1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/dom/bindings/TypedArray.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,335 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
1.5 +/* vim: set ts=2 sw=2 et tw=79: */
1.6 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this file,
1.8 + * You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#ifndef mozilla_dom_TypedArray_h
1.11 +#define mozilla_dom_TypedArray_h
1.12 +
1.13 +#include "jsapi.h"
1.14 +#include "jsfriendapi.h"
1.15 +#include "js/RootingAPI.h"
1.16 +#include "js/TracingAPI.h"
1.17 +#include "mozilla/Attributes.h"
1.18 +#include "mozilla/Move.h"
1.19 +#include "mozilla/dom/BindingDeclarations.h"
1.20 +#include "nsWrapperCache.h"
1.21 +
1.22 +namespace mozilla {
1.23 +namespace dom {
1.24 +
1.25 +/*
1.26 + * Class that just handles the JSObject storage and tracing for typed arrays
1.27 + */
1.28 +struct TypedArrayObjectStorage : AllTypedArraysBase {
1.29 +protected:
1.30 + JSObject* mObj;
1.31 +
1.32 + TypedArrayObjectStorage(JSObject *obj) : mObj(obj)
1.33 + {
1.34 + }
1.35 +
1.36 + explicit TypedArrayObjectStorage(TypedArrayObjectStorage&& aOther)
1.37 + : mObj(aOther.mObj)
1.38 + {
1.39 + aOther.mObj = nullptr;
1.40 + }
1.41 +
1.42 +public:
1.43 + inline void TraceSelf(JSTracer* trc)
1.44 + {
1.45 + if (mObj) {
1.46 + JS_CallObjectTracer(trc, &mObj, "TypedArray.mObj");
1.47 + }
1.48 + }
1.49 +
1.50 +private:
1.51 + TypedArrayObjectStorage(const TypedArrayObjectStorage&) MOZ_DELETE;
1.52 +};
1.53 +
1.54 +/*
1.55 + * Various typed array classes for argument conversion. We have a base class
1.56 + * that has a way of initializing a TypedArray from an existing typed array, and
1.57 + * a subclass of the base class that supports creation of a relevant typed array
1.58 + * or array buffer object.
1.59 + */
1.60 +template<typename T,
1.61 + JSObject* UnwrapArray(JSObject*),
1.62 + void GetLengthAndData(JSObject*, uint32_t*, T**)>
1.63 +struct TypedArray_base : public TypedArrayObjectStorage {
1.64 + typedef T element_type;
1.65 +
1.66 + TypedArray_base(JSObject* obj)
1.67 + : TypedArrayObjectStorage(obj),
1.68 + mData(nullptr),
1.69 + mLength(0),
1.70 + mComputed(false)
1.71 + {
1.72 + MOZ_ASSERT(obj != nullptr);
1.73 + }
1.74 +
1.75 + TypedArray_base()
1.76 + : TypedArrayObjectStorage(nullptr),
1.77 + mData(nullptr),
1.78 + mLength(0),
1.79 + mComputed(false)
1.80 + {
1.81 + }
1.82 +
1.83 + explicit TypedArray_base(TypedArray_base&& aOther)
1.84 + : TypedArrayObjectStorage(Move(aOther)),
1.85 + mData(aOther.mData),
1.86 + mLength(aOther.mLength)
1.87 + {
1.88 + aOther.mData = nullptr;
1.89 + aOther.mLength = 0;
1.90 + }
1.91 +
1.92 +private:
1.93 + mutable T* mData;
1.94 + mutable uint32_t mLength;
1.95 + mutable bool mComputed;
1.96 +
1.97 +public:
1.98 + inline bool Init(JSObject* obj)
1.99 + {
1.100 + MOZ_ASSERT(!inited());
1.101 + DoInit(obj);
1.102 + return inited();
1.103 + }
1.104 +
1.105 + inline bool inited() const {
1.106 + return !!mObj;
1.107 + }
1.108 +
1.109 + inline T *Data() const {
1.110 + MOZ_ASSERT(mComputed);
1.111 + return mData;
1.112 + }
1.113 +
1.114 + inline uint32_t Length() const {
1.115 + MOZ_ASSERT(mComputed);
1.116 + return mLength;
1.117 + }
1.118 +
1.119 + inline JSObject *Obj() const {
1.120 + MOZ_ASSERT(inited());
1.121 + return mObj;
1.122 + }
1.123 +
1.124 + inline bool WrapIntoNewCompartment(JSContext* cx)
1.125 + {
1.126 + return JS_WrapObject(cx,
1.127 + JS::MutableHandle<JSObject*>::fromMarkedLocation(&mObj));
1.128 + }
1.129 +
1.130 + inline void ComputeLengthAndData() const
1.131 + {
1.132 + MOZ_ASSERT(inited());
1.133 + MOZ_ASSERT(!mComputed);
1.134 + GetLengthAndData(mObj, &mLength, &mData);
1.135 + mComputed = true;
1.136 + }
1.137 +
1.138 +protected:
1.139 + inline void DoInit(JSObject* obj)
1.140 + {
1.141 + mObj = UnwrapArray(obj);
1.142 + }
1.143 +
1.144 + inline void ComputeData() const {
1.145 + MOZ_ASSERT(inited());
1.146 + if (!mComputed) {
1.147 + GetLengthAndData(mObj, &mLength, &mData);
1.148 + mComputed = true;
1.149 + }
1.150 + }
1.151 +
1.152 +private:
1.153 + TypedArray_base(const TypedArray_base&) MOZ_DELETE;
1.154 +};
1.155 +
1.156 +
1.157 +template<typename T,
1.158 + JSObject* UnwrapArray(JSObject*),
1.159 + T* GetData(JSObject*),
1.160 + void GetLengthAndData(JSObject*, uint32_t*, T**),
1.161 + JSObject* CreateNew(JSContext*, uint32_t)>
1.162 +struct TypedArray : public TypedArray_base<T, UnwrapArray, GetLengthAndData> {
1.163 + TypedArray(JSObject* obj) :
1.164 + TypedArray_base<T, UnwrapArray, GetLengthAndData>(obj)
1.165 + {}
1.166 +
1.167 + TypedArray() :
1.168 + TypedArray_base<T, UnwrapArray, GetLengthAndData>()
1.169 + {}
1.170 +
1.171 + explicit TypedArray(TypedArray&& aOther)
1.172 + : TypedArray_base<T, UnwrapArray, GetLengthAndData>(Move(aOther))
1.173 + {
1.174 + }
1.175 +
1.176 + static inline JSObject*
1.177 + Create(JSContext* cx, nsWrapperCache* creator, uint32_t length,
1.178 + const T* data = nullptr) {
1.179 + JS::Rooted<JSObject*> creatorWrapper(cx);
1.180 + Maybe<JSAutoCompartment> ac;
1.181 + if (creator && (creatorWrapper = creator->GetWrapperPreserveColor())) {
1.182 + ac.construct(cx, creatorWrapper);
1.183 + }
1.184 +
1.185 + return CreateCommon(cx, length, data);
1.186 + }
1.187 +
1.188 + static inline JSObject*
1.189 + Create(JSContext* cx, uint32_t length, const T* data = nullptr) {
1.190 + return CreateCommon(cx, length, data);
1.191 + }
1.192 +
1.193 +private:
1.194 + static inline JSObject*
1.195 + CreateCommon(JSContext* cx, uint32_t length, const T* data) {
1.196 + JSObject* obj = CreateNew(cx, length);
1.197 + if (!obj) {
1.198 + return nullptr;
1.199 + }
1.200 + if (data) {
1.201 + T* buf = static_cast<T*>(GetData(obj));
1.202 + memcpy(buf, data, length*sizeof(T));
1.203 + }
1.204 + return obj;
1.205 + }
1.206 +
1.207 + TypedArray(const TypedArray&) MOZ_DELETE;
1.208 +};
1.209 +
1.210 +typedef TypedArray<int8_t, js::UnwrapInt8Array, JS_GetInt8ArrayData,
1.211 + js::GetInt8ArrayLengthAndData, JS_NewInt8Array>
1.212 + Int8Array;
1.213 +typedef TypedArray<uint8_t, js::UnwrapUint8Array, JS_GetUint8ArrayData,
1.214 + js::GetUint8ArrayLengthAndData, JS_NewUint8Array>
1.215 + Uint8Array;
1.216 +typedef TypedArray<uint8_t, js::UnwrapUint8ClampedArray, JS_GetUint8ClampedArrayData,
1.217 + js::GetUint8ClampedArrayLengthAndData, JS_NewUint8ClampedArray>
1.218 + Uint8ClampedArray;
1.219 +typedef TypedArray<int16_t, js::UnwrapInt16Array, JS_GetInt16ArrayData,
1.220 + js::GetInt16ArrayLengthAndData, JS_NewInt16Array>
1.221 + Int16Array;
1.222 +typedef TypedArray<uint16_t, js::UnwrapUint16Array, JS_GetUint16ArrayData,
1.223 + js::GetUint16ArrayLengthAndData, JS_NewUint16Array>
1.224 + Uint16Array;
1.225 +typedef TypedArray<int32_t, js::UnwrapInt32Array, JS_GetInt32ArrayData,
1.226 + js::GetInt32ArrayLengthAndData, JS_NewInt32Array>
1.227 + Int32Array;
1.228 +typedef TypedArray<uint32_t, js::UnwrapUint32Array, JS_GetUint32ArrayData,
1.229 + js::GetUint32ArrayLengthAndData, JS_NewUint32Array>
1.230 + Uint32Array;
1.231 +typedef TypedArray<float, js::UnwrapFloat32Array, JS_GetFloat32ArrayData,
1.232 + js::GetFloat32ArrayLengthAndData, JS_NewFloat32Array>
1.233 + Float32Array;
1.234 +typedef TypedArray<double, js::UnwrapFloat64Array, JS_GetFloat64ArrayData,
1.235 + js::GetFloat64ArrayLengthAndData, JS_NewFloat64Array>
1.236 + Float64Array;
1.237 +typedef TypedArray_base<uint8_t, js::UnwrapArrayBufferView, js::GetArrayBufferViewLengthAndData>
1.238 + ArrayBufferView;
1.239 +typedef TypedArray<uint8_t, js::UnwrapArrayBuffer, JS_GetArrayBufferData,
1.240 + js::GetArrayBufferLengthAndData, JS_NewArrayBuffer>
1.241 + ArrayBuffer;
1.242 +
1.243 +// A class for converting an nsTArray to a TypedArray
1.244 +// Note: A TypedArrayCreator must not outlive the nsTArray it was created from.
1.245 +// So this is best used to pass from things that understand nsTArray to
1.246 +// things that understand TypedArray, as with Promise::ArgumentToJSValue.
1.247 +template<typename TypedArrayType>
1.248 +class TypedArrayCreator
1.249 +{
1.250 + typedef nsTArray<typename TypedArrayType::element_type> ArrayType;
1.251 +
1.252 + public:
1.253 + TypedArrayCreator(const ArrayType& aArray)
1.254 + : mArray(aArray)
1.255 + {}
1.256 +
1.257 + JSObject* Create(JSContext* aCx) const
1.258 + {
1.259 + return TypedArrayType::Create(aCx, mArray.Length(), mArray.Elements());
1.260 + }
1.261 +
1.262 + private:
1.263 + const ArrayType& mArray;
1.264 +};
1.265 +
1.266 +// A class for rooting an existing TypedArray struct
1.267 +template<typename ArrayType>
1.268 +class MOZ_STACK_CLASS TypedArrayRooter : private JS::CustomAutoRooter
1.269 +{
1.270 +public:
1.271 + TypedArrayRooter(JSContext* cx,
1.272 + ArrayType* aArray MOZ_GUARD_OBJECT_NOTIFIER_PARAM) :
1.273 + JS::CustomAutoRooter(cx MOZ_GUARD_OBJECT_NOTIFIER_PARAM_TO_PARENT),
1.274 + mArray(aArray)
1.275 + {
1.276 + }
1.277 +
1.278 + virtual void trace(JSTracer* trc) MOZ_OVERRIDE
1.279 + {
1.280 + mArray->TraceSelf(trc);
1.281 + }
1.282 +
1.283 +private:
1.284 + TypedArrayObjectStorage* const mArray;
1.285 +};
1.286 +
1.287 +// And a specialization for dealing with nullable typed arrays
1.288 +template<typename Inner> struct Nullable;
1.289 +template<typename ArrayType>
1.290 +class MOZ_STACK_CLASS TypedArrayRooter<Nullable<ArrayType> > :
1.291 + private JS::CustomAutoRooter
1.292 +{
1.293 +public:
1.294 + TypedArrayRooter(JSContext* cx,
1.295 + Nullable<ArrayType>* aArray MOZ_GUARD_OBJECT_NOTIFIER_PARAM) :
1.296 + JS::CustomAutoRooter(cx MOZ_GUARD_OBJECT_NOTIFIER_PARAM_TO_PARENT),
1.297 + mArray(aArray)
1.298 + {
1.299 + }
1.300 +
1.301 + virtual void trace(JSTracer* trc) MOZ_OVERRIDE
1.302 + {
1.303 + if (!mArray->IsNull()) {
1.304 + mArray->Value().TraceSelf(trc);
1.305 + }
1.306 + }
1.307 +
1.308 +private:
1.309 + Nullable<ArrayType>* const mArray;
1.310 +};
1.311 +
1.312 +// Class for easily setting up a rooted typed array object on the stack
1.313 +template<typename ArrayType>
1.314 +class MOZ_STACK_CLASS RootedTypedArray : public ArrayType,
1.315 + private TypedArrayRooter<ArrayType>
1.316 +{
1.317 +public:
1.318 + RootedTypedArray(JSContext* cx MOZ_GUARD_OBJECT_NOTIFIER_PARAM) :
1.319 + ArrayType(),
1.320 + TypedArrayRooter<ArrayType>(cx,
1.321 + MOZ_THIS_IN_INITIALIZER_LIST()
1.322 + MOZ_GUARD_OBJECT_NOTIFIER_PARAM_TO_PARENT)
1.323 + {
1.324 + }
1.325 +
1.326 + RootedTypedArray(JSContext* cx, JSObject* obj MOZ_GUARD_OBJECT_NOTIFIER_PARAM) :
1.327 + ArrayType(obj),
1.328 + TypedArrayRooter<ArrayType>(cx,
1.329 + MOZ_THIS_IN_INITIALIZER_LIST()
1.330 + MOZ_GUARD_OBJECT_NOTIFIER_PARAM_TO_PARENT)
1.331 + {
1.332 + }
1.333 +};
1.334 +
1.335 +} // namespace dom
1.336 +} // namespace mozilla
1.337 +
1.338 +#endif /* mozilla_dom_TypedArray_h */
