Bug 89042 – [V8] V8ArrayBufferViewCustom.cpp uses unnecessary v8::Script::Compile

• Component: DOM
• Status: RESOLVED WONTFIX

[Erik Arvidsson]

This code looks suspicious.

v8::Handle<v8::Value> installHiddenCopyMethod(v8::Handle<v8::Object> prototype) {
    v8::TryCatch tryCatch;
    tryCatch.SetVerbose(true);
    String source(reinterpret_cast<const char*>(V8ArrayBufferViewCustomScript_js),
                  sizeof(V8ArrayBufferViewCustomScript_js));
    v8::Handle<v8::Script> script = v8::Script::Compile(v8String(source));
    v8::Handle<v8::Value> value = script->Run();
    v8::Handle<v8::String> key = v8::String::New(hiddenCopyMethodName);
    prototype->SetHiddenValue(key, value);
    return value;
}

We should not invoke the compiler for this. We can just write the same code in C++.

[Kenneth Russell]

This code inserts a JavaScript-side shim developed by Ulan Degenbaev which provides a large speedup for setting a typed array from a JavaScript array. The same code in C++ is hugely slower due to the need to go across the V8 API for every incoming array element.

I'm closing this as WontFix. If I misunderstood why this bug was filed, please reopen it.

[Erik Arvidsson]

OK. Thanks for the clarification.