mercurial/revlog.py

36747:4c71a26a4009

    REVIDX_ISCENSORED,
    REVIDX_ELLIPSIS,
    REVIDX_EXTSTORED,
]
REVIDX_KNOWN_FLAGS = util.bitsfrom(REVIDX_FLAGS_ORDER)

# max size of revlog with inline data
_maxinline = 131072
_chunksize = 1048576

def addflagprocessor(flag, processor):
    """Register a flag processor on a revision data flag.

    Invariant:
    - Flags need to be defined in REVIDX_KNOWN_FLAGS and REVIDX_FLAGS_ORDER.
    - Only one flag processor can be registered on a specific flag.
    - flagprocessors must be 3-tuples of functions (read, write, raw) with the
      following signatures:
          - (read)  f(self, rawtext) -> text, bool
          - (write) f(self, text) -> rawtext, bool

        hlen = struct.calcsize(">lll")
        if delta[:hlen] == mdiff.replacediffheader(revlog.rawsize(baserev),
                                                   len(delta) - hlen):
            btext[0] = delta[hlen:]
        else:
            basetext = revlog.revision(baserev, _df=fh, raw=True)
            btext[0] = mdiff.patch(basetext, delta)

        try:
            res = revlog._processflags(btext[0], flags, 'read', raw=True)
            btext[0], validatehash = res

        deltainfo = None
        for candidaterevs in self._getcandidaterevs(p1, p2, cachedelta):
            nominateddeltas = []
            for candidaterev in candidaterevs:
                candidatedelta = self._builddeltainfo(revinfo, candidaterev, fh)
                if revlog._isgooddeltainfo(candidatedelta, revinfo.textlen):
                    nominateddeltas.append(candidatedelta)
            if nominateddeltas:
                deltainfo = min(nominateddeltas, key=lambda x: x.deltalen)

        try:
            self.rev(node)
            return True
        except KeyError:
            return False

    def clearcaches(self):
        self._cache = None
        self._chainbasecache.clear()
        self._chunkcache = (0, '')

        p1r, p2r = self.rev(p1), self.rev(p2)

        # full versions are inserted when the needed deltas
        # become comparable to the uncompressed text
        if rawtext is None:
            textlen = mdiff.patchedsize(self.rawsize(cachedelta[0]),
                                        cachedelta[1])
        else:
            textlen = len(rawtext)

        if deltacomputer is None:
            deltacomputer = _deltacomputer(self)

        revinfo = _revisioninfo(node, p1, p2, btext, textlen, cachedelta, flags)
        deltainfo = deltacomputer.finddeltainfo(revinfo, fh)

        if deltainfo is not None:
            base = deltainfo.base
            chainbase = deltainfo.chainbase
            data = deltainfo.data

36760:7bf80d9d9543

    REVIDX_ISCENSORED,
    REVIDX_ELLIPSIS,
    REVIDX_EXTSTORED,
]
REVIDX_KNOWN_FLAGS = util.bitsfrom(REVIDX_FLAGS_ORDER)
# bitmark for flags that could cause rawdata content change
REVIDX_RAWTEXT_CHANGING_FLAGS = REVIDX_ISCENSORED | REVIDX_EXTSTORED

# max size of revlog with inline data
_maxinline = 131072
_chunksize = 1048576

def addflagprocessor(flag, processor):
    """Register a flag processor on a revision data flag.

    Invariant:
    - Flags need to be defined in REVIDX_KNOWN_FLAGS and REVIDX_FLAGS_ORDER,
      and REVIDX_RAWTEXT_CHANGING_FLAGS if they can alter rawtext.
    - Only one flag processor can be registered on a specific flag.
    - flagprocessors must be 3-tuples of functions (read, write, raw) with the
      following signatures:
          - (read)  f(self, rawtext) -> text, bool
          - (write) f(self, text) -> rawtext, bool

        hlen = struct.calcsize(">lll")
        if delta[:hlen] == mdiff.replacediffheader(revlog.rawsize(baserev),
                                                   len(delta) - hlen):
            btext[0] = delta[hlen:]
        else:
            # deltabase is rawtext before changed by flag processors, which is
            # equivalent to non-raw text
            basetext = revlog.revision(baserev, _df=fh, raw=False)
            btext[0] = mdiff.patch(basetext, delta)

        try:
            res = revlog._processflags(btext[0], flags, 'read', raw=True)
            btext[0], validatehash = res

        deltainfo = None
        for candidaterevs in self._getcandidaterevs(p1, p2, cachedelta):
            nominateddeltas = []
            for candidaterev in candidaterevs:
                # no delta for rawtext-changing revs (see "candelta" for why)
                if revlog.flags(candidaterev) & REVIDX_RAWTEXT_CHANGING_FLAGS:
                    continue
                candidatedelta = self._builddeltainfo(revinfo, candidaterev, fh)
                if revlog._isgooddeltainfo(candidatedelta, revinfo.textlen):
                    nominateddeltas.append(candidatedelta)
            if nominateddeltas:
                deltainfo = min(nominateddeltas, key=lambda x: x.deltalen)

        try:
            self.rev(node)
            return True
        except KeyError:
            return False

    def candelta(self, baserev, rev):
        """whether two revisions (baserev, rev) can be delta-ed or not"""
        # Disable delta if either rev requires a content-changing flag
        # processor (ex. LFS). This is because such flag processor can alter
        # the rawtext content that the delta will be based on, and two clients
        # could have a same revlog node with different flags (i.e. different
        # rawtext contents) and the delta could be incompatible.
        if ((self.flags(baserev) & REVIDX_RAWTEXT_CHANGING_FLAGS)
            or (self.flags(rev) & REVIDX_RAWTEXT_CHANGING_FLAGS)):
            return False
        return True

    def clearcaches(self):
        self._cache = None
        self._chainbasecache.clear()
        self._chunkcache = (0, '')

        p1r, p2r = self.rev(p1), self.rev(p2)

        # full versions are inserted when the needed deltas
        # become comparable to the uncompressed text
        if rawtext is None:
            # need rawtext size, before changed by flag processors, which is
            # the non-raw size. use revlog explicitly to avoid filelog's extra
            # logic that might remove metadata size.
            textlen = mdiff.patchedsize(revlog.size(self, cachedelta[0]),
                                        cachedelta[1])
        else:
            textlen = len(rawtext)

        if deltacomputer is None:
            deltacomputer = _deltacomputer(self)

        revinfo = _revisioninfo(node, p1, p2, btext, textlen, cachedelta, flags)

        # no delta for flag processor revision (see "candelta" for why)
        # not calling candelta since only one revision needs test, also to
        # avoid overhead fetching flags again.
        if flags & REVIDX_RAWTEXT_CHANGING_FLAGS:
            deltainfo = None
        else:
            deltainfo = deltacomputer.finddeltainfo(revinfo, fh)

        if deltainfo is not None:
            base = deltainfo.base
            chainbase = deltainfo.chainbase
            data = deltainfo.data