0c1126d4cf
Summary: clean up the db_bench a little bit. also avoid allocating memory for key in the loop Test Plan: I verified a run with filluniquerandom & readrandom. Iterator seek will be used lot to measure performance. Will fix whatever comes up Reviewers: haobo, igor, yhchiang Reviewed By: igor CC: leveldb Differential Revision: https://reviews.facebook.net/D17559
134 lines
4.5 KiB
C++
134 lines
4.5 KiB
C++
// Copyright (c) 2013, Facebook, Inc. All rights reserved.
|
|
// This source code is licensed under the BSD-style license found in the
|
|
// LICENSE file in the root directory of this source tree. An additional grant
|
|
// of patent rights can be found in the PATENTS file in the same directory.
|
|
//
|
|
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style license that can be
|
|
// found in the LICENSE file. See the AUTHORS file for names of contributors.
|
|
//
|
|
// This file contains the specification, but not the implementations,
|
|
// of the types/operations/etc. that should be defined by a platform
|
|
// specific port_<platform>.h file. Use this file as a reference for
|
|
// how to port this package to a new platform.
|
|
|
|
#ifndef STORAGE_LEVELDB_PORT_PORT_EXAMPLE_H_
|
|
#define STORAGE_LEVELDB_PORT_PORT_EXAMPLE_H_
|
|
|
|
namespace rocksdb {
|
|
namespace port {
|
|
|
|
// TODO(jorlow): Many of these belong more in the environment class rather than
|
|
// here. We should try moving them and see if it affects perf.
|
|
|
|
// The following boolean constant must be true on a little-endian machine
|
|
// and false otherwise.
|
|
static const bool kLittleEndian = true /* or some other expression */;
|
|
|
|
// ------------------ Threading -------------------
|
|
|
|
// A Mutex represents an exclusive lock.
|
|
class Mutex {
|
|
public:
|
|
Mutex();
|
|
~Mutex();
|
|
|
|
// Lock the mutex. Waits until other lockers have exited.
|
|
// Will deadlock if the mutex is already locked by this thread.
|
|
void Lock();
|
|
|
|
// Unlock the mutex.
|
|
// REQUIRES: This mutex was locked by this thread.
|
|
void Unlock();
|
|
|
|
// Optionally crash if this thread does not hold this mutex.
|
|
// The implementation must be fast, especially if NDEBUG is
|
|
// defined. The implementation is allowed to skip all checks.
|
|
void AssertHeld();
|
|
};
|
|
|
|
class CondVar {
|
|
public:
|
|
explicit CondVar(Mutex* mu);
|
|
~CondVar();
|
|
|
|
// Atomically release *mu and block on this condition variable until
|
|
// either a call to SignalAll(), or a call to Signal() that picks
|
|
// this thread to wakeup.
|
|
// REQUIRES: this thread holds *mu
|
|
void Wait();
|
|
|
|
// If there are some threads waiting, wake up at least one of them.
|
|
void Signal();
|
|
|
|
// Wake up all waiting threads.
|
|
void SignallAll();
|
|
};
|
|
|
|
// Thread-safe initialization.
|
|
// Used as follows:
|
|
// static port::OnceType init_control = LEVELDB_ONCE_INIT;
|
|
// static void Initializer() { ... do something ...; }
|
|
// ...
|
|
// port::InitOnce(&init_control, &Initializer);
|
|
typedef intptr_t OnceType;
|
|
#define LEVELDB_ONCE_INIT 0
|
|
extern void InitOnce(port::OnceType*, void (*initializer)());
|
|
|
|
// A type that holds a pointer that can be read or written atomically
|
|
// (i.e., without word-tearing.)
|
|
class AtomicPointer {
|
|
private:
|
|
intptr_t rep_;
|
|
public:
|
|
// Initialize to arbitrary value
|
|
AtomicPointer();
|
|
|
|
// Initialize to hold v
|
|
explicit AtomicPointer(void* v) : rep_(v) { }
|
|
|
|
// Read and return the stored pointer with the guarantee that no
|
|
// later memory access (read or write) by this thread can be
|
|
// reordered ahead of this read.
|
|
void* Acquire_Load() const;
|
|
|
|
// Set v as the stored pointer with the guarantee that no earlier
|
|
// memory access (read or write) by this thread can be reordered
|
|
// after this store.
|
|
void Release_Store(void* v);
|
|
|
|
// Read the stored pointer with no ordering guarantees.
|
|
void* NoBarrier_Load() const;
|
|
|
|
// Set va as the stored pointer with no ordering guarantees.
|
|
void NoBarrier_Store(void* v);
|
|
};
|
|
|
|
// ------------------ Compression -------------------
|
|
|
|
// Store the snappy compression of "input[0,input_length-1]" in *output.
|
|
// Returns false if snappy is not supported by this port.
|
|
extern bool Snappy_Compress(const char* input, size_t input_length,
|
|
std::string* output);
|
|
|
|
// If input[0,input_length-1] looks like a valid snappy compressed
|
|
// buffer, store the size of the uncompressed data in *result and
|
|
// return true. Else return false.
|
|
extern bool Snappy_GetUncompressedLength(const char* input, size_t length,
|
|
size_t* result);
|
|
|
|
// Attempt to snappy uncompress input[0,input_length-1] into *output.
|
|
// Returns true if successful, false if the input is invalid lightweight
|
|
// compressed data.
|
|
//
|
|
// REQUIRES: at least the first "n" bytes of output[] must be writable
|
|
// where "n" is the result of a successful call to
|
|
// Snappy_GetUncompressedLength.
|
|
extern bool Snappy_Uncompress(const char* input_data, size_t input_length,
|
|
char* output);
|
|
|
|
} // namespace port
|
|
} // namespace rocksdb
|
|
|
|
#endif // STORAGE_LEVELDB_PORT_PORT_EXAMPLE_H_
|