# revlog.py - storage back-end for mercurial

#

# Copyright 2005-2007 Olivia Mackall <olivia@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.

"""Storage back-end for Mercurial.

This provides efficient delta storage with O(1) retrieve and append

and O(changes) merge between branches.

"""

from __future__ import absolute_import

import binascii

import collections

import contextlib

import errno

import io

import os

import struct

import zlib

# import stuff from node for others to import from revlog

from .node import (

    bin,

    hex,

    nullhex,

    nullid,

    nullrev,

    sha1nodeconstants,

    short,

    wdirfilenodeids,

    wdirhex,

    wdirid,

    wdirrev,

)

from .i18n import _

from .pycompat import getattr

from .revlogutils.constants import (

    FLAG_GENERALDELTA,

    FLAG_INLINE_DATA,

    INDEX_ENTRY_V0,

    INDEX_ENTRY_V1,

    INDEX_ENTRY_V2,

    INDEX_HEADER,

    REVLOGV0,

    REVLOGV1,

    REVLOGV1_FLAGS,

    REVLOGV2,

    REVLOGV2_FLAGS,

    REVLOG_DEFAULT_FLAGS,

    REVLOG_DEFAULT_FORMAT,

    REVLOG_DEFAULT_VERSION,

)

from .revlogutils.flagutil import (

    REVIDX_DEFAULT_FLAGS,

    REVIDX_ELLIPSIS,

    REVIDX_EXTSTORED,

    REVIDX_FLAGS_ORDER,

    REVIDX_HASCOPIESINFO,

    REVIDX_ISCENSORED,

    REVIDX_RAWTEXT_CHANGING_FLAGS,

    REVIDX_SIDEDATA,

)

from .thirdparty import attr

from . import (

    ancestor,

    dagop,

    error,

    mdiff,

    policy,

    pycompat,

    templatefilters,

    util,

)

from .interfaces import (

    repository,

    util as interfaceutil,

)

from .revlogutils import (

    deltas as deltautil,

    flagutil,

    nodemap as nodemaputil,

    sidedata as sidedatautil,

)

from .utils import (

    storageutil,

    stringutil,

)

# blanked usage of all the name to prevent pyflakes constraints

# We need these name available in the module for extensions.

REVLOGV0

REVLOGV1

REVLOGV2

FLAG_INLINE_DATA

FLAG_GENERALDELTA

REVLOG_DEFAULT_FLAGS

REVLOG_DEFAULT_FORMAT

REVLOG_DEFAULT_VERSION

REVLOGV1_FLAGS

REVLOGV2_FLAGS

REVIDX_ISCENSORED

REVIDX_ELLIPSIS

REVIDX_SIDEDATA

REVIDX_HASCOPIESINFO

REVIDX_EXTSTORED

REVIDX_DEFAULT_FLAGS

REVIDX_FLAGS_ORDER

REVIDX_RAWTEXT_CHANGING_FLAGS

parsers = policy.importmod('parsers')

rustancestor = policy.importrust('ancestor')

rustdagop = policy.importrust('dagop')

rustrevlog = policy.importrust('revlog')

# Aliased for performance.

_zlibdecompress = zlib.decompress

# max size of revlog with inline data

_maxinline = 131072

_chunksize = 1048576

# Flag processors for REVIDX_ELLIPSIS.

def ellipsisreadprocessor(rl, text):

    return text, False

def ellipsiswriteprocessor(rl, text):

    return text, False

def ellipsisrawprocessor(rl, text):

    return False

ellipsisprocessor = (

    ellipsisreadprocessor,

    ellipsiswriteprocessor,

    ellipsisrawprocessor,

)

def getoffset(q):

    return int(q >> 16)

def gettype(q):

    return int(q & 0xFFFF)

def offset_type(offset, type):

    if (type & ~flagutil.REVIDX_KNOWN_FLAGS) != 0:

        raise ValueError(b'unknown revlog index flags')

    return int(int(offset) << 16 | type)

def _verify_revision(rl, skipflags, state, node):

    """Verify the integrity of the given revlog ``node`` while providing a hook

    point for extensions to influence the operation."""

    if skipflags:

        state[b'skipread'].add(node)

    else:

        # Side-effect: read content and verify hash.

        rl.revision(node)

# True if a fast implementation for persistent-nodemap is available

#

# We also consider we have a "fast" implementation in "pure" python because

# people using pure don't really have performance consideration (and a

# wheelbarrow of other slowness source)

HAS_FAST_PERSISTENT_NODEMAP = rustrevlog is not None or util.safehasattr(

    parsers, 'BaseIndexObject'

)

@attr.s(slots=True, frozen=True)

class _revisioninfo(object):

    """Information about a revision that allows building its fulltext

    node:       expected hash of the revision

    p1, p2:     parent revs of the revision

    btext:      built text cache consisting of a one-element list

    cachedelta: (baserev, uncompressed_delta) or None

    flags:      flags associated to the revision storage

    One of btext[0] or cachedelta must be set.

    """

    node = attr.ib()

    p1 = attr.ib()

    p2 = attr.ib()

    btext = attr.ib()

    textlen = attr.ib()

    cachedelta = attr.ib()

    flags = attr.ib()

@interfaceutil.implementer(repository.irevisiondelta)

@attr.s(slots=True)

class revlogrevisiondelta(object):

    node = attr.ib()

    p1node = attr.ib()

    p2node = attr.ib()

    basenode = attr.ib()

    flags = attr.ib()

    baserevisionsize = attr.ib()

    revision = attr.ib()

    delta = attr.ib()

    sidedata = attr.ib()

    linknode = attr.ib(default=None)

@interfaceutil.implementer(repository.iverifyproblem)

@attr.s(frozen=True)

class revlogproblem(object):

    warning = attr.ib(default=None)

    error = attr.ib(default=None)

    node = attr.ib(default=None)

class revlogoldindex(list):

    @property

    def nodemap(self):

        msg = b"index.nodemap is deprecated, use index.[has_node|rev|get_rev]"

        util.nouideprecwarn(msg, b'5.3', stacklevel=2)

        return self._nodemap

    @util.propertycache

    def _nodemap(self):

        nodemap = nodemaputil.NodeMap({nullid: nullrev})

        for r in range(0, len(self)):

            n = self[r][7]

            nodemap[n] = r

        return nodemap

    def has_node(self, node):

        """return True if the node exist in the index"""

        return node in self._nodemap

    def rev(self, node):

        """return a revision for a node

        If the node is unknown, raise a RevlogError"""

        return self._nodemap[node]

    def get_rev(self, node):

        """return a revision for a node

        If the node is unknown, return None"""

        return self._nodemap.get(node)

    def append(self, tup):

        self._nodemap[tup[7]] = len(self)

        super(revlogoldindex, self).append(tup)

    def __delitem__(self, i):

        if not isinstance(i, slice) or not i.stop == -1 or i.step is not None:

            raise ValueError(b"deleting slices only supports a:-1 with step 1")

        for r in pycompat.xrange(i.start, len(self)):

            del self._nodemap[self[r][7]]

        super(revlogoldindex, self).__delitem__(i)

    def clearcaches(self):

        self.__dict__.pop('_nodemap', None)

    def __getitem__(self, i):

        if i == -1:

            return (0, 0, 0, -1, -1, -1, -1, nullid)

        return list.__getitem__(self, i)

class revlogoldio(object):

    def __init__(self):

        self.size = INDEX_ENTRY_V0.size

    def parseindex(self, data, inline):

        s = self.size

        index = []

        nodemap = nodemaputil.NodeMap({nullid: nullrev})

        n = off = 0

        l = len(data)

        while off + s <= l:

            cur = data[off : off + s]

            off += s

            e = INDEX_ENTRY_V0.unpack(cur)

            # transform to revlogv1 format

            e2 = (

                offset_type(e[0], 0),

                e[1],

                -1,

                e[2],

                e[3],

                nodemap.get(e[4], nullrev),

                nodemap.get(e[5], nullrev),

                e[6],

            )

            index.append(e2)

            nodemap[e[6]] = n

            n += 1

        index = revlogoldindex(index)

        return index, None

    def packentry(self, entry, node, version, rev):

        """return the binary representation of an entry

        entry:   a tuple containing all the values (see index.__getitem__)

        node:    a callback to convert a revision to nodeid

        version: the changelog version

        rev:     the revision number

        """

        if gettype(entry[0]):

            raise error.RevlogError(

                _(b'index entry flags need revlog version 1')

            )

        e2 = (

            getoffset(entry[0]),

            entry[1],

            entry[3],

            entry[4],

            node(entry[5]),

            node(entry[6]),

            entry[7],

        )

        return INDEX_ENTRY_V0.pack(*e2)

# corresponds to uncompressed length of indexformatng (2 gigs, 4-byte

# signed integer)

_maxentrysize = 0x7FFFFFFF

class revlogio(object):

    def __init__(self):

        self.size = INDEX_ENTRY_V1.size

    def parseindex(self, data, inline):

        # call the C implementation to parse the index data

        index, cache = parsers.parse_index2(data, inline)

        return index, cache

    def packentry(self, entry, node, version, rev):

        p = INDEX_ENTRY_V1.pack(*entry)

        if rev == 0:

            p = INDEX_HEADER.pack(version) + p[4:]

        return p

class revlogv2io(object):

    def __init__(self):

        self.size = INDEX_ENTRY_V2.size

    def parseindex(self, data, inline):

        index, cache = parsers.parse_index2(data, inline, revlogv2=True)

        return index, cache

    def packentry(self, entry, node, version, rev):

        p = INDEX_ENTRY_V2.pack(*entry)

        if rev == 0:

            p = INDEX_HEADER.pack(version) + p[4:]

        return p

NodemapRevlogIO = None

if util.safehasattr(parsers, 'parse_index_devel_nodemap'):

    class NodemapRevlogIO(revlogio):

        """A debug oriented IO class that return a PersistentNodeMapIndexObject

        The PersistentNodeMapIndexObject object is meant to test the persistent nodemap feature.

        """

        def parseindex(self, data, inline):

            index, cache = parsers.parse_index_devel_nodemap(data, inline)

            return index, cache

class rustrevlogio(revlogio):

    def parseindex(self, data, inline):

        index, cache = super(rustrevlogio, self).parseindex(data, inline)

        return rustrevlog.MixedIndex(index), cache

class revlog(object):

    """

    the underlying revision storage object

    A revlog consists of two parts, an index and the revision data.

    The index is a file with a fixed record size containing

    information on each revision, including its nodeid (hash), the