# parsers.py - Python implementation of parsers.c

#

# Copyright 2009 Olivia Mackall <olivia@selenic.com> and others

#

# 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

import struct

import zlib

from .. import (

    pycompat,

    util,

)

from ..revlogutils import nodemap as nodemaputil

from ..revlogutils import constants as revlog_constants

stringio = pycompat.bytesio

_pack = struct.pack

_unpack = struct.unpack

_compress = zlib.compress

_decompress = zlib.decompress

# Some code below makes tuples directly because it's more convenient. However,

# code outside this module should always use dirstatetuple.

def dirstatetuple(*x):

    # x is a tuple

    return x

def gettype(q):

    return int(q & 0xFFFF)

def offset_type(offset, type):

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

class BaseIndexObject(object):

    # Format of an index entry according to Python's `struct` language

    index_format = revlog_constants.INDEX_ENTRY_V1

    # Size of a C unsigned long long int, platform independent

    big_int_size = struct.calcsize(b'>Q')

    # Size of a C long int, platform independent

    int_size = struct.calcsize(b'>i')

    # An empty index entry, used as a default value to be overridden, or nullrev

    @util.propertycache

    def entry_size(self):

        return self.index_format.size

    @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):

        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 _stripnodes(self, start):

        if '_nodemap' in vars(self):

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

                n = self[r][7]

                del self._nodemap[n]

    def clearcaches(self):

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

    def __len__(self):

        return self._lgt + len(self._extra)

    def append(self, tup):

        if '_nodemap' in vars(self):

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

        data = self.index_format.pack(*tup)

        self._extra.append(data)

    def _check_index(self, i):

        if not isinstance(i, int):

            raise TypeError(b"expecting int indexes")

        if i < 0 or i >= len(self):

            raise IndexError

    def __getitem__(self, i):

        if i == -1:

            return self.null_item

        self._check_index(i)

        if i >= self._lgt:

            data = self._extra[i - self._lgt]

        else:

            index = self._calculate_index(i)

            data = self._data[index : index + self.entry_size]

        r = self.index_format.unpack(data)

        if self._lgt and i == 0:

            r = (offset_type(0, gettype(r[0])),) + r[1:]

        return r

class IndexObject(BaseIndexObject):

    def __init__(self, data):

        assert len(data) % self.entry_size == 0

        self._data = data

        self._lgt = len(data) // self.entry_size

        self._extra = []

    def _calculate_index(self, i):

        return i * self.entry_size

    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")

        i = i.start

        self._check_index(i)

        self._stripnodes(i)

        if i < self._lgt:

            self._data = self._data[: i * self.entry_size]

            self._lgt = i

            self._extra = []

        else:

            self._extra = self._extra[: i - self._lgt]

class PersistentNodeMapIndexObject(IndexObject):

    """a Debug oriented class to test persistent nodemap

    We need a simple python object to test API and higher level behavior. See

    the Rust implementation for  more serious usage. This should be used only

    through the dedicated `devel.persistent-nodemap` config.

    """

    def nodemap_data_all(self):

        """Return bytes containing a full serialization of a nodemap

        The nodemap should be valid for the full set of revisions in the

        index."""

        return nodemaputil.persistent_data(self)

    def nodemap_data_incremental(self):

        """Return bytes containing a incremental update to persistent nodemap

        This containst the data for an append-only update of the data provided

        in the last call to `update_nodemap_data`.

        """

        if self._nm_root is None:

            return None

        docket = self._nm_docket

        changed, data = nodemaputil.update_persistent_data(

            self, self._nm_root, self._nm_max_idx, self._nm_docket.tip_rev

        )

        self._nm_root = self._nm_max_idx = self._nm_docket = None

        return docket, changed, data

    def update_nodemap_data(self, docket, nm_data):

        """provide full block of persisted binary data for a nodemap

        The data are expected to come from disk. See `nodemap_data_all` for a

        produceur of such data."""

        if nm_data is not None:

            self._nm_root, self._nm_max_idx = nodemaputil.parse_data(nm_data)

            if self._nm_root:

                self._nm_docket = docket

            else:

                self._nm_root = self._nm_max_idx = self._nm_docket = None

class InlinedIndexObject(BaseIndexObject):

    def __init__(self, data, inline=0):

        self._data = data

        self._lgt = self._inline_scan(None)

        self._inline_scan(self._lgt)

        self._extra = []

    def _inline_scan(self, lgt):

        off = 0

        if lgt is not None:

            self._offsets = [0] * lgt

        count = 0

        while off <= len(self._data) - self.entry_size:

            start = off + self.big_int_size

            (s,) = struct.unpack(

                b'>i',

                self._data[start : start + self.int_size],

            )

            if lgt is not None:

                self._offsets[count] = off

            count += 1

            off += self.entry_size + s

        if off != len(self._data):

            raise ValueError(b"corrupted data")

        return count

    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")

        i = i.start

        self._check_index(i)

        self._stripnodes(i)

        if i < self._lgt:

            self._offsets = self._offsets[:i]

            self._lgt = i

            self._extra = []

        else:

            self._extra = self._extra[: i - self._lgt]

    def _calculate_index(self, i):

        return self._offsets[i]

def parse_index2(data, inline, revlogv2=False):

    if not inline:

        cls = IndexObject2 if revlogv2 else IndexObject

        return cls(data), None

    cls = InlinedIndexObject2 if revlogv2 else InlinedIndexObject

    return cls(data, inline), (0, data)

class Index2Mixin(object):

    index_format = revlog_constants.INDEX_ENTRY_V2

    def replace_sidedata_info(self, i, sidedata_offset, sidedata_length):

        """

        Replace an existing index entry's sidedata offset and length with new

        ones.

        This cannot be used outside of the context of sidedata rewriting,

        inside the transaction that creates the revision `i`.

        """

        if i < 0:

            raise KeyError

        self._check_index(i)

        sidedata_format = b">Qi"

        packed_size = struct.calcsize(sidedata_format)

        if i >= self._lgt:

            packed = _pack(sidedata_format, sidedata_offset, sidedata_length)

            old = self._extra[i - self._lgt]

            new = old[:64] + packed + old[64 + packed_size :]

            self._extra[i - self._lgt] = new

        else:

            msg = b"cannot rewrite entries outside of this transaction"

            raise KeyError(msg)

class IndexObject2(Index2Mixin, IndexObject):

    pass

class InlinedIndexObject2(Index2Mixin, InlinedIndexObject):

    def _inline_scan(self, lgt):

        sidedata_length_pos = 72

        off = 0

        if lgt is not None:

            self._offsets = [0] * lgt

        count = 0

        while off <= len(self._data) - self.entry_size:

            start = off + self.big_int_size

            (data_size,) = struct.unpack(

                b'>i',

                self._data[start : start + self.int_size],

            )

            start = off + sidedata_length_pos

            (side_data_size,) = struct.unpack(

                b'>i', self._data[start : start + self.int_size]

            )

            if lgt is not None:

                self._offsets[count] = off

            count += 1

            off += self.entry_size + data_size + side_data_size

        if off != len(self._data):

            raise ValueError(b"corrupted data")

        return count

def parse_index_devel_nodemap(data, inline):

    """like parse_index2, but alway return a PersistentNodeMapIndexObject"""

    return PersistentNodeMapIndexObject(data), None

def parse_dirstate(dmap, copymap, st):

    parents = [st[:20], st[20:40]]

    # dereference fields so they will be local in loop

    format = b">cllll"

    e_size = struct.calcsize(format)

    pos1 = 40

    l = len(st)

    # the inner loop

    while pos1 < l:

        pos2 = pos1 + e_size

        e = _unpack(b">cllll", st[pos1:pos2])  # a literal here is faster

        pos1 = pos2 + e[4]

        f = st[pos2:pos1]

        if b'\0' in f:

            f, c = f.split(b'\0')

            copymap[f] = c

        dmap[f] = e[:4]

    return parents

def pack_dirstate(dmap, copymap, pl, now):

    now = int(now)

    cs = stringio()

    write = cs.write

    write(b"".join(pl))

    for f, e in pycompat.iteritems(dmap):

        if e[0] == b'n' and e[3] == now:

            # The file was last modified "simultaneously" with the current

            # write to dirstate (i.e. within the same second for file-

            # systems with a granularity of 1 sec). This commonly happens

            # for at least a couple of files on 'update'.

            # The user could change the file without changing its size

            # within the same second. Invalidate the file's mtime in

            # dirstate, forcing future 'status' calls to compare the

            # contents of the file if the size is the same. This prevents

            # mistakenly treating such files as clean.

            e = dirstatetuple(e[0], e[1], e[2], -1)

            dmap[f] = e

        if f in copymap:

            f = b"%s\0%s" % (f, copymap[f])

        e = _pack(b">cllll", e[0], e[1], e[2], e[3], len(f))

        write(e)

        write(f)

    return cs.getvalue()