79 lines
		
	
	
	
		
			2.4 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			79 lines
		
	
	
	
		
			2.4 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| // Copyright 2018 The Abseil Authors.
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| //
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| // Licensed under the Apache License, Version 2.0 (the "License");
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| // you may not use this file except in compliance with the License.
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| // You may obtain a copy of the License at
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| //
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| //      https://www.apache.org/licenses/LICENSE-2.0
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| //
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| // Unless required by applicable law or agreed to in writing, software
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| // distributed under the License is distributed on an "AS IS" BASIS,
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| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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| // See the License for the specific language governing permissions and
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| // limitations under the License.
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| 
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| #ifndef ABSL_CONTAINER_INTERNAL_COUNTING_ALLOCATOR_H_
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| #define ABSL_CONTAINER_INTERNAL_COUNTING_ALLOCATOR_H_
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| 
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| #include <cassert>
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| #include <cstdint>
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| #include <memory>
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| 
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| namespace absl {
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| namespace container_internal {
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| 
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| // This is a stateful allocator, but the state lives outside of the
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| // allocator (in whatever test is using the allocator). This is odd
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| // but helps in tests where the allocator is propagated into nested
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| // containers - that chain of allocators uses the same state and is
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| // thus easier to query for aggregate allocation information.
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| template <typename T>
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| class CountingAllocator : public std::allocator<T> {
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|  public:
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|   using Alloc = std::allocator<T>;
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|   using pointer = typename Alloc::pointer;
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|   using size_type = typename Alloc::size_type;
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| 
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|   CountingAllocator() : bytes_used_(nullptr) {}
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|   explicit CountingAllocator(int64_t* b) : bytes_used_(b) {}
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| 
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|   template <typename U>
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|   CountingAllocator(const CountingAllocator<U>& x)
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|       : Alloc(x), bytes_used_(x.bytes_used_) {}
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| 
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|   pointer allocate(size_type n,
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|                    std::allocator<void>::const_pointer hint = nullptr) {
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|     assert(bytes_used_ != nullptr);
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|     *bytes_used_ += n * sizeof(T);
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|     return Alloc::allocate(n, hint);
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|   }
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| 
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|   void deallocate(pointer p, size_type n) {
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|     Alloc::deallocate(p, n);
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|     assert(bytes_used_ != nullptr);
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|     *bytes_used_ -= n * sizeof(T);
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|   }
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| 
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|   template<typename U>
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|   class rebind {
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|    public:
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|     using other = CountingAllocator<U>;
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|   };
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| 
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|   friend bool operator==(const CountingAllocator& a,
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|                          const CountingAllocator& b) {
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|     return a.bytes_used_ == b.bytes_used_;
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|   }
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| 
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|   friend bool operator!=(const CountingAllocator& a,
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|                          const CountingAllocator& b) {
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|     return !(a == b);
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|   }
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| 
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|   int64_t* bytes_used_;
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| };
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| 
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| }  // namespace container_internal
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| }  // namespace absl
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| 
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| #endif  // ABSL_CONTAINER_INTERNAL_COUNTING_ALLOCATOR_H_
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