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| 1 | +var fs = require('fs'), |
| 2 | + util = require('util'); |
| 3 | + |
| 4 | +function debug(message) { |
| 5 | +// util.debug(message); |
| 6 | +// console.log(message); |
| 7 | +} |
| 8 | + |
| 9 | +module.exports = BaseRollingFileStream; |
| 10 | + |
| 11 | +function BaseRollingFileStream(filename, options) { |
| 12 | + this.filename = filename; |
| 13 | + this.options = options || { encoding: 'utf8', mode: 0644, flags: 'a' }; |
| 14 | + this.rolling = false; |
| 15 | + this.writesWhileRolling = []; |
| 16 | + this.currentSize = 0; |
| 17 | + |
| 18 | + function currentFileSize(file) { |
| 19 | + var fileSize = 0; |
| 20 | + try { |
| 21 | + fileSize = fs.statSync(file).size; |
| 22 | + } catch (e) { |
| 23 | + // file does not exist |
| 24 | + } |
| 25 | + return fileSize; |
| 26 | + } |
| 27 | + |
| 28 | + function throwErrorIfArgumentsAreNotValid() { |
| 29 | + if (!filename) { |
| 30 | + throw new Error("You must specify a filename"); |
| 31 | + } |
| 32 | + } |
| 33 | + |
| 34 | + throwErrorIfArgumentsAreNotValid(); |
| 35 | + |
| 36 | + BaseRollingFileStream.super_.call(this, this.filename, this.options); |
| 37 | + this.currentSize = currentFileSize(this.filename); |
| 38 | +} |
| 39 | +util.inherits(BaseRollingFileStream, fs.FileWriteStream); |
| 40 | + |
| 41 | +BaseRollingFileStream.prototype.initRolling = function() { |
| 42 | + var that = this; |
| 43 | + |
| 44 | + function emptyRollingQueue() { |
| 45 | + debug("emptying the rolling queue"); |
| 46 | + var toWrite; |
| 47 | + while ((toWrite = that.writesWhileRolling.shift())) { |
| 48 | + BaseRollingFileStream.super_.prototype.write.call(that, toWrite.data, toWrite.encoding); |
| 49 | + that.currentSize += toWrite.data.length; |
| 50 | + if (that.shouldRoll()) { |
| 51 | + that.flush(); |
| 52 | + return true; |
| 53 | + } |
| 54 | + } |
| 55 | + that.flush(); |
| 56 | + return false; |
| 57 | + } |
| 58 | + |
| 59 | + this.rolling = true; |
| 60 | + this.roll(this.filename, function() { |
| 61 | + that.currentSize = 0; |
| 62 | + that.rolling = emptyRollingQueue(); |
| 63 | + if (that.rolling) { |
| 64 | + process.nextTick(function() { that.initRolling(); }); |
| 65 | + } |
| 66 | + }); |
| 67 | +}; |
| 68 | + |
| 69 | +BaseRollingFileStream.prototype.write = function(data, encoding) { |
| 70 | + if (this.rolling) { |
| 71 | + this.writesWhileRolling.push({ data: data, encoding: encoding }); |
| 72 | + return false; |
| 73 | + } else { |
| 74 | + var canWrite = BaseRollingFileStream.super_.prototype.write.call(this, data, encoding); |
| 75 | + this.currentSize += data.length; |
| 76 | + debug('current size = ' + this.currentSize); |
| 77 | + if (this.shouldRoll()) { |
| 78 | + this.initRolling(); |
| 79 | + } |
| 80 | + return canWrite; |
| 81 | + } |
| 82 | +}; |
| 83 | + |
| 84 | +BaseRollingFileStream.prototype.shouldRoll = function() { |
| 85 | + return false; // default behaviour is never to roll |
| 86 | +}; |
| 87 | + |
| 88 | +BaseRollingFileStream.prototype.roll = function(filename, callback) { |
| 89 | + callback(); // default behaviour is not to do anything |
| 90 | +}; |
| 91 | + |
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