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fs: pool size coincide with ReadStream bufferSize #4518

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fs: pool size coincide with ReadStream bufferSize #4518

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4762afd
fs: pool size coincide with ReadStream bufferSize
Jan 4, 2013
6ab6519
fs: remove unused default option in WriteStream
Jan 4, 2013
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8 changes: 3 additions & 5 deletions lib/fs.js
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Original file line number Diff line number Diff line change
Expand Up @@ -38,7 +38,6 @@ var Readable = Stream.Readable;
var Writable = Stream.Writable;

var kMinPoolSpace = 128;
var kPoolSize = 40 * 1024;

var O_APPEND = constants.O_APPEND || 0;
var O_CREAT = constants.O_CREAT || 0;
Expand Down Expand Up @@ -1370,8 +1369,8 @@ fs.realpath = function realpath(p, cache, cb) {

var pool;

function allocNewPool() {
pool = new Buffer(kPoolSize);
function allocNewPool(poolSize) {
pool = new Buffer(poolSize);
pool.used = 0;
}

Expand Down Expand Up @@ -1468,7 +1467,7 @@ ReadStream.prototype._read = function(n, cb) {
// discard the old pool. Can't add to the free list because
// users might have refernces to slices on it.
pool = null;
allocNewPool();
allocNewPool(this._readableState.bufferSize);
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What if this._readableState.bufferSize is very small?

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if this._readableState.bufferSize is very small, buffer of fs.read() gets small so that it takes more time to finish reading as in https://github.com/joyent/node/blob/master/lib/fs.js#L1491

If options.bufferSize is 0, it is set to 16k by default as in https://github.com/joyent/node/blob/master/lib/_stream_readable.js#L35

}

// Grab another reference to the pool in the case that while we're
Expand Down Expand Up @@ -1560,7 +1559,6 @@ function WriteStream(path, options) {

// a little bit bigger buffer and water marks by default
options = util._extend({
bufferSize: 64 * 1024,
lowWaterMark: 16 * 1024,
highWaterMark: 64 * 1024
}, options || {});
Expand Down