def pack_object_at(cursor, offset, as_stream):
"""
:return: Tuple(abs_data_offset, PackInfo|PackStream)
an object of the correct type according to the type_id of the object.
If as_stream is True, the object will contain a stream, allowing the
data to be read decompressed.
:param data: random accessible data containing all required information
:parma offset: offset in to the data at which the object information is located
:param as_stream: if True, a stream object will be returned that can read
the data, otherwise you receive an info object only"""
data = cursor.use_region(offset).buffer()
type_id, uncomp_size, data_rela_offset = pack_object_header_info(data)
total_rela_offset = None # set later, actual offset until data stream begins
delta_info = None
# OFFSET DELTA
if type_id == OFS_DELTA:
i = data_rela_offset
c = byte_ord(data[i])
i += 1
delta_offset = c & 0x7f
while c & 0x80:
c = byte_ord(data[i])
i += 1
delta_offset += 1
delta_offset = (delta_offset << 7) + (c & 0x7f)
# END character loop
delta_info = delta_offset
total_rela_offset = i
# REF DELTA
elif type_id == REF_DELTA:
total_rela_offset = data_rela_offset + 20
delta_info = data[data_rela_offset:total_rela_offset]
# BASE OBJECT
else:
# assume its a base object
total_rela_offset = data_rela_offset
# END handle type id
abs_data_offset = offset + total_rela_offset
if as_stream:
stream = DecompressMemMapReader(buffer(data, total_rela_offset), False,
uncomp_size)
if delta_info is None:
return abs_data_offset, OPackStream(offset, type_id, uncomp_size,
stream)
else:
return abs_data_offset, ODeltaPackStream(offset, type_id,
uncomp_size, delta_info,
stream)
else:
if delta_info is None:
return abs_data_offset, OPackInfo(offset, type_id, uncomp_size)
else:
return abs_data_offset, ODeltaPackInfo(offset, type_id,
uncomp_size, delta_info)
def store(self, istream):
zstream = ZippedStoreShaWriter()
self._db.set_ostream(zstream)
istream = self._db.store(istream)
zstream.close() # close to flush
zstream.seek(0)
# don't provide a size, the stream is written in object format, hence the
# header needs decompression
decomp_stream = DecompressMemMapReader(zstream.getvalue(), close_on_deletion=False)
self._cache[istream.binsha] = OStream(istream.binsha, istream.type, istream.size, decomp_stream)
return istream
def stream(self, sha):
m = self._map_loose_object(sha)
type, size, stream = DecompressMemMapReader.new(m, close_on_deletion=True)
return OStream(sha, type, size, stream)
def stream(self, sha):
m = self._map_loose_object(sha)
type, size, stream = DecompressMemMapReader.new(m,
close_on_deletion=True)
return OStream(sha, type, size, stream)