def DeserializeInstructions(self, frame, packing_instructions, huff):
""" Takes SPDY4 wire-format data and de-serializes it into in-memory
operations
It returns the group ID and these operations.
(group_id, ops)
"""
ops = []
bb = BitBucket()
bb.StoreBits(frame.GetAllBits())
flags = 0
#print 'DeserializeInstructions'
while flags == 0:
frame_len = bb.GetBits16() * 8 # in bits
#print 'frame_len: ', frame_len
frame_type = bb.GetBits8()
#print 'frame_type: ', frame_type
flags = bb.GetBits8()
#print 'flags: ', flags
stream_id = bb.GetBits32()
#print 'stream_id: ', stream_id
group_id = bb.GetBits8()
#print 'group_id: ', group_id
while frame_len > 8:
bits_remaining_at_start = bb.BitsRemaining()
try:
opcode_val_and_op_count = bb.GetBits8()
opcode_val = opcode_val_and_op_count >> 4
op_count = (opcode_val_and_op_count & 0x0f) + 1
opcode_description = g_opcode_to_op[opcode_val]
opcode = opcode_description[0]
fields = opcode_description[1:]
for i in xrange(op_count):
op = {'opcode': opcode}
for field_name in g_packing_order:
if not field_name in fields:
continue
(params, _,
unpack_fn) = packing_instructions[field_name]
val = unpack_fn(bb, params, huff)
#print val
op[field_name] = val
#print "BitsRemaining: %d (%d)" % (bb.BitsRemaining(), bb.BitsRemaining() % 8)
#print "Deser %d" % (bb.NumBits() - bb.BitsRemaining())
#print op
ops.append(op)
bits_consumed = (bits_remaining_at_start -
bb.BitsRemaining())
#if not bits_consumed % 8 == 0:
# print "somehow didn't consume whole bytes..."
# print "Bits consumed: %d (%d)" % (bits_consumed, bits_consumed % 8)
# raise StandardError()
frame_len -= bits_consumed
except:
break
#print 'ops: ', ops
return (group_id, ops)
def test_GetBits16(self):
bb = BitBucket()
inp = [0xdddd, 0xeeee, 0xaaaa, 0xdddd]
bitstr = "|11011101"*2 + \
"|11101110"*2 + \
"|10101010"*2 + \
"|11011101"*2 + \
" [0]"
for offset in xrange(32):
bb.Clear()
StoreBitsFromString(bb, ("1" * offset) + bitstr)
for i in xrange(offset):
bb.GetBit()
for i in xrange(len(inp)):
assert bb.GetBits16() == inp[i]
