1 // Copyright 2022 Google LLC. 2 // Use of this source code is governed by a BSD-style license that can be found in the LICENSE file. 3 4 #ifndef SkContainers_DEFINED 5 #define SkContainers_DEFINED 6 7 #include "include/private/base/SkAPI.h" 8 #include "include/private/base/SkAlign.h" 9 #include "include/private/base/SkSpan_impl.h" 10 11 #include <cstddef> 12 #include <cstdint> 13 14 class SK_SPI SkContainerAllocator { 15 public: SkContainerAllocator(size_t sizeOfT,int maxCapacity)16 SkContainerAllocator(size_t sizeOfT, int maxCapacity) 17 : fSizeOfT{sizeOfT} 18 , fMaxCapacity{maxCapacity} {} 19 20 // allocate will abort on failure. Given a capacity of 0, it will return the empty span. 21 // The bytes allocated are freed using sk_free(). 22 SkSpan<std::byte> allocate(int capacity, double growthFactor = 1.0); 23 24 // Rounds a requested capacity up towards `kCapacityMultiple` in a constexpr-friendly fashion. 25 template <typename T> RoundUp(size_t capacity)26 static constexpr size_t RoundUp(size_t capacity) { 27 return SkAlignTo(capacity * sizeof(T), kCapacityMultiple) / sizeof(T); 28 } 29 30 private: 31 friend struct SkContainerAllocatorTestingPeer; 32 33 // All capacity counts will be rounded up to kCapacityMultiple. This matches ASAN's shadow 34 // granularity, as well as our typical struct alignment on a 64-bit machine. 35 static constexpr int64_t kCapacityMultiple = 8; 36 37 // Rounds up capacity to next multiple of kCapacityMultiple and pin to fMaxCapacity. 38 size_t roundUpCapacity(int64_t capacity) const; 39 40 // Grows the capacity by growthFactor being sure to stay with in kMinBytes and fMaxCapacity. 41 size_t growthFactorCapacity(int capacity, double growthFactor) const; 42 43 const size_t fSizeOfT; 44 const int64_t fMaxCapacity; 45 }; 46 47 // sk_allocate_canfail returns the empty span on failure. Parameter size must be > 0. 48 SkSpan<std::byte> sk_allocate_canfail(size_t size); 49 50 // Returns the empty span if size is 0. sk_allocate_throw aborts on failure. 51 SkSpan<std::byte> sk_allocate_throw(size_t size); 52 53 SK_SPI void sk_report_container_overflow_and_die(); 54 #endif // SkContainers_DEFINED 55