Revision: 5918
Author: [email protected]
Date: Mon Dec 6 03:44:16 2010
Log: JSON stringify collects substrings in one builder array rather than
using regular
string cons.
Review URL: http://codereview.chromium.org/5567005
http://code.google.com/p/v8/source/detail?r=5918
Modified:
/branches/bleeding_edge/src/json.js
=======================================
--- /branches/bleeding_edge/src/json.js Fri Dec 3 03:12:02 2010
+++ /branches/bleeding_edge/src/json.js Mon Dec 6 03:44:16 2010
@@ -195,75 +195,100 @@
}
}
-function BasicSerializeArray(value, stack) {
+
+function BasicSerializeArray(value, stack, builder) {
if (StackContains(stack, value)) {
throw MakeTypeError('circular_structure', []);
}
stack.push(value);
- var partial = [];
+ builder.push("[");
var len = value.length;
for (var i = 0; i < len; i++) {
- var strP = BasicJSONSerialize($String(i), value, stack);
- if (IS_UNDEFINED(strP)) strP = "null";
- partial.push(strP);
+ var before = builder.length;
+ BasicJSONSerialize($String(i), value, stack, builder);
+ if (before == builder.length) builder.push("null");
+ builder.push(",");
}
stack.pop();
- return "[" + partial.join() + "]";
+ if (builder.pop() != ",") {
+ builder.push("[]"); // Zero length array. Push "[" back on.
+ } else {
+ builder.push("]");
+ }
+
}
-function BasicSerializeObject(value, stack) {
+
+function BasicSerializeObject(value, stack, builder) {
if (StackContains(stack, value)) {
throw MakeTypeError('circular_structure', []);
}
stack.push(value);
- var partial = [];
+ builder.push("{");
for (var p in value) {
if (ObjectHasOwnProperty.call(value, p)) {
- var strP = BasicJSONSerialize(p, value, stack);
- if (!IS_UNDEFINED(strP)) partial.push(%QuoteJSONString(p) + ":" +
strP);
+ builder.push(%QuoteJSONString(p), ":");
+ var before = builder.length;
+ BasicJSONSerialize(p, value, stack, builder);
+ if (before == builder.length) {
+ builder.pop();
+ builder.pop();
+ } else {
+ builder.push(",");
+ }
}
}
stack.pop();
- return "{" + partial.join() + "}";
+ if (builder.pop() != ",") {
+ builder.push("{}"); // Object has no own properties. Push "{" back on.
+ } else {
+ builder.push("}");
+ }
}
-function BasicJSONSerialize(key, holder, stack) {
+
+function BasicJSONSerialize(key, holder, stack, builder) {
var value = holder[key];
if (IS_OBJECT(value) && value) {
var toJSON = value.toJSON;
if (IS_FUNCTION(toJSON)) value = toJSON.call(value, key);
}
- // Unwrap value if necessary
- if (IS_OBJECT(value)) {
+ if (IS_STRING(value)) {
+ builder.push(%QuoteJSONString(value));
+ } else if (IS_NUMBER(value)) {
+ builder.push(($isFinite(value) ? %_NumberToString(value) : "null"));
+ } else if (IS_BOOLEAN(value)) {
+ builder.push((value ? "true" : "false"));
+ } else if (IS_OBJECT(value)) {
+ // Unwrap value if necessary
if (IS_NUMBER_WRAPPER(value)) {
- value = $Number(value);
+ value = %_ValueOf(value);
+ builder.push(($isFinite(value) ? %_NumberToString(value) : "null"));
} else if (IS_STRING_WRAPPER(value)) {
- value = $String(value);
+ builder.push(%QuoteJSONString(%_ValueOf(value)));
} else if (IS_BOOLEAN_WRAPPER(value)) {
- value = %_ValueOf(value);
- }
- }
- switch (typeof value) {
- case "string":
- return %QuoteJSONString(value);
- case "object":
+ builder.push((%_ValueOf(value) ? "true" : "false"));
+ } else {
+ // Regular non-wrapped object
if (!value) {
- return "null";
+ builder.push("null");
} else if (IS_ARRAY(value)) {
- return BasicSerializeArray(value, stack);
+ BasicSerializeArray(value, stack, builder);
} else {
- return BasicSerializeObject(value, stack);
- }
- case "number":
- return $isFinite(value) ? $String(value) : "null";
- case "boolean":
- return value ? "true" : "false";
+ BasicSerializeObject(value, stack, builder);
+ }
+ }
}
}
function JSONStringify(value, replacer, space) {
if (IS_UNDEFINED(replacer) && IS_UNDEFINED(space)) {
- return BasicJSONSerialize('', {'': value}, []);
+ var builder = [];
+ BasicJSONSerialize('', {'': value}, [], builder);
+ if (builder.length == 0) return;
+ var result = %_FastAsciiArrayJoin(builder, "");
+ if (!IS_UNDEFINED(result)) return result;
+ return %StringBuilderConcat(builder, builder.length, "");
}
if (IS_OBJECT(space)) {
// Unwrap 'space' if it is wrapped
--
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