# filelog.py - file history class 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 or any later version.

from __future__ import absolute_import

from . import (

    error,

    repository,

    revlog,

)

from .utils import (

    interfaceutil,

)

@interfaceutil.implementer(repository.ifilestorage)

class filelog(object):

    def __init__(self, opener, path):

        self._revlog = revlog.revlog(opener,

                                     '/'.join(('data', path + '.i')),

                                     censorable=True)

        self.filename = path

        self.index = self._revlog.index

        self.version = self._revlog.version

        self._generaldelta = self._revlog._generaldelta

    def __len__(self):

        return len(self._revlog)

    def __iter__(self):

        return self._revlog.__iter__()

    def revs(self, start=0, stop=None):

        return self._revlog.revs(start=start, stop=stop)

    def parents(self, node):

        return self._revlog.parents(node)

    def parentrevs(self, rev):

        return self._revlog.parentrevs(rev)

    def rev(self, node):

        return self._revlog.rev(node)

    def node(self, rev):

        return self._revlog.node(rev)

    def lookup(self, node):

        return self._revlog.lookup(node)

    def linkrev(self, rev):

        return self._revlog.linkrev(rev)

    def flags(self, rev):

        return self._revlog.flags(rev)

    def commonancestorsheads(self, node1, node2):

        return self._revlog.commonancestorsheads(node1, node2)

    def descendants(self, revs):

        return self._revlog.descendants(revs)

    def headrevs(self):

        return self._revlog.headrevs()

    def heads(self, start=None, stop=None):

        return self._revlog.heads(start, stop)

    def children(self, node):

        return self._revlog.children(node)

    def deltaparent(self, rev):

        return self._revlog.deltaparent(rev)

    def iscensored(self, rev):

        return self._revlog.iscensored(rev)

    def rawsize(self, rev):

        return self._revlog.rawsize(rev)

    def checkhash(self, text, node, p1=None, p2=None, rev=None):

        return self._revlog.checkhash(text, node, p1=p1, p2=p2, rev=rev)

    def revision(self, node, _df=None, raw=False):

        return self._revlog.revision(node, _df=_df, raw=raw)

    def revdiff(self, rev1, rev2):

        return self._revlog.revdiff(rev1, rev2)

    def emitrevisiondeltas(self, requests):

        return self._revlog.emitrevisiondeltas(requests)

    def addrevision(self, revisiondata, transaction, linkrev, p1, p2,

                    node=None, flags=revlog.REVIDX_DEFAULT_FLAGS,

                    cachedelta=None):

        return self._revlog.addrevision(revisiondata, transaction, linkrev,

                                    p1, p2, node=node, flags=flags,

                                    cachedelta=cachedelta)

    def addgroup(self, deltas, linkmapper, transaction, addrevisioncb=None):

        return self._revlog.addgroup(deltas, linkmapper, transaction,

                                 addrevisioncb=addrevisioncb)

    def getstrippoint(self, minlink):

        return self._revlog.getstrippoint(minlink)

    def strip(self, minlink, transaction):

        return self._revlog.strip(minlink, transaction)

    def censorrevision(self, tr, node, tombstone=b''):

        return self._revlog.censorrevision(node, tombstone=tombstone)

    def files(self):

        return self._revlog.files()

    def checksize(self):

        return self._revlog.checksize()

    def read(self, node):

        t = self.revision(node)

        if not t.startswith('\1\n'):

            return t

        s = t.index('\1\n', 2)

        return t[s + 2:]

    def add(self, text, meta, transaction, link, p1=None, p2=None):

        if meta or text.startswith('\1\n'):

            text = revlog.packmeta(meta, text)

        return self.addrevision(text, transaction, link, p1, p2)

    def renamed(self, node):

        if self.parents(node)[0] != revlog.nullid:

            return False

        t = self.revision(node)

        m = revlog.parsemeta(t)[0]

        # copy and copyrev occur in pairs. In rare cases due to bugs,

        # one can occur without the other.

        if m and "copy" in m and "copyrev" in m:

            return (m["copy"], revlog.bin(m["copyrev"]))

        return False

    def size(self, rev):

        """return the size of a given revision"""

        # for revisions with renames, we have to go the slow way

        node = self.node(rev)

        if self.renamed(node):

            return len(self.read(node))

        if self.iscensored(rev):

            return 0

        # XXX if self.read(node).startswith("\1\n"), this returns (size+4)

        return self._revlog.size(rev)

    def cmp(self, node, text):

        """compare text with a given file revision

        returns True if text is different than what is stored.

        """

        t = text

        if text.startswith('\1\n'):

            t = '\1\n\1\n' + text

        samehashes = not self._revlog.cmp(node, t)

        if samehashes:

            return False

        # censored files compare against the empty file

        if self.iscensored(self.rev(node)):

            return text != ''

        # renaming a file produces a different hash, even if the data

        # remains unchanged. Check if it's the case (slow):

        if self.renamed(node):

            t2 = self.read(node)

            return t2 != text

        return True

    @property

    def filename(self):

        return self._revlog.filename

    @filename.setter

    def filename(self, value):

        self._revlog.filename = value

    @property

    def indexfile(self):

        return self._revlog.indexfile

    @indexfile.setter

    def indexfile(self, value):

        self._revlog.indexfile = value

    @property

    def opener(self):

        return self._revlog.opener

    def clone(self, tr, destrevlog, **kwargs):

        if not isinstance(destrevlog, filelog):

            raise error.ProgrammingError('expected filelog to clone()')

        return self._revlog.clone(tr, destrevlog._revlog, **kwargs)

class narrowfilelog(filelog):

    """Filelog variation to be used with narrow stores."""

    def __init__(self, opener, path, narrowmatch):

        super(narrowfilelog, self).__init__(opener, path)

        self._narrowmatch = narrowmatch

    def renamed(self, node):

        res = super(narrowfilelog, self).renamed(node)

        # Renames that come from outside the narrowspec are problematic

        # because we may lack the base text for the rename. This can result

        # in code attempting to walk the ancestry or compute a diff

        # encountering a missing revision. We address this by silently

        # removing rename metadata if the source file is outside the

        # narrow spec.

        #

        # A better solution would be to see if the base revision is available,

        # rather than assuming it isn't.

        #

        # An even better solution would be to teach all consumers of rename

        # metadata that the base revision may not be available.

        #

        # TODO consider better ways of doing this.

        if res and not self._narrowmatch(res[0]):

            return None

        return res

    def size(self, rev):

        # Because we have a custom renamed() that may lie, we need to call

        # the base renamed() to report accurate results.

        node = self.node(rev)

        if super(narrowfilelog, self).renamed(node):

            return len(self.read(node))

        else:

            return super(narrowfilelog, self).size(rev)

    def cmp(self, node, text):

        different = super(narrowfilelog, self).cmp(node, text)

        # Because renamed() may lie, we may get false positives for

        # different content. Check for this by comparing against the original

        # renamed() implementation.

        if different:

            if super(narrowfilelog, self).renamed(node):

                t2 = self.read(node)

                return t2 != text

        return different