view mercurial/bundlerepo.py @ 9820:0b999aec64e8

bundle: don't send too many changesets (Issue1704)

The fast path in changegroupsubset can send too many csets. This happens
because it uses the parents of all bases as common nodes and then goes
forward from this again. If a base has a parent that has another child,
which is -not- a base, then this other child will nevertheless end up in
the changegroup.

The fix is to not use findmissing(), but use nodesbetween() instead, as
do the slow path and incoming/outgoing.

The change to test-notify.out is correct, because it actually hits this
bug, as can be seen by glog'ing the two repos:

@    22c88
|\
| o  0a184
| |
o |  0647d
|/
o  cb9a9

and

o  0647d
|
@  cb9a9

It used to pull 0647d again, which is unnecessary.

# bundlerepo.py - repository class for viewing uncompressed bundles
#
# Copyright 2006, 2007 Benoit Boissinot <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2, incorporated herein by reference.

"""Repository class for viewing uncompressed bundles.

This provides a read-only repository interface to bundles as if they
were part of the actual repository.
"""

from node import nullid
from i18n import _
import os, struct, bz2, zlib, tempfile, shutil
import changegroup, util, mdiff
import localrepo, changelog, manifest, filelog, revlog, error

class bundlerevlog(revlog.revlog):
    def __init__(self, opener, indexfile, 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.revlog.__init__(self, opener, indexfile)
        self.bundlefile = bundlefile
        self.basemap = {}
        def chunkpositer():
            for chunk in changegroup.chunkiter(bundlefile):
                pos = bundlefile.tell()
                yield chunk, pos - len(chunk)
        n = len(self)
        prev = None
        for chunk, start in chunkpositer():
            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 error.LookupError(p, self.indexfile,
                                            _("unknown parent"))
            if linkmapper is None:
                link = n
            else:
                link = linkmapper(cs)

            if not prev:
                prev = p1
            # start, size, full unc. size, base (unused), link, p1, p2, node
            e = (revlog.offset_type(start, 0), size, -1, -1, link,
                 self.rev(p1), self.rev(p2), node)
            self.basemap[n] = prev
            self.index.insert(-1, e)
            self.nodemap[node] = n
            prev = node
            n += 1

    def bundle(self, rev):
        """is rev from the bundle"""
        if rev < 0:
            return False
        return rev in self.basemap
    def bundlebase(self, rev): return self.basemap[rev]
    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.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.revlog.revdiff(self, rev1, 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"""
        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.revlog.revision(self, iter_node)

        while chain:
            delta = self._chunk(chain.pop())
            text = mdiff.patches(text, [delta])

        p1, p2 = self.parents(node)
        if node != revlog.hash(text, p1, p2):
            raise error.RevlogError(_("integrity check failed on %s:%d")
                                     % (self.datafile, self.rev(node)))

        self._cache = (node, self.rev(node), text)
        return text

    def addrevision(self, text, transaction, link, p1=None, p2=None, d=None):
        raise NotImplementedError
    def addgroup(self, revs, linkmapper, transaction):
        raise NotImplementedError
    def strip(self, rev, minlink):
        raise NotImplementedError
    def checksize(self):
        raise NotImplementedError

class bundlechangelog(bundlerevlog, changelog.changelog):
    def __init__(self, opener, bundlefile):
        changelog.changelog.__init__(self, opener)
        bundlerevlog.__init__(self, opener, self.indexfile, bundlefile)

class bundlemanifest(bundlerevlog, manifest.manifest):
    def __init__(self, opener, bundlefile, linkmapper):
        manifest.manifest.__init__(self, opener)
        bundlerevlog.__init__(self, opener, self.indexfile, bundlefile,
                              linkmapper)

class bundlefilelog(bundlerevlog, filelog.filelog):
    def __init__(self, opener, path, bundlefile, linkmapper):
        filelog.filelog.__init__(self, opener, path)
        bundlerevlog.__init__(self, opener, self.indexfile, bundlefile,
                              linkmapper)

class bundlerepository(localrepo.localrepository):
    def __init__(self, ui, path, bundlename):
        self._tempparent = None
        try:
            localrepo.localrepository.__init__(self, ui, path)
        except error.RepoError:
            self._tempparent = tempfile.mkdtemp()
            localrepo.instance(ui, self._tempparent, 1)
            localrepo.localrepository.__init__(self, ui, self._tempparent)

        if path:
            self._url = 'bundle:' + path + '+' + bundlename
        else:
            self._url = 'bundle:' + bundlename

        self.tempfile = None
        self.bundlefile = open(bundlename, "rb")
        header = self.bundlefile.read(6)
        if not header.startswith("HG"):
            raise util.Abort(_("%s: not a Mercurial bundle file") % bundlename)
        elif not header.startswith("HG10"):
            raise util.Abort(_("%s: unknown bundle version") % bundlename)
        elif (header == "HG10BZ") or (header == "HG10GZ"):
            fdtemp, temp = tempfile.mkstemp(prefix="hg-bundle-",
                                            suffix=".hg10un", dir=self.path)
            self.tempfile = temp
            fptemp = os.fdopen(fdtemp, 'wb')
            def generator(f):
                if header == "HG10BZ":
                    zd = bz2.BZ2Decompressor()
                    zd.decompress("BZ")
                elif header == "HG10GZ":
                    zd = zlib.decompressobj()
                for chunk in f:
                    yield zd.decompress(chunk)
            gen = generator(util.filechunkiter(self.bundlefile, 4096))

            try:
                fptemp.write("HG10UN")
                for chunk in gen:
                    fptemp.write(chunk)
            finally:
                fptemp.close()
                self.bundlefile.close()

            self.bundlefile = open(self.tempfile, "rb")
            # seek right after the header
            self.bundlefile.seek(6)
        elif header == "HG10UN":
            # nothing to do
            pass
        else:
            raise util.Abort(_("%s: unknown bundle compression type")
                             % bundlename)
        # dict with the mapping 'filename' -> position in the bundle
        self.bundlefilespos = {}

    @util.propertycache
    def changelog(self):
        c = bundlechangelog(self.sopener, self.bundlefile)
        self.manstart = self.bundlefile.tell()
        return c

    @util.propertycache
    def manifest(self):
        self.bundlefile.seek(self.manstart)
        m = bundlemanifest(self.sopener, self.bundlefile, self.changelog.rev)
        self.filestart = self.bundlefile.tell()
        return m

    @util.propertycache
    def manstart(self):
        self.changelog
        return self.manstart

    @util.propertycache
    def filestart(self):
        self.manifest
        return self.filestart

    def url(self):
        return self._url

    def file(self, f):
        if not self.bundlefilespos:
            self.bundlefile.seek(self.filestart)
            while 1:
                chunk = changegroup.getchunk(self.bundlefile)
                if not chunk:
                    break
                self.bundlefilespos[chunk] = self.bundlefile.tell()
                for c in changegroup.chunkiter(self.bundlefile):
                    pass

        if f[0] == '/':
            f = f[1:]
        if f in self.bundlefilespos:
            self.bundlefile.seek(self.bundlefilespos[f])
            return bundlefilelog(self.sopener, f, self.bundlefile,
                                 self.changelog.rev)
        else:
            return filelog.filelog(self.sopener, f)

    def close(self):
        """Close assigned bundle file immediately."""
        self.bundlefile.close()

    def __del__(self):
        bundlefile = getattr(self, 'bundlefile', None)
        if bundlefile and not bundlefile.closed:
            bundlefile.close()
        tempfile = getattr(self, 'tempfile', None)
        if tempfile is not None:
            os.unlink(tempfile)
        if self._tempparent:
            shutil.rmtree(self._tempparent, True)

    def cancopy(self):
        return False

    def getcwd(self):
        return os.getcwd() # always outside the repo

def instance(ui, path, create):
    if create:
        raise util.Abort(_('cannot create new bundle repository'))
    parentpath = ui.config("bundle", "mainreporoot", "")
    if parentpath:
        # Try to make the full path relative so we get a nice, short URL.
        # In particular, we don't want temp dir names in test outputs.
        cwd = os.getcwd()
        if parentpath == cwd:
            parentpath = ''
        else:
            cwd = os.path.join(cwd,'')
            if parentpath.startswith(cwd):
                parentpath = parentpath[len(cwd):]
    path = util.drop_scheme('file', path)
    if path.startswith('bundle:'):
        path = util.drop_scheme('bundle', path)
        s = path.split("+", 1)
        if len(s) == 1:
            repopath, bundlename = parentpath, s[0]
        else:
            repopath, bundlename = s
    else:
        repopath, bundlename = parentpath, path
    return bundlerepository(ui, repopath, bundlename)