100 lines
2.9 KiB
JavaScript
100 lines
2.9 KiB
JavaScript
var fs = require('fs'),
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util = require('util');
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function debug(message) {
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// console.log(message);
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}
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module.exports = BaseRollingFileStream;
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function BaseRollingFileStream(filename, options) {
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debug("In BaseRollingFileStream");
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this.filename = filename;
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this.options = options || { encoding: 'utf8', mode: 0644, flags: 'a' };
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this.rolling = false;
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this.writesWhileRolling = [];
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this.currentSize = 0;
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this.rollBeforeWrite = false;
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function currentFileSize(file) {
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var fileSize = 0;
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try {
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fileSize = fs.statSync(file).size;
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} catch (e) {
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// file does not exist
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}
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return fileSize;
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}
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function throwErrorIfArgumentsAreNotValid() {
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if (!filename) {
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throw new Error("You must specify a filename");
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}
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}
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throwErrorIfArgumentsAreNotValid();
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debug("Calling BaseRollingFileStream.super");
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BaseRollingFileStream.super_.call(this, this.filename, this.options);
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this.currentSize = currentFileSize(this.filename);
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}
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util.inherits(BaseRollingFileStream, fs.FileWriteStream);
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BaseRollingFileStream.prototype.initRolling = function() {
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var that = this;
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function emptyRollingQueue() {
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debug("emptying the rolling queue");
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var toWrite;
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while ((toWrite = that.writesWhileRolling.shift())) {
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BaseRollingFileStream.super_.prototype.write.call(that, toWrite.data, toWrite.encoding);
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that.currentSize += toWrite.data.length;
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if (that.shouldRoll()) {
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that.flush();
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return true;
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}
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}
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that.flush();
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return false;
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}
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this.rolling = true;
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this.roll(this.filename, function() {
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that.currentSize = 0;
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that.rolling = emptyRollingQueue();
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if (that.rolling) {
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process.nextTick(function() { that.initRolling(); });
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}
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});
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};
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BaseRollingFileStream.prototype.write = function(data, encoding) {
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var canWrite = false;
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if (this.rolling) {
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this.writesWhileRolling.push({ data: data, encoding: encoding });
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} else {
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if (this.rollBeforeWrite && this.shouldRoll()) {
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this.writesWhileRolling.push({ data: data, encoding: encoding });
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this.initRolling();
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} else {
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canWrite = BaseRollingFileStream.super_.prototype.write.call(this, data, encoding);
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this.currentSize += data.length;
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debug('current size = ' + this.currentSize);
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if (!this.rollBeforeWrite && this.shouldRoll()) {
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this.initRolling();
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}
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}
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}
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return canWrite;
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};
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BaseRollingFileStream.prototype.shouldRoll = function() {
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return false; // default behaviour is never to roll
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};
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BaseRollingFileStream.prototype.roll = function(filename, callback) {
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callback(); // default behaviour is not to do anything
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};
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