Summary: This patch splits the posix storage backend into Env and the actual *File implementations. The motivation is to allow other Envs to use posix as a library. This enables a storage backend different from posix to split its secondary storage between a normal file system partition managed by posix, and it own media. Test Plan: No new functionality is added to posix Env or the library, thus the current tests should suffice.main
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// Copyright (c) 2013, Facebook, Inc. All rights reserved.
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// This source code is licensed under the BSD-style license found in the
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// LICENSE file in the root directory of this source tree. An additional grant
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// of patent rights can be found in the PATENTS file in the same directory.
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//
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// 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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#include <deque> |
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#include <set> |
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#include <dirent.h> |
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#include <pthread.h> |
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#include <string.h> |
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#include <sys/time.h> |
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#include <time.h> |
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#include <signal.h> |
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#include <algorithm> |
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#include <fcntl.h> |
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#include <unistd.h> |
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#include <stdio.h> |
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#include <errno.h> |
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#include <stdlib.h> |
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#include <sys/ioctl.h> |
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#include <sys/stat.h> |
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#include <sys/types.h> |
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#include <sys/mman.h> |
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#ifdef OS_LINUX |
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#include <sys/statfs.h> |
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#include <sys/syscall.h> |
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#endif |
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#if defined(OS_LINUX) |
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#include <linux/fs.h> |
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#endif |
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#include "rocksdb/env.h" |
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#include "util/sync_point.h" |
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#include "util/iostats_context_imp.h" |
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#include "util/coding.h" |
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#include "rocksdb/slice.h" |
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#include "port/port.h" |
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#include "util/logging.h" |
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#include "util/posix_logger.h" |
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#include "util/random.h" |
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#include "util/string_util.h" |
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#include "util/thread_status_updater.h" |
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#include "util/thread_status_util.h" |
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// For non linux platform, the following macros are used only as place
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// holder.
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#if !(defined OS_LINUX) && !(defined CYGWIN) |
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#define POSIX_FADV_NORMAL 0 /* [MC1] no further special treatment */ |
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#define POSIX_FADV_RANDOM 1 /* [MC1] expect random page refs */ |
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#define POSIX_FADV_SEQUENTIAL 2 /* [MC1] expect sequential page refs */ |
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#define POSIX_FADV_WILLNEED 3 /* [MC1] will need these pages */ |
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#define POSIX_FADV_DONTNEED 4 /* [MC1] dont need these pages */ |
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#endif |
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namespace rocksdb { |
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static Status IOError(const std::string& context, int err_number) { |
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return Status::IOError(context, strerror(err_number)); |
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} |
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class PosixSequentialFile : public SequentialFile { |
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private: |
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std::string filename_; |
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FILE* file_; |
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int fd_; |
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bool use_os_buffer_; |
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public: |
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PosixSequentialFile(const std::string& fname, FILE* f, |
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const EnvOptions& options); |
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virtual ~PosixSequentialFile(); |
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virtual Status Read(size_t n, Slice* result, char* scratch) override; |
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virtual Status Skip(uint64_t n) override; |
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virtual Status InvalidateCache(size_t offset, size_t length) override; |
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}; |
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class PosixRandomAccessFile : public RandomAccessFile { |
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private: |
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std::string filename_; |
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int fd_; |
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bool use_os_buffer_; |
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public: |
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PosixRandomAccessFile(const std::string& fname, int fd, |
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const EnvOptions& options); |
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virtual ~PosixRandomAccessFile(); |
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virtual Status Read(uint64_t offset, size_t n, Slice* result, |
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char* scratch) const override; |
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#ifdef OS_LINUX |
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virtual size_t GetUniqueId(char* id, size_t max_size) const override; |
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#endif |
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virtual void Hint(AccessPattern pattern) override; |
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virtual Status InvalidateCache(size_t offset, size_t length) override; |
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}; |
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class PosixWritableFile : public WritableFile { |
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private: |
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const std::string filename_; |
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int fd_; |
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uint64_t filesize_; |
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#ifdef ROCKSDB_FALLOCATE_PRESENT |
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bool allow_fallocate_; |
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bool fallocate_with_keep_size_; |
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#endif |
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public: |
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PosixWritableFile(const std::string& fname, int fd, |
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const EnvOptions& options); |
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~PosixWritableFile(); |
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// Means Close() will properly take care of truncate
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// and it does not need any additional information
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virtual Status Truncate(uint64_t size) override { return Status::OK(); } |
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virtual Status Close() override; |
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virtual Status Append(const Slice& data) override; |
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virtual Status Flush() override; |
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virtual Status Sync() override; |
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virtual Status Fsync() override; |
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virtual bool IsSyncThreadSafe() const override; |
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virtual uint64_t GetFileSize() override; |
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virtual Status InvalidateCache(size_t offset, size_t length) override; |
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#ifdef ROCKSDB_FALLOCATE_PRESENT |
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virtual Status Allocate(off_t offset, off_t len) override; |
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virtual Status RangeSync(off_t offset, off_t nbytes) override; |
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virtual size_t GetUniqueId(char* id, size_t max_size) const override; |
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#endif |
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}; |
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class PosixMmapReadableFile : public RandomAccessFile { |
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private: |
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int fd_; |
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std::string filename_; |
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void* mmapped_region_; |
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size_t length_; |
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public: |
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PosixMmapReadableFile(const int fd, const std::string& fname, void* base, |
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size_t length, const EnvOptions& options); |
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virtual ~PosixMmapReadableFile(); |
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virtual Status Read(uint64_t offset, size_t n, Slice* result, |
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char* scratch) const override; |
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virtual Status InvalidateCache(size_t offset, size_t length) override; |
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}; |
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class PosixMmapFile : public WritableFile { |
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private: |
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std::string filename_; |
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int fd_; |
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size_t page_size_; |
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size_t map_size_; // How much extra memory to map at a time
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char* base_; // The mapped region
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char* limit_; // Limit of the mapped region
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char* dst_; // Where to write next (in range [base_,limit_])
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char* last_sync_; // Where have we synced up to
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uint64_t file_offset_; // Offset of base_ in file
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#ifdef ROCKSDB_FALLOCATE_PRESENT |
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bool allow_fallocate_; // If false, fallocate calls are bypassed
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bool fallocate_with_keep_size_; |
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#endif |
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// Roundup x to a multiple of y
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static size_t Roundup(size_t x, size_t y) { return ((x + y - 1) / y) * y; } |
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size_t TruncateToPageBoundary(size_t s) { |
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s -= (s & (page_size_ - 1)); |
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assert((s % page_size_) == 0); |
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return s; |
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} |
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Status MapNewRegion(); |
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Status UnmapCurrentRegion(); |
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Status Msync(); |
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public: |
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PosixMmapFile(const std::string& fname, int fd, size_t page_size, |
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const EnvOptions& options); |
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~PosixMmapFile(); |
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// Means Close() will properly take care of truncate
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// and it does not need any additional information
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virtual Status Truncate(uint64_t size) override { return Status::OK(); } |
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virtual Status Close() override; |
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virtual Status Append(const Slice& data) override; |
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virtual Status Flush() override; |
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virtual Status Sync() override; |
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virtual Status Fsync() override; |
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virtual uint64_t GetFileSize() override; |
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virtual Status InvalidateCache(size_t offset, size_t length) override; |
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#ifdef ROCKSDB_FALLOCATE_PRESENT |
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virtual Status Allocate(off_t offset, off_t len) override; |
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#endif |
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}; |
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class PosixDirectory : public Directory { |
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public: |
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explicit PosixDirectory(int fd) : fd_(fd) {} |
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~PosixDirectory() { close(fd_); } |
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virtual Status Fsync() override { |
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if (fsync(fd_) == -1) { |
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return IOError("directory", errno); |
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} |
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return Status::OK(); |
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} |
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private: |
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int fd_; |
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}; |
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} // namespace rocksdb
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// Copyright (c) 2013, Facebook, Inc. All rights reserved.
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// This source code is licensed under the BSD-style license found in the
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// LICENSE file in the root directory of this source tree. An additional grant
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// of patent rights can be found in the PATENTS file in the same directory.
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//
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// 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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#ifdef ROCKSDB_LIB_IO_POSIX |
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#include "posix/io_posix.h" |
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namespace rocksdb { |
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// A wrapper for fadvise, if the platform doesn't support fadvise,
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// it will simply return Status::NotSupport.
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int Fadvise(int fd, off_t offset, size_t len, int advice) { |
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#ifdef OS_LINUX |
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return posix_fadvise(fd, offset, len, advice); |
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#else |
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return 0; // simply do nothing.
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#endif |
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} |
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/*
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* PosixSequentialFile |
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*/ |
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PosixSequentialFile::PosixSequentialFile(const std::string& fname, FILE* f, |
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const EnvOptions& options) |
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: filename_(fname), |
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file_(f), |
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fd_(fileno(f)), |
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use_os_buffer_(options.use_os_buffer) {} |
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PosixSequentialFile::~PosixSequentialFile() { fclose(file_); } |
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Status PosixSequentialFile::Read(size_t n, Slice* result, char* scratch) { |
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Status s; |
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size_t r = 0; |
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do { |
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r = fread_unlocked(scratch, 1, n, file_); |
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} while (r == 0 && ferror(file_) && errno == EINTR); |
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*result = Slice(scratch, r); |
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if (r < n) { |
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if (feof(file_)) { |
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// We leave status as ok if we hit the end of the file
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// We also clear the error so that the reads can continue
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// if a new data is written to the file
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clearerr(file_); |
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} else { |
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// A partial read with an error: return a non-ok status
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s = IOError(filename_, errno); |
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} |
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} |
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if (!use_os_buffer_) { |
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// we need to fadvise away the entire range of pages because
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// we do not want readahead pages to be cached.
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Fadvise(fd_, 0, 0, POSIX_FADV_DONTNEED); // free OS pages
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} |
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return s; |
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} |
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Status PosixSequentialFile::Skip(uint64_t n) { |
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if (fseek(file_, static_cast<long int>(n), SEEK_CUR)) { |
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return IOError(filename_, errno); |
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} |
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return Status::OK(); |
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} |
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Status PosixSequentialFile::InvalidateCache(size_t offset, size_t length) { |
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#ifndef OS_LINUX |
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return Status::OK(); |
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#else |
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// free OS pages
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int ret = Fadvise(fd_, offset, length, POSIX_FADV_DONTNEED); |
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if (ret == 0) { |
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return Status::OK(); |
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} |
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return IOError(filename_, errno); |
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#endif |
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} |
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#if defined(OS_LINUX) |
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namespace { |
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static size_t GetUniqueIdFromFile(int fd, char* id, size_t max_size) { |
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if (max_size < kMaxVarint64Length * 3) { |
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return 0; |
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} |
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struct stat buf; |
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int result = fstat(fd, &buf); |
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if (result == -1) { |
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return 0; |
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} |
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long version = 0; |
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result = ioctl(fd, FS_IOC_GETVERSION, &version); |
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if (result == -1) { |
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return 0; |
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} |
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uint64_t uversion = (uint64_t)version; |
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char* rid = id; |
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rid = EncodeVarint64(rid, buf.st_dev); |
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rid = EncodeVarint64(rid, buf.st_ino); |
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rid = EncodeVarint64(rid, uversion); |
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assert(rid >= id); |
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return static_cast<size_t>(rid - id); |
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} |
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} |
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#endif |
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/*
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* PosixRandomAccessFile |
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* |
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* pread() based random-access |
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*/ |
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PosixRandomAccessFile::PosixRandomAccessFile(const std::string& fname, int fd, |
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const EnvOptions& options) |
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: filename_(fname), fd_(fd), use_os_buffer_(options.use_os_buffer) { |
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assert(!options.use_mmap_reads || sizeof(void*) < 8); |
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} |
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PosixRandomAccessFile::~PosixRandomAccessFile() { close(fd_); } |
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Status PosixRandomAccessFile::Read(uint64_t offset, size_t n, Slice* result, |
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char* scratch) const { |
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Status s; |
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ssize_t r = -1; |
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size_t left = n; |
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char* ptr = scratch; |
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while (left > 0) { |
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r = pread(fd_, ptr, left, static_cast<off_t>(offset)); |
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if (r <= 0) { |
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if (errno == EINTR) { |
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continue; |
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} |
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break; |
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} |
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ptr += r; |
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offset += r; |
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left -= r; |
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} |
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*result = Slice(scratch, (r < 0) ? 0 : n - left); |
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if (r < 0) { |
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// An error: return a non-ok status
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s = IOError(filename_, errno); |
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} |
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if (!use_os_buffer_) { |
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// we need to fadvise away the entire range of pages because
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// we do not want readahead pages to be cached.
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Fadvise(fd_, 0, 0, POSIX_FADV_DONTNEED); // free OS pages
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} |
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return s; |
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} |
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#ifdef OS_LINUX |
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size_t PosixRandomAccessFile::GetUniqueId(char* id, size_t max_size) const { |
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return GetUniqueIdFromFile(fd_, id, max_size); |
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} |
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#endif |
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void PosixRandomAccessFile::Hint(AccessPattern pattern) { |
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switch (pattern) { |
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case NORMAL: |
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Fadvise(fd_, 0, 0, POSIX_FADV_NORMAL); |
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break; |
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case RANDOM: |
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Fadvise(fd_, 0, 0, POSIX_FADV_RANDOM); |
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break; |
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case SEQUENTIAL: |
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Fadvise(fd_, 0, 0, POSIX_FADV_SEQUENTIAL); |
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break; |
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case WILLNEED: |
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Fadvise(fd_, 0, 0, POSIX_FADV_WILLNEED); |
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break; |
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case DONTNEED: |
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Fadvise(fd_, 0, 0, POSIX_FADV_DONTNEED); |
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break; |
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default: |
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assert(false); |
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break; |
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} |
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} |
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Status PosixRandomAccessFile::InvalidateCache(size_t offset, size_t length) { |
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#ifndef OS_LINUX |
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return Status::OK(); |
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#else |
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// free OS pages
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int ret = Fadvise(fd_, offset, length, POSIX_FADV_DONTNEED); |
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if (ret == 0) { |
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return Status::OK(); |
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} |
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return IOError(filename_, errno); |
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#endif |
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} |
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/*
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* PosixMmapReadableFile |
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* |
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* mmap() based random-access |
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*/ |
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// base[0,length-1] contains the mmapped contents of the file.
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PosixMmapReadableFile::PosixMmapReadableFile(const int fd, |
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const std::string& fname, |
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void* base, size_t length, |
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const EnvOptions& options) |
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: fd_(fd), filename_(fname), mmapped_region_(base), length_(length) { |
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fd_ = fd_ + 0; // suppress the warning for used variables
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assert(options.use_mmap_reads); |
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assert(options.use_os_buffer); |
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} |
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PosixMmapReadableFile::~PosixMmapReadableFile() { |
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int ret = munmap(mmapped_region_, length_); |
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if (ret != 0) { |
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fprintf(stdout, "failed to munmap %p length %" ROCKSDB_PRIszt " \n", |
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mmapped_region_, length_); |
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} |
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} |
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Status PosixMmapReadableFile::Read(uint64_t offset, size_t n, Slice* result, |
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char* scratch) const { |
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Status s; |
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if (offset > length_) { |
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*result = Slice(); |
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return IOError(filename_, EINVAL); |
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} else if (offset + n > length_) { |
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n = static_cast<size_t>(length_ - offset); |
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} |
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*result = Slice(reinterpret_cast<char*>(mmapped_region_) + offset, n); |
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return s; |
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} |
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Status PosixMmapReadableFile::InvalidateCache(size_t offset, size_t length) { |
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#ifndef OS_LINUX |
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return Status::OK(); |
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#else |
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// free OS pages
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int ret = Fadvise(fd_, offset, length, POSIX_FADV_DONTNEED); |
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if (ret == 0) { |
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return Status::OK(); |
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} |
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return IOError(filename_, errno); |
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#endif |
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} |
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/*
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* PosixMmapFile |
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* |
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* We preallocate up to an extra megabyte and use memcpy to append new |
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* data to the file. This is safe since we either properly close the |
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* file before reading from it, or for log files, the reading code |
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* knows enough to skip zero suffixes. |
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*/ |
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Status PosixMmapFile::UnmapCurrentRegion() { |
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TEST_KILL_RANDOM("PosixMmapFile::UnmapCurrentRegion:0", rocksdb_kill_odds); |
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if (base_ != nullptr) { |
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int munmap_status = munmap(base_, limit_ - base_); |
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if (munmap_status != 0) { |
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return IOError(filename_, munmap_status); |
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} |
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file_offset_ += limit_ - base_; |
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base_ = nullptr; |
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limit_ = nullptr; |
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last_sync_ = nullptr; |
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dst_ = nullptr; |
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// Increase the amount we map the next time, but capped at 1MB
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if (map_size_ < (1 << 20)) { |
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map_size_ *= 2; |
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} |
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} |
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return Status::OK(); |
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} |
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Status PosixMmapFile::MapNewRegion() { |
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#ifdef ROCKSDB_FALLOCATE_PRESENT |
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assert(base_ == nullptr); |
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TEST_KILL_RANDOM("PosixMmapFile::UnmapCurrentRegion:0", rocksdb_kill_odds); |
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// we can't fallocate with FALLOC_FL_KEEP_SIZE here
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if (allow_fallocate_) { |
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IOSTATS_TIMER_GUARD(allocate_nanos); |
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int alloc_status = fallocate(fd_, 0, file_offset_, map_size_); |
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if (alloc_status != 0) { |
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// fallback to posix_fallocate
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alloc_status = posix_fallocate(fd_, file_offset_, map_size_); |
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} |
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if (alloc_status != 0) { |
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return Status::IOError("Error allocating space to file : " + filename_ + |
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"Error : " + strerror(alloc_status)); |
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} |
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} |
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TEST_KILL_RANDOM("PosixMmapFile::Append:1", rocksdb_kill_odds); |
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void* ptr = mmap(nullptr, map_size_, PROT_READ | PROT_WRITE, MAP_SHARED, fd_, |
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file_offset_); |
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if (ptr == MAP_FAILED) { |
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return Status::IOError("MMap failed on " + filename_); |
||||
} |
||||
TEST_KILL_RANDOM("PosixMmapFile::Append:2", rocksdb_kill_odds); |
||||
|
||||
base_ = reinterpret_cast<char*>(ptr); |
||||
limit_ = base_ + map_size_; |
||||
dst_ = base_; |
||||
last_sync_ = base_; |
||||
return Status::OK(); |
||||
#else |
||||
return Status::NotSupported("This platform doesn't support fallocate()"); |
||||
#endif |
||||
} |
||||
|
||||
Status PosixMmapFile::Msync() { |
||||
if (dst_ == last_sync_) { |
||||
return Status::OK(); |
||||
} |
||||
// Find the beginnings of the pages that contain the first and last
|
||||
// bytes to be synced.
|
||||
size_t p1 = TruncateToPageBoundary(last_sync_ - base_); |
||||
size_t p2 = TruncateToPageBoundary(dst_ - base_ - 1); |
||||
last_sync_ = dst_; |
||||
TEST_KILL_RANDOM("PosixMmapFile::Msync:0", rocksdb_kill_odds); |
||||
if (msync(base_ + p1, p2 - p1 + page_size_, MS_SYNC) < 0) { |
||||
return IOError(filename_, errno); |
||||
} |
||||
return Status::OK(); |
||||
} |
||||
|
||||
PosixMmapFile::PosixMmapFile(const std::string& fname, int fd, size_t page_size, |
||||
const EnvOptions& options) |
||||
: filename_(fname), |
||||
fd_(fd), |
||||
page_size_(page_size), |
||||
map_size_(Roundup(65536, page_size)), |
||||
base_(nullptr), |
||||
limit_(nullptr), |
||||
dst_(nullptr), |
||||
last_sync_(nullptr), |
||||
file_offset_(0) { |
||||
#ifdef ROCKSDB_FALLOCATE_PRESENT |
||||
allow_fallocate_ = options.allow_fallocate; |
||||
fallocate_with_keep_size_ = options.fallocate_with_keep_size; |
||||
#endif |
||||
assert((page_size & (page_size - 1)) == 0); |
||||
assert(options.use_mmap_writes); |
||||
} |
||||
|
||||
PosixMmapFile::~PosixMmapFile() { |
||||
if (fd_ >= 0) { |
||||
PosixMmapFile::Close(); |
||||
} |
||||
} |
||||
|
||||
Status PosixMmapFile::Append(const Slice& data) { |
||||
const char* src = data.data(); |
||||
size_t left = data.size(); |
||||
while (left > 0) { |
||||
assert(base_ <= dst_); |
||||
assert(dst_ <= limit_); |
||||
size_t avail = limit_ - dst_; |
||||
if (avail == 0) { |
||||
Status s = UnmapCurrentRegion(); |
||||
if (!s.ok()) { |
||||
return s; |
||||
} |
||||
s = MapNewRegion(); |
||||
if (!s.ok()) { |
||||
return s; |
||||
} |
||||
TEST_KILL_RANDOM("PosixMmapFile::Append:0", rocksdb_kill_odds); |
||||
} |
||||
|
||||
size_t n = (left <= avail) ? left : avail; |
||||
memcpy(dst_, src, n); |
||||
dst_ += n; |
||||
src += n; |
||||
left -= n; |
||||
} |
||||
return Status::OK(); |
||||
} |
||||
|
||||
Status PosixMmapFile::Close() { |
||||
Status s; |
||||
size_t unused = limit_ - dst_; |
||||
|
||||
s = UnmapCurrentRegion(); |
||||
if (!s.ok()) { |
||||
s = IOError(filename_, errno); |
||||
} else if (unused > 0) { |
||||
// Trim the extra space at the end of the file
|
||||
if (ftruncate(fd_, file_offset_ - unused) < 0) { |
||||
s = IOError(filename_, errno); |
||||
} |
||||
} |
||||
|
||||
if (close(fd_) < 0) { |
||||
if (s.ok()) { |
||||
s = IOError(filename_, errno); |
||||
} |
||||
} |
||||
|
||||
fd_ = -1; |
||||
base_ = nullptr; |
||||
limit_ = nullptr; |
||||
return s; |
||||
} |
||||
|
||||
Status PosixMmapFile::Flush() { return Status::OK(); } |
||||
|
||||
Status PosixMmapFile::Sync() { |
||||
if (fdatasync(fd_) < 0) { |
||||
return IOError(filename_, errno); |
||||
} |
||||
|
||||
return Msync(); |
||||
} |
||||
|
||||
/**
|
||||
* Flush data as well as metadata to stable storage. |
||||
*/ |
||||
Status PosixMmapFile::Fsync() { |
||||
if (fsync(fd_) < 0) { |
||||
return IOError(filename_, errno); |
||||
} |
||||
|
||||
return Msync(); |
||||
} |
||||
|
||||
/**
|
||||
* Get the size of valid data in the file. This will not match the |
||||
* size that is returned from the filesystem because we use mmap |
||||
* to extend file by map_size every time. |
||||
*/ |
||||
uint64_t PosixMmapFile::GetFileSize() { |
||||
size_t used = dst_ - base_; |
||||
return file_offset_ + used; |
||||
} |
||||
|
||||
Status PosixMmapFile::InvalidateCache(size_t offset, size_t length) { |
||||
#ifndef OS_LINUX |
||||
return Status::OK(); |
||||
#else |
||||
// free OS pages
|
||||
int ret = Fadvise(fd_, offset, length, POSIX_FADV_DONTNEED); |
||||
if (ret == 0) { |
||||
return Status::OK(); |
||||
} |
||||
return IOError(filename_, errno); |
||||
#endif |
||||
} |
||||
|
||||
#ifdef ROCKSDB_FALLOCATE_PRESENT |
||||
Status PosixMmapFile::Allocate(off_t offset, off_t len) { |
||||
TEST_KILL_RANDOM("PosixMmapFile::Allocate:0", rocksdb_kill_odds); |
||||
int alloc_status = 0; |
||||
if (allow_fallocate_) { |
||||
alloc_status = fallocate( |
||||
fd_, fallocate_with_keep_size_ ? FALLOC_FL_KEEP_SIZE : 0, offset, len); |
||||
} |
||||
if (alloc_status == 0) { |
||||
return Status::OK(); |
||||
} else { |
||||
return IOError(filename_, errno); |
||||
} |
||||
} |
||||
#endif |
||||
|
||||
/*
|
||||
* PosixWritableFile |
||||
* |
||||
* Use posix write to write data to a file. |
||||
*/ |
||||
PosixWritableFile::PosixWritableFile(const std::string& fname, int fd, |
||||
const EnvOptions& options) |
||||
: filename_(fname), fd_(fd), filesize_(0) { |
||||
#ifdef ROCKSDB_FALLOCATE_PRESENT |
||||
allow_fallocate_ = options.allow_fallocate; |
||||
fallocate_with_keep_size_ = options.fallocate_with_keep_size; |
||||
#endif |
||||
assert(!options.use_mmap_writes); |
||||
} |
||||
|
||||
PosixWritableFile::~PosixWritableFile() { |
||||
if (fd_ >= 0) { |
||||
PosixWritableFile::Close(); |
||||
} |
||||
} |
||||
|
||||
Status PosixWritableFile::Append(const Slice& data) { |
||||
const char* src = data.data(); |
||||
size_t left = data.size(); |
||||
while (left != 0) { |
||||
ssize_t done = write(fd_, src, left); |
||||
if (done < 0) { |
||||
if (errno == EINTR) { |
||||
continue; |
||||
} |
||||
return IOError(filename_, errno); |
||||
} |
||||
left -= done; |
||||
src += done; |
||||
} |
||||
filesize_ += data.size(); |
||||
return Status::OK(); |
||||
} |
||||
|
||||
Status PosixWritableFile::Close() { |
||||
Status s; |
||||
|
||||
size_t block_size; |
||||
size_t last_allocated_block; |
||||
GetPreallocationStatus(&block_size, &last_allocated_block); |
||||
if (last_allocated_block > 0) { |
||||
// trim the extra space preallocated at the end of the file
|
||||
// NOTE(ljin): we probably don't want to surface failure as an IOError,
|
||||
// but it will be nice to log these errors.
|
||||
int dummy __attribute__((unused)); |
||||
dummy = ftruncate(fd_, filesize_); |
||||
#ifdef ROCKSDB_FALLOCATE_PRESENT |
||||
// in some file systems, ftruncate only trims trailing space if the
|
||||
// new file size is smaller than the current size. Calling fallocate
|
||||
// with FALLOC_FL_PUNCH_HOLE flag to explicitly release these unused
|
||||
// blocks. FALLOC_FL_PUNCH_HOLE is supported on at least the following
|
||||
// filesystems:
|
||||
// XFS (since Linux 2.6.38)
|
||||
// ext4 (since Linux 3.0)
|
||||
// Btrfs (since Linux 3.7)
|
||||
// tmpfs (since Linux 3.5)
|
||||
// We ignore error since failure of this operation does not affect
|
||||
// correctness.
|
||||
IOSTATS_TIMER_GUARD(allocate_nanos); |
||||
if (allow_fallocate_) { |
||||
fallocate(fd_, FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE, filesize_, |
||||
block_size * last_allocated_block - filesize_); |
||||
} |
||||
#endif |
||||
} |
||||
|
||||
if (close(fd_) < 0) { |
||||
s = IOError(filename_, errno); |
||||
} |
||||
fd_ = -1; |
||||
return s; |
||||
} |
||||
|
||||
// write out the cached data to the OS cache
|
||||
Status PosixWritableFile::Flush() { return Status::OK(); } |
||||
|
||||
Status PosixWritableFile::Sync() { |
||||
if (fdatasync(fd_) < 0) { |
||||
return IOError(filename_, errno); |
||||
} |
||||
return Status::OK(); |
||||
} |
||||
|
||||
Status PosixWritableFile::Fsync() { |
||||
if (fsync(fd_) < 0) { |
||||
return IOError(filename_, errno); |
||||
} |
||||
return Status::OK(); |
||||
} |
||||
|
||||
bool PosixWritableFile::IsSyncThreadSafe() const { return true; } |
||||
|
||||
uint64_t PosixWritableFile::GetFileSize() { return filesize_; } |
||||
|
||||
Status PosixWritableFile::InvalidateCache(size_t offset, size_t length) { |
||||
#ifndef OS_LINUX |
||||
return Status::OK(); |
||||
#else |
||||
// free OS pages
|
||||
int ret = Fadvise(fd_, offset, length, POSIX_FADV_DONTNEED); |
||||
if (ret == 0) { |
||||
return Status::OK(); |
||||
} |
||||
return IOError(filename_, errno); |
||||
#endif |
||||
} |
||||
|
||||
#ifdef ROCKSDB_FALLOCATE_PRESENT |
||||
Status PosixWritableFile::Allocate(off_t offset, off_t len) { |
||||
TEST_KILL_RANDOM("PosixWritableFile::Allocate:0", rocksdb_kill_odds); |
||||
IOSTATS_TIMER_GUARD(allocate_nanos); |
||||
int alloc_status = 0; |
||||
if (allow_fallocate_) { |
||||
alloc_status = fallocate( |
||||
fd_, fallocate_with_keep_size_ ? FALLOC_FL_KEEP_SIZE : 0, offset, len); |
||||
} |
||||
if (alloc_status == 0) { |
||||
return Status::OK(); |
||||
} else { |
||||
return IOError(filename_, errno); |
||||
} |
||||
} |
||||
|
||||
Status PosixWritableFile::RangeSync(off_t offset, off_t nbytes) { |
||||
if (sync_file_range(fd_, offset, nbytes, SYNC_FILE_RANGE_WRITE) == 0) { |
||||
return Status::OK(); |
||||
} else { |
||||
return IOError(filename_, errno); |
||||
} |
||||
} |
||||
|
||||
size_t PosixWritableFile::GetUniqueId(char* id, size_t max_size) const { |
||||
return GetUniqueIdFromFile(fd_, id, max_size); |
||||
} |
||||
#endif |
||||
} // namespace rocksdb
|
||||
#endif |
Loading…
Reference in new issue