diff options
Diffstat (limited to 'youtube/proto.py')
| -rw-r--r-- | youtube/proto.py | 128 |
1 files changed, 64 insertions, 64 deletions
diff --git a/youtube/proto.py b/youtube/proto.py index 9f9dbcc..6230e51 100644 --- a/youtube/proto.py +++ b/youtube/proto.py @@ -1,65 +1,65 @@ -from math import ceil
-import base64
-
-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.
- encoded_bytes = bytearray(needed_bytes)
- for i in range(0, needed_bytes - 1):
- 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)
-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'')
-
-def as_bytes(value):
- if isinstance(value, str):
- return value.encode('ascii')
- return value
-
+from math import ceil +import base64 + +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. + encoded_bytes = bytearray(needed_bytes) + for i in range(0, needed_bytes - 1): + 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) +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'') + +def as_bytes(value): + if isinstance(value, str): + return value.encode('ascii') + return value +
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