~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2007, 2008 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

"""Helper functions for DirState.

This is the python implementation for DirState functions.

"""

import binascii

import bisect

import errno

import os

import stat

import sys

from bzrlib import cache_utf8, errors, osutils

from bzrlib.dirstate import DirState

from bzrlib.osutils import pathjoin, splitpath

# This is the Windows equivalent of ENOTDIR

# It is defined in pywin32.winerror, but we don't want a strong dependency for

# just an error code.

# XXX: Perhaps we could get it from a windows header ?

cdef int ERROR_PATH_NOT_FOUND

ERROR_PATH_NOT_FOUND = 3

cdef int ERROR_DIRECTORY

ERROR_DIRECTORY = 267

#python2.4 support, and other platform-dependent includes

cdef extern from "python-compat.h":

    unsigned long htonl(unsigned long)

# Give Pyrex some function definitions for it to understand.

# All of these are just hints to Pyrex, so that it can try to convert python

# objects into similar C objects. (such as PyInt => int).

# In anything defined 'cdef extern from XXX' the real C header will be

# imported, and the real definition will be used from there. So these are just

# hints, and do not need to match exactly to the C definitions.

cdef extern from *:

    ctypedef unsigned long size_t

cdef extern from "_dirstate_helpers_c.h":

    ctypedef int intptr_t

cdef extern from "stdlib.h":

    unsigned long int strtoul(char *nptr, char **endptr, int base)

cdef extern from 'sys/stat.h':

    int S_ISDIR(int mode)

    int S_ISREG(int mode)

    # On win32, this actually comes from "python-compat.h"

    int S_ISLNK(int mode)

    int S_IXUSR

# These functions allow us access to a bit of the 'bare metal' of python

# objects, rather than going through the object abstraction. (For example,

# PyList_Append, rather than getting the 'append' attribute of the object, and

# creating a tuple, and then using PyCallObject).

# Functions that return (or take) a void* are meant to grab a C PyObject*. This

# differs from the Pyrex 'object'. If you declare a variable as 'object' Pyrex

# will automatically Py_INCREF and Py_DECREF when appropriate. But for some

# inner loops, we don't need to do that at all, as the reference only lasts for

# a very short time.

# Note that the C API GetItem calls borrow references, so pyrex does the wrong

# thing if you declare e.g. object PyList_GetItem(object lst, int index) - you

# need to manually Py_INCREF yourself.

cdef extern from "Python.h":

    ctypedef int Py_ssize_t

    ctypedef struct PyObject:

        pass

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

    void *PyList_GetItem_object_void "PyList_GET_ITEM" (object lst, int index)

    void *PyList_GetItem_void_void "PyList_GET_ITEM" (void * lst, int index)

    object PyList_GET_ITEM(object lst, Py_ssize_t index)

    int PyList_CheckExact(object)

    Py_ssize_t PyList_GET_SIZE (object p)

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

    object PyTuple_GetItem_void_object "PyTuple_GET_ITEM" (void* tpl, int index)

    object PyTuple_GET_ITEM(object tpl, Py_ssize_t index)

    char *PyString_AsString(object p)

    char *PyString_AsString_obj "PyString_AsString" (PyObject *string)

    char *PyString_AS_STRING_void "PyString_AS_STRING" (void *p)

    int PyString_AsStringAndSize(object str, char **buffer, Py_ssize_t *length) except -1

    object PyString_FromString(char *)

    object PyString_FromStringAndSize(char *, Py_ssize_t)

    int PyString_Size(object p)

    int PyString_GET_SIZE_void "PyString_GET_SIZE" (void *p)

    int PyString_CheckExact(object p)

    void Py_INCREF(object o)

    void Py_DECREF(object o)

cdef extern from "string.h":

    int strncmp(char *s1, char *s2, int len)

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

    int memcmp(void *b1, void *b2, size_t len)

    # ??? memrchr is a GNU extension :(

    # void *memrchr(void *s, int c, size_t len)

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 _py_memrchr(s, c):

    """Just to expose _my_memrchr for testing.

    :param s: The Python string to search

    :param c: The character to search for

    :return: The offset to the last instance of 'c' in s

    """

    cdef void *_s

    cdef void *found

    cdef int length

    cdef char *_c

    _s = PyString_AsString(s)

    length = PyString_Size(s)

    _c = PyString_AsString(c)

    assert PyString_Size(c) == 1,\

        'Must be a single character string, not %s' % (c,)

    found = _my_memrchr(_s, _c[0], length)

    if found == NULL:

        return None

    return <char*>found - <char*>_s

cdef object safe_string_from_size(char *s, Py_ssize_t size):

    if size < 0:

        # XXX: On 64-bit machines the <int> cast causes a C compiler warning.

        raise AssertionError(

            'tried to create a string with an invalid size: %d @0x%x'

            % (size, <int>s))

    return PyString_FromStringAndSize(s, size)

cdef int _is_aligned(void *ptr):

    """Is this pointer aligned to an integer size offset?

    :return: 1 if this pointer is aligned, 0 otherwise.

    """

    return ((<intptr_t>ptr) & ((sizeof(int))-1)) == 0

cdef int _cmp_by_dirs(char *path1, int size1, char *path2, int size2):

    cdef unsigned char *cur1

    cdef unsigned char *cur2

    cdef unsigned char *end1

    cdef unsigned char *end2

    cdef int *cur_int1

    cdef int *cur_int2

    cdef int *end_int1

    cdef int *end_int2

    if path1 == path2 and size1 == size2:

        return 0

    end1 = <unsigned char*>path1+size1

    end2 = <unsigned char*>path2+size2

    # Use 32-bit comparisons for the matching portion of the string.

    # Almost all CPU's are faster at loading and comparing 32-bit integers,

    # than they are at 8-bit integers.

    # 99% of the time, these will be aligned, but in case they aren't just skip

    # this loop

    if _is_aligned(path1) and _is_aligned(path2):

        cur_int1 = <int*>path1

        cur_int2 = <int*>path2

        end_int1 = <int*>(path1 + size1 - (size1 % sizeof(int)))

        end_int2 = <int*>(path2 + size2 - (size2 % sizeof(int)))

        while cur_int1 < end_int1 and cur_int2 < end_int2:

            if cur_int1[0] != cur_int2[0]:

                break

            cur_int1 = cur_int1 + 1

            cur_int2 = cur_int2 + 1

        cur1 = <unsigned char*>cur_int1

        cur2 = <unsigned char*>cur_int2

    else:

        cur1 = <unsigned char*>path1

        cur2 = <unsigned char*>path2

    while cur1 < end1 and cur2 < end2:

        if cur1[0] == cur2[0]:

            # This character matches, just go to the next one

            cur1 = cur1 + 1

            cur2 = cur2 + 1

            continue

        # The current characters do not match

        if cur1[0] == c'/':

            return -1 # Reached the end of path1 segment first

        elif cur2[0] == c'/':

            return 1 # Reached the end of path2 segment first

        elif cur1[0] < cur2[0]:

            return -1

        else:

            return 1

    # We reached the end of at least one of the strings

    if cur1 < end1:

        return 1 # Not at the end of cur1, must be at the end of cur2

    if cur2 < end2:

        return -1 # At the end of cur1, but not at cur2

    # We reached the end of both strings

    return 0

def cmp_by_dirs_c(path1, path2):

    """Compare two paths directory by directory.

    This is equivalent to doing::

       cmp(path1.split('/'), path2.split('/'))

    The idea is that you should compare path components separately. This

    differs from plain ``cmp(path1, path2)`` for paths like ``'a-b'`` and

    ``a/b``. "a-b" comes after "a" but would come before "a/b" lexically.

    :param path1: first path

    :param path2: second path

    :return: negative number if ``path1`` comes first,

        0 if paths are equal,

        and positive number if ``path2`` sorts first

    """

    if not PyString_CheckExact(path1):

        raise TypeError("'path1' must be a plain string, not %s: %r"

                        % (type(path1), path1))

    if not PyString_CheckExact(path2):

        raise TypeError("'path2' must be a plain string, not %s: %r"

                        % (type(path2), path2))

    return _cmp_by_dirs(PyString_AsString(path1),

                        PyString_Size(path1),

                        PyString_AsString(path2),

                        PyString_Size(path2))

def _cmp_path_by_dirblock_c(path1, path2):

    """Compare two paths based on what directory they are in.

    This generates a sort order, such that all children of a directory are

    sorted together, and grandchildren are in the same order as the

    children appear. But all grandchildren come after all children.

    In other words, all entries in a directory are sorted together, and

    directorys are sorted in cmp_by_dirs order.

    :param path1: first path

    :param path2: the second path

    :return: negative number if ``path1`` comes first,

        0 if paths are equal

        and a positive number if ``path2`` sorts first

    """

    if not PyString_CheckExact(path1):

        raise TypeError("'path1' must be a plain string, not %s: %r"

                        % (type(path1), path1))

    if not PyString_CheckExact(path2):

        raise TypeError("'path2' must be a plain string, not %s: %r"

                        % (type(path2), path2))

    return _cmp_path_by_dirblock(PyString_AsString(path1),

                                 PyString_Size(path1),

                                 PyString_AsString(path2),

                                 PyString_Size(path2))

cdef int _cmp_path_by_dirblock(char *path1, int path1_len,

                               char *path2, int path2_len):

    """Compare two paths by what directory they are in.

    see ``_cmp_path_by_dirblock_c`` for details.

    """

    cdef char *dirname1

    cdef int dirname1_len

    cdef char *dirname2

    cdef int dirname2_len

    cdef char *basename1

    cdef int basename1_len

    cdef char *basename2

    cdef int basename2_len

    cdef int cur_len

    cdef int cmp_val

    if path1_len == 0 and path2_len == 0:

        return 0

    if path1 == path2 and path1_len == path2_len:

        return 0

    if path1_len == 0:

        return -1

    if path2_len == 0:

        return 1

    basename1 = <char*>_my_memrchr(path1, c'/', path1_len)

    if basename1 == NULL:

        basename1 = path1

        basename1_len = path1_len

        dirname1 = ''

        dirname1_len = 0

    else:

        dirname1 = path1

        dirname1_len = basename1 - path1

        basename1 = basename1 + 1

        basename1_len = path1_len - dirname1_len - 1

    basename2 = <char*>_my_memrchr(path2, c'/', path2_len)

    if basename2 == NULL:

        basename2 = path2

        basename2_len = path2_len

        dirname2 = ''

        dirname2_len = 0

    else:

        dirname2 = path2

        dirname2_len = basename2 - path2

        basename2 = basename2 + 1

        basename2_len = path2_len - dirname2_len - 1

    cmp_val = _cmp_by_dirs(dirname1, dirname1_len,

                           dirname2, dirname2_len)

    if cmp_val != 0:

        return cmp_val

    cur_len = basename1_len

    if basename2_len < basename1_len:

        cur_len = basename2_len

    cmp_val = memcmp(basename1, basename2, cur_len)

    if cmp_val != 0:

        return cmp_val

    if basename1_len == basename2_len:

        return 0

    if basename1_len < basename2_len:

        return -1

    return 1

def _bisect_path_left_c(paths, path):

    """Return the index where to insert path into paths.

    This uses a path-wise comparison so we get::

        a

        a-b

        a=b

        a/b

    Rather than::

        a

        a-b

        a/b

        a=b

    :param paths: A list of paths to search through

    :param path: A single path to insert

    :return: An offset where 'path' can be inserted.

    :seealso: bisect.bisect_left

    """

    cdef int _lo

    cdef int _hi

    cdef int _mid

    cdef char *path_cstr

    cdef int path_size

    cdef char *cur_cstr

    cdef int cur_size

    cdef void *cur

    if not PyList_CheckExact(paths):

        raise TypeError("you must pass a python list for 'paths' not: %s %r"

                        % (type(paths), paths))

    if not PyString_CheckExact(path):

        raise TypeError("you must pass a string for 'path' not: %s %r"

                        % (type(path), path))

    _hi = len(paths)

    _lo = 0

    path_cstr = PyString_AsString(path)

    path_size = PyString_Size(path)

    while _lo < _hi:

        _mid = (_lo + _hi) / 2

        cur = PyList_GetItem_object_void(paths, _mid)

        cur_cstr = PyString_AS_STRING_void(cur)

        cur_size = PyString_GET_SIZE_void(cur)

        if _cmp_path_by_dirblock(cur_cstr, cur_size, path_cstr, path_size) < 0:

            _lo = _mid + 1

        else:

            _hi = _mid

    return _lo

def _bisect_path_right_c(paths, path):

    """Return the index where to insert path into paths.

    This uses a path-wise comparison so we get::

        a

        a-b

        a=b

        a/b

    Rather than::

        a

        a-b

        a/b

        a=b

    :param paths: A list of paths to search through

    :param path: A single path to insert

    :return: An offset where 'path' can be inserted.

    :seealso: bisect.bisect_right

    """

    cdef int _lo

    cdef int _hi

    cdef int _mid

    cdef char *path_cstr

    cdef int path_size

    cdef char *cur_cstr

    cdef int cur_size

    cdef void *cur

    if not PyList_CheckExact(paths):

        raise TypeError("you must pass a python list for 'paths' not: %s %r"

                        % (type(paths), paths))

    if not PyString_CheckExact(path):

        raise TypeError("you must pass a string for 'path' not: %s %r"

                        % (type(path), path))

    _hi = len(paths)

    _lo = 0

    path_cstr = PyString_AsString(path)

    path_size = PyString_Size(path)

    while _lo < _hi:

        _mid = (_lo + _hi) / 2

        cur = PyList_GetItem_object_void(paths, _mid)

        cur_cstr = PyString_AS_STRING_void(cur)

        cur_size = PyString_GET_SIZE_void(cur)

        if _cmp_path_by_dirblock(path_cstr, path_size, cur_cstr, cur_size) < 0:

            _hi = _mid

        else:

            _lo = _mid + 1

    return _lo

def bisect_dirblock_c(dirblocks, dirname, lo=0, hi=None, cache=None):

    """Return the index where to insert dirname into the dirblocks.

    The return value idx is such that all directories blocks in dirblock[:idx]

    have names < dirname, and all blocks in dirblock[idx:] have names >=

    dirname.

    Optional args lo (default 0) and hi (default len(dirblocks)) bound the

    slice of a to be searched.

    """

    cdef int _lo

    cdef int _hi

    cdef int _mid

    cdef char *dirname_cstr

    cdef int dirname_size

    cdef char *cur_cstr

    cdef int cur_size

    cdef void *cur

    if not PyList_CheckExact(dirblocks):

        raise TypeError("you must pass a python list for 'dirblocks' not: %s %r"

                        % (type(dirblocks), dirblocks))

    if not PyString_CheckExact(dirname):

        raise TypeError("you must pass a string for dirname not: %s %r"

                        % (type(dirname), dirname))

    if hi is None:

        _hi = len(dirblocks)

    else:

        _hi = hi

    _lo = lo

    dirname_cstr = PyString_AsString(dirname)

    dirname_size = PyString_Size(dirname)

    while _lo < _hi:

        _mid = (_lo + _hi) / 2

        # Grab the dirname for the current dirblock

        # cur = dirblocks[_mid][0]

        cur = PyTuple_GetItem_void_void(

                PyList_GetItem_object_void(dirblocks, _mid), 0)

        cur_cstr = PyString_AS_STRING_void(cur)

        cur_size = PyString_GET_SIZE_void(cur)

        if _cmp_by_dirs(cur_cstr, cur_size, dirname_cstr, dirname_size) < 0:

            _lo = _mid + 1

        else:

            _hi = _mid

    return _lo

cdef class Reader:

    """Maintain the current location, and return fields as you parse them."""

    cdef object state # The DirState object

    cdef object text # The overall string object

    cdef char *text_cstr # Pointer to the beginning of text

    cdef int text_size # Length of text

    cdef char *end_cstr # End of text

    cdef char *cur_cstr # Pointer to the current record

    cdef char *next # Pointer to the end of this record

    def __init__(self, text, state):

        self.state = state

        self.text = text

        self.text_cstr = PyString_AsString(text)

        self.text_size = PyString_Size(text)

        self.end_cstr = self.text_cstr + self.text_size

        self.cur_cstr = self.text_cstr

    cdef char *get_next(self, int *size) except NULL:

        """Return a pointer to the start of the next field."""

        cdef char *next

        cdef Py_ssize_t extra_len

        if self.cur_cstr == NULL:

            raise AssertionError('get_next() called when cur_str is NULL')

        elif self.cur_cstr >= self.end_cstr:

            raise AssertionError('get_next() called when there are no chars'

                                 ' left')

        next = self.cur_cstr

        self.cur_cstr = <char*>memchr(next, c'\0', self.end_cstr - next)

        if self.cur_cstr == NULL:

            extra_len = self.end_cstr - next

            raise errors.DirstateCorrupt(self.state,

                'failed to find trailing NULL (\\0).'

                ' Trailing garbage: %r'

                % safe_string_from_size(next, extra_len))

        size[0] = self.cur_cstr - next

        self.cur_cstr = self.cur_cstr + 1

        return next

    cdef object get_next_str(self):

        """Get the next field as a Python string."""

        cdef int size

        cdef char *next

        next = self.get_next(&size)

        return safe_string_from_size(next, size)

    cdef int _init(self) except -1:

        """Get the pointer ready.

        This assumes that the dirstate header has already been read, and we

        already have the dirblock string loaded into memory.

        This just initializes our memory pointers, etc for parsing of the

        dirblock string.

        """

        cdef char *first

        cdef int size

        # The first field should be an empty string left over from the Header

        first = self.get_next(&size)

        if first[0] != c'\0' and size == 0:

            raise AssertionError('First character should be null not: %s'

                                 % (first,))

        return 0

    cdef object _get_entry(self, int num_trees, void **p_current_dirname,

                           int *new_block):

        """Extract the next entry.

        This parses the next entry based on the current location in

        ``self.cur_cstr``.

        Each entry can be considered a "row" in the total table. And each row

        has a fixed number of columns. It is generally broken up into "key"

        columns, then "current" columns, and then "parent" columns.

        :param num_trees: How many parent trees need to be parsed

        :param p_current_dirname: A pointer to the current PyString

            representing the directory name.

            We pass this in as a void * so that pyrex doesn't have to

            increment/decrement the PyObject reference counter for each

            _get_entry call.

            We use a pointer so that _get_entry can update it with the new

            value.

        :param new_block: This is to let the caller know that it needs to

            create a new directory block to store the next entry.

        """

        cdef object path_name_file_id_key

        cdef char *entry_size_cstr

        cdef unsigned long int entry_size

        cdef char* executable_cstr

        cdef int is_executable

        cdef char* dirname_cstr

        cdef char* trailing

        cdef int cur_size

        cdef int i

        cdef object minikind

        cdef object fingerprint

        cdef object info

        # Read the 'key' information (dirname, name, file_id)

        dirname_cstr = self.get_next(&cur_size)

        # Check to see if we have started a new directory block.

        # If so, then we need to create a new dirname PyString, so that it can

        # be used in all of the tuples. This saves time and memory, by re-using

        # the same object repeatedly.

        # Do the cheap 'length of string' check first. If the string is a

        # different length, then we *have* to be a different directory.

        if (cur_size != PyString_GET_SIZE_void(p_current_dirname[0])

            or strncmp(dirname_cstr,

                       # Extract the char* from our current dirname string.  We

                       # know it is a PyString, so we can use

                       # PyString_AS_STRING, we use the _void version because

                       # we are tricking Pyrex by using a void* rather than an

                       # <object>

                       PyString_AS_STRING_void(p_current_dirname[0]),

                       cur_size+1) != 0):

            dirname = safe_string_from_size(dirname_cstr, cur_size)

            p_current_dirname[0] = <void*>dirname

            new_block[0] = 1

        else:

            new_block[0] = 0

        # Build up the key that will be used.

        # By using <object>(void *) Pyrex will automatically handle the

        # Py_INCREF that we need.

        path_name_file_id_key = (<object>p_current_dirname[0],

                                 self.get_next_str(),

                                 self.get_next_str(),

                                )

        # Parse all of the per-tree information. current has the information in

        # the same location as parent trees. The only difference is that 'info'

        # is a 'packed_stat' for current, while it is a 'revision_id' for

        # parent trees.

        # minikind, fingerprint, and info will be returned as regular python

        # strings

        # entry_size and is_executable will be parsed into a python Long and

        # python Boolean, respectively.

        # TODO: jam 20070718 Consider changin the entry_size conversion to

        #       prefer python Int when possible. They are generally faster to

        #       work with, and it will be rare that we have a file >2GB.

        #       Especially since this code is pretty much fixed at a max of

        #       4GB.

        trees = []

        for i from 0 <= i < num_trees:

            minikind = self.get_next_str()

            fingerprint = self.get_next_str()

            entry_size_cstr = self.get_next(&cur_size)

            entry_size = strtoul(entry_size_cstr, NULL, 10)

            executable_cstr = self.get_next(&cur_size)

            is_executable = (executable_cstr[0] == c'y')

            info = self.get_next_str()

            PyList_Append(trees, (

                minikind,     # minikind

                fingerprint,  # fingerprint

                entry_size,   # size

                is_executable,# executable

                info,         # packed_stat or revision_id

            ))

        # The returned tuple is (key, [trees])

        ret = (path_name_file_id_key, trees)

        # Ignore the trailing newline, but assert that it does exist, this

        # ensures that we always finish parsing a line on an end-of-entry

        # marker.

        trailing = self.get_next(&cur_size)

        if cur_size != 1 or trailing[0] != c'\n':

            raise errors.DirstateCorrupt(self.state,

                'Bad parse, we expected to end on \\n, not: %d %s: %s'