Support packed arrays of booleans in Mojo messages

mojo/public/js/bindings/codec.js

Index: mojo/public/js/bindings/codec.js
diff --git a/mojo/public/js/bindings/codec.js b/mojo/public/js/bindings/codec.js
index 84c86c1299125a654fdf3a9dec84b6295bcf6bbc..7aff9bf5edfef44112577d995775f94832bd7486 100644
--- a/mojo/public/js/bindings/codec.js
+++ b/mojo/public/js/bindings/codec.js
@@ -229,6 +229,23 @@ define("mojo/public/js/bindings/codec", [
     return val;
   };
 
+  Decoder.prototype.decodeBoolArray = function() {
+    var numberOfBytes = this.readUint32();
+    var numberOfElements = this.readUint32();
+
+    var bitsLength = Math.ceil(numberOfElements / 8);
+    var bits = new Uint8Array(bitsLength);

[abarth-chromium, 2014/07/08 02:00:33]

You should be able to do this work without allocating a new Uint8Array.  Can't
you just call readInt8 in a loop?

+    for (var i = 0; i < bitsLength; ++i) {
+      bits[i] = Uint8.decode(this);
+    }
+
+    var val = new Array(numberOfElements);
+    for (var i = 0; i < numberOfElements; ++i) {
+      val[i] = (bits[Math.floor(i / 8)] & (1 << i % 8)) ? true : false;
+    }
+    return val;
+  };
+
   Decoder.prototype.decodeStruct = function(cls) {
     return cls.decode(this);
   };
@@ -249,6 +266,14 @@ define("mojo/public/js/bindings/codec", [
     return this.decodeAndCreateDecoder(pointer).decodeArray(cls);
   };
 
+  Decoder.prototype.decodeBoolArrayPointer = function() {
+    var pointer = this.decodePointer();
+    if (!pointer) {
+      return null;
+    }
+    return this.decodeAndCreateDecoder(pointer).decodeBoolArray();
+  };
+
   Decoder.prototype.decodeStringPointer = function() {
     var pointer = this.decodePointer();
     if (!pointer) {
@@ -364,12 +389,13 @@ define("mojo/public/js/bindings/codec", [
     this.next += numberOfElements;
   };
 
-  Encoder.prototype.encodeArray = function(cls, val) {
-    var numberOfElements = val.length;
-    var numberOfBytes = kArrayHeaderSize + cls.encodedSize * numberOfElements;
+  Encoder.prototype.encodeArray = function(cls, val, numberOfElements) {
+    if (numberOfElements === undefined)
+      numberOfElements = val.length;
+    var numberOfBytes = kArrayHeaderSize + cls.encodedSize * val.length;
     this.writeUint32(numberOfBytes);
     this.writeUint32(numberOfElements);
-    for (var i = 0; i < numberOfElements; ++i) {
+    for (var i = 0; i < val.length; ++i) {
       cls.encode(this, val[i]);
     }
   };
@@ -397,6 +423,23 @@ define("mojo/public/js/bindings/codec", [
     encoder.encodeArray(cls, val);
   };
 
+  Encoder.prototype.encodeBoolArrayPointer = function(val) {
+    if (!val) {
+      this.encodePointer(val);
+      return;
+    }
+    var numberOfElements = val.length;
+    var encodedSize = kArrayHeaderSize + Math.ceil(numberOfElements / 8);
+    var encoder = this.createAndEncodeEncoder(encodedSize);
+
+    var bits = new Uint8Array(Math.ceil(numberOfElements / 8));
+    for (var i = 0; i < numberOfElements; i++) {
+        if (val[i])
+            bits[Math.floor(i / 8)] |= (1 << i % 8);
+    }
+    encoder.encodeArray(Uint8, bits, numberOfElements);
+  };
+
   Encoder.prototype.encodeStringPointer = function(val) {
     if (!val) {
       this.encodePointer(val);
@@ -696,6 +739,19 @@ define("mojo/public/js/bindings/codec", [
     encoder.encodeArrayPointer(this.cls, val);
   };
 
+  function ArrayOfBoolArrayPointers() {
+  }
+
+  ArrayOfBoolArrayPointers.prototype.encodedSize = 8;
+
+  ArrayOfBoolArrayPointers.prototype.decode = function(decoder) {
+    return decoder.decodeBoolArrayPointer();
+  };
+
+  ArrayOfBoolArrayPointers.prototype.encode = function(encoder, val) {
+    encoder.encodeBoolArrayPointer(val);
+  };
+
   function Handle() {
   }
 
@@ -734,6 +790,7 @@ define("mojo/public/js/bindings/codec", [
   exports.String = String;
   exports.PointerTo = PointerTo;
   exports.ArrayOf = ArrayOf;
+  exports.ArrayOfBoolArrayPointers = ArrayOfBoolArrayPointers;
   exports.Handle = Handle;
   return exports;
 });