~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2009 Canonical Ltd

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

#python2.4 support

cdef extern from "python-compat.h":

    pass

cdef extern from *:

    ctypedef unsigned int size_t

    int memcmp(void *, void*, size_t)

    void memcpy(void *, void*, size_t)

    void *memchr(void *s, int c, size_t len)

    long strtol(char *, char **, int)

    void sprintf(char *, char *, ...)

cdef extern from "Python.h":

    ctypedef int Py_ssize_t # Required for older pyrex versions

    ctypedef struct PyObject:

        pass

    int PyTuple_CheckExact(object p)

    Py_ssize_t PyTuple_GET_SIZE(object t)

    int PyString_CheckExact(object)

    char *PyString_AS_STRING(object s)

    Py_ssize_t PyString_GET_SIZE(object)

    int PyDict_SetItem(object d, object k, object v) except -1

    object PyTuple_New(Py_ssize_t count)

    void PyTuple_SET_ITEM(object t, Py_ssize_t offset, object)

    void Py_INCREF(object)

    PyObject * PyTuple_GET_ITEM_ptr "PyTuple_GET_ITEM" (object t,

                                                        Py_ssize_t offset)

    int PyString_CheckExact_ptr "PyString_CheckExact" (PyObject *p)

    Py_ssize_t PyString_GET_SIZE_ptr "PyString_GET_SIZE" (PyObject *s)

    char *PyString_AS_STRING_ptr "PyString_AS_STRING" (PyObject *s)

    object PyString_FromStringAndSize(char*, Py_ssize_t)

# cimport all of the definitions we will need to access

from _static_tuple_c cimport StaticTuple,\

    import_static_tuple_c, StaticTuple_New, \

    StaticTuple_Intern, StaticTuple_SET_ITEM, StaticTuple_CheckExact

cdef extern from "_static_tuple_c.h":

    # Defined explicitly rather than cimport-ing. Trying to use cimport, the

    # type for PyObject is a different class that happens to have the same

    # name...

    PyObject * StaticTuple_GET_ITEM_ptr "StaticTuple_GET_ITEM" (StaticTuple,

                                                                Py_ssize_t)

cdef extern from "zlib.h":

    ctypedef unsigned long uLong

    ctypedef unsigned int uInt

    ctypedef unsigned char Bytef

    uLong crc32(uLong crc, Bytef *buf, uInt len)

# Set up the StaticTuple C_API functionality

import_static_tuple_c()

cdef object _LeafNode

_LeafNode = None

cdef object _InternalNode

_InternalNode = None

cdef object _unknown

_unknown = None

# We shouldn't just copy this from _dirstate_helpers_pyx

cdef void* _my_memrchr(void *s, int c, size_t n):

    # memrchr seems to be a GNU extension, so we have to implement it ourselves

    cdef char *pos

    cdef char *start

    start = <char*>s

    pos = start + n - 1

    while pos >= start:

        if pos[0] == c:

            return <void*>pos

        pos = pos - 1

    return NULL

def _search_key_16(key):

    """See chk_map._search_key_16."""

    cdef Py_ssize_t num_bits

    cdef Py_ssize_t i, j

    cdef Py_ssize_t num_out_bytes

    cdef Bytef *c_bit

    cdef uLong c_len

    cdef uInt crc_val

    cdef Py_ssize_t out_off

    cdef char *c_out

    cdef PyObject *bit

    if not StaticTuple_CheckExact(key):

        raise TypeError('key %r is not a StaticTuple' % (key,))

    num_bits = len(key)

    # 4 bytes per crc32, and another 1 byte between bits

    num_out_bytes = (9 * num_bits) - 1

    out = PyString_FromStringAndSize(NULL, num_out_bytes)

    c_out = PyString_AS_STRING(out)

    for i from 0 <= i < num_bits:

        if i > 0:

            c_out[0] = c'\x00'

            c_out = c_out + 1

        # We use the _ptr variant, because GET_ITEM returns a borrowed

        # reference, and Pyrex assumes that returned 'object' are a new

        # reference

        bit = StaticTuple_GET_ITEM_ptr(key, i)

        if not PyString_CheckExact_ptr(bit):

            raise TypeError('Bit %d of %r is not a string' % (i, key))

        c_bit = <Bytef *>PyString_AS_STRING_ptr(bit)

        c_len = PyString_GET_SIZE_ptr(bit)

        crc_val = crc32(0, c_bit, c_len)

        # Hex(val) order

        sprintf(c_out, '%08X', crc_val)

        c_out = c_out + 8

    return out

def _search_key_255(key):

    """See chk_map._search_key_255."""

    cdef Py_ssize_t num_bits

    cdef Py_ssize_t i, j

    cdef Py_ssize_t num_out_bytes

    cdef Bytef *c_bit

    cdef uLong c_len

    cdef uInt crc_val

    cdef Py_ssize_t out_off

    cdef char *c_out

    cdef PyObject *bit

    if not StaticTuple_CheckExact(key):

        raise TypeError('key %r is not a StaticTuple' % (key,))

    num_bits = len(key)

    # 4 bytes per crc32, and another 1 byte between bits

    num_out_bytes = (5 * num_bits) - 1

    out = PyString_FromStringAndSize(NULL, num_out_bytes)

    c_out = PyString_AS_STRING(out)

    for i from 0 <= i < num_bits:

        if i > 0:

            c_out[0] = c'\x00'

            c_out = c_out + 1

        bit = StaticTuple_GET_ITEM_ptr(key, i)

        if not PyString_CheckExact_ptr(bit):

            raise TypeError('Bit %d of %r is not a string: %r'

                            % (i, key, <object>bit))

        c_bit = <Bytef *>PyString_AS_STRING_ptr(bit)

        c_len = PyString_GET_SIZE_ptr(bit)

        crc_val = crc32(0, c_bit, c_len)

        # MSB order

        c_out[0] = (crc_val >> 24) & 0xFF

        c_out[1] = (crc_val >> 16) & 0xFF

        c_out[2] = (crc_val >> 8) & 0xFF

        c_out[3] = (crc_val >> 0) & 0xFF

        for j from 0 <= j < 4:

            if c_out[j] == c'\n':

                c_out[j] = c'_'

        c_out = c_out + 4

    return out

cdef int _get_int_from_line(char **cur, char *end, char *message) except -1:

    """Read a positive integer from the data stream.

    :param cur: The start of the data, this will be moved to after the

        trailing newline when done.

    :param end: Do not parse any data past this byte.

    :return: The integer stored in those bytes

    """

    cdef int value

    cdef char *next_line, *next

    next_line = <char *>memchr(cur[0], c'\n', end - cur[0])

    if next_line == NULL:

        raise ValueError("Missing %s line\n" % message)

    value = strtol(cur[0], &next, 10)

    if next != next_line:

        raise ValueError("%s line not a proper int\n" % message)

    cur[0] = next_line + 1

    return value

def _deserialise_leaf_node(bytes, key, search_key_func=None):

    """Deserialise bytes, with key key, into a LeafNode.

    :param bytes: The bytes of the node.

    :param key: The key that the serialised node has.

    """

    cdef char *c_bytes, *cur, *next, *end

    cdef char *next_line

    cdef Py_ssize_t c_bytes_len, prefix_length, items_length

    cdef int maximum_size, width, length, i, prefix_tail_len

    cdef int num_value_lines, num_prefix_bits

    cdef char *prefix, *value_start, *prefix_tail

    cdef char *next_null, *last_null, *line_start

    cdef char *c_entry, *entry_start

    cdef StaticTuple entry_bits

    if _LeafNode is None:

        from bzrlib import chk_map

        _LeafNode = chk_map.LeafNode

        _InternalNode = chk_map.InternalNode

        _unknown = chk_map._unknown

    result = _LeafNode(search_key_func=search_key_func)

    # Splitlines can split on '\r' so don't use it, split('\n') adds an

    # extra '' if the bytes ends in a final newline.

    if not PyString_CheckExact(bytes):

        raise TypeError('bytes must be a plain string not %s' % (type(bytes),))

    c_bytes = PyString_AS_STRING(bytes)

    c_bytes_len = PyString_GET_SIZE(bytes)

    if c_bytes_len < 9 or memcmp(c_bytes, "chkleaf:\n", 9) != 0:

        raise ValueError("not a serialised leaf node: %r" % bytes)

    if c_bytes[c_bytes_len - 1] != c'\n':

        raise ValueError("bytes does not end in a newline")

    end = c_bytes + c_bytes_len

    cur = c_bytes + 9

    maximum_size = _get_int_from_line(&cur, end, "maximum_size")

    width = _get_int_from_line(&cur, end, "width")

    length = _get_int_from_line(&cur, end, "length")

    next_line = <char *>memchr(cur, c'\n', end - cur)

    if next_line == NULL:

        raise ValueError('Missing the prefix line\n')

    prefix = cur

    prefix_length = next_line - cur

    cur = next_line + 1

    prefix_bits = []

    prefix_tail = prefix

    num_prefix_bits = 0

    next_null = <char *>memchr(prefix, c'\0', prefix_length)

    while next_null != NULL:

        num_prefix_bits = num_prefix_bits + 1

        prefix_bits.append(

            PyString_FromStringAndSize(prefix_tail, next_null - prefix_tail))

        prefix_tail = next_null + 1

        next_null = <char *>memchr(prefix_tail, c'\0', next_line - prefix_tail)

    prefix_tail_len = next_line - prefix_tail

    if num_prefix_bits >= width:

        raise ValueError('Prefix has too many nulls versus width')

    items_length = end - cur

    items = {}

    while cur < end:

        line_start = cur

        next_line = <char *>memchr(cur, c'\n', end - cur)

        if next_line == NULL:

            raise ValueError('null line\n')

        last_null = <char *>_my_memrchr(cur, c'\0', next_line - cur)

        if last_null == NULL:

            raise ValueError('fail to find the num value lines null')

        next_null = last_null + 1 # move past NULL

        num_value_lines = _get_int_from_line(&next_null, next_line + 1,

                                             "num value lines")

        cur = next_line + 1

        value_start = cur

        # Walk num_value_lines forward

        for i from 0 <= i < num_value_lines:

            next_line = <char *>memchr(cur, c'\n', end - cur)

            if next_line == NULL:

                raise ValueError('missing trailing newline')

            cur = next_line + 1

        entry_bits = StaticTuple_New(width)

        for i from 0 <= i < num_prefix_bits:

            # TODO: Use PyList_GetItem, or turn prefix_bits into a

            #       tuple/StaticTuple

            entry = prefix_bits[i]

            # SET_ITEM 'steals' a reference

            Py_INCREF(entry)

            StaticTuple_SET_ITEM(entry_bits, i, entry)

        value = PyString_FromStringAndSize(value_start, next_line - value_start)

        # The next entry bit needs the 'tail' from the prefix, and first part

        # of the line

        entry_start = line_start

        next_null = <char *>memchr(entry_start, c'\0',

                                   last_null - entry_start + 1)

        if next_null == NULL:

            raise ValueError('bad no null, bad')

        entry = PyString_FromStringAndSize(NULL,

                    prefix_tail_len + next_null - line_start)

        c_entry = PyString_AS_STRING(entry)

        if prefix_tail_len > 0:

            memcpy(c_entry, prefix_tail, prefix_tail_len)

        if next_null - line_start > 0:

            memcpy(c_entry + prefix_tail_len, line_start, next_null - line_start)

        Py_INCREF(entry)

        i = num_prefix_bits

        StaticTuple_SET_ITEM(entry_bits, i, entry)

        while next_null != last_null: # We have remaining bits

            i = i + 1

            if i > width:

                raise ValueError("Too many bits for entry")

            entry_start = next_null + 1

            next_null = <char *>memchr(entry_start, c'\0',

                                       last_null - entry_start + 1)

            if next_null == NULL:

                raise ValueError('bad no null')

            entry = PyString_FromStringAndSize(entry_start,

                                               next_null - entry_start)

            Py_INCREF(entry)

            StaticTuple_SET_ITEM(entry_bits, i, entry)

        if len(entry_bits) != width:

            raise AssertionError(

                'Incorrect number of elements (%d vs %d)'

                % (len(entry_bits)+1, width + 1))

        entry_bits = StaticTuple_Intern(entry_bits)

        PyDict_SetItem(items, entry_bits, value)

    if len(items) != length:

        raise ValueError("item count (%d) mismatch for key %s,"

                         " bytes %r" % (length, entry_bits, bytes))

    result._items = items

    result._len = length

    result._maximum_size = maximum_size

    result._key = key

    result._key_width = width

    result._raw_size = items_length + length * prefix_length

    if length == 0:

        result._search_prefix = None

        result._common_serialised_prefix = None

    else:

        result._search_prefix = _unknown

        result._common_serialised_prefix = PyString_FromStringAndSize(prefix,

                                                prefix_length)

    if c_bytes_len != result._current_size():

        raise AssertionError('_current_size computed incorrectly %d != %d',

            c_bytes_len, result._current_size())

    return result

def _deserialise_internal_node(bytes, key, search_key_func=None):

    cdef char *c_bytes, *cur, *next, *end

    cdef char *next_line

    cdef Py_ssize_t c_bytes_len, prefix_length

    cdef int maximum_size, width, length, i, prefix_tail_len

    cdef char *prefix, *line_prefix, *next_null, *c_item_prefix

    if _InternalNode is None:

        from bzrlib import chk_map

        _LeafNode = chk_map.LeafNode

        _InternalNode = chk_map.InternalNode

        _unknown = chk_map._unknown

    result = _InternalNode(search_key_func=search_key_func)

    if not StaticTuple_CheckExact(key):

        raise TypeError('key %r is not a StaticTuple' % (key,))

    if not PyString_CheckExact(bytes):

        raise TypeError('bytes must be a plain string not %s' % (type(bytes),))

    c_bytes = PyString_AS_STRING(bytes)

    c_bytes_len = PyString_GET_SIZE(bytes)

    if c_bytes_len < 9 or memcmp(c_bytes, "chknode:\n", 9) != 0:

        raise ValueError("not a serialised internal node: %r" % bytes)

    if c_bytes[c_bytes_len - 1] != c'\n':

        raise ValueError("bytes does not end in a newline")

    items = {}

    cur = c_bytes + 9

    end = c_bytes + c_bytes_len

    maximum_size = _get_int_from_line(&cur, end, "maximum_size")

    width = _get_int_from_line(&cur, end, "width")

    length = _get_int_from_line(&cur, end, "length")

    next_line = <char *>memchr(cur, c'\n', end - cur)

    if next_line == NULL:

        raise ValueError('Missing the prefix line\n')

    prefix = cur

    prefix_length = next_line - cur

    cur = next_line + 1

    while cur < end:

        # Find the null separator

        next_line = <char *>memchr(cur, c'\n', end - cur)

        if next_line == NULL:

            raise ValueError('missing trailing newline')

        next_null = <char *>_my_memrchr(cur, c'\0', next_line - cur)

        if next_null == NULL:

            raise ValueError('bad no null')

        item_prefix = PyString_FromStringAndSize(NULL,

            prefix_length + next_null - cur)

        c_item_prefix = PyString_AS_STRING(item_prefix)

        if prefix_length:

            memcpy(c_item_prefix, prefix, prefix_length)

        memcpy(c_item_prefix + prefix_length, cur, next_null - cur)

        flat_key = PyString_FromStringAndSize(next_null + 1,

                                              next_line - next_null - 1)

        flat_key = StaticTuple(flat_key).intern()

        PyDict_SetItem(items, item_prefix, flat_key)

        cur = next_line + 1

    assert len(items) > 0

    result._items = items

    result._len = length

    result._maximum_size = maximum_size

    result._key = key

    result._key_width = width

    # XXX: InternalNodes don't really care about their size, and this will

    #      change if we add prefix compression

    result._raw_size = None # len(bytes)

    result._node_width = len(item_prefix)

    result._search_prefix = PyString_FromStringAndSize(prefix, prefix_length)

    return result