Added pause/resume to renderer. When the renderer is paused, it will …

…buffer up the results until resumed.
lstoll · Jan 29, 2010 · ee72f78 · ee72f78
1 parent 6f7b1a8
commit ee72f78
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Showing 3 changed files with 60 additions and 20 deletions.
diff --git a/demo.js b/demo.js
@@ -12,12 +12,21 @@ var ctx = {
   in_ca: true
 };
 
-Mu.render('simple.html', ctx)
+sys.puts("Outputting examples/simple.html.mu with a chunkSize of 10\n");
+
+Mu.render('simple.html', ctx, {chunkSize: 10})
   .addCallback(function (output) {
     var buffer = '';
 
-    output.addListener('data', function (c) {buffer += c; })
-          .addListener('eof', function () { sys.puts(buffer); });
+    output
+      .addListener('data', function (c) {
+        sys.print(c); // output chunk
+        output.pause(); // pause for demo
+        setTimeout(function () { // wait 500ms and resume for demo
+          output.resume();
+        }, 500);
+      })
+      .addListener('eof', function () { sys.puts("\n\nDONE"); });
   })
   .addErrback(function (e) {
     sys.puts(e.stack);

diff --git a/lib/mu.js b/lib/mu.js
@@ -70,13 +70,13 @@ Mu.compile = function Mu_compile(filename) {
  * @returns {Promise} Returns a promise that will emit when the parse/compile/rendering
  *        is completed. Emits the final result.
  */
-Mu.render = function Mu_render(filename, context) {
+Mu.render = function Mu_render(filename, context, options) {
   var promise = new process.Promise();
 
   if (Mu.cache[filename]) {
     process.nextTick(function () {
       try {
-        promise.emit('success', Mu.cache[filename](context));
+        promise.emit('success', Mu.cache[filename](context, options));
       } catch (e) {
         promise.emit('error', e);
       }
@@ -85,7 +85,7 @@ Mu.render = function Mu_render(filename, context) {
     Mu.compile(filename)
       .addCallback(function (compiled) {
         try {
-          promise.emit('success', compiled(context));
+          promise.emit('success', compiled(context, options));
         } catch (e) {
           promise.emit('error', e);
         }

diff --git a/lib/mu/compiler.js b/lib/mu/compiler.js
@@ -8,15 +8,11 @@ exports.compilePartial = compilePartial;
 function compile(parsed) {
   var M = Mu;
 
-  var code = '(function COMPILED(context) {\n var result = "";\n';
-  code += 'var Mu = M;\n';
-  code += compilePartial(parsed);
-  code += '\n return result;\n})';
-
   var code =
-    '(function COMPILED(context) {\n' +
+    '(function COMPILED(context, options) {\n' +
+    '  options = options || {};\n' +
     '  var Mu = M;\n' +
-    '  var REE = new RenderEventEmitter();\n' +
+    '  var REE = new RenderEventEmitter(options);\n' +
     '  process.nextTick(function () {\n' +
          compilePartial(parsed) + '\n' +
     '    REE.close();\n' +
@@ -67,24 +63,59 @@ function compilePartial(parsed) {
 }
 
 
-function RenderEventEmitter() {
+function RenderEventEmitter(options) {
+  this.chunkSize = options.chunkSize || 1024;
   this.buffer = '';
+  this.paused = false;
+  this.closed = false;
+  this.emittedEOF = false;
 }
 process.inherits(RenderEventEmitter, process.EventEmitter);
 
 process.mixin(RenderEventEmitter.prototype, {
   write: function (chunk) {
-    this.buffer += chunk;
-    if (this.buffer.length >= 1024) {
-      this.emit('data', this.buffer);
-      this.buffer = '';
+    if (this.closed) {
+      return;
     }
+
+    this.buffer += chunk;
+    this.emitChunks();
   },
 
   close: function () {
-    if (this.buffer.length > 0) {
+    this.closed = true;
+    this.emitChunks();
+  },
+
+  pause: function () {
+    this.paused = true;
+  },
+
+  resume: function () {
+    this.paused = false;
+    this.emitChunks();
+  },
+
+  emitChunks: function () {
+    while (this.buffer.length >= this.chunkSize) {
+      if (this.paused) {
+        return;
+      }
+
+      var chunk = this.buffer.substring(0, this.chunkSize);
+      this.buffer = this.buffer.substring(this.chunkSize);
+
+      this.emit('data', chunk);
+    }
+
+    if (this.closed && !this.paused && this.buffer.length) {
       this.emit('data', this.buffer);
+      this.buffer = '';
+    }
+
+    if (this.closed && !this.emittedEOF && !this.buffer.length) {
+      this.emittedEOF = true;
+      this.emit('eof');
     }
-    this.emit('eof');
   }
 });