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stuf

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commit e6d6ac1803bc4c8efe5b5ad43e2e606a5ef4c82a 1 parent 647b747
Scott Chacon authored
Showing with 94 additions and 90 deletions.
  1. +2 −2 TODO
  2. +92 −88 dulwich/pack.py
View
4 TODO
@@ -3,13 +3,12 @@ TODO
* Web UI
- check key/values in any of the keyspaces
- - simple browsing UI
= object API
* Implementation Fixes
= fetches hangup gracefully
= partial packfile cache usage
- - re-packcache removes old pack caches (at least the index entries)
+ - re-packcache removes old pack caches
* Multi-node Test Environment
- multi-node project loading/updating
@@ -34,3 +33,4 @@ TODO
- if the client split up blobs, be able to reconstruct and pack them
- split long revtree entries
- reconstruct long revtree entries (possibly done)
+
View
180 dulwich/pack.py
@@ -1,17 +1,17 @@
# pack.py -- For dealing wih packed git objects.
# Copyright (C) 2007 James Westby <jw+debian@jameswestby.net>
# 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,
@@ -73,7 +73,7 @@
def take_msb_bytes(map, offset):
"""Read bytes marked with most significant bit.
-
+
:param map: The buffer.
:param offset: Offset in the buffer at which to start reading.
"""
@@ -86,10 +86,10 @@ def take_msb_bytes(map, offset):
def read_zlib_chunks(data, offset):
"""Read chunks of zlib data from a buffer.
-
+
:param data: Buffer to read from
:param offset: Offset at which to start reading
- :return: Tuple with list of chunks and length of
+ :return: Tuple with list of chunks and length of
compressed data length
"""
obj = zlib.decompressobj()
@@ -108,7 +108,7 @@ def read_zlib_chunks(data, offset):
def read_zlib(data, offset, dec_size):
"""Read zlib-compressed data from a buffer.
-
+
:param data: Buffer
:param offset: Offset in the buffer at which to read
:param dec_size: Size of the decompressed buffer
@@ -122,7 +122,7 @@ def read_zlib(data, offset, dec_size):
def iter_sha1(iter):
"""Return the hexdigest of the SHA1 over a set of names.
-
+
:param iter: Iterator over string objects
:return: 40-byte hex sha1 digest
"""
@@ -165,7 +165,7 @@ def load_pack_index(filename):
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
@@ -188,10 +188,10 @@ def bisect_find_sha(start, end, sha, unpack_name):
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
@@ -199,10 +199,10 @@ class PackIndex(object):
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):
"""Create a pack index object.
-
+
Provide it with the name of the index file to consider, and it will map
it whenever required.
"""
@@ -216,14 +216,14 @@ def __init__(self, filename, file=None):
self._file = file
self._contents, map_offset = simple_mmap(self._file, 0, self._size)
assert map_offset == 0
-
+
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()):
if name1 != name2:
return False
@@ -231,25 +231,25 @@ def __eq__(self, other):
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
+
+ :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)
@@ -257,41 +257,41 @@ def _unpack_offset(self, i):
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.
"""
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])
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.
@@ -301,21 +301,21 @@ def calculate_checksum(self):
def get_pack_checksum(self):
"""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: 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.
@@ -323,10 +323,10 @@ def object_index(self, sha):
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
@@ -340,7 +340,7 @@ def _object_index(self, sha):
if i is None:
raise KeyError(sha)
return self._unpack_offset(i)
-
+
class PackIndex1(PackIndex):
@@ -352,22 +352,22 @@ def __init__(self, filename, file=None):
self._fan_out_table = self._read_fan_out_table(0)
def _unpack_entry(self, i):
- (offset, name) = unpack_from(">L20s", self._contents,
+ (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."""
@@ -383,21 +383,21 @@ def __init__(self, filename, file=None):
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):
@@ -458,37 +458,37 @@ def _compute_object_size((num, 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.
"""
-
+
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.
-
+
Currently there is a restriction on the size of the pack as the python
mmap implementation is flawed.
"""
@@ -499,21 +499,21 @@ def __init__(self, filename):
assert self._size >= self._header_size, "%s is too small for a packfile (%d < %d)" % (filename, self._size, self._header_size)
self._file = open(self._filename, 'rb')
self._read_header()
- self._offset_cache = LRUSizeCache(1024*1024*20,
+ self._offset_cache = LRUSizeCache(1024*1024*20,
compute_size=_compute_object_size)
def close(self):
self._file.close()
-
+
def _read_header(self):
(version, self._num_objects) = read_pack_header(self._file)
self._file.seek(self._size-20)
self._stored_checksum = self._file.read(20)
-
+
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.
@@ -527,7 +527,7 @@ def calculate_checksum(self):
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
@@ -535,7 +535,7 @@ def resolve_object(self, offset, type, obj, get_ref, get_offset=None):
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)
@@ -557,11 +557,11 @@ def resolve_object(self, offset, type, obj, get_ref, get_offset=None):
self._offset_cache[base_offset] = type, base_text
ret = (type, apply_delta(base_text, delta))
return ret
-
+
def iterobjects(self, progress=None):
class ObjectIterator(object):
-
+
def __init__(self, pack):
self.i = 0
self.offset = pack._header_size
@@ -576,7 +576,7 @@ def __iter__(self):
def __len__(self):
return self.num
-
+
def next(self):
if self.i == self.num:
raise StopIteration
@@ -589,7 +589,7 @@ def next(self):
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.
@@ -604,7 +604,7 @@ def iterentries(self, ext_resolve_ref=None, progress=None):
postponed = defaultdict(list)
class Postpone(Exception):
"""Raised to postpone delta resolving."""
-
+
def get_ref_text(sha):
assert len(sha) == 20
if sha in found:
@@ -633,7 +633,7 @@ def get_ref_text(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, progress=None):
"""Return entries in this pack, sorted by SHA.
@@ -646,7 +646,7 @@ def sorted_entries(self, resolve_ext_ref=None, progress=None):
ret = list(self.iterentries(resolve_ext_ref, progress=progress))
ret.sort()
return ret
-
+
def create_index_v1(self, filename, resolve_ext_ref=None, progress=None):
"""Create a version 1 file for this data file.
@@ -657,7 +657,7 @@ def create_index_v1(self, filename, resolve_ext_ref=None, progress=None):
"""
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, progress=None):
"""Create a version 2 index file for this data file.
@@ -684,18 +684,18 @@ def create_index(self, filename, resolve_ext_ref=None, progress=None,
self.create_index_v2(filename, resolve_ext_ref, progress)
else:
raise ValueError("unknown index format %d" % version)
-
+
def get_stored_checksum(self):
"""Return the expected checksum stored in this pack."""
return self._stored_checksum
-
+
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
function.
@@ -714,7 +714,7 @@ def get_object_at(self, offset):
class SHA1Reader(object):
- """Wrapper around a file-like object that remembers the SHA1 of
+ """Wrapper around a file-like object that remembers the SHA1 of
the data read from it."""
def __init__(self, f):
@@ -739,9 +739,9 @@ def tell(self):
class SHA1Writer(object):
- """Wrapper around a file-like object that remembers the SHA1 of
+ """Wrapper around a file-like object that remembers the SHA1 of
the data written to it."""
-
+
def __init__(self, f):
self.f = f
self.sha1 = make_sha("")
@@ -843,7 +843,10 @@ def write_pack_data(f, objects, num_objects, window=10, progress=None, backend=N
shas = set()
for sha, path in objects.itershas():
shas.add(sha)
-
+
+ progress("sent packed: %d\n" % len(sent))
+ progress("getting loose: %d\n" % len(shas - sent))
+
for sha in (shas - sent):
o = backend.repo[sha]
offset, crc32 = write_pack_object(f, o.type, o.as_raw_string())
@@ -937,7 +940,7 @@ def encode_size(size):
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
"""
@@ -966,17 +969,17 @@ def get_delta_header_size(delta, index):
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
@@ -988,7 +991,7 @@ def get_delta_header_size(delta, index):
index += cmd
else:
raise ApplyDeltaError("Invalid opcode 0")
-
+
if index != delta_length:
raise ApplyDeltaError("delta not empty: %r" % delta[index:])
@@ -1062,7 +1065,7 @@ def data(self):
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
@@ -1142,3 +1145,4 @@ def iterobjects(self, get_raw=None):
from dulwich._pack import apply_delta, bisect_find_sha
except ImportError:
pass
+
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