add bundlerepo.py: a read-only repo that can use uncompressed bundles
The idea is to create a repo consisting of a normal local repository
plus all the changesets contained in a bundle.
The bundle needs to be uncompressed. A futur version could implement
the seeking through a compressed bundle.
"""
bundlerepo.py - repository class for viewing uncompressed bundles
This provides a read-only repository interface to bundles as if
they were part of the actual repository.
Copyright 2006 Benoit Boissinot <benoit.boissinot@ens-lyon.org>
This software may be used and distributed according to the terms
of the GNU General Public License, incorporated herein by reference.
"""
from node import *
from i18n import gettext as _
from demandload import demandload
demandload(globals(), "util os struct")
from changelog import changelog
from manifest import manifest
from filelog import filelog
from localrepo import localrepository
from revlog import *
def getchunk(source):
"""get a chunk from a group"""
d = source.read(4)
if not d:
return ""
l = struct.unpack(">l", d)[0]
if l <= 4:
return ""
d = source.read(l - 4)
if len(d) < l - 4:
raise util.Abort(_("premature EOF reading chunk"
" (got %d bytes, expected %d)")
% (len(d), l - 4))
return d
class bundlerevlog(revlog):
def __init__(self, opener, indexfile, datafile, bundlefile,
linkmapper=None):
# How it works:
# to retrieve a revision, we need to know the offset of
# the revision in the bundlefile (an opened file).
#
# We store this offset in the index (start), to differentiate a
# rev in the bundle and from a rev in the revlog, we check
# len(index[r]). If the tuple is bigger than 7, it is a bundle
# (it is bigger since we store the node to which the delta is)
#
revlog.__init__(self, opener, indexfile, datafile)
self.bundlefile = bundlefile
def genchunk():
while 1:
pos = bundlefile.tell()
chunk = getchunk(bundlefile)
if not chunk:
break
yield chunk, pos + 4 # XXX struct.calcsize(">l") == 4
n = self.count()
prev = None
for chunk, start in genchunk():
size = len(chunk)
if size < 80:
raise util.Abort("invalid changegroup")
start += 80
size -= 80
node, p1, p2, cs = struct.unpack("20s20s20s20s", chunk[:80])
if node in self.nodemap:
prev = node
continue
for p in (p1, p2):
if not p in self.nodemap:
raise RevlogError(_("unknown parent %s") % short(p1))
if linkmapper is None:
link = n
else:
link = linkmapper(cs)
if not prev:
prev = p1
# start, size, base is not used, link, p1, p2, delta ref
# warning:
e = (start, size, None, link, p1, p2, node, prev)
self.index.append(e)
self.nodemap[node] = n
prev = node
n += 1
def bundle(self, rev):
"""is rev from the bundle"""
if rev < 0:
return False
return len(self.index[rev]) > 7
def bundlebase(self, rev): return self.index[rev][7]
def chunk(self, rev):
# Warning: in case of bundle, the diff is against bundlebase,
# not against rev - 1
# XXX: could use some caching
if not self.bundle(rev):
return revlog.chunk(self, rev)
self.bundlefile.seek(self.start(rev))
return self.bundlefile.read(self.length(rev))
def revdiff(self, rev1, rev2):
"""return or calculate a delta between two revisions"""
if self.bundle(rev1) and self.bundle(rev2):
# hot path for bundle
revb = self.rev(self.bundlebase(rev2))
if revb == rev1:
return self.chunk(rev2)
elif not self.bundle(rev1) and not self.bundle(rev2):
return revlog.chunk(self, rev1, rev2)
return self.diff(self.revision(self.node(rev1)),
self.revision(self.node(rev2)))
def revision(self, node):
"""return an uncompressed revision of a given"""
if node == nullid: return ""
text = None
chain = []
iter_node = node
rev = self.rev(iter_node)
# reconstruct the revision if it is from a changegroup
while self.bundle(rev):
if self.cache and self.cache[0] == iter_node:
text = self.cache[2]
break
chain.append(rev)
iter_node = self.bundlebase(rev)
rev = self.rev(iter_node)
if text is None:
text = revlog.revision(self, iter_node)
while chain:
delta = self.chunk(chain.pop())
text = self.patches(text, [delta])
p1, p2 = self.parents(node)
if node != hash(text, p1, p2):
raise RevlogError(_("integrity check failed on %s:%d")
% (self.datafile, self.rev(node)))
self.cache = (node, rev, text)
return text
def addrevision(self, text, transaction, link, p1=None, p2=None, d=None):
raise NotImplementedError
def addgroup(self, revs, linkmapper, transaction, unique=0):
raise NotImplementedError
def strip(self, rev, minlink):
raise NotImplementedError
def checksize(self):
raise NotImplementedError
class bundlechangelog(bundlerevlog, changelog):
def __init__(self, opener, bundlefile):
changelog.__init__(self, opener)
bundlerevlog.__init__(self, opener, "00changelog.i", "00changelog.d",
bundlefile)
class bundlemanifest(bundlerevlog, manifest):
def __init__(self, opener, bundlefile, linkmapper):
manifest.__init__(self, opener)
bundlerevlog.__init__(self, opener, self.indexfile, self.datafile,
bundlefile, linkmapper)
class bundlefilelog(bundlerevlog, filelog):
def __init__(self, opener, path, bundlefile, linkmapper):
filelog.__init__(self, opener, path)
bundlerevlog.__init__(self, opener, self.indexfile, self.datafile,
bundlefile, linkmapper)
class bundlerepository(localrepository):
def __init__(self, ui, path, bundlename):
localrepository.__init__(self, ui, path)
f = open(bundlename, "rb")
s = os.fstat(f.fileno())
self.bundlefile = f
header = self.bundlefile.read(4)
if header == "HG10":
raise util.Abort(_("%s: compressed bundle not supported")
% bundlename)
elif header != "HG11":
raise util.Abort(_("%s: not a Mercurial bundle file") % bundlename)
self.changelog = bundlechangelog(self.opener, self.bundlefile)
self.manifest = bundlemanifest(self.opener, self.bundlefile,
self.changelog.rev)
# dict with the mapping 'filename' -> position in the bundle
self.bundlefilespos = {}
while 1:
f = getchunk(self.bundlefile)
if not f:
break
self.bundlefilespos[f] = self.bundlefile.tell()
while getchunk(self.bundlefile):
pass
def dev(self):
return -1
def file(self, f):
if f[0] == '/':
f = f[1:]
if f in self.bundlefilespos:
self.bundlefile.seek(self.bundlefilespos[f])
return bundlefilelog(self.opener, f, self.bundlefile,
self.changelog.rev)
else:
return filelog(self.opener, f)