mirror of https://github.com/vacp2p/nim-libp2p.git
48 lines
1.5 KiB
Nim
48 lines
1.5 KiB
Nim
## Nim-LibP2P
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## Copyright (c) 2018 Status Research & Development GmbH
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## Licensed under either of
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## * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
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## * MIT license ([LICENSE-MIT](LICENSE-MIT))
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## at your option.
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## This file may not be copied, modified, or distributed except according to
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## those terms.
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import chronos
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import types,
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../../connection,
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../../varint,
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../../vbuffer,
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../../stream/lpstream,
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nimcrypto/utils
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proc readHeader*(conn: Connection): Future[(uint, MessageType)] {.async, gcsafe.} =
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var
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header: uint
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length: int
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res: VarintStatus
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var buffer = newSeq[byte](10)
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try:
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for i in 0..<len(buffer):
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await conn.readExactly(addr buffer[i], 1)
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res = LP.getUVarint(buffer.toOpenArray(0, i), length, header)
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if res == VarintStatus.Success:
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return (header shr 3, MessageType(header and 0x7))
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if res != VarintStatus.Success:
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buffer.setLen(0)
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return
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except LPStreamIncompleteError:
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buffer.setLen(0)
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raise newException(CatchableError, "Could not decode header!")
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proc writeHeader*(conn: Connection,
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id: int,
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msgType: MessageType,
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size: int = 0) {.async, gcsafe.} =
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## write lenght prefixed
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var buf = initVBuffer()
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buf.writeVarint(LPSomeUVarint(id.uint shl 3 or msgType.uint))
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if size > 0:
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buf.writeVarint(LPSomeUVarint(size.uint))
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buf.finish()
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result = conn.write(buf.buffer)
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