Permalink
Switch branches/tags
Nothing to show
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
694 lines (557 sloc) 15.5 KB
// 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.
#include <deque>
#ifdef WIN32
#include <windows.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <time.h>
#include <io.h>
#else
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/param.h>
#include <time.h>
#include <unistd.h>
#endif
#if defined(LEVELDB_PLATFORM_ANDROID)
#include <sys/stat.h>
#endif
#include "leveldb/env.h"
#include "leveldb/slice.h"
#include "port/port.h"
#include "util/logging.h"
#ifdef __linux
#include <sys/sysinfo.h>
#include <linux/unistd.h>
#endif
#include <fstream>
#include <boost/date_time/gregorian/gregorian.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>
#include <boost/filesystem/convenience.hpp>
#include <boost/thread/once.hpp>
#include <boost/thread/thread.hpp>
#include <boost/bind.hpp>
#include <boost/scoped_ptr.hpp>
#include <boost/interprocess/sync/file_lock.hpp>
#include <boost/thread/condition_variable.hpp>
namespace leveldb {
namespace {
// returns the ID of the current process
static boost::uint32_t current_process_id(void)
{
#ifdef _WIN32
return static_cast<boost::uint32_t>(::GetCurrentProcessId());
#else
return static_cast<boost::uint32_t>(::getpid());
#endif
}
// returns the ID of the current thread
static boost::uint32_t current_thread_id(void)
{
#ifdef _WIN32
return static_cast<boost::uint32_t>(::GetCurrentThreadId());
#else
#ifdef __linux
return static_cast<boost::uint32_t>(::syscall(__NR_gettid));
#else
// just return the pid
return current_process_id();
#endif
#endif
}
static char global_read_only_buf[0x8000];
class PosixSequentialFile: public SequentialFile {
private:
std::string filename_;
FILE* file_;
public:
PosixSequentialFile(const std::string& fname, FILE* f)
: filename_(fname), file_(f) { }
virtual ~PosixSequentialFile() { fclose(file_); }
virtual Status Read(size_t n, Slice* result, char* scratch) {
Status s;
#ifdef BSD
// fread_unlocked doesn't exist on FreeBSD
size_t r = fread(scratch, 1, n, file_);
#else
size_t r = fread_unlocked(scratch, 1, n, file_);
#endif
*result = Slice(scratch, r);
if (r < n) {
if (feof(file_)) {
// We leave status as ok if we hit the end of the file
} else {
// A partial read with an error: return a non-ok status
s = Status::IOError(filename_, strerror(errno));
}
}
return s;
}
virtual Status Skip(uint64_t n) {
if (fseek(file_, n, SEEK_CUR)) {
return Status::IOError(filename_, strerror(errno));
}
return Status::OK();
}
};
class PosixRandomAccessFile: public RandomAccessFile {
private:
std::string filename_;
int fd_;
mutable boost::mutex mu_;
public:
PosixRandomAccessFile(const std::string& fname, int fd)
: filename_(fname), fd_(fd) { }
virtual ~PosixRandomAccessFile() { close(fd_); }
virtual Status Read(uint64_t offset, size_t n, Slice* result,
char* scratch) const
{
Status s;
#ifdef WIN32
// no pread on Windows so we emulate it with a mutex
boost::unique_lock<boost::mutex> lock(mu_);
if (::_lseeki64(fd_, offset, SEEK_SET) == -1L)
{
return Status::IOError(filename_, strerror(errno));
}
int r = ::_read(fd_, scratch, n);
*result = Slice(scratch, (r < 0) ? 0 : r);
lock.unlock();
#else
ssize_t r = pread(fd_, scratch, n, static_cast<off_t>(offset));
*result = Slice(scratch, (r < 0) ? 0 : r);
#endif
if (r < 0) {
// An error: return a non-ok status
s = Status::IOError(filename_, strerror(errno));
}
return s;
}
};
// We preallocate up to an extra megabyte and use memcpy to append new
// data to the file. This is safe since we either properly close the
// file before reading from it, or for log files, the reading code
// knows enough to skip zero suffixes.
class BoostFile : public WritableFile
{
public:
explicit BoostFile(std::string path) : path_(path), written_(0)
{
Open();
}
virtual ~BoostFile()
{
Close();
}
private:
void Open()
{
// we truncate the file as implemented in env_posix
file_.open(path_.generic_string().c_str(), std::ios_base::trunc | std::ios_base::out | std::ios_base::binary);
written_ = 0;
}
public:
virtual Status Append(const Slice& data)
{
Status result;
file_.write(data.data(), data.size());
if (!file_.good())
{
result = Status::IOError(path_.generic_string() + " Append", "cannot write");
}
return result;
}
virtual Status Close()
{
Status result;
try
{
if (file_.is_open())
{
Sync();
file_.close();
}
}
catch (std::exception e)
{
result = Status::IOError(path_.generic_string() + " close", e.what());
}
return result;
}
virtual Status Flush()
{
file_.flush();
return Status::OK();
}
virtual Status Sync()
{
Status result;
try
{
Flush();
}
catch (std::exception e)
{
result = Status::IOError(path_.string() + " sync", e.what());
}
return result;
}
private:
boost::filesystem::path path_;
boost::uint64_t written_;
std::ofstream file_;
};
class BoostFileLock : public FileLock {
public:
boost::interprocess::file_lock fl_;
};
class PosixEnv : public Env {
public:
PosixEnv();
virtual ~PosixEnv() {
fprintf(stderr, "Destroying Env::Default()\n");
exit(1);
}
virtual Status NewSequentialFile(const std::string& fname,
SequentialFile** result) {
FILE* f = fopen(fname.c_str(), "rb");
if (f == NULL) {
*result = NULL;
return Status::IOError(fname, strerror(errno));
} else {
*result = new PosixSequentialFile(fname, f);
return Status::OK();
}
}
virtual Status NewRandomAccessFile(const std::string& fname,
RandomAccessFile** result) {
#ifdef WIN32
int fd = _open(fname.c_str(), _O_RDONLY | _O_RANDOM | _O_BINARY);
#else
int fd = open(fname.c_str(), O_RDONLY);
#endif
if (fd < 0) {
*result = NULL;
return Status::IOError(fname, strerror(errno));
}
*result = new PosixRandomAccessFile(fname, fd);
return Status::OK();
}
virtual Status NewWritableFile(const std::string& fname,
WritableFile** result) {
Status s;
try
{
// will create a new empty file to write to
*result = new BoostFile(fname);
}
catch (std::exception e)
{
s = Status::IOError(fname, e.what());
}
return s;
}
virtual bool FileExists(const std::string& fname)
{
return boost::filesystem::exists(fname);
}
virtual Status GetChildren(const std::string& dir,
std::vector<std::string>* result) {
result->clear();
boost::system::error_code ec;
boost::filesystem::directory_iterator current(dir, ec);
if (ec)
{
return Status::IOError(dir, ec.message());
}
boost::filesystem::directory_iterator end;
for(; current != end; ++current)
{
result->push_back(current->path().filename().generic_string());
}
return Status::OK();
}
virtual Status DeleteFile(const std::string& fname)
{
boost::system::error_code ec;
boost::filesystem::remove(fname, ec);
Status result;
if (ec)
{
result = Status::IOError(fname, ec.message());
}
return result;
}
virtual Status CreateDir(const std::string& name) {
Status result;
if (boost::filesystem::exists(name) && boost::filesystem::is_directory(name))
{
return result;
}
boost::system::error_code ec;
if (!boost::filesystem::create_directories(name, ec))
{
result = Status::IOError(name, ec.message());
}
return result;
};
virtual Status DeleteDir(const std::string& name) {
Status result;
boost::system::error_code ec;
if (!boost::filesystem::remove_all(name, ec))
{
result = Status::IOError(name, ec.message());
}
return result;
};
virtual Status GetFileSize(const std::string& fname, uint64_t* size)
{
boost::system::error_code ec;
Status result;
*size = static_cast<uint64_t>(boost::filesystem::file_size(fname, ec));
if (ec)
{
*size = 0;
result = Status::IOError(fname, ec.message());
}
return result;
}
virtual Status RenameFile(const std::string& src, const std::string& target)
{
boost::system::error_code ec;
boost::filesystem::rename(src, target, ec);
Status result;
if (ec)
{
result = Status::IOError(src, ec.message());
}
return result;
}
virtual Status LockFile(const std::string& fname, FileLock** lock) {
*lock = NULL;
Status result;
try
{
if (!boost::filesystem::exists(fname))
{
std::ofstream of(fname, std::ios_base::trunc | std::ios_base::out);
}
assert(boost::filesystem::exists(fname));
boost::interprocess::file_lock fl(fname.c_str());
BoostFileLock * my_lock = new BoostFileLock();
my_lock->fl_ = std::move(fl);
my_lock->fl_.lock();
*lock = my_lock;
}
catch (std::exception e)
{
result = Status::IOError("lock " + fname, e.what());
}
return result;
}
virtual Status UnlockFile(FileLock* lock)
{
Status result;
try
{
BoostFileLock * my_lock = static_cast<BoostFileLock *>(lock);
my_lock->fl_.unlock();
delete my_lock;
}
catch (std::exception e)
{
result = Status::IOError("unlock", e.what());
}
return result;
}
virtual void Schedule(void (*function)(void*), void* arg);
virtual void StartThread(void (*function)(void* arg), void* arg);
virtual Status GetTestDirectory(std::string* result)
{
boost::system::error_code ec;
boost::filesystem::path temp_dir = boost::filesystem::temp_directory_path(ec);
if (ec)
{
temp_dir = "tmp";
}
temp_dir /= "leveldb_tests";
temp_dir /= boost::lexical_cast<std::string>(current_process_id());
// Directory may already exist
CreateDir(temp_dir.generic_string());
*result = temp_dir.generic_string();
return Status::OK();
}
virtual void Logv(WritableFile* info_log, const char* format, va_list ap)
{
// we really need to rewrite this crappy routine to something more C++y
uint64_t thread_id = static_cast<uint64_t>(current_thread_id());
// We try twice: the first time with a fixed-size stack allocated buffer,
// and the second time with a much larger dynamically allocated buffer.
char buffer[500];
for (int iter = 0; iter < 2; iter++) {
char* base;
int bufsize;
if (iter == 0) {
bufsize = sizeof(buffer);
base = buffer;
} else {
bufsize = 30000;
base = new char[bufsize];
}
char* p = base;
char* limit = base + bufsize;
boost::posix_time::ptime now = boost::posix_time::second_clock::universal_time();
p += snprintf(p, limit - p,
"%04d/%02d/%02d-%02d:%02d:%02d.%06d %llx ",
static_cast<int>(now.date().year()),
static_cast<int>(now.date().month()),
static_cast<int>(now.date().day()),
now.time_of_day().hours(),
now.time_of_day().minutes(),
now.time_of_day().seconds(),
0,
static_cast<long long unsigned int>(thread_id));
// Print the message
#ifdef WIN32
if (p < limit) {
va_list backup_ap = ap;
p += vsnprintf(p, limit - p, format, backup_ap);
va_end(backup_ap);
}
#else
if (p < limit) {
va_list backup_ap;
va_copy(backup_ap, ap);
p += vsnprintf(p, limit - p, format, backup_ap);
va_end(backup_ap);
}
#endif
// Truncate to available space if necessary
if (p >= limit) {
if (iter == 0) {
continue; // Try again with larger buffer
} else {
p = limit - 1;
}
}
// Add newline if necessary
if (p == base || p[-1] != '\n') {
*p++ = '\n';
}
assert(p <= limit);
info_log->Append(Slice(base, p - base));
info_log->Flush();
if (base != buffer) {
delete [] base;
}
break;
}
}
virtual uint64_t NowMicros()
{
return static_cast<uint64_t>(boost::posix_time::microsec_clock::universal_time().time_of_day().total_microseconds());
}
virtual void SleepForMicroseconds(int micros)
{
boost::this_thread::sleep(boost::posix_time::microseconds(micros));
}
private:
void PthreadCall(const char* label, int result) {
if (result != 0) {
fprintf(stderr, "pthread %s: %s\n", label, strerror(result));
exit(1);
}
}
// BGThread() is the body of the background thread
void BGThread();
static void* BGThreadWrapper(void* arg) {
reinterpret_cast<PosixEnv*>(arg)->BGThread();
return NULL;
}
boost::mutex mu_;
boost::condition_variable bgsignal_;
boost::scoped_ptr<boost::thread> bgthread_;
// Entry per Schedule() call
struct BGItem { void* arg; void (*function)(void*); };
typedef std::deque<BGItem> BGQueue;
BGQueue queue_;
};
PosixEnv::PosixEnv()
{
}
void PosixEnv::Schedule(void (*function)(void*), void* arg) {
boost::unique_lock<boost::mutex> lock(mu_);
// Start background thread if necessary
if (!bgthread_)
{
bgthread_.reset(new boost::thread(boost::bind(&PosixEnv::BGThreadWrapper, this)));
}
// Add to priority queue
queue_.push_back(BGItem());
queue_.back().function = function;
queue_.back().arg = arg;
lock.unlock();
bgsignal_.notify_one();
}
void PosixEnv::BGThread() {
while (true) {
// Wait until there is an item that is ready to run
boost::unique_lock<boost::mutex> lock(mu_);
while (queue_.empty()) {
bgsignal_.wait(lock);
}
void (*function)(void*) = queue_.front().function;
void* arg = queue_.front().arg;
queue_.pop_front();
lock.unlock();
(*function)(arg);
}
}
namespace {
struct StartThreadState {
void (*user_function)(void*);
void* arg;
};
}
static void* StartThreadWrapper(void* arg) {
StartThreadState* state = reinterpret_cast<StartThreadState*>(arg);
state->user_function(state->arg);
delete state;
return NULL;
}
void PosixEnv::StartThread(void (*function)(void* arg), void* arg)
{
StartThreadState* state = new StartThreadState;
state->user_function = function;
state->arg = arg;
boost::thread t(boost::bind(&StartThreadWrapper, state));
}
}
static boost::once_flag once = BOOST_ONCE_INIT;
static Env* default_env;
static void InitDefaultEnv()
{
::memset(global_read_only_buf, 0, sizeof(global_read_only_buf));
default_env = new PosixEnv;
}
Env* Env::Default() {
boost::call_once(once, InitDefaultEnv);
return default_env;
}
}