Streamers

A library of stream classes, pipe functions and other stream-related utilities for node.js

Synopsis

var streamers = require("streamers");

var source = new streamers.BufferReadStream("first\nsecond\nthird\n");
var reader = new streamers.ProactiveReadStream(source);

function readNextLine(reader, lineNumber){
    reader.read("\n", function(line, error){
        if(line){
            console.log("Line " + lineNumber + ": " + line.toString());
            readNextLine(reader, lineNumber + 1);
        }
    });
}

readNextLine(reader, 1);

BufferReadStream

Use a buffer object as the source for a readable stream

• new streamers.BufferReadStream(source, [options])
• stream.setEncoding(encoding)
• stream.pause()
• stream.resume()
• stream.destroy()
• stream.readable
• Event: 'data'
• Event: 'end'

Constructor options:

{
    chunkSize: undefined,
    readDelay: 0
}

chunkSize sets the buffer length of the chunk given as the data argument in data events, a value of undefined or null means a single data event will be emitted with a reference to the entire buffer data. readDelay sets the idle time between data events.

BufferWriteStream

Creates a growable buffer object to use as a sink for a writable stream

• new streamers.BufferWriteStream([options])
• stream.write(string, encoding)
• stream.write(buffer)
• stream.destroy()
• stream.getBuffer()
• stream.getCommittedSlice()
• stream.consume(length)
• stream.writable
• Event: 'drain'

Constructor options:

{
    onWrite: undefined,
    onFull: <reference to an internal function that grows the buffer>,
    onEnd: <reference to a noop function>,
    minBlockAllocSize: 0,
    maxBlockAllocSize: undefined,
    drainDelay: 0
}

onWrite is an optional callback function (function(continuationCallback, thisCallback)) that allows the constructor caller to be notified when data is written to the buffer, the onWrite callback function can perform async operations and then call the continuationCallback function (it must do this in every case). onFull is a function that's called (function(buffer, extraSize, continuationCallback)) when the buffer runs out of space, the continuationCallback function is called with two buffer object arguments (the second argument should be a buffer slice of the first argument). onEnd is a function that's called when the stream user calls .end(). minBlockAllocSize and maxBlockAllocSize sets the minimum and maximum value range for the extra buffer length that is requested when the buffer becomes full. minBlockAllocSize also sets the initial buffer length. drainDelay sets the time duration to wait before emitting a drain event.

ProactiveReadStream

Perform asynchronous read operations on a readable stream

• new streamers.ProactiveReadStream(source, [bufferWriteStreamOptions])
• proactor.read(completionCondition, callback)
• proactor.read(string, callback)
• proactor.read(number, callback)
• proactor.cancel()