mirror of https://github.com/facebook/rocksdb.git
86 lines
2.2 KiB
C++
86 lines
2.2 KiB
C++
/*
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* Licensed to the Apache Software Foundation (ASF) under one
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* or more contributor license agreements. See the NOTICE file
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* distributed with this work for additional information
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* regarding copyright ownership. The ASF licenses this file
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* to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance
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* with the License. You may obtain a copy of the License at
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*
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* http://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,
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* software distributed under the License is distributed on an
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* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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* KIND, either express or implied. See the License for the
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* specific language governing permissions and limitations
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* under the License.
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*/
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#ifndef _THRIFT_TRANSPORT_TMEMPAGEDFACTORY_H_
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#define _THRIFT_TRANSPORT_TMEMPAGEDFACTORY_H_ 1
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#include "external/google_base/spinlock.h"
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namespace apache { namespace thrift { namespace transport {
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/*
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* struct keeps information about memory usage for specific page
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*/
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struct FixedSizeMemoryPage {
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FixedSizeMemoryPage* next_; //!< chain hook
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uint8_t buffer_[]; //!< pointer to the buffer
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};
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/**
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* Fixed size memory pages factory
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* Thread safe
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*
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*/
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class FixedSizeMemoryPageFactory {
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public:
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/**
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* Constructor
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*/
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FixedSizeMemoryPageFactory(size_t pageSize, //!< page size in bytes
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size_t maxMemoryUsage, //!< max memory usage
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size_t cacheMemorySize); //!< max memory in cache
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/**
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* Destructor
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*/
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~FixedSizeMemoryPageFactory();
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/**
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* Releases all unused memory
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*/
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void releaseMemory();
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/**
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* Requests for a page allocation
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*/
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FixedSizeMemoryPage* getPage(bool throwOnError = true);
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/**
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* Returns current page size
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*/
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size_t getPageSize() const;
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/**
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* Returns page back to factory
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*/
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void returnPage(FixedSizeMemoryPage* page);
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private:
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const size_t pageSize_;
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const size_t maxMemoryUsage_;
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const size_t cacheMemorySize_;
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size_t numAllocatedPages_;
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size_t numCachedPages_;
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FixedSizeMemoryPage* cachedPages_;
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mutable facebook::SpinLock lock_;
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};
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}}} // apache::thrift::transport
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#endif // #ifndef _THRIFT_TRANSPORT_TMEMPAGEDFACTORY_H_
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