File size: 4,232 Bytes
19605ab |
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'use strict';
// Provides a stream to write to.
// When rotate is called, a new stream is provisioned.
// The original stream is closed and the file archived
// according to the archival rules.
var fs = require('fs');
var async = require('async');
var _ = require('lodash');
var zlib = require('zlib');
var EventEmitter = require('events').EventEmitter;
var NumberedFileOps = require('./numberedfileops');
var DateStampedFileOps = require('./datestampedfileops');
var _DEBUG = false;
function FileRotator(logpath, totalFiles, totalSize, gzip) {
var base = new EventEmitter();
var stream;
var streamPath;
var fileops = null;
if (DateStampedFileOps.isDateStamped(logpath)) {
fileops = DateStampedFileOps(logpath, totalFiles, totalSize, gzip);
} else {
fileops = NumberedFileOps(logpath, totalFiles, totalSize, gzip);
}
function gzipCurrentFile(next) {
if (!gzip) {
return next();
}
var unzippedPath = fileops.getStreamFilepath(false);
var zippedPath = fileops.getStreamFilepath(true);
fs.createReadStream(unzippedPath)
.on('error', function (err) {
base.emit('error', err);
next();
})
.pipe(zlib.createGzip())
.pipe(fs.createWriteStream(zippedPath))
.on('finish', function () {
fs.unlink(unzippedPath, next);
})
}
function streamErrorHandler(err) {
base.emit('error', err);
};
function initialiseNewFile(triggerinfo) {
return function (next) {
triggerinfo = triggerinfo || {};
fileops.newStreamFilepath(triggerinfo, function (err, filePath) {
if (err) {
return next(err);
}
stream = fs.createWriteStream(filePath,
{flags: 'a', encoding: 'utf8'});
streamPath = filePath;
stream.on('error', streamErrorHandler);
stream.once('open', function () {
fs.stat(filePath, function (err, stats) {
if (err) {
base.emit('error', err);
} else {
base.emit('newfile', {
stream: stream,
logpath: streamPath,
stats: stats
});
}
if (next) {
next();
}
});
});
});
};
}
function shutdownCurrentStream(next) {
base.emit('closefile');
if (stream) {
var streamCopy = stream;
stream.end(function () {
streamCopy.removeListener('error', streamErrorHandler);
if (next) {
next();
}
});
stream = null;
}
};
// Calling rotate gives us a new stream
// Once called, the previous stream is not valid and
// you won't get another one until the callback has been called.
function rotate(triggerinfo, callback) {
async.series([
shutdownCurrentStream,
gzipCurrentFile,
fileops.moveIntermediateFiles,
fileops.deleteFiles,
initialiseNewFile(triggerinfo)
], function (err) {
callback(err, stream, streamPath);
});
}
// This gives us an initial stream.
// If a file already exists, we'll just append to it.
var initialised = false;
function initialise(startNewFile, callback) {
if (!initialised) {
initialised = true;
async.series([
fileops.deleteFiles,
initialiseNewFile({ startNewFile: startNewFile })
], function (err) {
callback(err, stream, streamPath);
});
} else {
callback();
}
}
return _.extend({}, {
initialise: initialise,
rotate: rotate,
end: shutdownCurrentStream
}, base);
}
module.exports = FileRotator;
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