JSGenericTypedArrayViewConstructorInlines.h   [plain text]

/*
 * Copyright (C) 2013 Apple Inc. All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
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 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
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#ifndef JSGenericTypedArrayViewConstructorInlines_h
#define JSGenericTypedArrayViewConstructorInlines_h

#include "Error.h"
#include "JSArrayBuffer.h"
#include "JSGenericTypedArrayViewConstructor.h"
#include "JSGlobalObject.h"

namespace JSC {

template<typename ViewClass>
JSGenericTypedArrayViewConstructor<ViewClass>::JSGenericTypedArrayViewConstructor(VM& vm, Structure* structure)
    : Base(vm, structure)
{
}

template<typename ViewClass>
void JSGenericTypedArrayViewConstructor<ViewClass>::finishCreation(VM& vm, JSObject* prototype, const String& name)
{
    Base::finishCreation(vm, name);
    putDirectWithoutTransition(vm, vm.propertyNames->prototype, prototype, DontEnum | DontDelete | ReadOnly);
    putDirectWithoutTransition(vm, vm.propertyNames->length, jsNumber(3), DontEnum | DontDelete | ReadOnly);
    putDirectWithoutTransition(vm, vm.propertyNames->BYTES_PER_ELEMENT, jsNumber(ViewClass::elementSize), DontEnum | ReadOnly | DontDelete);
}

template<typename ViewClass>
JSGenericTypedArrayViewConstructor<ViewClass>*
JSGenericTypedArrayViewConstructor<ViewClass>::create(
    VM& vm, Structure* structure, JSObject* prototype,
    const String& name)
{
    JSGenericTypedArrayViewConstructor* result =
        new (NotNull, allocateCell<JSGenericTypedArrayViewConstructor>(vm.heap))
        JSGenericTypedArrayViewConstructor(vm, structure);
    result->finishCreation(vm, prototype, name);
    return result;
}

template<typename ViewClass>
Structure* JSGenericTypedArrayViewConstructor<ViewClass>::createStructure(
    VM& vm, JSGlobalObject* globalObject, JSValue prototype)
{
    return Structure::create(
        vm, globalObject, prototype, TypeInfo(ObjectType, StructureFlags), info());
}

template<typename ViewClass>
static EncodedJSValue JSC_HOST_CALL constructGenericTypedArrayView(ExecState* exec)
{
    Structure* structure =
        asInternalFunction(exec->callee())->globalObject()->typedArrayStructure(
            ViewClass::TypedArrayStorageType);
    
    if (!exec->argumentCount()) {
        if (ViewClass::TypedArrayStorageType == TypeDataView)
            return throwVMError(exec, createTypeError(exec, "DataView constructor requires at least one argument."));
        
        // Even though the documentation doesn't say so, it's correct to say
        // "new Int8Array()". This is the same as allocating an array of zero
        // length.
        return JSValue::encode(ViewClass::create(exec, structure, 0));
    }
    
    if (JSArrayBuffer* jsBuffer = jsDynamicCast<JSArrayBuffer*>(exec->argument(0))) {
        RefPtr<ArrayBuffer> buffer = jsBuffer->impl();
        
        unsigned offset = (exec->argumentCount() > 1) ? exec->uncheckedArgument(1).toUInt32(exec) : 0;
        if (exec->hadException())
            return JSValue::encode(jsUndefined());
        unsigned length = 0;
        if (exec->argumentCount() > 2) {
            length = exec->uncheckedArgument(2).toUInt32(exec);
            if (exec->hadException())
                return JSValue::encode(jsUndefined());
        } else {
            if ((buffer->byteLength() - offset) % ViewClass::elementSize)
                return throwVMError(exec, createRangeError(exec, "ArrayBuffer length minus the byteOffset is not a multiple of the element size"));
            length = (buffer->byteLength() - offset) / ViewClass::elementSize;
        }
        return JSValue::encode(ViewClass::create(exec, structure, buffer, offset, length));
    }
    
    if (ViewClass::TypedArrayStorageType == TypeDataView)
        return throwVMError(exec, createTypeError(exec, "Expected ArrayBuffer for the first argument."));
    
    // For everything but DataView, we allow construction with any of:
    // - Another array. This creates a copy of the of that array.
    // - An integer. This creates a new typed array of that length and zero-initializes it.
    
    if (JSObject* object = jsDynamicCast<JSObject*>(exec->uncheckedArgument(0))) {
        unsigned length =
            object->get(exec, exec->vm().propertyNames->length).toUInt32(exec);
        if (exec->hadException())
            return JSValue::encode(jsUndefined());
        
        ViewClass* result = ViewClass::createUninitialized(exec, structure, length);
        if (!result) {
            ASSERT(exec->hadException());
            return JSValue::encode(jsUndefined());
        }
        
        if (!result->set(exec, object, 0, length))
            return JSValue::encode(jsUndefined());
        
        return JSValue::encode(result);
    }
    
    int length;
    if (exec->uncheckedArgument(0).isInt32())
        length = exec->uncheckedArgument(0).asInt32();
    else if (!exec->uncheckedArgument(0).isNumber())
        return throwVMError(exec, createTypeError(exec, "Invalid array length argument"));
    else {
        length = static_cast<int>(exec->uncheckedArgument(0).asNumber());
        if (length != exec->uncheckedArgument(0).asNumber())
            return throwVMError(exec, createTypeError(exec, "Invalid array length argument (fractional lengths not allowed)"));
    }

    if (length < 0)
        return throwVMError(exec, createRangeError(exec, "Requested length is negative"));
    return JSValue::encode(ViewClass::create(exec, structure, length));
}

template<typename ViewClass>
ConstructType JSGenericTypedArrayViewConstructor<ViewClass>::getConstructData(JSCell*, ConstructData& constructData)
{
    constructData.native.function = constructGenericTypedArrayView<ViewClass>;
    return ConstructTypeHost;
}

template<typename ViewClass>
CallType JSGenericTypedArrayViewConstructor<ViewClass>::getCallData(JSCell*, CallData& callData)
{
    callData.native.function = constructGenericTypedArrayView<ViewClass>;
    return CallTypeNone;
}

} // namespace JSC

#endif // JSGenericTypedArrayViewConstructorInlines_h