diff options
Diffstat (limited to 'youtube/proto.py')
| -rw-r--r-- | youtube/proto.py | 28 |
1 files changed, 14 insertions, 14 deletions
diff --git a/youtube/proto.py b/youtube/proto.py index d966455..5fd16d5 100644 --- a/youtube/proto.py +++ b/youtube/proto.py @@ -5,13 +5,13 @@ import io def byte(n): return bytes((n,)) - + def varint_encode(offset): '''In this encoding system, for each 8-bit byte, the first bit is 1 if there are more bytes, and 0 is this is the last one. The next 7 bits are data. These 7-bit sections represent the data in Little endian order. For example, suppose the data is aaaaaaabbbbbbbccccccc (each of these sections is 7 bits). It will be encoded as: 1ccccccc 1bbbbbbb 0aaaaaaa - + This encoding is used in youtube parameters to encode offsets and to encode the length for length-prefixed data. See https://developers.google.com/protocol-buffers/docs/encoding#varints for more info.''' needed_bytes = ceil(offset.bit_length()/7) or 1 # (0).bit_length() returns 0, but we need 1 in that case. @@ -20,20 +20,20 @@ def varint_encode(offset): encoded_bytes[i] = (offset & 127) | 128 # 7 least significant bits offset = offset >> 7 encoded_bytes[-1] = offset & 127 # leave first bit as zero for last byte - + return bytes(encoded_bytes) - + def varint_decode(encoded): decoded = 0 for i, byte in enumerate(encoded): decoded |= (byte & 127) << 7*i - + if not (byte & 128): break return decoded - + def string(field_number, data): data = as_bytes(data) return _proto_field(2, field_number, varint_encode(len(data)) + data) @@ -41,20 +41,20 @@ nested = string def uint(field_number, value): return _proto_field(0, field_number, varint_encode(value)) - - - + + + def _proto_field(wire_type, field_number, data): ''' See https://developers.google.com/protocol-buffers/docs/encoding#structure ''' return varint_encode( (field_number << 3) | wire_type) + data - + def percent_b64encode(data): return base64.urlsafe_b64encode(data).replace(b'=', b'%3D') - - + + def unpadded_b64encode(data): return base64.urlsafe_b64encode(data).replace(b'=', b'') @@ -81,7 +81,7 @@ def read_varint(data): i += 1 return result - + def read_group(data, end_sequence): start = data.tell() index = data.original.find(end_sequence, start) @@ -101,7 +101,7 @@ def read_protobuf(data): break wire_type = tag & 7 field_number = tag >> 3 - + if wire_type == 0: value = read_varint(data) elif wire_type == 1: |