avoid open file handle limit by saving writes

lib/winston-logrotate.js

@@ -37,9 +37,8 @@ var Rotate = exports.Rotate = function (options) {
 
     this.formatter = options.formatter;
 
+    this.state = 'uninitialized'
     this.stringify =  options.stringify || DEFAULT_STRINGIFY;
-
-    this.ready = false;
 };
 
 //
@@ -66,6 +65,9 @@ Rotate.prototype.name = 'rotate';
 // #### @callback {function} Continuation to respond to when complete.
 // Core logging method exposed to Winston. Metadata is optional.
 //
+
+var pendingWrites = {}
+
 Rotate.prototype.log = function (level, msg, meta, callback) {
     var self = this;
 
@@ -82,14 +84,16 @@ Rotate.prototype.log = function (level, msg, meta, callback) {
         label: this.label
     });
 
-    if (this.ready) {
-        this._write(level, output, callback);
+    if (this.state == 'uninitialized') {
+      this.state = 'initializing';
+      pendingWrites[this.file] = [{ level: level, output: output, callback: callback }];
+      this._init();
     } else {
-        this._init().done(function () {
-            self._write(level, output, callback);
-        }, function (err) {
-            throw err;
-        });
+      if (this.state == 'initializing') {
+        pendingWrites[this.file].push({ level: level, output: output, callback: callback });
+      } else {
+        self._write(level, output, callback);
+      }
     }
 };
 
@@ -103,7 +107,6 @@ Rotate.prototype.close = function() {
 
 Rotate.prototype._write = function (level, output, callback) {
     var self = this;
-
     this.log_stream.write(output + '\n', function () {
         self.emit('logged');
         callback(null, true);
@@ -132,8 +135,17 @@ Rotate.prototype._configure_log_stream = function (resolve, reject) {
     });
 
     log_stream.on('ready', function () {
-        self.ready = true;
+        self.state = 'ready'
         self.emit('ready', log_stream);
+
+        if (self.file in pendingWrites) {
+          for (var i = 0; i < pendingWrites[self.file].length; ++i) {
+            var pendingWrite = pendingWrites[self.file][i]
+            self._write(pendingWrite.level, pendingWrite.output, pendingWrite.callback);
+          }
+          delete pendingWrites[self.file]
+        }
+
         resolve();
     });
 

test/winston-logrotate.spec.js

@@ -158,4 +158,20 @@ describe('winston logrotate tests', function () {
 
         recursive_log(6);
     });
+
+    it('max file handles', function(done) {
+      this.timeout(10000)
+      var temp_dir = temp.mkdirSync('winston-logrotate-test');
+      var file = path.join(temp_dir, 'rotate.log');
+      var logger = new Rotate({
+          file: file,
+          size: '1k',
+          keep: 1
+      });
+
+      for (var i = 0; i < 100000; ++ i) {
+        logger.log('max log test');
+      }
+      done();
+    })
 });