~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2007-2010 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

"""Pyrex extensions to knit parsing."""

import sys

from bzrlib import errors

cdef extern from "stdlib.h":

    ctypedef unsigned size_t

    long int strtol(char *nptr, char **endptr, int base)

cdef extern from "Python.h":

    int PyDict_CheckExact(object)

    void *PyDict_GetItem_void "PyDict_GetItem" (object p, object key)

    int PyDict_SetItem(object p, object key, object val) except -1

    int PyList_Append(object lst, object item) except -1

    object PyList_GET_ITEM(object lst, int index)

    int PyList_CheckExact(object)

    void *PyTuple_GetItem_void_void "PyTuple_GET_ITEM" (void* tpl, int index)

    char *PyString_AsString(object p)

    object PyString_FromStringAndSize(char *, int)

    int PyString_Size(object p)

    void Py_INCREF(object)

cdef extern from "string.h":

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

cdef int string_to_int_safe(char *s, char *end, int *out) except -1:

    """Convert a base10 string to an integer.

    This makes sure the whole string is consumed, or it raises ValueError.

    This is similar to how int(s) works, except you don't need a Python

    String object.

    :param s: The string to convert

    :param end: The character after the integer. So if the string is '12\0',

        this should be pointing at the '\0'. If the string was '12 ' then this

        should point at the ' '.

    :param out: This is the integer that will be returned

    :return: -1 if an exception is raised. 0 otherwise

    """

    cdef char *integer_end

    # We can't just return the integer because of how pyrex determines when

    # there is an exception.

    out[0] = <int>strtol(s, &integer_end, 10)

    if integer_end != end:

        py_s = PyString_FromStringAndSize(s, end-s)

        raise ValueError('%r is not a valid integer' % (py_s,))

    return 0

cdef class KnitIndexReader:

    cdef object kndx

    cdef object fp

    cdef object cache

    cdef object history

    cdef char * cur_str

    cdef char * end_str

    cdef int history_len

    def __init__(self, kndx, fp):

        self.kndx = kndx

        self.fp = fp

        self.cache = kndx._cache

        self.history = kndx._history

        self.cur_str = NULL

        self.end_str = NULL

        self.history_len = 0

    cdef int validate(self) except -1:

        if not PyDict_CheckExact(self.cache):

            raise TypeError('kndx._cache must be a python dict')

        if not PyList_CheckExact(self.history):

            raise TypeError('kndx._history must be a python list')

        return 0

    cdef object process_options(self, char *option_str, char *end):

        """Process the options string into a list."""

        cdef char *next

        # This is alternative code which creates a python string and splits it.

        # It is "correct" and more obvious, but slower than the following code.

        # It can be uncommented to switch in case the other code is seen as

        # suspect.

        # options = PyString_FromStringAndSize(option_str,

        #                                      end - option_str)

        # return options.split(',')

        final_options = []

        while option_str < end:

            next = <char*>memchr(option_str, c',', end - option_str)

            if next == NULL:

                next = end

            next_option = PyString_FromStringAndSize(option_str,

                                                     next - option_str)

            PyList_Append(final_options, next_option)

            # Move past the ','

            option_str = next+1

        return final_options

    cdef object process_parents(self, char *parent_str, char *end):

        cdef char *next

        cdef int int_parent

        cdef char *parent_end

        # Alternative, correct but slower code.

        #

        # parents = PyString_FromStringAndSize(parent_str,

        #                                      end - parent_str)

        # real_parents = []

        # for parent in parents.split():

        #     if parent[0].startswith('.'):

        #         real_parents.append(parent[1:])

        #     else:

        #         real_parents.append(self.history[int(parent)])

        # return real_parents

        parents = []

        while parent_str <= end:

            next = <char*>memchr(parent_str, c' ', end - parent_str)

            if next == NULL or next >= end or next == parent_str:

                break

            if parent_str[0] == c'.':

                # This is an explicit revision id

                parent_str = parent_str + 1

                parent = PyString_FromStringAndSize(parent_str,

                                                    next - parent_str)

            else:

                # This in an integer mapping to original

                string_to_int_safe(parent_str, next, &int_parent)

                if int_parent >= self.history_len:

                    raise IndexError('Parent index refers to a revision which'

                        ' does not exist yet.'

                        ' %d > %d' % (int_parent, self.history_len))

                parent = PyList_GET_ITEM(self.history, int_parent)

                # PyList_GET_ITEM steals a reference

                Py_INCREF(parent)

            PyList_Append(parents, parent)

            parent_str = next + 1

        return tuple(parents)

    cdef int process_one_record(self, char *start, char *end) except -1:

        """Take a simple string and split it into an index record."""

        cdef char *version_id_str

        cdef int version_id_size

        cdef char *option_str

        cdef char *option_end

        cdef char *pos_str

        cdef int pos

        cdef char *size_str

        cdef int size

        cdef char *parent_str

        cdef int parent_size

        cdef void *cache_entry

        version_id_str = start

        option_str = <char*>memchr(version_id_str, c' ', end - version_id_str)

        if option_str == NULL or option_str >= end:

            # Short entry

            return 0

        version_id_size = <int>(option_str - version_id_str)

        # Move past the space character

        option_str = option_str + 1

        pos_str = <char*>memchr(option_str, c' ', end - option_str)

        if pos_str == NULL or pos_str >= end:

            # Short entry

            return 0

        option_end = pos_str

        pos_str = pos_str + 1

        size_str = <char*>memchr(pos_str, c' ', end - pos_str)

        if size_str == NULL or size_str >= end:

            # Short entry

            return 0

        size_str = size_str + 1

        parent_str = <char*>memchr(size_str, c' ', end - size_str)

        if parent_str == NULL or parent_str >= end:

            # Missing parents

            return 0

        parent_str = parent_str + 1

        version_id = PyString_FromStringAndSize(version_id_str,

                                                version_id_size)

        options = self.process_options(option_str, option_end)

        try:

            string_to_int_safe(pos_str, size_str - 1, &pos)

            string_to_int_safe(size_str, parent_str - 1, &size)

            parents = self.process_parents(parent_str, end)

        except (ValueError, IndexError), e:

            py_line = PyString_FromStringAndSize(start, end - start)

            raise errors.KnitCorrupt(self.kndx._filename,

                                     "line %r: %s" % (py_line, e))

        cache_entry = PyDict_GetItem_void(self.cache, version_id)

        if cache_entry == NULL:

            PyList_Append(self.history, version_id)

            index = self.history_len

            self.history_len = self.history_len + 1

        else:

            # PyTuple_GetItem_void_void does *not* increment the reference

            # counter, but casting to <object> does.

            index = <object>PyTuple_GetItem_void_void(cache_entry, 5)

        PyDict_SetItem(self.cache, version_id,

                       (version_id,

                        options,

                        pos,

                        size,

                        parents,

                        index,

                       ))

        return 1

    cdef int process_next_record(self) except -1:

        """Process the next record in the file."""

        cdef char *last

        cdef char *start

        start = self.cur_str

        # Find the next newline

        last = <char*>memchr(start, c'\n', self.end_str - start)

        if last == NULL:

            # Process until the end of the file

            last = self.end_str - 1

            self.cur_str = self.end_str

        else:

            # The last character is right before the '\n'

            # And the next string is right after it

            self.cur_str = last + 1

            last = last - 1

        if last <= start or last[0] != c':':

            # Incomplete record

            return 0

        return self.process_one_record(start, last)

    def read(self):

        cdef int text_size

        self.validate()

        self.kndx.check_header(self.fp)

        # We read the whole thing at once

        # TODO: jam 2007-05-09 Consider reading incrementally rather than

        #       having to have the whole thing read up front.

        #       we already know that calling f.readlines() versus lots of

        #       f.readline() calls is faster.

        #       The other possibility is to avoid a Python String here

        #       completely. However self.fp may be a 'file-like' object

        #       it is not guaranteed to be a real file.

        text = self.fp.read()

        text_size = PyString_Size(text)

        self.cur_str = PyString_AsString(text)

        # This points to the last character in the string

        self.end_str = self.cur_str + text_size

        while self.cur_str < self.end_str:

            self.process_next_record()

def _load_data_c(kndx, fp):

    """Load the knit index file into memory."""

    reader = KnitIndexReader(kndx, fp)

    reader.read()