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import struct
from typing import Callable
def assert_uint32(value):
if not (0 <= value <= 0xFFFFFFFF):
raise ValueError("Value is not a valid uint32")
def assert_int32(value):
if not (-0x80000000 <= value <= 0x7FFFFFFF):
raise ValueError("Value is not a valid int32")
def varint32write(value, buf):
while value > 0x7F:
buf.append((value & 0x7F) | 0x80)
value >>= 7
buf.append(value)
def varint64write(lo, hi, buf):
for _ in range(9): # max 10 bytes
if hi == 0 and lo < 0x80:
buf.append(lo)
return
buf.append((lo & 0x7F) | 0x80)
carry = (lo >> 7)
lo = ((hi << 25) | (lo >> 7)) & 0xFFFFFFFF
hi = hi >> 7
buf.append(lo)
def read_varint32(buf: bytes, pos: int):
result = shift = 0
while True:
if pos >= len(buf):
raise EOFError("Unexpected end of buffer while reading varint32")
b = buf[pos]
pos += 1
result |= (b & 0x7F) << shift
if not (b & 0x80):
break
shift += 7
if shift > 35:
raise ValueError("Varint32 too long")
return result, pos
def read_varint64(buf, pos):
low_bits = 0
high_bits = 0
for shift in range(0, 28, 7):
b = buf[pos]
pos += 1
low_bits |= (b & 0x7F) << shift
if (b & 0x80) == 0:
return low_bits, high_bits, pos
middle_byte = buf[pos]
pos += 1
low_bits |= (middle_byte & 0x0F) << 28
high_bits = (middle_byte & 0x70) >> 4
if (middle_byte & 0x80) == 0:
return low_bits, high_bits, pos
for shift in range(3, 32, 7):
b = buf[pos]
pos += 1
high_bits |= (b & 0x7F) << shift
if (b & 0x80) == 0:
return low_bits, high_bits, pos
raise ValueError("invalid varint")
def decode_int64(lo: int, hi: int) -> int:
value = (hi << 32) | lo
if hi & 0x80000000:
value -= 1 << 64
return value
def decode_uint64(lo: int, hi: int) -> int:
return (hi << 32) | lo
class ProtoInt64:
@staticmethod
def enc(value: int):
"""Signed 64-bit -> lo/hi pair (int32 each)."""
if value < 0:
value += 1 << 64
lo = value & 0xFFFFFFFF
hi = (value >> 32) & 0xFFFFFFFF
return {'lo': lo, 'hi': hi}
@staticmethod
def uEnc(value: int):
"""Unsigned 64-bit -> lo/hi pair (int32 each)."""
lo = value & 0xFFFFFFFF
hi = (value >> 32) & 0xFFFFFFFF
return {'lo': lo, 'hi': hi}
class BinaryWriter:
def __init__(self, encode_utf8: Callable[[str], bytes] = lambda s: s.encode('utf-8')):
self.encode_utf8 = encode_utf8
self.stack = []
self.chunks = []
self.buf = bytearray()
def finish(self) -> bytes:
if self.buf:
self.chunks.append(bytes(self.buf))
self.buf.clear()
return b''.join(self.chunks)
def fork(self):
self.stack.append((self.chunks, self.buf))
self.chunks = []
self.buf = bytearray()
return self
def join(self):
chunk = self.finish()
if not self.stack:
raise RuntimeError("Invalid state, fork stack empty")
self.chunks, self.buf = self.stack.pop()
self.uint32(len(chunk))
return self.raw(chunk)
def tag(self, field_no: int, wire_type: int):
return self.uint32((field_no << 3) | wire_type)
def raw(self, chunk: bytes):
if self.buf:
self.chunks.append(bytes(self.buf))
self.buf.clear()
self.chunks.append(chunk)
return self
def uint32(self, value: int):
assert_uint32(value)
varint32write(value, self.buf)
return self
def int32(self, value: int):
assert_int32(value)
varint32write(value & 0xFFFFFFFF, self.buf)
return self
def bool(self, value: bool):
self.buf.append(1 if value else 0)
return self
def bytes(self, value: bytes):
self.uint32(len(value))
return self.raw(value)
def string(self, value: str):
encoded = self.encode_utf8(value)
self.uint32(len(encoded))
return self.raw(encoded)
def float(self, value: float):
self.raw(struct.pack('<f', value))
return self
def double(self, value: float):
self.raw(struct.pack('<d', value))
return self
def fixed32(self, value: int):
assert_uint32(value)
self.raw(struct.pack('<I', value))
return self
def sfixed32(self, value: int):
assert_int32(value)
self.raw(struct.pack('<i', value))
return self
def sint32(self, value: int):
assert_int32(value)
encoded = (value << 1) ^ (value >> 31)
varint32write(encoded, self.buf)
return self
def sfixed64(self, value: int):
tc = ProtoInt64.enc(value)
self.raw(struct.pack('<ii', tc['lo'], tc['hi']))
return self
def fixed64(self, value: int):
tc = ProtoInt64.uEnc(value)
self.raw(struct.pack('<II', tc['lo'], tc['hi']))
return self
def int64(self, value: int):
tc = ProtoInt64.enc(value)
varint64write(tc['lo'], tc['hi'], self.buf)
return self
def sint64(self, value: int):
tc = ProtoInt64.enc(value)
sign = tc['hi'] >> 31
lo = (tc['lo'] << 1) ^ sign
hi = ((tc['hi'] << 1) | (tc['lo'] >> 31)) ^ sign
varint64write(lo, hi, self.buf)
return self
def uint64(self, value: int):
tc = ProtoInt64.uEnc(value)
varint64write(tc['lo'], tc['hi'], self.buf)
return self
class BinaryReader:
def __init__(self, buf, decode_utf8: Callable[[bytes], str] = lambda b: b.decode('utf-8')):
if isinstance(buf, list):
buf = bytes(buf)
elif isinstance(buf, bytearray):
buf = bytes(buf)
elif not isinstance(buf, bytes):
raise TypeError(f"Unsupported buffer type: {type(buf)}")
self.decode_utf8 = decode_utf8
self.buf = buf
self.len = len(buf)
self.pos = 0
def tag(self):
tag, self.pos = read_varint32(self.buf, self.pos)
field_no = tag >> 3
wire_type = tag & 0x7
if field_no <= 0 or wire_type < 0 or wire_type > 5:
raise ValueError(f"Illegal tag: field no {field_no} wire type {wire_type}")
return field_no, wire_type
def skip(self, wire_type: int, field_no=None):
start = self.pos
if wire_type == 0: # Varint
while self.buf[self.pos] & 0x80:
self.pos += 1
self.pos += 1
elif wire_type == 1: # 64-bit
self.pos += 8
elif wire_type == 2: # Length-delimited
length, self.pos = read_varint32(self.buf, self.pos)
self.pos += length
elif wire_type == 3: # Start group
while True:
fn, wt = self.tag()
if wt == 4: # End group
if field_no is not None and fn != field_no:
raise ValueError("Invalid end group tag")
break
self.skip(wt, fn)
elif wire_type == 5: # 32-bit
self.pos += 4
else:
raise ValueError(f"Can't skip unknown wire type {wire_type}")
self.assert_bounds()
return self.buf[start:self.pos]
def assert_bounds(self):
if self.pos > self.len:
raise EOFError("Premature EOF")
def uint32(self):
value, self.pos = read_varint32(self.buf, self.pos)
return value
def int32(self):
return self.uint32() | 0
def sint32(self):
value = self.uint32()
return (value >> 1) ^ -(value & 1)
def varint64(self):
lo, hi, self.pos = read_varint64(self.buf, self.pos)
return lo, hi
def int64(self):
return decode_int64(*self.varint64())
def uint64(self):
return decode_uint64(*self.varint64())
def sint64(self):
lo, hi = self.varint64()
sign = -(lo & 1)
lo = ((lo >> 1) | ((hi & 1) << 31)) ^ sign
hi = (hi >> 1) ^ sign
return decode_int64(lo, hi)
def bool(self):
lo, hi = self.varint64()
return lo != 0 or hi != 0
def fixed32(self):
value = struct.unpack_from('<I', self.buf, self.pos)[0]
self.pos += 4
return value
def sfixed32(self):
value = struct.unpack_from('<i', self.buf, self.pos)[0]
self.pos += 4
return value
def fixed64(self):
lo = self.sfixed32()
hi = self.sfixed32()
return decode_uint64(lo, hi)
def sfixed64(self):
lo = self.sfixed32()
hi = self.sfixed32()
return decode_int64(lo, hi)
def float(self):
value = struct.unpack_from('<f', self.buf, self.pos)[0]
self.pos += 4
return value
def double(self):
value = struct.unpack_from('<d', self.buf, self.pos)[0]
self.pos += 8
return value
def bytes(self):
length = self.uint32()
start = self.pos
self.pos += length
self.assert_bounds()
return self.buf[start:self.pos]
def string(self):
return self.decode_utf8(self.bytes()) |