unknown parent'))
if not chain:
# retrieve the parent revision of the delta chain
chain = p1
if not chain in self.nodemap:
raise LookupError(chain, self.indexfile, _('unknown base'))
# full versions are inserted when the needed deltas become
# comparable to the uncompressed text or when the previous
# version is not the one we have a delta against. We use
# the size of the previous full rev as a proxy for the
# current size.
if chain == prev:
cdelta = compress(delta)
cdeltalen = len(cdelta[0]) + len(cdelta[1])
textlen = mdiff.patchedsize(textlen, delta)
if chain != prev or (end - start + cdeltalen) > textlen * 2:
# flush our writes here so we can read it in revision
if dfh:
dfh.flush()
ifh.flush()
text = self.revision(chain)
if len(text) == 0:
# skip over trivial delta header
text = buffer(delta, 12)
else:
text = mdiff.patches(text, [delta])
del delta
chk = self._addrevision(text, transaction, link, p1, p2, None,
ifh, dfh)
if not dfh and not self._inline:
# addrevision switched from inline to conventional
# reopen the index
dfh = self.opener(self.datafile, "a")
ifh = self.opener(self.indexfile, "a")
if chk != node:
raise RevlogError(_("consistency error adding group"))
textlen = len(text)
else:
e = (offset_type(end, 0), cdeltalen, textlen, base,
link, self.rev(p1), self.rev(p2), node)
self.index.insert(-1, e)
self.nodemap[node] = r
entry = self._io.packentry(e, self.node, self.version, r)
if self._inline:
ifh.write(entry)
ifh.write(cdelta[0])
ifh.write(cdelta[1])
self.checkinlinesize(transaction, ifh)
if not self._inline:
dfh = self.opener(self.datafile, "a")
ifh = self.opener(self.indexfile, "a")
else:
dfh.write(cdelta[0])
dfh.write(cdelta[1])
ifh.write(entry)
t, r, chain, prev = r, r + 1, node, node
base = self.base(t)
start = self.start(base)
end = self.end(t)
finally:
if dfh:
dfh.close()
ifh.close()
return node
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 readd them after this truncation.
"""
if len(self) == 0:
return
if isinstance(self.index, lazyindex):
self._loadindexmap()
for rev in self:
if self.index[rev][4] >= minlink:
break
else:
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._chunkclear()
for x in xrange(rev, len(self)):
del self.nodemap[self.node(x)]
del self.index[rev:-1]
def checksize(self):
expected = 0
if len(self):
expected = max(0, self.end(len(self) - 1))
try:
f = self.opener(self.datafile)
f.seek(0, 2)
actual = f.tell()
dd = actual - expected
except IOError, inst:
if inst.errno != errno.ENOENT:
raise
dd = 0
try:
f = self.opener(self.indexfile)
f.seek(0, 2)
actual = f.tell()
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, 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