/**
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* Collection of buffers to be shared between async processes.
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* Avoids allocating buffers each time async process starts.
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* bufSize - size of each buffer
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* bufNo - number of buffers
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* Caller has to make sure no more than bufNo async processes run simultaneously.
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*/
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function BufferPool(bufSize, bufNo) {
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var bufferPool = []
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for (var i = 0; i < bufNo; i++) {
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bufferPool.push({
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buf1: alloc(bufSize),
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buf2: alloc(bufSize),
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busy: false
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})
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}
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var allocateBuffers = function () {
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for (var j = 0; j < bufNo; j++) {
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var bufferPair = bufferPool[j]
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if (!bufferPair.busy) {
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bufferPair.busy = true
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return bufferPair
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}
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}
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throw new Error('Async buffer limit reached')
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}
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return {
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allocateBuffers: allocateBuffers,
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freeBuffers: freeBuffers
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}
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function freeBuffers(bufferPair) {
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bufferPair.busy = false
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}
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}
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function alloc(bufSize) {
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if (Buffer.alloc) {
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return Buffer.alloc(bufSize)
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}
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return new Buffer(bufSize)
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}
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module.exports = BufferPool
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