/* * Copyright 2006 The Android Open Source Project * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #ifndef SkDescriptor_DEFINED #define SkDescriptor_DEFINED #include #include "include/private/SkMacros.h" #include "include/private/SkNoncopyable.h" #include "src/core/SkScalerContext.h" class SkDescriptor : SkNoncopyable { public: static size_t ComputeOverhead(int entryCount) { SkASSERT(entryCount >= 0); return sizeof(SkDescriptor) + entryCount * sizeof(Entry); } static std::unique_ptr Alloc(size_t length); // Ensure the unsized delete is called. void operator delete(void* p); void init() { fLength = sizeof(SkDescriptor); fCount = 0; } uint32_t getLength() const { return fLength; } void* addEntry(uint32_t tag, size_t length, const void* data = nullptr); void computeChecksum(); // Assumes that getLength <= capacity of this SkDescriptor. bool isValid() const; #ifdef SK_DEBUG void assertChecksum() const { SkASSERT(SkDescriptor::ComputeChecksum(this) == fChecksum); } #endif const void* findEntry(uint32_t tag, uint32_t* length) const; std::unique_ptr copy() const; // This assumes that all memory added has a length that is a multiple of 4. This is checked // by the assert in addEntry. bool operator==(const SkDescriptor& other) const; bool operator!=(const SkDescriptor& other) const { return !(*this == other); } uint32_t getChecksum() const { return fChecksum; } struct Entry { uint32_t fTag; uint32_t fLen; }; #ifdef SK_DEBUG uint32_t getCount() const { return fCount; } #endif private: // private so no one can create one except our factories SkDescriptor() = default; friend class SkDescriptorTestHelper; static uint32_t ComputeChecksum(const SkDescriptor* desc); uint32_t fChecksum; // must be first uint32_t fLength; // must be second uint32_t fCount; }; class SkAutoDescriptor { public: SkAutoDescriptor(); explicit SkAutoDescriptor(size_t size); explicit SkAutoDescriptor(const SkDescriptor& desc); SkAutoDescriptor(const SkAutoDescriptor& ad); SkAutoDescriptor& operator= (const SkAutoDescriptor& ad); SkAutoDescriptor(SkAutoDescriptor&&) = delete; SkAutoDescriptor& operator= (SkAutoDescriptor&&) = delete; ~SkAutoDescriptor(); void reset(size_t size); void reset(const SkDescriptor& desc); SkDescriptor* getDesc() const { SkASSERT(fDesc); return fDesc; } private: void free(); static constexpr size_t kStorageSize = sizeof(SkDescriptor) + sizeof(SkDescriptor::Entry) + sizeof(SkScalerContextRec) // for rec + sizeof(SkDescriptor::Entry) + sizeof(void*) // for typeface + 32; // slop for occasional small extras SkDescriptor* fDesc{nullptr}; std::aligned_storage::type fStorage; }; #endif //SkDescriptor_DEFINED