bta-proxy/bta_proxy/datainputstream.py

166 lines
4.9 KiB
Python

from asyncio.queues import Queue
from logging import getLogger
import struct
logger = getLogger(__name__)
class AsyncDataInputStream:
def __init__(self, queue: Queue):
self.queue = queue
self.buffer = b''
self.last = b''
self.offset = 0
def peek_rest(self):
return self.buffer
def read_rest(self):
out = self.buffer
self.buffer = b''
return out
async def read_bytes(self, n: int) -> bytes:
logger.debug(f"trying to read {n} bytes")
if len(self.buffer) < n:
self.last = (await self.queue.get())
logger.debug(f"new packet from the queue {self.last!r}")
if not self.last:
raise EOFError('empty packet was received')
self.buffer += self.last
self.offset -= len(self.last)
out, self.buffer = self.buffer[:n], self.buffer[n:]
self.offset += n
return out
async def read(self) -> int:
self.offset += 1
return (await self.read_bytes(1))[0]
read_ubyte = read
async def read_byte(self) -> int:
return struct.unpack('b', await self.read_bytes(1))[0]
async def read_boolean(self) -> bool:
return (await self.read()) != 0
async def read_short(self) -> int:
return struct.unpack('>h', await self.read_bytes(2))[0]
async def read_ushort(self) -> int:
return struct.unpack('>H', await self.read_bytes(2))[0]
async def read_int(self) -> int:
return struct.unpack('>i', await self.read_bytes(4))[0]
async def read_uint(self) -> int:
return struct.unpack('>I', await self.read_bytes(4))[0]
async def read_long(self) -> int:
return struct.unpack('>q', await self.read_bytes(8))[0]
async def read_ulong(self) -> int:
return struct.unpack('>Q', await self.read_bytes(8))[0]
async def read_float(self) -> float:
return struct.unpack('>f', await self.read_bytes(4))[0]
async def read_double(self) -> float:
return struct.unpack('>d', await self.read_bytes(8))[0]
async def read_char(self) -> str:
return chr(await self.read_ushort())
async def read_varint(self, bits: int = 32) -> int:
value: int = 0
position: int = 0
while True:
byte = await self.read()
value |= (byte & 0x7F) << position
if ((byte & 0x80) == 0):
break
position += 7
if position >= bits:
raise ValueError('varint too big')
return value
async def read_string(self) -> str:
last = self.last
size = await self.read_short()
try:
return (await self.read_bytes(size)).decode('utf-8')
except Exception as e:
raise ValueError(f'failed reading string of size {size} in {last!r}') from e
class SyncDataInputStream:
def __init__(self, buffer: bytes):
self._buffer = buffer
self._cursor = 0
def read_bytes(self, n: int) -> bytes:
if self._cursor + n > len(self._buffer):
raise EOFError('stream overread')
blob = self._buffer[self._cursor : self._cursor + n]
self._cursor += n
return blob
def empty(self):
return self._cursor >= len(self._buffer) - 1
def end(self) -> bytes:
return self.read_bytes(len(self._buffer) - self._cursor)
def read(self) -> int:
if self._cursor >= len(self._buffer):
raise EOFError(f'stream overread in {self._buffer!r} at {self._cursor}')
self._cursor += 1
return self._buffer[self._cursor - 1]
def read_boolean(self) -> bool:
return self.read() != 0
def read_short(self) -> int:
return struct.unpack('>h', self.read_bytes(2))[0]
def read_ushort(self) -> int:
return struct.unpack('>H', self.read_bytes(2))[0]
def read_int(self) -> int:
return struct.unpack('>i', self.read_bytes(4))[0]
def read_uint(self) -> int:
return struct.unpack('>I', self.read_bytes(4))[0]
def read_long(self) -> int:
return struct.unpack('>q', self.read_bytes(8))[0]
def read_ulong(self) -> int:
return struct.unpack('>Q', self.read_bytes(8))[0]
def read_float(self) -> float:
return struct.unpack('>f', self.read_bytes(4))[0]
def read_double(self) -> float:
return struct.unpack('>d', self.read_bytes(8))[0]
def read_char(self) -> str:
return chr(self.read_ushort())
def read_varint(self, bits: int = 32) -> int:
value: int = 0
position: int = 0
while True:
byte = self.read()
value |= (byte & 0x7F) << position
if ((byte & 0x80) == 0):
break
position += 7
if position >= bits:
raise ValueError('varint too big')
return value
def read_string(self) -> str:
size = self.read_short()
return self.read_bytes(size).decode('utf-8')