ccf0fcd5c2
- Implemented Get() directly instead of building on top of a full merging iterator stack. This speeds up the "readrandom" benchmark by up to 15-30%. - Fixed an opensource compilation problem. Added --db=<name> flag to control where the database is placed. - Automatically compact a file when we have done enough overlapping seeks to that file. - Fixed a performance bug where we would read from at least one file in a level even if none of the files overlapped the key being read. - Makefile fix for Mac OSX installations that have XCode 4 without XCode 3. - Unified the two occurrences of binary search in a file-list into one routine. - Found and fixed a bug where we would unnecessarily search the last file when looking for a key larger than all data in the level. - A fix to avoid the need for trivial move compactions and therefore gets rid of two out of five syncs in "fillseq". - Removed the MANIFEST file write when switching to a new memtable/log-file for a 10-20% improvement on fill speed on ext4. - Adding a SNAPPY setting in the Makefile for folks who have Snappy installed. Snappy compresses values and speeds up writes. git-svn-id: https://leveldb.googlecode.com/svn/trunk@32 62dab493-f737-651d-591e-8d6aee1b9529
113 lines
2.4 KiB
C++
113 lines
2.4 KiB
C++
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file. See the AUTHORS file for names of contributors.
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//
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// See port_example.h for documentation for the following types/functions.
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#ifndef STORAGE_LEVELDB_PORT_PORT_POSIX_H_
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#define STORAGE_LEVELDB_PORT_PORT_POSIX_H_
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#include <endian.h>
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#include <pthread.h>
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#ifdef SNAPPY
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#include <snappy.h>
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#endif
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#include <stdint.h>
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#include <string>
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#include <cstdatomic>
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#include <cstring>
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namespace leveldb {
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namespace port {
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static const bool kLittleEndian = (__BYTE_ORDER == __LITTLE_ENDIAN);
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class CondVar;
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class Mutex {
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public:
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Mutex();
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~Mutex();
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void Lock();
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void Unlock();
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void AssertHeld() { }
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private:
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friend class CondVar;
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pthread_mutex_t mu_;
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// No copying
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Mutex(const Mutex&);
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void operator=(const Mutex&);
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};
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class CondVar {
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public:
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explicit CondVar(Mutex* mu);
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~CondVar();
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void Wait();
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void Signal();
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void SignalAll();
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private:
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pthread_cond_t cv_;
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Mutex* mu_;
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};
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// Storage for a lock-free pointer
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class AtomicPointer {
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private:
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std::atomic<void*> rep_;
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public:
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AtomicPointer() { }
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explicit AtomicPointer(void* v) : rep_(v) { }
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inline void* Acquire_Load() const {
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return rep_.load(std::memory_order_acquire);
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}
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inline void Release_Store(void* v) {
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rep_.store(v, std::memory_order_release);
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}
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inline void* NoBarrier_Load() const {
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return rep_.load(std::memory_order_relaxed);
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}
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inline void NoBarrier_Store(void* v) {
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rep_.store(v, std::memory_order_relaxed);
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}
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};
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inline bool Snappy_Compress(const char* input, size_t input_length,
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std::string* output) {
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#ifdef SNAPPY
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output->resize(snappy::MaxCompressedLength(input_length));
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size_t outlen;
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snappy::RawCompress(input, input_length, &(*output)[0], &outlen);
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output->resize(outlen);
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return true;
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#endif
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return false;
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}
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inline bool Snappy_Uncompress(const char* input_data, size_t input_length,
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std::string* output) {
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#ifdef SNAPPY
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size_t ulength;
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if (!snappy::GetUncompressedLength(input_data, ulength, &ulength)) {
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return false;
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}
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output->resize(ulength);
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return snappy::RawUncompress(input_data, input_length, &(*output)[0]);
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#endif
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return false;
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}
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inline bool GetHeapProfile(void (*func)(void*, const char*, int), void* arg) {
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return false;
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}
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}
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}
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#endif // STORAGE_LEVELDB_PORT_PORT_POSIX_H_
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