2016-04-23 01:18:33 +02:00
|
|
|
// Copyright (c) 2013, Facebook, Inc. All rights reserved.
|
2017-07-16 01:03:42 +02:00
|
|
|
// This source code is licensed under both the GPLv2 (found in the
|
|
|
|
// COPYING file in the root directory) and Apache 2.0 License
|
|
|
|
// (found in the LICENSE.Apache file in the root directory).
|
2016-04-23 01:18:33 +02:00
|
|
|
#pragma once
|
|
|
|
|
|
|
|
#ifndef ROCKSDB_LITE
|
|
|
|
|
|
|
|
#include <list>
|
|
|
|
#include <memory>
|
|
|
|
#include <string>
|
|
|
|
#include <vector>
|
|
|
|
|
|
|
|
#include "rocksdb/comparator.h"
|
|
|
|
#include "rocksdb/env.h"
|
|
|
|
|
|
|
|
#include "utilities/persistent_cache/block_cache_tier_file_buffer.h"
|
|
|
|
#include "utilities/persistent_cache/lrulist.h"
|
|
|
|
#include "utilities/persistent_cache/persistent_cache_tier.h"
|
|
|
|
#include "utilities/persistent_cache/persistent_cache_util.h"
|
|
|
|
|
2016-08-03 02:15:18 +02:00
|
|
|
#include "port/port.h"
|
2016-04-23 01:18:33 +02:00
|
|
|
#include "util/crc32c.h"
|
2017-02-27 21:59:34 +01:00
|
|
|
#include "util/file_reader_writer.h"
|
2016-04-23 01:18:33 +02:00
|
|
|
#include "util/mutexlock.h"
|
|
|
|
|
|
|
|
// The io code path of persistent cache uses pipelined architecture
|
|
|
|
//
|
|
|
|
// client -> In Queue <-- BlockCacheTier --> Out Queue <-- Writer <--> Kernel
|
|
|
|
//
|
|
|
|
// This would enable the system to scale for GB/s of throughput which is
|
|
|
|
// expected with modern devies like NVM.
|
|
|
|
//
|
|
|
|
// The file level operations are encapsulated in the following abstractions
|
|
|
|
//
|
|
|
|
// BlockCacheFile
|
|
|
|
// ^
|
|
|
|
// |
|
|
|
|
// |
|
|
|
|
// RandomAccessCacheFile (For reading)
|
|
|
|
// ^
|
|
|
|
// |
|
|
|
|
// |
|
|
|
|
// WriteableCacheFile (For writing)
|
|
|
|
//
|
|
|
|
// Write IO code path :
|
|
|
|
//
|
|
|
|
namespace rocksdb {
|
|
|
|
|
|
|
|
class WriteableCacheFile;
|
|
|
|
struct BlockInfo;
|
|
|
|
|
|
|
|
// Represents a logical record on device
|
|
|
|
//
|
|
|
|
// (L)ogical (B)lock (Address = { cache-file-id, offset, size }
|
|
|
|
struct LogicalBlockAddress {
|
|
|
|
LogicalBlockAddress() {}
|
|
|
|
explicit LogicalBlockAddress(const uint32_t cache_id, const uint32_t off,
|
|
|
|
const uint16_t size)
|
|
|
|
: cache_id_(cache_id), off_(off), size_(size) {}
|
|
|
|
|
|
|
|
uint32_t cache_id_ = 0;
|
|
|
|
uint32_t off_ = 0;
|
|
|
|
uint32_t size_ = 0;
|
|
|
|
};
|
|
|
|
|
|
|
|
typedef LogicalBlockAddress LBA;
|
|
|
|
|
|
|
|
// class Writer
|
|
|
|
//
|
|
|
|
// Writer is the abstraction used for writing data to file. The component can be
|
|
|
|
// multithreaded. It is the last step of write pipeline
|
|
|
|
class Writer {
|
|
|
|
public:
|
|
|
|
explicit Writer(PersistentCacheTier* const cache) : cache_(cache) {}
|
|
|
|
virtual ~Writer() {}
|
|
|
|
|
|
|
|
// write buffer to file at the given offset
|
|
|
|
virtual void Write(WritableFile* const file, CacheWriteBuffer* buf,
|
|
|
|
const uint64_t file_off,
|
|
|
|
const std::function<void()> callback) = 0;
|
|
|
|
// stop the writer
|
|
|
|
virtual void Stop() = 0;
|
|
|
|
|
|
|
|
PersistentCacheTier* const cache_;
|
|
|
|
};
|
|
|
|
|
|
|
|
// class BlockCacheFile
|
|
|
|
//
|
|
|
|
// Generic interface to support building file specialized for read/writing
|
|
|
|
class BlockCacheFile : public LRUElement<BlockCacheFile> {
|
|
|
|
public:
|
|
|
|
explicit BlockCacheFile(const uint32_t cache_id)
|
|
|
|
: LRUElement<BlockCacheFile>(), cache_id_(cache_id) {}
|
|
|
|
|
|
|
|
explicit BlockCacheFile(Env* const env, const std::string& dir,
|
|
|
|
const uint32_t cache_id)
|
|
|
|
: LRUElement<BlockCacheFile>(),
|
|
|
|
env_(env),
|
|
|
|
dir_(dir),
|
|
|
|
cache_id_(cache_id) {}
|
|
|
|
|
|
|
|
virtual ~BlockCacheFile() {}
|
|
|
|
|
|
|
|
// append key/value to file and return LBA locator to user
|
2017-07-21 23:50:24 +02:00
|
|
|
virtual bool Append(const Slice& /*key*/, const Slice& /*val*/,
|
|
|
|
LBA* const /*lba*/) {
|
2016-04-23 01:18:33 +02:00
|
|
|
assert(!"not implemented");
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
|
|
|
|
// read from the record locator (LBA) and return key, value and status
|
2017-07-21 23:50:24 +02:00
|
|
|
virtual bool Read(const LBA& /*lba*/, Slice* /*key*/, Slice* /*block*/,
|
|
|
|
char* /*scratch*/) {
|
2016-04-23 01:18:33 +02:00
|
|
|
assert(!"not implemented");
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
|
|
|
|
// get file path
|
2016-05-03 20:05:42 +02:00
|
|
|
std::string Path() const {
|
|
|
|
return dir_ + "/" + std::to_string(cache_id_) + ".rc";
|
|
|
|
}
|
2016-04-23 01:18:33 +02:00
|
|
|
// get cache ID
|
|
|
|
uint32_t cacheid() const { return cache_id_; }
|
|
|
|
// Add block information to file data
|
|
|
|
// Block information is the list of index reference for this file
|
|
|
|
virtual void Add(BlockInfo* binfo) {
|
|
|
|
WriteLock _(&rwlock_);
|
|
|
|
block_infos_.push_back(binfo);
|
|
|
|
}
|
|
|
|
// get block information
|
|
|
|
std::list<BlockInfo*>& block_infos() { return block_infos_; }
|
|
|
|
// delete file and return the size of the file
|
2016-07-20 01:36:25 +02:00
|
|
|
virtual Status Delete(uint64_t* size);
|
2016-04-23 01:18:33 +02:00
|
|
|
|
|
|
|
protected:
|
|
|
|
port::RWMutex rwlock_; // synchronization mutex
|
|
|
|
Env* const env_ = nullptr; // Env for IO
|
|
|
|
const std::string dir_; // Directory name
|
|
|
|
const uint32_t cache_id_; // Cache id for the file
|
|
|
|
std::list<BlockInfo*> block_infos_; // List of index entries mapping to the
|
|
|
|
// file content
|
|
|
|
};
|
|
|
|
|
|
|
|
// class RandomAccessFile
|
|
|
|
//
|
|
|
|
// Thread safe implementation for reading random data from file
|
|
|
|
class RandomAccessCacheFile : public BlockCacheFile {
|
|
|
|
public:
|
|
|
|
explicit RandomAccessCacheFile(Env* const env, const std::string& dir,
|
|
|
|
const uint32_t cache_id,
|
|
|
|
const shared_ptr<Logger>& log)
|
|
|
|
: BlockCacheFile(env, dir, cache_id), log_(log) {}
|
|
|
|
|
|
|
|
virtual ~RandomAccessCacheFile() {}
|
|
|
|
|
|
|
|
// open file for reading
|
2016-05-03 20:05:42 +02:00
|
|
|
bool Open(const bool enable_direct_reads);
|
2016-04-23 01:18:33 +02:00
|
|
|
// read data from the disk
|
|
|
|
bool Read(const LBA& lba, Slice* key, Slice* block, char* scratch) override;
|
|
|
|
|
|
|
|
private:
|
2017-02-27 21:59:34 +01:00
|
|
|
std::unique_ptr<RandomAccessFileReader> freader_;
|
2016-04-23 01:18:33 +02:00
|
|
|
|
|
|
|
protected:
|
2016-05-03 20:05:42 +02:00
|
|
|
bool OpenImpl(const bool enable_direct_reads);
|
2016-04-23 01:18:33 +02:00
|
|
|
bool ParseRec(const LBA& lba, Slice* key, Slice* val, char* scratch);
|
|
|
|
|
|
|
|
std::shared_ptr<Logger> log_; // log file
|
|
|
|
};
|
|
|
|
|
|
|
|
// class WriteableCacheFile
|
|
|
|
//
|
|
|
|
// All writes to the files are cached in buffers. The buffers are flushed to
|
|
|
|
// disk as they get filled up. When file size reaches a certain size, a new file
|
|
|
|
// will be created provided there is free space
|
|
|
|
class WriteableCacheFile : public RandomAccessCacheFile {
|
|
|
|
public:
|
|
|
|
explicit WriteableCacheFile(Env* const env, CacheWriteBufferAllocator* alloc,
|
|
|
|
Writer* writer, const std::string& dir,
|
|
|
|
const uint32_t cache_id, const uint32_t max_size,
|
|
|
|
const std::shared_ptr<Logger>& log)
|
|
|
|
: RandomAccessCacheFile(env, dir, cache_id, log),
|
|
|
|
alloc_(alloc),
|
|
|
|
writer_(writer),
|
|
|
|
max_size_(max_size) {}
|
|
|
|
|
|
|
|
virtual ~WriteableCacheFile();
|
|
|
|
|
|
|
|
// create file on disk
|
2016-05-03 20:05:42 +02:00
|
|
|
bool Create(const bool enable_direct_writes, const bool enable_direct_reads);
|
2016-04-23 01:18:33 +02:00
|
|
|
|
|
|
|
// read data from logical file
|
|
|
|
bool Read(const LBA& lba, Slice* key, Slice* block, char* scratch) override {
|
|
|
|
ReadLock _(&rwlock_);
|
|
|
|
const bool closed = eof_ && bufs_.empty();
|
|
|
|
if (closed) {
|
|
|
|
// the file is closed, read from disk
|
|
|
|
return RandomAccessCacheFile::Read(lba, key, block, scratch);
|
|
|
|
}
|
|
|
|
// file is still being written, read from buffers
|
|
|
|
return ReadBuffer(lba, key, block, scratch);
|
|
|
|
}
|
|
|
|
|
|
|
|
// append data to end of file
|
2016-08-03 02:15:18 +02:00
|
|
|
bool Append(const Slice&, const Slice&, LBA* const) override;
|
2016-04-23 01:18:33 +02:00
|
|
|
// End-of-file
|
|
|
|
bool Eof() const { return eof_; }
|
|
|
|
|
|
|
|
private:
|
|
|
|
friend class ThreadedWriter;
|
|
|
|
|
2016-05-03 20:05:42 +02:00
|
|
|
static const size_t kFileAlignmentSize = 4 * 1024; // align file size
|
2016-04-23 01:18:33 +02:00
|
|
|
|
|
|
|
bool ReadBuffer(const LBA& lba, Slice* key, Slice* block, char* scratch);
|
|
|
|
bool ReadBuffer(const LBA& lba, char* data);
|
|
|
|
bool ExpandBuffer(const size_t size);
|
|
|
|
void DispatchBuffer();
|
|
|
|
void BufferWriteDone();
|
|
|
|
void CloseAndOpenForReading();
|
|
|
|
void ClearBuffers();
|
|
|
|
void Close();
|
|
|
|
|
|
|
|
// File layout in memory
|
|
|
|
//
|
|
|
|
// +------+------+------+------+------+------+
|
|
|
|
// | b0 | b1 | b2 | b3 | b4 | b5 |
|
|
|
|
// +------+------+------+------+------+------+
|
|
|
|
// ^ ^
|
|
|
|
// | |
|
|
|
|
// buf_doff_ buf_woff_
|
|
|
|
// (next buffer to (next buffer to fill)
|
|
|
|
// flush to disk)
|
|
|
|
//
|
|
|
|
// The buffers are flushed to disk serially for a given file
|
|
|
|
|
|
|
|
CacheWriteBufferAllocator* const alloc_ = nullptr; // Buffer provider
|
|
|
|
Writer* const writer_ = nullptr; // File writer thread
|
|
|
|
std::unique_ptr<WritableFile> file_; // RocksDB Env file abstraction
|
|
|
|
std::vector<CacheWriteBuffer*> bufs_; // Written buffers
|
|
|
|
uint32_t size_ = 0; // Size of the file
|
|
|
|
const uint32_t max_size_; // Max size of the file
|
|
|
|
bool eof_ = false; // End of file
|
|
|
|
uint32_t disk_woff_ = 0; // Offset to write on disk
|
|
|
|
size_t buf_woff_ = 0; // off into bufs_ to write
|
|
|
|
size_t buf_doff_ = 0; // off into bufs_ to dispatch
|
|
|
|
size_t pending_ios_ = 0; // Number of ios to disk in-progress
|
2016-05-03 20:05:42 +02:00
|
|
|
bool enable_direct_reads_ = false; // Should we enable direct reads
|
|
|
|
// when reading from disk
|
2016-04-23 01:18:33 +02:00
|
|
|
};
|
|
|
|
|
|
|
|
//
|
|
|
|
// Abstraction to do writing to device. It is part of pipelined architecture.
|
|
|
|
//
|
|
|
|
class ThreadedWriter : public Writer {
|
|
|
|
public:
|
|
|
|
// Representation of IO to device
|
|
|
|
struct IO {
|
|
|
|
explicit IO(const bool signal) : signal_(signal) {}
|
|
|
|
explicit IO(WritableFile* const file, CacheWriteBuffer* const buf,
|
|
|
|
const uint64_t file_off, const std::function<void()> callback)
|
|
|
|
: file_(file), buf_(buf), file_off_(file_off), callback_(callback) {}
|
|
|
|
|
|
|
|
IO(const IO&) = default;
|
|
|
|
IO& operator=(const IO&) = default;
|
|
|
|
size_t Size() const { return sizeof(IO); }
|
|
|
|
|
|
|
|
WritableFile* file_ = nullptr; // File to write to
|
|
|
|
CacheWriteBuffer* const buf_ = nullptr; // buffer to write
|
|
|
|
uint64_t file_off_ = 0; // file offset
|
|
|
|
bool signal_ = false; // signal to exit thread loop
|
|
|
|
std::function<void()> callback_; // Callback on completion
|
|
|
|
};
|
|
|
|
|
|
|
|
explicit ThreadedWriter(PersistentCacheTier* const cache, const size_t qdepth,
|
|
|
|
const size_t io_size);
|
2016-05-03 20:05:42 +02:00
|
|
|
virtual ~ThreadedWriter() { assert(threads_.empty()); }
|
2016-04-23 01:18:33 +02:00
|
|
|
|
|
|
|
void Stop() override;
|
|
|
|
void Write(WritableFile* const file, CacheWriteBuffer* buf,
|
|
|
|
const uint64_t file_off,
|
|
|
|
const std::function<void()> callback) override;
|
|
|
|
|
|
|
|
private:
|
|
|
|
void ThreadMain();
|
|
|
|
void DispatchIO(const IO& io);
|
|
|
|
|
|
|
|
const size_t io_size_ = 0;
|
|
|
|
BoundedQueue<IO> q_;
|
2017-02-06 23:43:55 +01:00
|
|
|
std::vector<port::Thread> threads_;
|
2016-04-23 01:18:33 +02:00
|
|
|
};
|
|
|
|
|
|
|
|
} // namespace rocksdb
|
|
|
|
|
|
|
|
#endif
|