mercurial/bundlerepo.py

purge: abort with missing files avoiding problems with name-mangling fs

In a name mangling filesystem (e.g. a case insensitive one)
dirstate.walk() can yield filenames different from the ones
stored in the dirstate. This already confuses the status and
add commands, but with purge this may cause data loss.

To prevent this purge refuses to work if there are missing
files and has a 'force' option if the user knows it is safe.

Even with the force option purge checks if any of the missing
files is still available in the working dir: if so there
may be some problem with the underlying filesystem, so it
unconditionally aborts.

"""
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 _
import changegroup, util, os, struct, bz2, tempfile

import localrepo, changelog, manifest, filelog, revlog

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 = self.count()
        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 revlog.LookupError(_("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
            if self.version == revlog.REVLOGV0:
                e = (start, size, None, link, p1, p2, node)
            else:
                e = (self.offset_type(start, 0), size, -1, None, link,
                     self.rev(p1), self.rev(p2), node)
            self.basemap[n] = 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 rev in self.basemap
    def bundlebase(self, rev): return self.basemap[rev]
    def chunk(self, rev, df=None, cachelen=4096):
        # 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, df, cachelen)
        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 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 revlog.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, 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, 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):
        localrepo.localrepository.__init__(self, ui, path)

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

        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":
            fdtemp, temp = tempfile.mkstemp(prefix="hg-bundle-",
                                            suffix=".hg10un", dir=self.path)
            self.tempfile = temp
            fptemp = os.fdopen(fdtemp, 'wb')
            def generator(f):
                zd = bz2.BZ2Decompressor()
                zd.decompress("BZ")
                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)
        self.changelog = bundlechangelog(self.sopener, self.bundlefile)
        self.manifest = bundlemanifest(self.sopener, self.bundlefile,
                                       self.changelog.rev)
        # dict with the mapping 'filename' -> position in the bundle
        self.bundlefilespos = {}
        while 1:
            f = changegroup.getchunk(self.bundlefile)
            if not f:
                break
            self.bundlefilespos[f] = self.bundlefile.tell()
            for c in changegroup.chunkiter(self.bundlefile):
                pass

    def url(self):
        return self._url

    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.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)

def instance(ui, path, create):
    if create:
        raise util.Abort(_('cannot create new bundle repository'))
    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 = "", s[0]
        else:
            repopath, bundlename = s
    else:
        repopath, bundlename = '', path
    return bundlerepository(ui, repopath, bundlename)