class PackIdx:
- """Object representation of a Git pack index file."""
- def __init__(self, filename):
- self.name = filename
- self.idxnames = [self.name]
- self.map = mmap_read(open(filename))
- assert(str(self.map[0:8]) == '\377tOc\0\0\0\2')
- self.fanout = list(struct.unpack('!256I',
- str(buffer(self.map, 8, 256*4))))
- self.fanout.append(0) # entry "-1"
- nsha = self.fanout[255]
- self.ofstable = buffer(self.map,
- 8 + 256*4 + nsha*20 + nsha*4,
- nsha*4)
- self.ofs64table = buffer(self.map,
- 8 + 256*4 + nsha*20 + nsha*4 + nsha*4)
+ def __init__(self):
+ assert(0)
+
+ def find_offset(self, hash):
+ """Get the offset of an object inside the index file."""
+ idx = self._idx_from_hash(hash)
+ if idx != None:
+ return self._ofs_from_idx(idx)
+ return None
- def _ofs_from_idx(self, idx):
- ofs = struct.unpack('!I', str(buffer(self.ofstable, idx*4, 4)))[0]
- if ofs & 0x80000000:
- idx64 = ofs & 0x7fffffff
- ofs = struct.unpack('!I',
- str(buffer(self.ofs64table, idx64*8, 8)))[0]
- return ofs
+ def exists(self, hash):
+ """Return nonempty if the object exists in this index."""
+ return hash and (self._idx_from_hash(hash) != None) and True or None
+
+ def __len__(self):
+ return int(self.fanout[255])
def _idx_from_hash(self, hash):
global _total_searches, _total_steps
b1 = ord(hash[0])
start = self.fanout[b1-1] # range -1..254
end = self.fanout[b1] # range 0..255
- buf = buffer(self.map, 8 + 256*4, end*20)
want = str(hash)
_total_steps += 1 # lookup table is a step
while start < end:
_total_steps += 1
mid = start + (end-start)/2
- v = str(buf[mid*20:(mid+1)*20])
+ v = self._idx_to_hash(mid)
if v < want:
start = mid+1
elif v > want:
return mid
return None
- def find_offset(self, hash):
- """Get the offset of an object inside the index file."""
- idx = self._idx_from_hash(hash)
- if idx != None:
- return self._ofs_from_idx(idx)
- return None
- def exists(self, hash):
- """Return nonempty if the object exists in this index."""
- return hash and (self._idx_from_hash(hash) != None) and True or None
+class PackIdxV1(PackIdx):
+ """Object representation of a Git pack index (version 1) file."""
+ def __init__(self, filename, f):
+ self.name = filename
+ self.idxnames = [self.name]
+ self.map = mmap_read(f)
+ self.fanout = list(struct.unpack('!256I',
+ str(buffer(self.map, 0, 256*4))))
+ self.fanout.append(0) # entry "-1"
+ nsha = self.fanout[255]
+ self.shatable = buffer(self.map, 256*4, nsha*24)
+
+ def _ofs_from_idx(self, idx):
+ return struct.unpack('!I', str(self.shatable[idx*24 : idx*24+4]))[0]
+
+ def _idx_to_hash(self, idx):
+ return str(self.shatable[idx*24+4 : idx*24+24])
def __iter__(self):
for i in xrange(self.fanout[255]):
- yield buffer(self.map, 8 + 256*4 + 20*i, 20)
+ yield buffer(self.map, 256*4 + 24*i + 4, 20)
- def __len__(self):
- return int(self.fanout[255])
+
+class PackIdxV2(PackIdx):
+ """Object representation of a Git pack index (version 2) file."""
+ def __init__(self, filename, f):
+ self.name = filename
+ self.idxnames = [self.name]
+ self.map = mmap_read(f)
+ assert(str(self.map[0:8]) == '\377tOc\0\0\0\2')
+ self.fanout = list(struct.unpack('!256I',
+ str(buffer(self.map, 8, 256*4))))
+ self.fanout.append(0) # entry "-1"
+ nsha = self.fanout[255]
+ self.shatable = buffer(self.map, 8 + 256*4, nsha*20)
+ self.ofstable = buffer(self.map,
+ 8 + 256*4 + nsha*20 + nsha*4,
+ nsha*4)
+ self.ofs64table = buffer(self.map,
+ 8 + 256*4 + nsha*20 + nsha*4 + nsha*4)
+
+ def _ofs_from_idx(self, idx):
+ ofs = struct.unpack('!I', str(buffer(self.ofstable, idx*4, 4)))[0]
+ if ofs & 0x80000000:
+ idx64 = ofs & 0x7fffffff
+ ofs = struct.unpack('!I',
+ str(buffer(self.ofs64table, idx64*8, 8)))[0]
+ return ofs
+
+ def _idx_to_hash(self, idx):
+ return str(self.shatable[idx*20:(idx+1)*20])
+
+ def __iter__(self):
+ for i in xrange(self.fanout[255]):
+ yield buffer(self.map, 8 + 256*4 + 20*i, 20)
extract_bits = _helpers.extract_bits
for f in os.listdir(self.dir):
full = os.path.join(self.dir, f)
if f.endswith('.idx') and not d.get(full):
- ix = PackIdx(full)
+ ix = open_idx(full)
d[full] = ix
self.packs = list(set(d.values()))
debug1('PackIdxList: using %d index%s.\n'
def open_idx(filename):
if filename.endswith('.idx'):
- return PackIdx(filename)
+ f = open(filename, 'rb')
+ header = f.read(8)
+ if header[0:4] == '\377tOc':
+ version = struct.unpack('!I', header[4:8])[0]
+ if version == 2:
+ return PackIdxV2(filename, f)
+ else:
+ raise GitError('%s: expected idx file version 2, got %d'
+ % (filename, version))
+ else:
+ return PackIdxV1(filename, f)
elif filename.endswith('.midx'):
return PackMidx(filename)
else:
assert(not self.inprogress)
assert(id.find('\n') < 0)
assert(id.find('\r') < 0)
- assert(id[0] != '-')
+ assert(not id.startswith('-'))
self.inprogress = id
self.p.stdin.write('%s\n' % id)
hdr = self.p.stdout.readline()
if hdr.endswith(' missing\n'):
+ self.inprogress = None
raise KeyError('blob %r is missing' % id)
spl = hdr.split(' ')
if len(spl) != 3 or len(spl[0]) != 40:
projects / bup.git / blobdiff