parser_api.md

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Message Parser API Reference

new MessageParser()

Extends streams.Duplex.

A finite-state machine for handling Lair protocol messsages. It has 2 states

• 0 - Get header
• 1 - Get payload

The header event is emitted as soon as 0 state (Get header) completes. The corrosponding payload is automatically attached to the emitted request object so that the payload event is not required for processing full messages.

Basic example

let parser = new MessageParser();

<some readable stream>.pipe( parser );

for await ( let req of this.parser ) {
    if ( req === null )
	continue;

    ...handle request
}

Or manual writing

let parser = new MessageParser();

parser.write( Buffer.from("00010000100000ff0100000000000000", "hex") );

for await ( let req of parser ) {
    req.wire_type_id; // 4278190096
}

MessageParser[Symbol.asyncIterator]()

Iterator that yields the request object for each header event.

for await ( let req of parser ) {
    ...handle request
}

<MessageParser>.stop()

Stop all iterators next tick.

<MessageParser>._write()

Where incoming chunks are added to the internal buffers for consumption.

<MessageParser>._processBuffers()

Loop for processing avilable buffers until more chunks are needed.

<MessageParser>._consume( length )

A method for getting a given number of bytes from available buffers.

• length - the number of bytes to be consumed

<MessageParser>._parseHeader()

Where header bytes are parsed into request objects and emitted.

<MessageParser>._parsePayload()

Where payload bytes are gathered and emitted.