moved streams code around, added stub for DateRollingFileStream

2012-09-05 10:58:28 +10:00
parent cbc1dd32f9
commit be1272cd7c
9 changed files with 349 additions and 271 deletions
--- a/lib/streams/RollingFileStream.js
+++ b/lib/streams/RollingFileStream.js
@@ -0,0 +1,110 @@
+var BaseRollingFileStream = require('./BaseRollingFileStream'),
+    util = require('util'),
+    path = require('path'),
+    fs = require('fs'),
+    async = require('async');
+
+function debug(message) {
+//    util.debug(message);
+//    console.log(message);
+}
+
+module.exports = RollingFileStream;
+
+function RollingFileStream (filename, size, backups, options) {
+    this.size = size;
+    this.backups = backups || 1;
+
+    function throwErrorIfArgumentsAreNotValid() {
+        if (!filename || !size || size <= 0) {
+            throw new Error("You must specify a filename and file size");
+        }
+    }
+
+    throwErrorIfArgumentsAreNotValid();
+
+    RollingFileStream.super_.call(this, filename, options);
+}
+util.inherits(RollingFileStream, BaseRollingFileStream);
+
+RollingFileStream.prototype.shouldRoll = function() {
+    return this.currentSize >= this.size;
+};
+
+RollingFileStream.prototype.roll = function(filename, callback) {
+    var that = this,
+        nameMatcher = new RegExp('^' + path.basename(filename));
+
+    function justTheseFiles (item) {
+        return nameMatcher.test(item);
+    }
+
+    function index(filename_) {
+        return parseInt(filename_.substring((path.basename(filename) + '.').length), 10) || 0;
+    }
+
+    function byIndex(a, b) {
+        if (index(a) > index(b)) {
+            return 1;
+        } else if (index(a) < index(b) ) {
+            return -1;
+        } else {
+            return 0;
+        }
+    }
+
+    function increaseFileIndex (fileToRename, cb) {
+        var idx = index(fileToRename);
+        debug('Index of ' + fileToRename + ' is ' + idx);
+        if (idx < that.backups) {
+            //on windows, you can get a EEXIST error if you rename a file to an existing file
+            //so, we'll try to delete the file we're renaming to first
+            fs.unlink(filename + '.' + (idx+1), function (err) {
+                //ignore err: if we could not delete, it's most likely that it doesn't exist
+                debug('Renaming ' + fileToRename + ' -> ' + filename + '.' + (idx+1));
+                fs.rename(path.join(path.dirname(filename), fileToRename), filename + '.' + (idx + 1), cb);
+            });
+        } else {
+            cb();
+        }
+    }
+
+    function renameTheFiles(cb) {
+        //roll the backups (rename file.n to file.n+1, where n <= numBackups)
+        debug("Renaming the old files");
+        fs.readdir(path.dirname(filename), function (err, files) {
+            async.forEachSeries(
+                files.filter(justTheseFiles).sort(byIndex).reverse(),
+                increaseFileIndex,
+                cb
+            );
+        });
+    }
+
+    function openANewFile(cb) {
+        debug("Opening a new file");
+        fs.open(
+            filename,
+            that.options.flags,
+            that.options.mode,
+            function (err, fd) {
+                debug("opened new file");
+                var oldLogFileFD = that.fd;
+                that.fd = fd;
+                that.writable = true;
+                fs.close(oldLogFileFD, cb);
+            }
+        );
+    }
+
+    debug("Starting roll");
+    debug("Queueing up data until we've finished rolling");
+    debug("Flushing underlying stream");
+    this.flush();
+
+    async.series([
+        renameTheFiles,
+        openANewFile
+    ], callback);
+
+};