# pack.py -- For dealing wih packed git objects.
# Copyright (C) 2007 James Westby <jw+debian@jameswestby.net>
-# Copryight (C) 2008 Jelmer Vernooij <jelmer@samba.org>
-#
+# Copryight (C) 2008-2009 Jelmer Vernooij <jelmer@samba.org>
+#
# 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; version 2
# of the License or (at your option) a 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,
except ImportError:
from misc import defaultdict
-from itertools import imap, izip
+import difflib
+import errno
+from itertools import (
+ chain,
+ imap,
+ izip,
+ )
import mmap
import os
import struct
from dulwich.misc import unpack_from
import sys
import zlib
-import difflib
from dulwich.errors import (
ApplyDeltaError,
ChecksumMismatch,
)
+from dulwich.file import GitFile
from dulwich.lru_cache import (
LRUSizeCache,
)
hex_to_sha,
sha_to_hex,
)
-from dulwich.misc import make_sha
+from dulwich.misc import (
+ make_sha,
+ )
supports_mmap_offset = (sys.version_info[0] >= 3 or
(sys.version_info[0] == 2 and sys.version_info[1] >= 6))
-def take_msb_bytes(map, offset):
+def take_msb_bytes(read):
+ """Read bytes marked with most significant bit.
+
+ :param read: Read function
+ """
ret = []
while len(ret) == 0 or ret[-1] & 0x80:
- ret.append(ord(map[offset]))
- offset += 1
+ ret.append(ord(read(1)))
return ret
-def read_zlib(data, offset, dec_size):
+def read_zlib_chunks(read_some, dec_size, buffer_size=4096):
+ """Read zlib data from a buffer.
+
+ This function requires that the buffer have additional data following the
+ compressed data, which is guaranteed to be the case for git pack files.
+
+ :param read_some: Read function that returns at least one byte, but may
+ return less than the requested size
+ :param dec_size: Expected size of the decompressed buffer
+ :param buffer_size: Size of the read buffer
+ :return: Tuple with list of chunks, length of compressed data length and
+ and unused read data.
+ :raise zlib.error: if a decompression error occurred.
+ """
+ if dec_size <= -1:
+ raise ValueError("non-negative zlib data stream size expected")
obj = zlib.decompressobj()
ret = []
fed = 0
+ size = 0
while obj.unused_data == "":
- base = offset+fed
- add = data[base:base+1024]
- if len(add) < 1024:
- add += "Z"
+ add = read_some(buffer_size)
+ if not add:
+ raise zlib.error("EOF before end of zlib stream")
fed += len(add)
- ret.append(obj.decompress(add))
- x = "".join(ret)
- assert len(x) == dec_size
- comp_len = fed-len(obj.unused_data)
- return x, comp_len
-
+ decomp = obj.decompress(add)
+ size += len(decomp)
+ ret.append(decomp)
+ if size != dec_size:
+ raise zlib.error("decompressed data does not match expected size")
+ comp_len = fed - len(obj.unused_data)
+ return ret, comp_len, obj.unused_data
def iter_sha1(iter):
- """Return the hexdigest of the SHA1 over a set of names."""
+ """Return the hexdigest of the SHA1 over a set of names.
+
+ :param iter: Iterator over string objects
+ :return: 40-byte hex sha1 digest
+ """
sha1 = make_sha()
for name in iter:
sha1.update(name)
return sha1.hexdigest()
-def simple_mmap(f, offset, size, access=mmap.ACCESS_READ):
- """Simple wrapper for mmap() which always supports the offset parameter.
+def load_pack_index(path):
+ """Load an index file by path.
- :param f: File object.
- :param offset: Offset in the file, from the beginning of the file.
- :param size: Size of the mmap'ed area
- :param access: Access mechanism.
- :return: MMAP'd area.
+ :param filename: Path to the index file
+ :return: A PackIndex loaded from the given path
"""
- if supports_mmap_offset:
- return mmap.mmap(f.fileno(), size, access=access, offset=offset), 0
- else:
- mem = mmap.mmap(f.fileno(), size+offset, access=access)
- return mem, offset
+ f = GitFile(path, 'rb')
+ return load_pack_index_file(path, f)
-def load_pack_index(filename):
- f = open(filename, 'r')
- if f.read(4) == '\377tOc':
- version = struct.unpack(">L", f.read(4))[0]
+def _load_file_contents(f, size=None):
+ fileno = getattr(f, 'fileno', None)
+ # Attempt to use mmap if possible
+ if fileno is not None:
+ fd = f.fileno()
+ if size is None:
+ size = os.fstat(fd).st_size
+ try:
+ contents = mmap.mmap(fd, size, access=mmap.ACCESS_READ)
+ except mmap.error:
+ # Perhaps a socket?
+ pass
+ else:
+ return contents, size
+ contents = f.read()
+ size = len(contents)
+ return contents, size
+
+
+def load_pack_index_file(path, f):
+ """Load an index file from a file-like object.
+
+ :param path: Path for the index file
+ :param f: File-like object
+ :return: A PackIndex loaded from the given file
+ """
+ contents, size = _load_file_contents(f)
+ if contents[:4] == '\377tOc':
+ version = struct.unpack(">L", contents[4:8])[0]
if version == 2:
- f.seek(0)
- return PackIndex2(filename, file=f)
+ return PackIndex2(path, file=f, contents=contents,
+ size=size)
else:
raise KeyError("Unknown pack index format %d" % version)
else:
- f.seek(0)
- return PackIndex1(filename, file=f)
+ return PackIndex1(path, file=f, contents=contents, size=size)
def bisect_find_sha(start, end, sha, unpack_name):
+ """Find a SHA in a data blob with sorted SHAs.
+
+ :param start: Start index of range to search
+ :param end: End index of range to search
+ :param sha: Sha to find
+ :param unpack_name: Callback to retrieve SHA by index
+ :return: Index of the SHA, or None if it wasn't found
+ """
assert start <= end
while start <= end:
i = (start + end)/2
class PackIndex(object):
"""An index in to a packfile.
-
+
Given a sha id of an object a pack index can tell you the location in the
packfile of that object if it has it.
-
+
To do the loop it opens the file, and indexes first 256 4 byte groups
with the first byte of the sha id. The value in the four byte group indexed
is the end of the group that shares the same starting byte. Subtract one
The values are sorted by sha id within the group, so do the math to find
the start and end offset and then bisect in to find if the value is present.
"""
-
- def __init__(self, filename, file=None):
+
+ def __init__(self, filename, file=None, contents=None, size=None):
"""Create a pack index object.
-
+
Provide it with the name of the index file to consider, and it will map
it whenever required.
"""
self._filename = filename
# Take the size now, so it can be checked each time we map the file to
# ensure that it hasn't changed.
- self._size = os.path.getsize(filename)
if file is None:
- self._file = open(filename, 'r')
+ self._file = GitFile(filename, 'rb')
else:
self._file = file
- self._contents, map_offset = simple_mmap(self._file, 0, self._size)
- assert map_offset == 0
-
+ if contents is None:
+ self._contents, self._size = _load_file_contents(file, size)
+ else:
+ self._contents, self._size = (contents, size)
+
def __eq__(self, other):
if not isinstance(other, PackIndex):
return False
-
+
if self._fan_out_table != other._fan_out_table:
return False
-
- for (name1, _, _), (name2, _, _) in izip(self.iterentries(), other.iterentries()):
+
+ for (name1, _, _), (name2, _, _) in izip(self.iterentries(),
+ other.iterentries()):
if name1 != name2:
return False
return True
-
+
+ def __ne__(self, other):
+ return not self.__eq__(other)
+
def close(self):
self._file.close()
-
+
def __len__(self):
"""Return the number of entries in this pack index."""
return self._fan_out_table[-1]
-
+
def _unpack_entry(self, i):
"""Unpack the i-th entry in the index file.
-
- :return: Tuple with object name (SHA), offset in pack file and
- CRC32 checksum (if known)."""
+
+ :return: Tuple with object name (SHA), offset in pack file and CRC32
+ checksum (if known)."""
raise NotImplementedError(self._unpack_entry)
-
+
def _unpack_name(self, i):
"""Unpack the i-th name from the index file."""
raise NotImplementedError(self._unpack_name)
-
+
def _unpack_offset(self, i):
"""Unpack the i-th object offset from the index file."""
raise NotImplementedError(self._unpack_offset)
def _unpack_crc32_checksum(self, i):
"""Unpack the crc32 checksum for the i-th object from the index file."""
raise NotImplementedError(self._unpack_crc32_checksum)
-
+
def __iter__(self):
+ """Iterate over the SHAs in this pack."""
return imap(sha_to_hex, self._itersha())
-
+
def _itersha(self):
for i in range(len(self)):
yield self._unpack_name(i)
-
+
def objects_sha1(self):
"""Return the hex SHA1 over all the shas of all objects in this pack.
-
+
:note: This is used for the filename of the pack.
"""
return iter_sha1(self._itersha())
-
+
def iterentries(self):
"""Iterate over the entries in this pack index.
-
- Will yield tuples with object name, offset in packfile and crc32 checksum.
+
+ Will yield tuples with object name, offset in packfile and crc32
+ checksum.
"""
for i in range(len(self)):
yield self._unpack_entry(i)
-
+
def _read_fan_out_table(self, start_offset):
ret = []
for i in range(0x100):
- ret.append(struct.unpack(">L", self._contents[start_offset+i*4:start_offset+(i+1)*4])[0])
+ fanout_entry = self._contents[start_offset+i*4:start_offset+(i+1)*4]
+ ret.append(struct.unpack(">L", fanout_entry)[0])
return ret
-
+
def check(self):
"""Check that the stored checksum matches the actual checksum."""
+ # TODO: Check pack contents, too
return self.calculate_checksum() == self.get_stored_checksum()
-
+
def calculate_checksum(self):
+ """Calculate the SHA1 checksum over this pack index.
+
+ :return: This is a 20-byte binary digest
+ """
return make_sha(self._contents[:-20]).digest()
def get_pack_checksum(self):
- """Return the SHA1 checksum stored for the corresponding packfile."""
+ """Return the SHA1 checksum stored for the corresponding packfile.
+
+ :return: 20-byte binary digest
+ """
return str(self._contents[-40:-20])
-
+
def get_stored_checksum(self):
- """Return the SHA1 checksum stored for this index."""
+ """Return the SHA1 checksum stored for this index.
+
+ :return: 20-byte binary digest
+ """
return str(self._contents[-20:])
-
+
def object_index(self, sha):
"""Return the index in to the corresponding packfile for the object.
-
- Given the name of an object it will return the offset that object lives
- at within the corresponding pack file. If the pack file doesn't have the
- object then None will be returned.
+
+ Given the name of an object it will return the offset that object
+ lives at within the corresponding pack file. If the pack file doesn't
+ have the object then None will be returned.
"""
if len(sha) == 40:
sha = hex_to_sha(sha)
return self._object_index(sha)
-
+
def _object_index(self, sha):
"""See object_index.
-
+
:param sha: A *binary* SHA string. (20 characters long)_
"""
assert len(sha) == 20
end = self._fan_out_table[idx]
i = bisect_find_sha(start, end, sha, self._unpack_name)
if i is None:
- return None
+ raise KeyError(sha)
return self._unpack_offset(i)
-
class PackIndex1(PackIndex):
"""Version 1 Pack Index."""
- def __init__(self, filename, file=None):
- PackIndex.__init__(self, filename, file)
+ def __init__(self, filename, file=None, contents=None, size=None):
+ PackIndex.__init__(self, filename, file, contents, size)
self.version = 1
self._fan_out_table = self._read_fan_out_table(0)
def _unpack_entry(self, i):
- (offset, name) = unpack_from(">L20s", self._contents,
- (0x100 * 4) + (i * 24))
+ (offset, name) = unpack_from(">L20s", self._contents,
+ (0x100 * 4) + (i * 24))
return (name, offset, None)
-
+
def _unpack_name(self, i):
offset = (0x100 * 4) + (i * 24) + 4
return self._contents[offset:offset+20]
-
+
def _unpack_offset(self, i):
offset = (0x100 * 4) + (i * 24)
return unpack_from(">L", self._contents, offset)[0]
-
+
def _unpack_crc32_checksum(self, i):
# Not stored in v1 index files
- return None
-
+ return None
+
class PackIndex2(PackIndex):
"""Version 2 Pack Index."""
- def __init__(self, filename, file=None):
- PackIndex.__init__(self, filename, file)
+ def __init__(self, filename, file=None, contents=None, size=None):
+ PackIndex.__init__(self, filename, file, contents, size)
assert self._contents[:4] == '\377tOc', "Not a v2 pack index file"
(self.version, ) = unpack_from(">L", self._contents, 4)
assert self.version == 2, "Version was %d" % self.version
self._fan_out_table = self._read_fan_out_table(8)
self._name_table_offset = 8 + 0x100 * 4
self._crc32_table_offset = self._name_table_offset + 20 * len(self)
- self._pack_offset_table_offset = self._crc32_table_offset + 4 * len(self)
+ self._pack_offset_table_offset = (self._crc32_table_offset +
+ 4 * len(self))
def _unpack_entry(self, i):
- return (self._unpack_name(i), self._unpack_offset(i),
+ return (self._unpack_name(i), self._unpack_offset(i),
self._unpack_crc32_checksum(i))
-
+
def _unpack_name(self, i):
offset = self._name_table_offset + i * 20
return self._contents[offset:offset+20]
-
+
def _unpack_offset(self, i):
offset = self._pack_offset_table_offset + i * 4
return unpack_from(">L", self._contents, offset)[0]
-
+
def _unpack_crc32_checksum(self, i):
- return unpack_from(">L", self._contents,
+ return unpack_from(">L", self._contents,
self._crc32_table_offset + i * 4)[0]
-
-def read_pack_header(f):
- header = f.read(12)
+def read_pack_header(read):
+ """Read the header of a pack file.
+
+ :param read: Read function
+ """
+ header = read(12)
assert header[:4] == "PACK"
(version,) = unpack_from(">L", header, 4)
assert version in (2, 3), "Version was %d" % version
return (version, num_objects)
-def read_pack_tail(f):
- return (f.read(20),)
+def chunks_length(chunks):
+ return sum(imap(len, chunks))
+
+def unpack_object(read_all, read_some=None):
+ """Unpack a Git object.
-def unpack_object(map, offset=0):
- bytes = take_msb_bytes(map, offset)
+ :param read_all: Read function that blocks until the number of requested
+ bytes are read.
+ :param read_some: Read function that returns at least one byte, but may not
+ return the number of bytes requested.
+ :return: tuple with type, uncompressed data, compressed size and tail data.
+ """
+ if read_some is None:
+ read_some = read_all
+ bytes = take_msb_bytes(read_all)
type = (bytes[0] >> 4) & 0x07
size = bytes[0] & 0x0f
for i, byte in enumerate(bytes[1:]):
size += (byte & 0x7f) << ((i * 7) + 4)
raw_base = len(bytes)
if type == 6: # offset delta
- bytes = take_msb_bytes(map, raw_base + offset)
+ bytes = take_msb_bytes(read_all)
+ raw_base += len(bytes)
assert not (bytes[-1] & 0x80)
delta_base_offset = bytes[0] & 0x7f
for byte in bytes[1:]:
delta_base_offset += 1
delta_base_offset <<= 7
delta_base_offset += (byte & 0x7f)
- raw_base+=len(bytes)
- uncomp, comp_len = read_zlib(map, offset + raw_base, size)
- assert size == len(uncomp)
- return type, (delta_base_offset, uncomp), comp_len+raw_base
+ uncomp, comp_len, unused = read_zlib_chunks(read_some, size)
+ assert size == chunks_length(uncomp)
+ return type, (delta_base_offset, uncomp), comp_len+raw_base, unused
elif type == 7: # ref delta
- basename = map[offset+raw_base:offset+raw_base+20]
- uncomp, comp_len = read_zlib(map, offset+raw_base+20, size)
- assert size == len(uncomp)
- return type, (basename, uncomp), comp_len+raw_base+20
+ basename = read_all(20)
+ raw_base += 20
+ uncomp, comp_len, unused = read_zlib_chunks(read_some, size)
+ assert size == chunks_length(uncomp)
+ return type, (basename, uncomp), comp_len+raw_base, unused
else:
- uncomp, comp_len = read_zlib(map, offset+raw_base, size)
- assert len(uncomp) == size
- return type, uncomp, comp_len+raw_base
+ uncomp, comp_len, unused = read_zlib_chunks(read_some, size)
+ assert chunks_length(uncomp) == size
+ return type, uncomp, comp_len+raw_base, unused
-def compute_object_size((num, obj)):
+def _compute_object_size((num, obj)):
+ """Compute the size of a unresolved object for use with LRUSizeCache."""
if num in (6, 7):
- return len(obj[1])
- assert isinstance(obj, str)
- return len(obj)
+ return chunks_length(obj[1])
+ return chunks_length(obj)
class PackData(object):
"""The data contained in a packfile.
-
+
Pack files can be accessed both sequentially for exploding a pack, and
directly with the help of an index to retrieve a specific object.
-
+
The objects within are either complete or a delta aginst another.
-
+
The header is variable length. If the MSB of each byte is set then it
indicates that the subsequent byte is still part of the header.
For the first byte the next MS bits are the type, which tells you the type
of object, and whether it is a delta. The LS byte is the lowest bits of the
size. For each subsequent byte the LS 7 bits are the next MS bits of the
size, i.e. the last byte of the header contains the MS bits of the size.
-
+
For the complete objects the data is stored as zlib deflated data.
The size in the header is the uncompressed object size, so to uncompress
you need to just keep feeding data to zlib until you get an object back,
or it errors on bad data. This is done here by just giving the complete
buffer from the start of the deflated object on. This is bad, but until I
get mmap sorted out it will have to do.
-
- Currently there are no integrity checks done. Also no attempt is made to try
- and detect the delta case, or a request for an object at the wrong position.
- It will all just throw a zlib or KeyError.
+
+ Currently there are no integrity checks done. Also no attempt is made to
+ try and detect the delta case, or a request for an object at the wrong
+ position. It will all just throw a zlib or KeyError.
"""
-
- def __init__(self, filename):
- """Create a PackData object that represents the pack in the given filename.
-
- The file must exist and stay readable until the object is disposed of. It
- must also stay the same size. It will be mapped whenever needed.
-
+
+ def __init__(self, filename, file=None, size=None):
+ """Create a PackData object representing the pack in the given filename.
+
+ The file must exist and stay readable until the object is disposed of.
+ It must also stay the same size. It will be mapped whenever needed.
+
Currently there is a restriction on the size of the pack as the python
mmap implementation is flawed.
"""
self._filename = filename
- assert os.path.exists(filename), "%s is not a packfile" % filename
- self._size = os.path.getsize(filename)
+ self._size = size
self._header_size = 12
- assert self._size >= self._header_size, "%s is too small for a packfile (%d < %d)" % (filename, self._size, self._header_size)
- self._read_header()
- self._offset_cache = LRUSizeCache(1024*1024*100,
- compute_size=compute_object_size)
-
- def _read_header(self):
- f = open(self._filename, 'rb')
- try:
- (version, self._num_objects) = \
- read_pack_header(f)
- f.seek(self._size-20)
- (self._stored_checksum,) = read_pack_tail(f)
- finally:
- f.close()
-
+ if file is None:
+ self._file = GitFile(self._filename, 'rb')
+ else:
+ self._file = file
+ (version, self._num_objects) = read_pack_header(self._file.read)
+ self._offset_cache = LRUSizeCache(1024*1024*20,
+ compute_size=_compute_object_size)
+
+ @classmethod
+ def from_file(cls, file, size):
+ return cls(str(file), file=file, size=size)
+
+ @classmethod
+ def from_path(cls, path):
+ return cls(filename=path)
+
+ def close(self):
+ self._file.close()
+
+ def _get_size(self):
+ if self._size is not None:
+ return self._size
+ self._size = os.path.getsize(self._filename)
+ errmsg = ("%s is too small for a packfile (%d < %d)" %
+ (self._filename, self._size, self._header_size))
+ assert self._size >= self._header_size, errmsg
+ return self._size
+
def __len__(self):
"""Returns the number of objects in this pack."""
return self._num_objects
-
+
def calculate_checksum(self):
- """Calculate the checksum for this pack."""
- f = open(self._filename, 'rb')
- try:
- map, map_offset = simple_mmap(f, 0, self._size - 20)
- return make_sha(map[map_offset:self._size-20]).digest()
- finally:
- f.close()
+ """Calculate the checksum for this pack.
+
+ :return: 20-byte binary SHA1 digest
+ """
+ s = make_sha()
+ self._file.seek(0)
+ todo = self._get_size() - 20
+ while todo > 0:
+ x = self._file.read(min(todo, 1<<16))
+ s.update(x)
+ todo -= len(x)
+ return s.digest()
def resolve_object(self, offset, type, obj, get_ref, get_offset=None):
"""Resolve an object, possibly resolving deltas when necessary.
-
+
:return: Tuple with object type and contents.
"""
if type not in (6, 7): # Not a delta
if get_offset is None:
get_offset = self.get_object_at
-
+
if type == 6: # offset delta
(delta_offset, delta) = obj
assert isinstance(delta_offset, int)
- assert isinstance(delta, str)
base_offset = offset-delta_offset
type, base_obj = get_offset(base_offset)
assert isinstance(type, int)
elif type == 7: # ref delta
(basename, delta) = obj
assert isinstance(basename, str) and len(basename) == 20
- assert isinstance(delta, str)
type, base_obj = get_ref(basename)
assert isinstance(type, int)
# Can't be a ofs delta, as we wouldn't know the base offset
assert type != 6
base_offset = None
- type, base_text = self.resolve_object(base_offset, type, base_obj, get_ref)
+ type, base_chunks = self.resolve_object(base_offset, type, base_obj,
+ get_ref)
if base_offset is not None:
- self._offset_cache[base_offset] = type, base_text
- ret = (type, apply_delta(base_text, delta))
- return ret
-
- def iterobjects(self):
- offset = self._header_size
- f = open(self._filename, 'rb')
- num = len(self)
- map, _ = simple_mmap(f, 0, self._size)
- for i in range(num):
- (type, obj, total_size) = unpack_object(map, offset)
- crc32 = zlib.crc32(map[offset:offset+total_size]) & 0xffffffff
- yield offset, type, obj, crc32
- offset += total_size
- f.close()
-
- def iterentries(self, ext_resolve_ref=None):
+ self._offset_cache[base_offset] = type, base_chunks
+ return (type, apply_delta(base_chunks, delta))
+
+ def iterobjects(self, progress=None):
+
+ class ObjectIterator(object):
+
+ def __init__(self, pack):
+ self.i = 0
+ self.offset = pack._header_size
+ self.num = len(pack)
+ self.map = pack._file
+
+ def __iter__(self):
+ return self
+
+ def __len__(self):
+ return self.num
+
+ def next(self):
+ if self.i == self.num:
+ raise StopIteration
+ self.map.seek(self.offset)
+ (type, obj, total_size, unused) = unpack_object(self.map.read)
+ self.map.seek(self.offset)
+ crc32 = zlib.crc32(self.map.read(total_size)) & 0xffffffff
+ ret = (self.offset, type, obj, crc32)
+ self.offset += total_size
+ if progress:
+ progress(self.i, self.num)
+ self.i+=1
+ return ret
+ return ObjectIterator(self)
+
+ def iterentries(self, ext_resolve_ref=None, progress=None):
+ """Yield entries summarizing the contents of this pack.
+
+ :param ext_resolve_ref: Optional function to resolve base
+ objects (in case this is a thin pack)
+ :param progress: Progress function, called with current and
+ total object count.
+
+ This will yield tuples with (sha, offset, crc32)
+ """
found = {}
postponed = defaultdict(list)
class Postpone(Exception):
"""Raised to postpone delta resolving."""
-
+
def get_ref_text(sha):
+ assert len(sha) == 20
if sha in found:
- return found[sha]
+ return self.get_object_at(found[sha])
if ext_resolve_ref:
try:
return ext_resolve_ref(sha)
except KeyError:
pass
raise Postpone, (sha, )
- todo = list(self.iterobjects())
- while todo:
- (offset, type, obj, crc32) = todo.pop(0)
+ extra = []
+ todo = chain(self.iterobjects(progress=progress), extra)
+ for (offset, type, obj, crc32) in todo:
assert isinstance(offset, int)
assert isinstance(type, int)
- assert isinstance(obj, tuple) or isinstance(obj, str)
try:
- type, obj = self.resolve_object(offset, type, obj, get_ref_text)
+ type, obj = self.resolve_object(offset, type, obj,
+ get_ref_text)
except Postpone, (sha, ):
postponed[sha].append((offset, type, obj))
else:
- shafile = ShaFile.from_raw_string(type, obj)
+ shafile = ShaFile.from_raw_chunks(type, obj)
sha = shafile.sha().digest()
- found[sha] = (type, obj)
+ found[sha] = offset
yield sha, offset, crc32
- todo += postponed.get(sha, [])
+ extra.extend(postponed.get(sha, []))
if postponed:
raise KeyError([sha_to_hex(h) for h in postponed.keys()])
-
- def sorted_entries(self, resolve_ext_ref=None):
- ret = list(self.iterentries(resolve_ext_ref))
+
+ def sorted_entries(self, resolve_ext_ref=None, progress=None):
+ """Return entries in this pack, sorted by SHA.
+
+ :param resolve_ext_ref: Optional function to resolve base
+ objects (in case this is a thin pack)
+ :param progress: Progress function, called with current and
+ total object count
+ :return: List of tuples with (sha, offset, crc32)
+ """
+ ret = list(self.iterentries(resolve_ext_ref, progress=progress))
ret.sort()
return ret
-
- def create_index_v1(self, filename, resolve_ext_ref=None):
- entries = self.sorted_entries(resolve_ext_ref)
+
+ def create_index_v1(self, filename, resolve_ext_ref=None, progress=None):
+ """Create a version 1 file for this data file.
+
+ :param filename: Index filename.
+ :param resolve_ext_ref: Function to use for resolving externally
+ referenced SHA1s (for thin packs)
+ :param progress: Progress report function
+ """
+ entries = self.sorted_entries(resolve_ext_ref, progress=progress)
write_pack_index_v1(filename, entries, self.calculate_checksum())
-
- def create_index_v2(self, filename, resolve_ext_ref=None):
- entries = self.sorted_entries(resolve_ext_ref)
+
+ def create_index_v2(self, filename, resolve_ext_ref=None, progress=None):
+ """Create a version 2 index file for this data file.
+
+ :param filename: Index filename.
+ :param resolve_ext_ref: Function to use for resolving externally
+ referenced SHA1s (for thin packs)
+ :param progress: Progress report function
+ """
+ entries = self.sorted_entries(resolve_ext_ref, progress=progress)
write_pack_index_v2(filename, entries, self.calculate_checksum())
-
+
+ def create_index(self, filename, resolve_ext_ref=None, progress=None,
+ version=2):
+ """Create an index file for this data file.
+
+ :param filename: Index filename.
+ :param resolve_ext_ref: Function to use for resolving externally
+ referenced SHA1s (for thin packs)
+ :param progress: Progress report function
+ """
+ if version == 1:
+ self.create_index_v1(filename, resolve_ext_ref, progress)
+ elif version == 2:
+ self.create_index_v2(filename, resolve_ext_ref, progress)
+ else:
+ raise ValueError("unknown index format %d" % version)
+
def get_stored_checksum(self):
- return self._stored_checksum
-
+ """Return the expected checksum stored in this pack."""
+ self._file.seek(self._get_size()-20)
+ return self._file.read(20)
+
def check(self):
+ """Check the consistency of this pack."""
return (self.calculate_checksum() == self.get_stored_checksum())
-
+
def get_object_at(self, offset):
"""Given an offset in to the packfile return the object that is there.
-
- Using the associated index the location of an object can be looked up, and
- then the packfile can be asked directly for that object using this
+
+ Using the associated index the location of an object can be looked up,
+ and then the packfile can be asked directly for that object using this
function.
"""
if offset in self._offset_cache:
assert isinstance(offset, long) or isinstance(offset, int),\
"offset was %r" % offset
assert offset >= self._header_size
- f = open(self._filename, 'rb')
- try:
- map, map_offset = simple_mmap(f, offset, self._size-offset)
- ret = unpack_object(map, map_offset)[:2]
- return ret
- finally:
- f.close()
+ self._file.seek(offset)
+ return unpack_object(self._file.read)[:2]
+
+
+class SHA1Reader(object):
+ """Wrapper around a file-like object that remembers the SHA1 of its data."""
+
+ def __init__(self, f):
+ self.f = f
+ self.sha1 = make_sha("")
+
+ def read(self, num=None):
+ data = self.f.read(num)
+ self.sha1.update(data)
+ return data
+
+ def check_sha(self):
+ stored = self.f.read(20)
+ if stored != self.sha1.digest():
+ raise ChecksumMismatch(self.sha1.hexdigest(), sha_to_hex(stored))
+
+ def close(self):
+ return self.f.close()
+
+ def tell(self):
+ return self.f.tell()
class SHA1Writer(object):
-
+ """Wrapper around a file-like object that remembers the SHA1 of its data."""
+
def __init__(self, f):
self.f = f
self.sha1 = make_sha("")
"""Write pack object to a file.
:param f: File to write to
- :param o: Object to write
+ :param type: Numeric type of the object
+ :param object: Object to write
:return: Tuple with offset at which the object was written, and crc32
"""
- ret = f.tell()
+ offset = f.tell()
packed_data_hdr = ""
- if type == 6: # ref delta
+ if type == 6: # offset delta
(delta_base_offset, object) = object
- elif type == 7: # offset delta
+ elif type == 7: # ref delta
(basename, object) = object
size = len(object)
c = (type << 4) | (size & 15)
packed_data_hdr += basename
packed_data = packed_data_hdr + zlib.compress(object)
f.write(packed_data)
- return (f.tell(), (zlib.crc32(packed_data) & 0xffffffff))
+ return (offset, (zlib.crc32(packed_data) & 0xffffffff))
def write_pack(filename, objects, num_objects):
- f = open(filename + ".pack", 'w')
+ """Write a new pack data file.
+
+ :param filename: Path to the new pack file (without .pack extension)
+ :param objects: Iterable over (object, path) tuples to write
+ :param num_objects: Number of objects to write
+ """
+ f = GitFile(filename + ".pack", 'wb')
try:
entries, data_sum = write_pack_data(f, objects, num_objects)
finally:
# This helps us find good objects to diff against us
magic = []
for obj, path in recency:
- magic.append( (obj.type, path, 1, -len(obj.as_raw_string()[1]), obj) )
+ magic.append( (obj.type_num, path, 1, -obj.raw_length(), obj) )
magic.sort()
- # Build a map of objects and their index in magic - so we can find preceeding objects
- # to diff against
+ # Build a map of objects and their index in magic - so we can find
+ # preceeding objects to diff against
offs = {}
for i in range(len(magic)):
offs[magic[i][4]] = i
f.write(struct.pack(">L", num_objects)) # Number of objects in pack
for o, path in recency:
sha1 = o.sha().digest()
- orig_t, raw = o.as_raw_string()
+ orig_t = o.type_num
+ raw = o.as_raw_string()
winner = raw
t = orig_t
#for i in range(offs[o]-window, window):
# if i < 0 or i >= len(offs): continue
# b = magic[i][4]
- # if b.type != orig_t: continue
- # _, base = b.as_raw_string()
+ # if b.type_num != orig_t: continue
+ # base = b.as_raw_string()
# delta = create_delta(base, raw)
# if len(delta) < len(winner):
# winner = delta
"""Write a new pack index file.
:param filename: The filename of the new pack index file.
- :param entries: List of tuples with object name (sha), offset_in_pack, and
- crc32_checksum.
+ :param entries: List of tuples with object name (sha), offset_in_pack,
+ and crc32_checksum.
:param pack_checksum: Checksum of the pack file.
"""
- f = open(filename, 'w')
+ f = GitFile(filename, 'wb')
f = SHA1Writer(f)
fan_out_table = defaultdict(lambda: 0)
for (name, offset, entry_checksum) in entries:
def create_delta(base_buf, target_buf):
- """Use python difflib to work out how to transform base_buf to target_buf"""
+ """Use python difflib to work out how to transform base_buf to target_buf.
+
+ :param base_buf: Base buffer
+ :param target_buf: Target buffer
+ """
assert isinstance(base_buf, str)
assert isinstance(target_buf, str)
out_buf = ""
o = i1
for i in range(4):
if o & 0xff << i*8:
- scratch += chr(o >> i)
+ scratch += chr((o >> i*8) & 0xff)
op |= 1 << i
s = i2 - i1
for i in range(2):
if s & 0xff << i*8:
- scratch += chr(s >> i)
+ scratch += chr((s >> i*8) & 0xff)
op |= 1 << (4+i)
out_buf += chr(op)
out_buf += scratch
def apply_delta(src_buf, delta):
"""Based on the similar function in git's patch-delta.c.
-
+
:param src_buf: Source buffer
:param delta: Delta instructions
"""
- assert isinstance(src_buf, str), "was %r" % (src_buf,)
- assert isinstance(delta, str)
+ if type(src_buf) != str:
+ src_buf = "".join(src_buf)
+ if type(delta) != str:
+ delta = "".join(delta)
out = []
index = 0
delta_length = len(delta)
if cmd & 0x80:
cp_off = 0
for i in range(4):
- if cmd & (1 << i):
+ if cmd & (1 << i):
x = ord(delta[index])
index += 1
cp_off |= x << (i * 8)
cp_size = 0
for i in range(3):
- if cmd & (1 << (4+i)):
+ if cmd & (1 << (4+i)):
x = ord(delta[index])
index += 1
cp_size |= x << (i * 8)
- if cp_size == 0:
+ if cp_size == 0:
cp_size = 0x10000
if (cp_off + cp_size < cp_size or
cp_off + cp_size > src_size or
index += cmd
else:
raise ApplyDeltaError("Invalid opcode 0")
-
+
if index != delta_length:
raise ApplyDeltaError("delta not empty: %r" % delta[index:])
- out = ''.join(out)
- if dest_size != len(out):
+ if dest_size != chunks_length(out):
raise ApplyDeltaError("dest size incorrect")
return out
"""Write a new pack index file.
:param filename: The filename of the new pack index file.
- :param entries: List of tuples with object name (sha), offset_in_pack, and
- crc32_checksum.
+ :param entries: List of tuples with object name (sha), offset_in_pack, and
+ crc32_checksum.
:param pack_checksum: Checksum of the pack file.
"""
- f = open(filename, 'w')
+ f = GitFile(filename, 'wb')
f = SHA1Writer(f)
f.write('\377tOc') # Magic!
f.write(struct.pack(">L", 2))
class Pack(object):
+ """A Git pack object."""
def __init__(self, basename):
self._basename = basename
self._data = None
self._idx = None
+ @classmethod
+ def from_objects(self, data, idx):
+ """Create a new pack object from pack data and index objects."""
+ ret = Pack("")
+ ret._data = data
+ ret._idx = idx
+ return ret
+
def name(self):
"""The SHA over the SHAs of the objects in this pack."""
- return self.idx.objects_sha1()
+ return self.index.objects_sha1()
@property
def data(self):
+ """The pack data object being used."""
if self._data is None:
self._data = PackData(self._data_path)
- assert len(self.idx) == len(self._data)
- idx_stored_checksum = self.idx.get_pack_checksum()
+ assert len(self.index) == len(self._data)
+ idx_stored_checksum = self.index.get_pack_checksum()
data_stored_checksum = self._data.get_stored_checksum()
if idx_stored_checksum != data_stored_checksum:
- raise ChecksumMismatch(sha_to_hex(idx_stored_checksum),
+ raise ChecksumMismatch(sha_to_hex(idx_stored_checksum),
sha_to_hex(data_stored_checksum))
return self._data
@property
- def idx(self):
+ def index(self):
+ """The index being used.
+
+ :note: This may be an in-memory index
+ """
if self._idx is None:
self._idx = load_pack_index(self._idx_path)
return self._idx
def close(self):
if self._data is not None:
self._data.close()
- self.idx.close()
+ self.index.close()
def __eq__(self, other):
- return type(self) == type(other) and self.idx == other.idx
+ return type(self) == type(other) and self.index == other.index
def __len__(self):
"""Number of entries in this pack."""
- return len(self.idx)
+ return len(self.index)
def __repr__(self):
- return "Pack(%r)" % self._basename
+ return "%s(%r)" % (self.__class__.__name__, self._basename)
def __iter__(self):
"""Iterate over all the sha1s of the objects in this pack."""
- return iter(self.idx)
+ return iter(self.index)
def check(self):
- if not self.idx.check():
+ """Check the integrity of this pack."""
+ if not self.index.check():
return False
if not self.data.check():
return False
def __contains__(self, sha1):
"""Check whether this pack contains a particular SHA1."""
- return (self.idx.object_index(sha1) is not None)
+ try:
+ self.index.object_index(sha1)
+ return True
+ except KeyError:
+ return False
def get_raw(self, sha1, resolve_ref=None):
- offset = self.idx.object_index(sha1)
- if offset is None:
- raise KeyError(sha1)
- type, obj = self.data.get_object_at(offset)
- if isinstance(offset, long):
+ offset = self.index.object_index(sha1)
+ obj_type, obj = self.data.get_object_at(offset)
+ if type(offset) is long:
offset = int(offset)
if resolve_ref is None:
resolve_ref = self.get_raw
- assert isinstance(offset, int)
- return self.data.resolve_object(offset, type, obj, resolve_ref)
+ kind, chunks = self.data.resolve_object(offset, obj_type, obj,
+ resolve_ref)
+ return kind, "".join(chunks)
def __getitem__(self, sha1):
"""Retrieve the specified SHA1."""
return ShaFile.from_raw_string(type, uncomp)
def iterobjects(self, get_raw=None):
+ """Iterate over the objects in this pack."""
if get_raw is None:
get_raw = self.get_raw
for offset, type, obj, crc32 in self.data.iterobjects():
assert isinstance(offset, int)
- yield ShaFile.from_raw_string(
- *self.data.resolve_object(offset, type, obj, get_raw))
-
-
-def load_packs(path):
- if not os.path.exists(path):
- return
- for name in os.listdir(path):
- if name.startswith("pack-") and name.endswith(".pack"):
- yield Pack(os.path.join(path, name[:-len(".pack")]))
+ type, obj = self.data.resolve_object(offset, type, obj, get_raw)
+ yield ShaFile.from_raw_chunks(type, obj)
try:
git.samba.org / jelmer / dulwich-libgit2.git / blobdiff