| // Copyright 2012 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef V8_ELEMENTS_H_ |
| #define V8_ELEMENTS_H_ |
| |
| #include "src/elements-kind.h" |
| #include "src/heap/heap.h" |
| #include "src/isolate.h" |
| #include "src/key-accumulator.h" |
| #include "src/objects.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| // Abstract base class for handles that can operate on objects with differing |
| // ElementsKinds. |
| class ElementsAccessor { |
| public: |
| explicit ElementsAccessor(const char* name) : name_(name) { } |
| virtual ~ElementsAccessor() { } |
| |
| const char* name() const { return name_; } |
| |
| // Returns a shared ElementsAccessor for the specified ElementsKind. |
| static ElementsAccessor* ForKind(ElementsKind elements_kind) { |
| DCHECK(static_cast<int>(elements_kind) < kElementsKindCount); |
| return elements_accessors_[elements_kind]; |
| } |
| |
| static ElementsAccessor* ForArray(Handle<FixedArrayBase> array); |
| |
| // Checks the elements of an object for consistency, asserting when a problem |
| // is found. |
| virtual void Validate(Handle<JSObject> obj) = 0; |
| |
| // Returns true if a holder contains an element with the specified index |
| // without iterating up the prototype chain. The caller can optionally pass |
| // in the backing store to use for the check, which must be compatible with |
| // the ElementsKind of the ElementsAccessor. If backing_store is NULL, the |
| // holder->elements() is used as the backing store. If a |filter| is |
| // specified the PropertyAttributes of the element at the given index |
| // are compared to the given |filter|. If they match/overlap the given |
| // index is ignored. Note that only Dictionary elements have custom |
| // PropertyAttributes associated, hence the |filter| argument is ignored for |
| // all but DICTIONARY_ELEMENTS and SLOW_SLOPPY_ARGUMENTS_ELEMENTS. |
| virtual bool HasElement(Handle<JSObject> holder, uint32_t index, |
| Handle<FixedArrayBase> backing_store, |
| PropertyFilter filter = ALL_PROPERTIES) = 0; |
| |
| inline bool HasElement(Handle<JSObject> holder, uint32_t index, |
| PropertyFilter filter = ALL_PROPERTIES) { |
| return HasElement(holder, index, handle(holder->elements()), filter); |
| } |
| |
| // Returns true if the backing store is compact in the given range |
| virtual bool IsPacked(Handle<JSObject> holder, |
| Handle<FixedArrayBase> backing_store, uint32_t start, |
| uint32_t end) = 0; |
| |
| virtual Handle<Object> Get(Handle<FixedArrayBase> backing_store, |
| uint32_t entry) = 0; |
| |
| // Modifies the length data property as specified for JSArrays and resizes the |
| // underlying backing store accordingly. The method honors the semantics of |
| // changing array sizes as defined in EcmaScript 5.1 15.4.5.2, i.e. array that |
| // have non-deletable elements can only be shrunk to the size of highest |
| // element that is non-deletable. |
| virtual void SetLength(Handle<JSArray> holder, uint32_t new_length) = 0; |
| |
| // Deletes an element in an object. |
| virtual void Delete(Handle<JSObject> holder, uint32_t entry) = 0; |
| |
| // If kCopyToEnd is specified as the copy_size to CopyElements, it copies all |
| // of elements from source after source_start to the destination array. |
| static const int kCopyToEnd = -1; |
| // If kCopyToEndAndInitializeToHole is specified as the copy_size to |
| // CopyElements, it copies all of elements from source after source_start to |
| // destination array, padding any remaining uninitialized elements in the |
| // destination array with the hole. |
| static const int kCopyToEndAndInitializeToHole = -2; |
| |
| // Copy elements from one backing store to another. Typically, callers specify |
| // the source JSObject or JSArray in source_holder. If the holder's backing |
| // store is available, it can be passed in source and source_holder is |
| // ignored. |
| virtual void CopyElements( |
| Handle<FixedArrayBase> source, |
| uint32_t source_start, |
| ElementsKind source_kind, |
| Handle<FixedArrayBase> destination, |
| uint32_t destination_start, |
| int copy_size) = 0; |
| |
| // NOTE: this method violates the handlified function signature convention: |
| // raw pointer parameter |source_holder| in the function that allocates. |
| // This is done intentionally to avoid ArrayConcat() builtin performance |
| // degradation. |
| virtual void CopyElements( |
| JSObject* source_holder, |
| uint32_t source_start, |
| ElementsKind source_kind, |
| Handle<FixedArrayBase> destination, |
| uint32_t destination_start, |
| int copy_size) = 0; |
| |
| inline void CopyElements( |
| Handle<JSObject> from_holder, |
| Handle<FixedArrayBase> to, |
| ElementsKind from_kind) { |
| CopyElements( |
| *from_holder, 0, from_kind, to, 0, kCopyToEndAndInitializeToHole); |
| } |
| |
| // Copy all indices that have elements from |object| into the given |
| // KeyAccumulator. For Dictionary-based element-kinds we filter out elements |
| // whose PropertyAttribute match |filter|. |
| virtual void CollectElementIndices(Handle<JSObject> object, |
| Handle<FixedArrayBase> backing_store, |
| KeyAccumulator* keys, |
| uint32_t range = kMaxUInt32, |
| PropertyFilter filter = ALL_PROPERTIES, |
| uint32_t offset = 0) = 0; |
| |
| inline void CollectElementIndices(Handle<JSObject> object, |
| KeyAccumulator* keys, |
| uint32_t range = kMaxUInt32, |
| PropertyFilter filter = ALL_PROPERTIES, |
| uint32_t offset = 0) { |
| CollectElementIndices(object, handle(object->elements()), keys, range, |
| filter, offset); |
| } |
| |
| virtual void AddElementsToKeyAccumulator(Handle<JSObject> receiver, |
| KeyAccumulator* accumulator, |
| AddKeyConversion convert) = 0; |
| |
| virtual void GrowCapacityAndConvert(Handle<JSObject> object, |
| uint32_t capacity) = 0; |
| |
| static void InitializeOncePerProcess(); |
| static void TearDown(); |
| |
| virtual void Set(FixedArrayBase* backing_store, uint32_t entry, |
| Object* value) = 0; |
| |
| virtual void Reconfigure(Handle<JSObject> object, |
| Handle<FixedArrayBase> backing_store, uint32_t entry, |
| Handle<Object> value, |
| PropertyAttributes attributes) = 0; |
| |
| virtual void Add(Handle<JSObject> object, uint32_t index, |
| Handle<Object> value, PropertyAttributes attributes, |
| uint32_t new_capacity) = 0; |
| |
| static Handle<JSArray> Concat(Isolate* isolate, Arguments* args, |
| uint32_t concat_size); |
| |
| virtual uint32_t Push(Handle<JSArray> receiver, |
| Handle<FixedArrayBase> backing_store, Arguments* args, |
| uint32_t push_size) = 0; |
| |
| virtual uint32_t Unshift(Handle<JSArray> receiver, |
| Handle<FixedArrayBase> backing_store, |
| Arguments* args, uint32_t unshift_size) = 0; |
| |
| virtual Handle<JSArray> Slice(Handle<JSObject> receiver, |
| Handle<FixedArrayBase> backing_store, |
| uint32_t start, uint32_t end) = 0; |
| |
| virtual Handle<JSArray> Splice(Handle<JSArray> receiver, |
| Handle<FixedArrayBase> backing_store, |
| uint32_t start, uint32_t delete_count, |
| Arguments* args, uint32_t add_count) = 0; |
| |
| virtual Handle<Object> Pop(Handle<JSArray> receiver, |
| Handle<FixedArrayBase> backing_store) = 0; |
| |
| virtual Handle<Object> Shift(Handle<JSArray> receiver, |
| Handle<FixedArrayBase> backing_store) = 0; |
| |
| protected: |
| friend class LookupIterator; |
| |
| static ElementsAccessor* ForArray(FixedArrayBase* array); |
| |
| |
| // Element handlers distinguish between entries and indices when they |
| // manipulate elements. Entries refer to elements in terms of their location |
| // in the underlying storage's backing store representation, and are between 0 |
| // and GetCapacity. Indices refer to elements in terms of the value that would |
| // be specified in JavaScript to access the element. In most implementations, |
| // indices are equivalent to entries. In the NumberDictionary |
| // ElementsAccessor, entries are mapped to an index using the KeyAt method on |
| // the NumberDictionary. |
| virtual uint32_t GetEntryForIndex(JSObject* holder, |
| FixedArrayBase* backing_store, |
| uint32_t index) = 0; |
| virtual PropertyDetails GetDetails(FixedArrayBase* backing_store, |
| uint32_t entry) = 0; |
| |
| private: |
| virtual uint32_t GetCapacity(JSObject* holder, |
| FixedArrayBase* backing_store) = 0; |
| static ElementsAccessor** elements_accessors_; |
| const char* name_; |
| |
| DISALLOW_COPY_AND_ASSIGN(ElementsAccessor); |
| }; |
| |
| void CheckArrayAbuse(Handle<JSObject> obj, const char* op, uint32_t index, |
| bool allow_appending = false); |
| |
| MUST_USE_RESULT MaybeHandle<Object> ArrayConstructInitializeElements( |
| Handle<JSArray> array, |
| Arguments* args); |
| |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_ELEMENTS_H_ |