view mercurial/bundlerepo.py @ 1974:0d54675cd566

Delete bundle file of hg incoming in case of errors, preserve existing files.
Let write_bundle always create the bundle file, check if target doesn't exist
and delete it in case of errors.
This way incoming only has to delete the bundle file if it was meant to
be a temporary file.

"""
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 <[e-mail]>

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")

import localrepo, changelog, manifest, filelog, revlog

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.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.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
            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.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.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.revlog.revision(self, iter_node)

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

        p1, p2 = self.parents(node)
        if node != revlog.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.changelog):
    def __init__(self, opener, bundlefile):
        changelog.changelog.__init__(self, opener)
        bundlerevlog.__init__(self, opener, "00changelog.i", "00changelog.d",
                              bundlefile)

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

class bundlerepository(localrepo.localrepository):
    def __init__(self, ui, path, bundlename):
        localrepo.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.filelog(self.opener, f)

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