Buffer all operations before load and no more pipelining

lib/datastore.js

@@ -14,7 +14,7 @@ var fs = require('fs')
  * Create a new collection
  * @param {String} options.filename Optional, datastore will be in-memory only if not provided
  * @param {Boolean} options.inMemoryOnly Optional, default to false
- * @param {Boolean} options.pipeline Optional, defaults to false, pipeline appends to the data file (enable to return before writes are persisted to disk for greater speed)
+ * @param {Boolean} options.pipeline DEPRECATED, doesn't have any effect anymore
  * @param {Boolean} options.nodeWebkitAppName Optional, specify the name of your NW app if you want options.filename to be relative to the directory where
  *                                            Node Webkit stores application data such as cookies and local storage (the best place to store data in my opinion)
  */
@@ -25,12 +25,10 @@ function Datastore (options) {
   if (typeof options === 'string') {
     filename = options;
     this.inMemoryOnly = false;   // Default
-    this.pipeline = false;       // Default
   } else {
     options = options || {};
     filename = options.filename;
     this.inMemoryOnly = options.inMemoryOnly || false;
-    this.pipeline = options.pipeline || false;
   }
 
   // Determine whether in memory or persistent
@@ -47,7 +45,6 @@ function Datastore (options) {
   }
 
   this.executor = new Executor();
-  if (this.pipeline) { this.persistenceExecutor = new Executor(); }
 
   // We keep internally the number of lines in the datafile
   // This will be used when/if I implement autocompacting when the datafile grows too big
@@ -255,12 +252,14 @@ Datastore.prototype._loadDatabase = function (cb) {
   // In-memory only datastore
   if (self.inMemoryOnly) { return callback(null); }
 
+  async.waterfall([
+    function (cb) {
       customUtils.ensureDirectoryExists(path.dirname(self.filename), function (err) {
         fs.exists(self.filename, function (exists) {
-      if (!exists) { return fs.writeFile(self.filename, '', 'utf8', function (err) { callback(err); }); }
+          if (!exists) { return fs.writeFile(self.filename, '', 'utf8', function (err) { cb(err); }); }
 
           fs.readFile(self.filename, 'utf8', function (err, rawData) {
-        if (err) { return callback(err); }
+            if (err) { return cb(err); }
             var treatedData = Datastore.treatRawData(rawData);
 
             try {
@@ -268,22 +267,25 @@ Datastore.prototype._loadDatabase = function (cb) {
             } catch (e) {
               self.resetIndexes();   // Rollback any index which didn't fail
               self.datafileSize = 0;
-          return callback(e);
+              return cb(e);
             }
 
             self.datafileSize = treatedData.length;
-        self.persistCachedDatabase(callback);
+            self.persistCachedDatabase(cb);
           });
         });
       });
+    }
+  ], function (err) {
+       if (err) { return callback(err); }
+
+       self.executor.processBuffer();
+       return callback(null);
+     });
 };
 
 Datastore.prototype.loadDatabase = function () {
-  if (this.pipeline) {
-    this.persistenceExecutor.push({ this: this, fn: this._loadDatabase, arguments: arguments });
-  } else {
-    this.executor.push({ this: this, fn: this._loadDatabase, arguments: arguments });
-  }
+  this.executor.push({ this: this, fn: this._loadDatabase, arguments: arguments }, true);
 };
 
 
@@ -371,18 +373,10 @@ Datastore.prototype._persistNewState = function (newDocs, cb) {
 };
 Datastore.prototype.persistNewState = function (newDocs, cb) {
   if (this.inMemoryOnly) {
-    cb();   // No persistence
-    return;
-  }
-
-  if (this.pipeline) {
-    this.persistenceExecutor.push({ this: this, fn: this._persistNewState, arguments: [newDocs] });
-    cb ();   // Return right away with no error
-    return;
-  }
-
-  // Default behaviour
+    cb();
+  } else {
     this._persistNewState(newDocs, cb);
+  }
 };
 
 
@@ -424,6 +418,8 @@ Datastore.prototype.insert = function () {
 /**
  * Find all documents matching the query
  * @param {Object} query MongoDB-style query
+ *
+ * @api private Use find
  */
 Datastore.prototype._find = function (query, callback) {
   var res = []
@@ -453,6 +449,8 @@ Datastore.prototype.find = function () {
 /**
  * Find one document matching the query
  * @param {Object} query MongoDB-style query
+ *
+ * @api private Use findOne
  */
 Datastore.prototype._findOne = function (query, callback) {
   var self = this

lib/executor.js

@@ -6,12 +6,17 @@ var async = require('async')
   ;
 
 function Executor () {
+  this.buffer = [];
+  this.ready = false;
+
+  // This queue will execute all commands, one-by-one in order
   this.queue = async.queue(function (task, cb) {
     var callback
       , lastArg = task.arguments[task.arguments.length - 1]
       , i, newArguments = []
       ;
 
+    // task.arguments is an array-like object on which adding a new field doesn't work, so we transform it into a real array
     for (i = 0; i < task.arguments.length; i += 1) { newArguments.push(task.arguments[i]); }
 
     // Always tell the queue task is complete. Execute callback if any was given.
@@ -34,13 +39,32 @@ function Executor () {
 
 
 /**
- * @param {Object} options
- *                 options.this - Object to use as this
- *                 options.fn - Function to execute
- *                 options.arguments - Array of arguments
+ * If executor is ready, queue task (and process it immediately if executor was idle)
+ * If not, buffer task for later processing
+ * @param {Object} task
+ *                 task.this - Object to use as this
+ *                 task.fn - Function to execute
+ *                 task.arguments - Array of arguments
+ * @param {Boolean} forceQueuing Optional (defaults to false) force executor to queue task even if it is not ready
+ */
+Executor.prototype.push = function (task, forceQueuing) {
+  if (this.ready || forceQueuing) {
+    this.queue.push(task);
+  } else {
+    this.buffer.push(task);
+  }
+};
+
+
+/**
+ * Queue all tasks in buffer (in the same order they came in)
+ * Automatically sets executor as ready
  */
-Executor.prototype.push = function () {
-  this.queue.push.apply(this, arguments);
+Executor.prototype.processBuffer = function () {
+  var i;
+  this.ready = true;
+  for (i = 0; i < this.buffer.length; i += 1) { this.queue.push(this.buffer[i]); }
+  this.buffer = [];
 };
 
 

test/db.test.js

@@ -17,7 +17,6 @@ describe('Database', function () {
   beforeEach(function (done) {
     d = new Datastore({ filename: testDb });
     d.filename.should.equal(testDb);
-    d.pipeline.should.equal(false);
     d.inMemoryOnly.should.equal(false);
 
     async.waterfall([
@@ -45,17 +44,14 @@ describe('Database', function () {
   it('Constructor compatibility with v0.6-', function () {
     var dbef = new Datastore('somefile');
     dbef.filename.should.equal('somefile');
-    dbef.pipeline.should.equal(false);
     dbef.inMemoryOnly.should.equal(false);
 
     var dbef = new Datastore('');
     assert.isNull(dbef.filename);
-    dbef.pipeline.should.equal(false);
     dbef.inMemoryOnly.should.equal(true);
 
     var dbef = new Datastore();
     assert.isNull(dbef.filename);
-    dbef.pipeline.should.equal(false);
     dbef.inMemoryOnly.should.equal(true);
   });
 
@@ -304,7 +300,7 @@ describe('Database', function () {
 
   describe('Insert', function () {
 
-    it('Able to insert a document in the database, setting an _id if none provided, and retrieve it even after a reload', function (done) {
+    it.only('Able to insert a document in the database, setting an _id if none provided, and retrieve it even after a reload', function (done) {
       d.find({}, function (err, docs) {
         docs.length.should.equal(0);
 
@@ -2029,108 +2025,4 @@ describe('Database', function () {
   });   // ==== End of 'Using indexes' ==== //
 
 
-  describe('Pipelining', function () {
-
-    it('Can insert documents and persist them', function (done) {
-      d = new Datastore({ filename: testDb, pipeline: true });
-      d.filename.should.equal(testDb);
-      d.pipeline.should.equal(true);
-      d.inMemoryOnly.should.equal(false);
-      assert.isDefined(d.persistenceExecutor);
-
-      d.insert({ f: 12 }, function (err, doc12) {
-        assert.isNull(err);
-        d.insert({ f: 5 }, function (err, doc5) {
-          assert.isNull(err);
-          d.insert({ f: 31 }, function (err, doc31) {
-            assert.isNull(err);
-
-            // Need to wait a bit for persistence pipeline to be taken care of
-            // 2ms is enough but let's use 50 to be really sure tests don't fail for a bad reason
-            setTimeout(function () {
-              var rawData = fs.readFileSync(testDb, 'utf8')
-                , treatedData = Datastore.treatRawData(rawData)
-                ;
-
-              treatedData.sort(function (a, b) { return a.f - b.f; });
-              treatedData.length.should.equal(3);
-              assert.deepEqual(treatedData[0], doc5);
-              assert.deepEqual(treatedData[1], doc12);
-              assert.deepEqual(treatedData[2], doc31);
-
-              done();
-            }, 50);
-          });
-        });
-      });
-    });
-
-    it('Can remove documents in persistence file too', function (done) {
-      d = new Datastore({ filename: testDb, pipeline: true });
-      d.filename.should.equal(testDb);
-      d.pipeline.should.equal(true);
-      d.inMemoryOnly.should.equal(false);
-      assert.isDefined(d.persistenceExecutor);
-
-      d.insert({ f: 12 }, function (err, doc12) {
-        assert.isNull(err);
-        d.insert({ f: 5 }, function (err, doc5) {
-          assert.isNull(err);
-          d.remove({ f: 12 }, {}, function (err, doc31) {
-            assert.isNull(err);
-
-            // Need to wait a bit for persistence pipeline to be taken care of
-            // 2ms is enough but let's use 50 to be really sure tests don't fail for a bad reason
-            setTimeout(function () {
-              var rawData = fs.readFileSync(testDb, 'utf8')
-                , treatedData = Datastore.treatRawData(rawData)
-                ;
-
-              treatedData.sort(function (a, b) { return a.f - b.f; });
-              treatedData.length.should.equal(1);
-              assert.deepEqual(treatedData[0], doc5);
-
-              done();
-            }, 50);
-          });
-        });
-      });
-    });
-
-    it('Can update documents in persistence file too', function (done) {
-      d = new Datastore({ filename: testDb, pipeline: true });
-      d.filename.should.equal(testDb);
-      d.pipeline.should.equal(true);
-      d.inMemoryOnly.should.equal(false);
-      assert.isDefined(d.persistenceExecutor);
-
-      d.insert({ f: 12 }, function (err, doc12) {
-        assert.isNull(err);
-        d.insert({ f: 5 }, function (err, doc5) {
-          assert.isNull(err);
-          d.update({ f: 12 }, { $set: { f: 555 } }, {}, function (err) {
-            assert.isNull(err);
-
-            // Need to wait a bit for persistence pipeline to be taken care of
-            // 2ms is enough but let's use 50 to be really sure tests don't fail for a bad reason
-            setTimeout(function () {
-              var rawData = fs.readFileSync(testDb, 'utf8')
-                , treatedData = Datastore.treatRawData(rawData)
-                ;
-
-              treatedData.sort(function (a, b) { return a.f - b.f; });
-              treatedData.length.should.equal(2);
-              assert.deepEqual(treatedData[0], doc5);
-              assert.deepEqual(treatedData[1], { f: 555, _id: doc12._id });
-
-              done();
-            }, 50);
-          });
-        });
-      });
-    });
-
-  });   // ==== End of 'Pipelining' ==== //
-
-
 });