diff options
Diffstat (limited to 'youtube/proto.py')
| -rw-r--r-- | youtube/proto.py | 68 |
1 files changed, 66 insertions, 2 deletions
diff --git a/youtube/proto.py b/youtube/proto.py index 6230e51..004375a 100644 --- a/youtube/proto.py +++ b/youtube/proto.py @@ -1,5 +1,6 @@ from math import ceil import base64 +import io def byte(n): return bytes((n,)) @@ -61,5 +62,68 @@ def as_bytes(value): if isinstance(value, str): return value.encode('ascii') return value - -
\ No newline at end of file + + +def read_varint(data): + result = 0 + i = 0 + while True: + try: + byte = data.read(1)[0] + except IndexError: + if i == 0: + raise EOFError() + raise Exception('Unterminated varint starting at ' + str(data.tell() - i)) + result |= (byte & 127) << 7*i + if not byte & 128: + break + + i += 1 + return result + + +def read_group(data, end_sequence): + start = data.tell() + index = data.original.find(end_sequence, start) + if index == -1: + raise Exception('Unterminated group') + data.seek(index + len(end_sequence)) + return data.original[start:index] + +def read_protobuf(data): + data_original = data + data = io.BytesIO(data) + data.original = data_original + while True: + try: + tag = read_varint(data) + except EOFError: + break + wire_type = tag & 7 + field_number = tag >> 3 + + if wire_type == 0: + value = read_varint(data) + elif wire_type == 1: + value = data.read(8) + elif wire_type == 2: + length = read_varint(data) + value = data.read(length) + elif wire_type == 3: + end_bytes = encode_varint((field_number << 3) | 4) + value = read_group(data, end_bytes) + elif wire_type == 5: + value = data.read(4) + else: + raise Exception("Unknown wire type: " + str(wire_type) + ", Tag: " + bytes_to_hex(succinct_encode(tag)) + ", at position " + str(data.tell())) + yield (wire_type, field_number, value) + +def parse(data): + return {field_number: value for _, field_number, value in read_protobuf(data)} + +def b64_to_bytes(data): + if isinstance(data, bytes): + data = data.decode('ascii') + data = data.replace("%3D", "=") + return base64.urlsafe_b64decode(data + "="*((4 - len(data)%4)%4) ) + |