Mojo JS Bindings: add support for associative arrays (Mojo map type)

mojo/public/js/bindings/validator.js

Index: mojo/public/js/bindings/validator.js
diff --git a/mojo/public/js/bindings/validator.js b/mojo/public/js/bindings/validator.js
index de756566224f09228b5bd6cd0443c1b6eaa8a619..d83987173992a66504ecccd32fa1db8c0d5adb6c 100644
--- a/mojo/public/js/bindings/validator.js
+++ b/mojo/public/js/bindings/validator.js
@@ -176,7 +176,7 @@ define("mojo/public/js/bindings/validator", [
   }
 
   Validator.prototype.validateStructPointer = function(
-        offset, structClass, nullable) {
+      offset, structClass, nullable) {
     var structOffset = this.decodePointer(offset);
     if (structOffset === null)
       return validationError.ILLEGAL_POINTER;
@@ -188,6 +188,38 @@ define("mojo/public/js/bindings/validator", [
     return structClass.validate(this, structOffset);
   }
 
+  Validator.prototype.validateMapPointer = function(

[yzshen1, 2014/10/15 22:22:13]

This probably misses fixed-size array dimensions, right?
map<uint8, array<int8, 5>>

[hansmuller, 2014/10/16 20:11:04]

I've integrated the patch with the fixed-size array dimensions changes and fixed
the support for map array values.

In a subsequent patch I'd like to change the way that arrays are represented to
the validator. We should be able to just pass a codec ArrayOf type that
characterizes an array completely.

+      offset, mapIsNullable, keyClass, valueClass, valueIsNullable) {
+    var structOffset = this.decodePointer(offset);
+    if (structOffset === null)
+      return validationError.ILLEGAL_POINTER;
+
+    if (structOffset === NULL_MOJO_POINTER)
+      return mapIsNullable ?
+          validationError.NONE : validationError.UNEXPECTED_NULL_POINTER;
+
+    var mapEncodedSize = codec.kStructHeaderSize + codec.kMapStructPayloadSize;
+    var err = this.validateStructHeader(structOffset, mapEncodedSize, 2);
+    if (err !== validationError.NONE)
+        return err;
+
+    var keysArrayPointerOffset = structOffset + codec.kStructHeaderSize;
+    err = this.validateArrayPointer(
+        keysArrayPointerOffset, keyClass.encodedSize, 0, keyClass, false);
+    if (err !== validationError.NONE)
+        return err;
+
+    var keysArrayOffset = this.decodePointer(keysArrayPointerOffset);
+    var keysArrayLength = this.message.buffer.getUint32(keysArrayOffset + 4);
+
+    var valuesArrayPointerOffset = keysArrayPointerOffset + 8;
+    return this.validateArrayPointer(valuesArrayPointerOffset,
+                                     valueClass.encodedSize,
+                                     keysArrayLength,

[yzshen1, 2014/10/15 22:22:13]

This will detect the validation failure, but with a different error code.

[hansmuller, 2014/10/16 20:11:04]

I've changed this to first validate the keys and values arrays, and then verify
that their lengths are the same. 

+                                     valueClass,
+                                     valueIsNullable);
+  }
+
   Validator.prototype.validateStringPointer = function(offset, nullable) {
     return this.validateArrayPointer(
         offset, codec.Uint8.encodedSize, 0, codec.Uint8, nullable);