1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/src/core/SkTRefArray.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,112 @@
1.4 +//
1.5 +// SkTRefArray.h
1.6 +// core
1.7 +//
1.8 +// Created by Mike Reed on 7/17/12.
1.9 +// Copyright (c) 2012 __MyCompanyName__. All rights reserved.
1.10 +//
1.11 +
1.12 +#ifndef SkTRefArray_DEFINED
1.13 +#define SkTRefArray_DEFINED
1.14 +
1.15 +#include "SkRefCnt.h"
1.16 +#include <new>
1.17 +
1.18 +/**
1.19 + * Wrapper to manage thread-safe sharing of an array of T objects. The array
1.20 + * cannot be grown or shrunk.
1.21 + */
1.22 +template <typename T> class SkTRefArray : public SkRefCnt {
1.23 + /*
1.24 + * Shared factory to allocate the space needed for our instance plus N
1.25 + * T entries at the end. We call our constructor, but not the constructors
1.26 + * for the elements. Those are called by the proper Create method.
1.27 + */
1.28 + static SkTRefArray<T>* Alloc(int count) {
1.29 + // space for us, and our [count] elements
1.30 + size_t size = sizeof(SkTRefArray<T>) + count * sizeof(T);
1.31 + SkTRefArray<T>* obj = (SkTRefArray<T>*)sk_malloc_throw(size);
1.32 +
1.33 + SkNEW_PLACEMENT(obj, SkTRefArray<T>);
1.34 + obj->fCount = count;
1.35 + return obj;
1.36 + }
1.37 +
1.38 +public:
1.39 + /**
1.40 + * Return a new array with 'count' elements, initialized to their default
1.41 + * value. To change them to some other value, use writableBegin/End or
1.42 + * writableAt(), but do that before this array is given to another thread.
1.43 + */
1.44 + static SkTRefArray<T>* Create(int count) {
1.45 + SkTRefArray<T>* obj = Alloc(count);
1.46 + T* array = const_cast<T*>(obj->begin());
1.47 + for (int i = 0; i < count; ++i) {
1.48 + SkNEW_PLACEMENT(&array[i], T);
1.49 + }
1.50 + return obj;
1.51 + }
1.52 +
1.53 + /**
1.54 + * Return a new array with 'count' elements, initialized from the provided
1.55 + * src array. To change them to some other value, use writableBegin/End or
1.56 + * writableAt(), but do that before this array is given to another thread.
1.57 + */
1.58 + static SkTRefArray<T>* Create(const T src[], int count) {
1.59 + SkTRefArray<T>* obj = Alloc(count);
1.60 + T* array = const_cast<T*>(obj->begin());
1.61 + for (int i = 0; i < count; ++i) {
1.62 + SkNEW_PLACEMENT_ARGS(&array[i], T, (src[i]));
1.63 + }
1.64 + return obj;
1.65 + }
1.66 +
1.67 + int count() const { return fCount; }
1.68 + const T* begin() const { return (const T*)(this + 1); }
1.69 + const T* end() const { return this->begin() + fCount; }
1.70 + const T& at(int index) const {
1.71 + SkASSERT((unsigned)index < (unsigned)fCount);
1.72 + return this->begin()[index];
1.73 + }
1.74 + const T& operator[](int index) const { return this->at(index); }
1.75 +
1.76 + // For the writable methods, we assert that we are the only owner if we
1.77 + // call these, since other owners are not informed if we change an element.
1.78 +
1.79 + T* writableBegin() {
1.80 + SkASSERT(this->unique());
1.81 + return (T*)(this + 1);
1.82 + }
1.83 + T* writableEnd() {
1.84 + return this->writableBegin() + fCount;
1.85 + }
1.86 + T& writableAt(int index) {
1.87 + SkASSERT((unsigned)index < (unsigned)fCount);
1.88 + return this->writableBegin()[index];
1.89 + }
1.90 +
1.91 +protected:
1.92 + virtual void internal_dispose() const SK_OVERRIDE {
1.93 + T* array = const_cast<T*>(this->begin());
1.94 + int n = fCount;
1.95 +
1.96 + for (int i = 0; i < n; ++i) {
1.97 + array->~T();
1.98 + array += 1;
1.99 + }
1.100 +
1.101 + this->internal_dispose_restore_refcnt_to_1();
1.102 + this->~SkTRefArray<T>();
1.103 + sk_free((void*)this);
1.104 + }
1.105 +
1.106 +private:
1.107 + int fCount;
1.108 +
1.109 + // hide this
1.110 + virtual ~SkTRefArray() {}
1.111 +
1.112 + typedef SkRefCnt INHERITED;
1.113 +};
1.114 +
1.115 +#endif
