72 lines
2.0 KiB
Python
72 lines
2.0 KiB
Python
"""Sans I/O wire protocol for Hypercore"""
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from typing import List, Optional, Tuple
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import attr
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from pyvarint import encode, encoding_length
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__all__ = ["SimpleMessageChannel"]
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@attr.s(auto_attribs=True)
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class SimpleMessageChannel:
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"""A simple message channel."""
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messages: List[Tuple[int, int, bytes]] = attr.Factory(list)
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varint: int = 0
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factor: int = 1
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length: int = 0
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header: int = 0
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state: int = 0
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consumed = 0
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max_size = 8 * 1024 * 1024
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def send(self, channel: int, type: int, message: bytes) -> bytes:
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"""Encode a channel, type and message data to be sent.
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:param channel: the message channel identifier
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:param type: the type of message
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:param message: the message data
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"""
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header = channel << 4 or type
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length = len(message) + encoding_length(header)
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return encode(length) + encode(header) + message
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def send_batch(self, messages: List[Tuple[int, int, bytes]]) -> bytes:
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"""Encodes a series of messages into a single payload of bytes.
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:param messages: Several data messages
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"""
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payload = b""
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for (channel, type, message) in messages:
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payload += self.send(channel, type, message)
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return payload
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def recv(self, data: bytes) -> None:
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"""Encode a channel, type, message to be sent.
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:param data: the message data
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"""
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offset = 0
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while offset < len(data):
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if self.state == 2:
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offset = self._read_msg(data, offset)
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else:
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offset = self._read_varint(data, offset)
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if self.state == 2 and self.length == 0:
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self._read_msg(data, offset)
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def _read_msg(self, data: bytes, offset: int) -> int:
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"""TODO."""
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pass
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def _read_varint(self, data: bytes, offset: int) -> int:
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"""TODO."""
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pass
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def _next_state(self, data: bytes, offset: int) -> None:
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"""TODO."""
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pass
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