diff options
Diffstat (limited to 'src/leveldb/port')
-rw-r--r-- | src/leveldb/port/README.md | 10 | ||||
-rw-r--r-- | src/leveldb/port/port.h | 19 | ||||
-rw-r--r-- | src/leveldb/port/port_config.h.in | 39 | ||||
-rw-r--r-- | src/leveldb/port/port_example.h | 104 | ||||
-rw-r--r-- | src/leveldb/port/port_stdcxx.h | 153 | ||||
-rw-r--r-- | src/leveldb/port/thread_annotations.h | 108 |
6 files changed, 433 insertions, 0 deletions
diff --git a/src/leveldb/port/README.md b/src/leveldb/port/README.md new file mode 100644 index 0000000000..8b171532e1 --- /dev/null +++ b/src/leveldb/port/README.md @@ -0,0 +1,10 @@ +This directory contains interfaces and implementations that isolate the +rest of the package from platform details. + +Code in the rest of the package includes "port.h" from this directory. +"port.h" in turn includes a platform specific "port_<platform>.h" file +that provides the platform specific implementation. + +See port_stdcxx.h for an example of what must be provided in a platform +specific header file. + diff --git a/src/leveldb/port/port.h b/src/leveldb/port/port.h new file mode 100644 index 0000000000..4b247f74f9 --- /dev/null +++ b/src/leveldb/port/port.h @@ -0,0 +1,19 @@ +// 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. + +#ifndef STORAGE_LEVELDB_PORT_PORT_H_ +#define STORAGE_LEVELDB_PORT_PORT_H_ + +#include <string.h> + +// Include the appropriate platform specific file below. If you are +// porting to a new platform, see "port_example.h" for documentation +// of what the new port_<platform>.h file must provide. +#if defined(LEVELDB_PLATFORM_POSIX) || defined(LEVELDB_PLATFORM_WINDOWS) +#include "port/port_stdcxx.h" +#elif defined(LEVELDB_PLATFORM_CHROMIUM) +#include "port/port_chromium.h" +#endif + +#endif // STORAGE_LEVELDB_PORT_PORT_H_ diff --git a/src/leveldb/port/port_config.h.in b/src/leveldb/port/port_config.h.in new file mode 100644 index 0000000000..21273153a3 --- /dev/null +++ b/src/leveldb/port/port_config.h.in @@ -0,0 +1,39 @@ +// Copyright 2017 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. + +#ifndef STORAGE_LEVELDB_PORT_PORT_CONFIG_H_ +#define STORAGE_LEVELDB_PORT_PORT_CONFIG_H_ + +// Define to 1 if you have a definition for fdatasync() in <unistd.h>. +#if !defined(HAVE_FDATASYNC) +#cmakedefine01 HAVE_FDATASYNC +#endif // !defined(HAVE_FDATASYNC) + +// Define to 1 if you have a definition for F_FULLFSYNC in <fcntl.h>. +#if !defined(HAVE_FULLFSYNC) +#cmakedefine01 HAVE_FULLFSYNC +#endif // !defined(HAVE_FULLFSYNC) + +// Define to 1 if you have a definition for O_CLOEXEC in <fcntl.h>. +#if !defined(HAVE_O_CLOEXEC) +#cmakedefine01 HAVE_O_CLOEXEC +#endif // !defined(HAVE_O_CLOEXEC) + +// Define to 1 if you have Google CRC32C. +#if !defined(HAVE_CRC32C) +#cmakedefine01 HAVE_CRC32C +#endif // !defined(HAVE_CRC32C) + +// Define to 1 if you have Google Snappy. +#if !defined(HAVE_SNAPPY) +#cmakedefine01 HAVE_SNAPPY +#endif // !defined(HAVE_SNAPPY) + +// Define to 1 if your processor stores words with the most significant byte +// first (like Motorola and SPARC, unlike Intel and VAX). +#if !defined(LEVELDB_IS_BIG_ENDIAN) +#cmakedefine01 LEVELDB_IS_BIG_ENDIAN +#endif // !defined(LEVELDB_IS_BIG_ENDIAN) + +#endif // STORAGE_LEVELDB_PORT_PORT_CONFIG_H_
\ No newline at end of file diff --git a/src/leveldb/port/port_example.h b/src/leveldb/port/port_example.h new file mode 100644 index 0000000000..1a8fca24b3 --- /dev/null +++ b/src/leveldb/port/port_example.h @@ -0,0 +1,104 @@ +// 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_ + +#include "port/thread_annotations.h" + +namespace leveldb { +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 LOCKABLE 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() EXCLUSIVE_LOCK_FUNCTION(); + + // Unlock the mutex. + // REQUIRES: This mutex was locked by this thread. + void Unlock() UNLOCK_FUNCTION(); + + // 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() ASSERT_EXCLUSIVE_LOCK(); +}; + +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(); +}; + +// ------------------ Compression ------------------- + +// Store the snappy compression of "input[0,input_length-1]" in *output. +// Returns false if snappy is not supported by this port. +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. +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. +bool Snappy_Uncompress(const char* input_data, size_t input_length, + char* output); + +// ------------------ Miscellaneous ------------------- + +// If heap profiling is not supported, returns false. +// Else repeatedly calls (*func)(arg, data, n) and then returns true. +// The concatenation of all "data[0,n-1]" fragments is the heap profile. +bool GetHeapProfile(void (*func)(void*, const char*, int), void* arg); + +// Extend the CRC to include the first n bytes of buf. +// +// Returns zero if the CRC cannot be extended using acceleration, else returns +// the newly extended CRC value (which may also be zero). +uint32_t AcceleratedCRC32C(uint32_t crc, const char* buf, size_t size); + +} // namespace port +} // namespace leveldb + +#endif // STORAGE_LEVELDB_PORT_PORT_EXAMPLE_H_ diff --git a/src/leveldb/port/port_stdcxx.h b/src/leveldb/port/port_stdcxx.h new file mode 100644 index 0000000000..e9cb0e53af --- /dev/null +++ b/src/leveldb/port/port_stdcxx.h @@ -0,0 +1,153 @@ +// Copyright (c) 2018 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. + +#ifndef STORAGE_LEVELDB_PORT_PORT_STDCXX_H_ +#define STORAGE_LEVELDB_PORT_PORT_STDCXX_H_ + +// port/port_config.h availability is automatically detected via __has_include +// in newer compilers. If LEVELDB_HAS_PORT_CONFIG_H is defined, it overrides the +// configuration detection. +#if defined(LEVELDB_HAS_PORT_CONFIG_H) + +#if LEVELDB_HAS_PORT_CONFIG_H +#include "port/port_config.h" +#endif // LEVELDB_HAS_PORT_CONFIG_H + +#elif defined(__has_include) + +#if __has_include("port/port_config.h") +#include "port/port_config.h" +#endif // __has_include("port/port_config.h") + +#endif // defined(LEVELDB_HAS_PORT_CONFIG_H) + +#if HAVE_CRC32C +#include <crc32c/crc32c.h> +#endif // HAVE_CRC32C +#if HAVE_SNAPPY +#include <snappy.h> +#endif // HAVE_SNAPPY + +#include <cassert> +#include <condition_variable> // NOLINT +#include <cstddef> +#include <cstdint> +#include <mutex> // NOLINT +#include <string> + +#include "port/thread_annotations.h" + +namespace leveldb { +namespace port { + +static const bool kLittleEndian = !LEVELDB_IS_BIG_ENDIAN; + +class CondVar; + +// Thinly wraps std::mutex. +class LOCKABLE Mutex { + public: + Mutex() = default; + ~Mutex() = default; + + Mutex(const Mutex&) = delete; + Mutex& operator=(const Mutex&) = delete; + + void Lock() EXCLUSIVE_LOCK_FUNCTION() { mu_.lock(); } + void Unlock() UNLOCK_FUNCTION() { mu_.unlock(); } + void AssertHeld() ASSERT_EXCLUSIVE_LOCK() {} + + private: + friend class CondVar; + std::mutex mu_; +}; + +// Thinly wraps std::condition_variable. +class CondVar { + public: + explicit CondVar(Mutex* mu) : mu_(mu) { assert(mu != nullptr); } + ~CondVar() = default; + + CondVar(const CondVar&) = delete; + CondVar& operator=(const CondVar&) = delete; + + void Wait() { + std::unique_lock<std::mutex> lock(mu_->mu_, std::adopt_lock); + cv_.wait(lock); + lock.release(); + } + void Signal() { cv_.notify_one(); } + void SignalAll() { cv_.notify_all(); } + + private: + std::condition_variable cv_; + Mutex* const mu_; +}; + +inline bool Snappy_Compress(const char* input, size_t length, + std::string* output) { +#if HAVE_SNAPPY + output->resize(snappy::MaxCompressedLength(length)); + size_t outlen; + snappy::RawCompress(input, length, &(*output)[0], &outlen); + output->resize(outlen); + return true; +#else + // Silence compiler warnings about unused arguments. + (void)input; + (void)length; + (void)output; +#endif // HAVE_SNAPPY + + return false; +} + +inline bool Snappy_GetUncompressedLength(const char* input, size_t length, + size_t* result) { +#if HAVE_SNAPPY + return snappy::GetUncompressedLength(input, length, result); +#else + // Silence compiler warnings about unused arguments. + (void)input; + (void)length; + (void)result; + return false; +#endif // HAVE_SNAPPY +} + +inline bool Snappy_Uncompress(const char* input, size_t length, char* output) { +#if HAVE_SNAPPY + return snappy::RawUncompress(input, length, output); +#else + // Silence compiler warnings about unused arguments. + (void)input; + (void)length; + (void)output; + return false; +#endif // HAVE_SNAPPY +} + +inline bool GetHeapProfile(void (*func)(void*, const char*, int), void* arg) { + // Silence compiler warnings about unused arguments. + (void)func; + (void)arg; + return false; +} + +inline uint32_t AcceleratedCRC32C(uint32_t crc, const char* buf, size_t size) { +#if HAVE_CRC32C + return ::crc32c::Extend(crc, reinterpret_cast<const uint8_t*>(buf), size); +#else + // Silence compiler warnings about unused arguments. + (void)crc; + (void)buf; + (void)size; + return 0; +#endif // HAVE_CRC32C +} + +} // namespace port +} // namespace leveldb + +#endif // STORAGE_LEVELDB_PORT_PORT_STDCXX_H_ diff --git a/src/leveldb/port/thread_annotations.h b/src/leveldb/port/thread_annotations.h new file mode 100644 index 0000000000..1547df908f --- /dev/null +++ b/src/leveldb/port/thread_annotations.h @@ -0,0 +1,108 @@ +// Copyright (c) 2012 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. + +#ifndef STORAGE_LEVELDB_PORT_THREAD_ANNOTATIONS_H_ +#define STORAGE_LEVELDB_PORT_THREAD_ANNOTATIONS_H_ + +// Use Clang's thread safety analysis annotations when available. In other +// environments, the macros receive empty definitions. +// Usage documentation: https://clang.llvm.org/docs/ThreadSafetyAnalysis.html + +#if !defined(THREAD_ANNOTATION_ATTRIBUTE__) + +#if defined(__clang__) + +#define THREAD_ANNOTATION_ATTRIBUTE__(x) __attribute__((x)) +#else +#define THREAD_ANNOTATION_ATTRIBUTE__(x) // no-op +#endif + +#endif // !defined(THREAD_ANNOTATION_ATTRIBUTE__) + +#ifndef GUARDED_BY +#define GUARDED_BY(x) THREAD_ANNOTATION_ATTRIBUTE__(guarded_by(x)) +#endif + +#ifndef PT_GUARDED_BY +#define PT_GUARDED_BY(x) THREAD_ANNOTATION_ATTRIBUTE__(pt_guarded_by(x)) +#endif + +#ifndef ACQUIRED_AFTER +#define ACQUIRED_AFTER(...) \ + THREAD_ANNOTATION_ATTRIBUTE__(acquired_after(__VA_ARGS__)) +#endif + +#ifndef ACQUIRED_BEFORE +#define ACQUIRED_BEFORE(...) \ + THREAD_ANNOTATION_ATTRIBUTE__(acquired_before(__VA_ARGS__)) +#endif + +#ifndef EXCLUSIVE_LOCKS_REQUIRED +#define EXCLUSIVE_LOCKS_REQUIRED(...) \ + THREAD_ANNOTATION_ATTRIBUTE__(exclusive_locks_required(__VA_ARGS__)) +#endif + +#ifndef SHARED_LOCKS_REQUIRED +#define SHARED_LOCKS_REQUIRED(...) \ + THREAD_ANNOTATION_ATTRIBUTE__(shared_locks_required(__VA_ARGS__)) +#endif + +#ifndef LOCKS_EXCLUDED +#define LOCKS_EXCLUDED(...) \ + THREAD_ANNOTATION_ATTRIBUTE__(locks_excluded(__VA_ARGS__)) +#endif + +#ifndef LOCK_RETURNED +#define LOCK_RETURNED(x) THREAD_ANNOTATION_ATTRIBUTE__(lock_returned(x)) +#endif + +#ifndef LOCKABLE +#define LOCKABLE THREAD_ANNOTATION_ATTRIBUTE__(lockable) +#endif + +#ifndef SCOPED_LOCKABLE +#define SCOPED_LOCKABLE THREAD_ANNOTATION_ATTRIBUTE__(scoped_lockable) +#endif + +#ifndef EXCLUSIVE_LOCK_FUNCTION +#define EXCLUSIVE_LOCK_FUNCTION(...) \ + THREAD_ANNOTATION_ATTRIBUTE__(exclusive_lock_function(__VA_ARGS__)) +#endif + +#ifndef SHARED_LOCK_FUNCTION +#define SHARED_LOCK_FUNCTION(...) \ + THREAD_ANNOTATION_ATTRIBUTE__(shared_lock_function(__VA_ARGS__)) +#endif + +#ifndef EXCLUSIVE_TRYLOCK_FUNCTION +#define EXCLUSIVE_TRYLOCK_FUNCTION(...) \ + THREAD_ANNOTATION_ATTRIBUTE__(exclusive_trylock_function(__VA_ARGS__)) +#endif + +#ifndef SHARED_TRYLOCK_FUNCTION +#define SHARED_TRYLOCK_FUNCTION(...) \ + THREAD_ANNOTATION_ATTRIBUTE__(shared_trylock_function(__VA_ARGS__)) +#endif + +#ifndef UNLOCK_FUNCTION +#define UNLOCK_FUNCTION(...) \ + THREAD_ANNOTATION_ATTRIBUTE__(unlock_function(__VA_ARGS__)) +#endif + +#ifndef NO_THREAD_SAFETY_ANALYSIS +#define NO_THREAD_SAFETY_ANALYSIS \ + THREAD_ANNOTATION_ATTRIBUTE__(no_thread_safety_analysis) +#endif + +#ifndef ASSERT_EXCLUSIVE_LOCK +#define ASSERT_EXCLUSIVE_LOCK(...) \ + THREAD_ANNOTATION_ATTRIBUTE__(assert_exclusive_lock(__VA_ARGS__)) +#endif + +#ifndef ASSERT_SHARED_LOCK +#define ASSERT_SHARED_LOCK(...) \ + THREAD_ANNOTATION_ATTRIBUTE__(assert_shared_lock(__VA_ARGS__)) +#endif + +#endif // STORAGE_LEVELDB_PORT_THREAD_ANNOTATIONS_H_ |