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-rw-r--r--src/leveldb/util/env_posix.cc698
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diff --git a/src/leveldb/util/env_posix.cc b/src/leveldb/util/env_posix.cc
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--- a/src/leveldb/util/env_posix.cc
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@@ -1,698 +0,0 @@
-// 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>
-#include <set>
-#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 <time.h>
-#include <unistd.h>
-#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"
-#include "util/mutexlock.h"
-#include "util/posix_logger.h"
-
-namespace leveldb {
-
-namespace {
-
-static Status IOError(const std::string& context, int err_number) {
- return Status::IOError(context, strerror(err_number));
-}
-
-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;
- size_t r = fread_unlocked(scratch, 1, n, file_);
- *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 = IOError(filename_, errno);
- }
- }
- return s;
- }
-
- virtual Status Skip(uint64_t n) {
- if (fseek(file_, n, SEEK_CUR)) {
- return IOError(filename_, errno);
- }
- return Status::OK();
- }
-};
-
-// pread() based random-access
-class PosixRandomAccessFile: public RandomAccessFile {
- private:
- std::string filename_;
- int fd_;
-
- 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;
- ssize_t r = pread(fd_, scratch, n, static_cast<off_t>(offset));
- *result = Slice(scratch, (r < 0) ? 0 : r);
- if (r < 0) {
- // An error: return a non-ok status
- s = IOError(filename_, errno);
- }
- return s;
- }
-};
-
-// Helper class to limit mmap file usage so that we do not end up
-// running out virtual memory or running into kernel performance
-// problems for very large databases.
-class MmapLimiter {
- public:
- // Up to 1000 mmaps for 64-bit binaries; none for smaller pointer sizes.
- MmapLimiter() {
- SetAllowed(sizeof(void*) >= 8 ? 1000 : 0);
- }
-
- // If another mmap slot is available, acquire it and return true.
- // Else return false.
- bool Acquire() {
- if (GetAllowed() <= 0) {
- return false;
- }
- MutexLock l(&mu_);
- intptr_t x = GetAllowed();
- if (x <= 0) {
- return false;
- } else {
- SetAllowed(x - 1);
- return true;
- }
- }
-
- // Release a slot acquired by a previous call to Acquire() that returned true.
- void Release() {
- MutexLock l(&mu_);
- SetAllowed(GetAllowed() + 1);
- }
-
- private:
- port::Mutex mu_;
- port::AtomicPointer allowed_;
-
- intptr_t GetAllowed() const {
- return reinterpret_cast<intptr_t>(allowed_.Acquire_Load());
- }
-
- // REQUIRES: mu_ must be held
- void SetAllowed(intptr_t v) {
- allowed_.Release_Store(reinterpret_cast<void*>(v));
- }
-
- MmapLimiter(const MmapLimiter&);
- void operator=(const MmapLimiter&);
-};
-
-// mmap() based random-access
-class PosixMmapReadableFile: public RandomAccessFile {
- private:
- std::string filename_;
- void* mmapped_region_;
- size_t length_;
- MmapLimiter* limiter_;
-
- public:
- // base[0,length-1] contains the mmapped contents of the file.
- PosixMmapReadableFile(const std::string& fname, void* base, size_t length,
- MmapLimiter* limiter)
- : filename_(fname), mmapped_region_(base), length_(length),
- limiter_(limiter) {
- }
-
- virtual ~PosixMmapReadableFile() {
- munmap(mmapped_region_, length_);
- limiter_->Release();
- }
-
- virtual Status Read(uint64_t offset, size_t n, Slice* result,
- char* scratch) const {
- Status s;
- if (offset + n > length_) {
- *result = Slice();
- s = IOError(filename_, EINVAL);
- } else {
- *result = Slice(reinterpret_cast<char*>(mmapped_region_) + offset, n);
- }
- 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 PosixMmapFile : public WritableFile {
- private:
- std::string filename_;
- int fd_;
- size_t page_size_;
- size_t map_size_; // How much extra memory to map at a time
- char* base_; // The mapped region
- char* limit_; // Limit of the mapped region
- char* dst_; // Where to write next (in range [base_,limit_])
- char* last_sync_; // Where have we synced up to
- uint64_t file_offset_; // Offset of base_ in file
-
- // Have we done an munmap of unsynced data?
- bool pending_sync_;
-
- // Roundup x to a multiple of y
- static size_t Roundup(size_t x, size_t y) {
- return ((x + y - 1) / y) * y;
- }
-
- size_t TruncateToPageBoundary(size_t s) {
- s -= (s & (page_size_ - 1));
- assert((s % page_size_) == 0);
- return s;
- }
-
- bool UnmapCurrentRegion() {
- bool result = true;
- if (base_ != NULL) {
- if (last_sync_ < limit_) {
- // Defer syncing this data until next Sync() call, if any
- pending_sync_ = true;
- }
- if (munmap(base_, limit_ - base_) != 0) {
- result = false;
- }
- file_offset_ += limit_ - base_;
- base_ = NULL;
- limit_ = NULL;
- last_sync_ = NULL;
- dst_ = NULL;
-
- // Increase the amount we map the next time, but capped at 1MB
- if (map_size_ < (1<<20)) {
- map_size_ *= 2;
- }
- }
- return result;
- }
-
- bool MapNewRegion() {
- assert(base_ == NULL);
- if (ftruncate(fd_, file_offset_ + map_size_) < 0) {
- return false;
- }
- void* ptr = mmap(NULL, map_size_, PROT_READ | PROT_WRITE, MAP_SHARED,
- fd_, file_offset_);
- if (ptr == MAP_FAILED) {
- return false;
- }
- base_ = reinterpret_cast<char*>(ptr);
- limit_ = base_ + map_size_;
- dst_ = base_;
- last_sync_ = base_;
- return true;
- }
-
- public:
- PosixMmapFile(const std::string& fname, int fd, size_t page_size)
- : filename_(fname),
- fd_(fd),
- page_size_(page_size),
- map_size_(Roundup(65536, page_size)),
- base_(NULL),
- limit_(NULL),
- dst_(NULL),
- last_sync_(NULL),
- file_offset_(0),
- pending_sync_(false) {
- assert((page_size & (page_size - 1)) == 0);
- }
-
-
- ~PosixMmapFile() {
- if (fd_ >= 0) {
- PosixMmapFile::Close();
- }
- }
-
- virtual Status 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) {
- if (!UnmapCurrentRegion() ||
- !MapNewRegion()) {
- return IOError(filename_, errno);
- }
- }
-
- size_t n = (left <= avail) ? left : avail;
- memcpy(dst_, src, n);
- dst_ += n;
- src += n;
- left -= n;
- }
- return Status::OK();
- }
-
- virtual Status Close() {
- Status s;
- size_t unused = limit_ - dst_;
- if (!UnmapCurrentRegion()) {
- 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_ = NULL;
- limit_ = NULL;
- return s;
- }
-
- virtual Status Flush() {
- return Status::OK();
- }
-
- virtual Status Sync() {
- Status s;
-
- if (pending_sync_) {
- // Some unmapped data was not synced
- pending_sync_ = false;
- if (fdatasync(fd_) < 0) {
- s = IOError(filename_, errno);
- }
- }
-
- if (dst_ > last_sync_) {
- // 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_;
- if (msync(base_ + p1, p2 - p1 + page_size_, MS_SYNC) < 0) {
- s = IOError(filename_, errno);
- }
- }
-
- return s;
- }
-};
-
-static int LockOrUnlock(int fd, bool lock) {
- errno = 0;
- struct flock f;
- memset(&f, 0, sizeof(f));
- f.l_type = (lock ? F_WRLCK : F_UNLCK);
- f.l_whence = SEEK_SET;
- f.l_start = 0;
- f.l_len = 0; // Lock/unlock entire file
- return fcntl(fd, F_SETLK, &f);
-}
-
-class PosixFileLock : public FileLock {
- public:
- int fd_;
- std::string name_;
-};
-
-// Set of locked files. We keep a separate set instead of just
-// relying on fcntrl(F_SETLK) since fcntl(F_SETLK) does not provide
-// any protection against multiple uses from the same process.
-class PosixLockTable {
- private:
- port::Mutex mu_;
- std::set<std::string> locked_files_;
- public:
- bool Insert(const std::string& fname) {
- MutexLock l(&mu_);
- return locked_files_.insert(fname).second;
- }
- void Remove(const std::string& fname) {
- MutexLock l(&mu_);
- locked_files_.erase(fname);
- }
-};
-
-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(), "r");
- if (f == NULL) {
- *result = NULL;
- return IOError(fname, errno);
- } else {
- *result = new PosixSequentialFile(fname, f);
- return Status::OK();
- }
- }
-
- virtual Status NewRandomAccessFile(const std::string& fname,
- RandomAccessFile** result) {
- *result = NULL;
- Status s;
- int fd = open(fname.c_str(), O_RDONLY);
- if (fd < 0) {
- s = IOError(fname, errno);
- } else if (mmap_limit_.Acquire()) {
- uint64_t size;
- s = GetFileSize(fname, &size);
- if (s.ok()) {
- void* base = mmap(NULL, size, PROT_READ, MAP_SHARED, fd, 0);
- if (base != MAP_FAILED) {
- *result = new PosixMmapReadableFile(fname, base, size, &mmap_limit_);
- } else {
- s = IOError(fname, errno);
- }
- }
- close(fd);
- if (!s.ok()) {
- mmap_limit_.Release();
- }
- } else {
- *result = new PosixRandomAccessFile(fname, fd);
- }
- return s;
- }
-
- virtual Status NewWritableFile(const std::string& fname,
- WritableFile** result) {
- Status s;
- const int fd = open(fname.c_str(), O_CREAT | O_RDWR | O_TRUNC, 0644);
- if (fd < 0) {
- *result = NULL;
- s = IOError(fname, errno);
- } else {
- *result = new PosixMmapFile(fname, fd, page_size_);
- }
- return s;
- }
-
- virtual bool FileExists(const std::string& fname) {
- return access(fname.c_str(), F_OK) == 0;
- }
-
- virtual Status GetChildren(const std::string& dir,
- std::vector<std::string>* result) {
- result->clear();
- DIR* d = opendir(dir.c_str());
- if (d == NULL) {
- return IOError(dir, errno);
- }
- struct dirent* entry;
- while ((entry = readdir(d)) != NULL) {
- result->push_back(entry->d_name);
- }
- closedir(d);
- return Status::OK();
- }
-
- virtual Status DeleteFile(const std::string& fname) {
- Status result;
- if (unlink(fname.c_str()) != 0) {
- result = IOError(fname, errno);
- }
- return result;
- };
-
- virtual Status CreateDir(const std::string& name) {
- Status result;
- if (mkdir(name.c_str(), 0755) != 0) {
- result = IOError(name, errno);
- }
- return result;
- };
-
- virtual Status DeleteDir(const std::string& name) {
- Status result;
- if (rmdir(name.c_str()) != 0) {
- result = IOError(name, errno);
- }
- return result;
- };
-
- virtual Status GetFileSize(const std::string& fname, uint64_t* size) {
- Status s;
- struct stat sbuf;
- if (stat(fname.c_str(), &sbuf) != 0) {
- *size = 0;
- s = IOError(fname, errno);
- } else {
- *size = sbuf.st_size;
- }
- return s;
- }
-
- virtual Status RenameFile(const std::string& src, const std::string& target) {
- Status result;
- if (rename(src.c_str(), target.c_str()) != 0) {
- result = IOError(src, errno);
- }
- return result;
- }
-
- virtual Status LockFile(const std::string& fname, FileLock** lock) {
- *lock = NULL;
- Status result;
- int fd = open(fname.c_str(), O_RDWR | O_CREAT, 0644);
- if (fd < 0) {
- result = IOError(fname, errno);
- } else if (!locks_.Insert(fname)) {
- close(fd);
- result = Status::IOError("lock " + fname, "already held by process");
- } else if (LockOrUnlock(fd, true) == -1) {
- result = IOError("lock " + fname, errno);
- close(fd);
- locks_.Remove(fname);
- } else {
- PosixFileLock* my_lock = new PosixFileLock;
- my_lock->fd_ = fd;
- my_lock->name_ = fname;
- *lock = my_lock;
- }
- return result;
- }
-
- virtual Status UnlockFile(FileLock* lock) {
- PosixFileLock* my_lock = reinterpret_cast<PosixFileLock*>(lock);
- Status result;
- if (LockOrUnlock(my_lock->fd_, false) == -1) {
- result = IOError("unlock", errno);
- }
- locks_.Remove(my_lock->name_);
- close(my_lock->fd_);
- delete my_lock;
- 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) {
- const char* env = getenv("TEST_TMPDIR");
- if (env && env[0] != '\0') {
- *result = env;
- } else {
- char buf[100];
- snprintf(buf, sizeof(buf), "/tmp/leveldbtest-%d", int(geteuid()));
- *result = buf;
- }
- // Directory may already exist
- CreateDir(*result);
- return Status::OK();
- }
-
- static uint64_t gettid() {
- pthread_t tid = pthread_self();
- uint64_t thread_id = 0;
- memcpy(&thread_id, &tid, std::min(sizeof(thread_id), sizeof(tid)));
- return thread_id;
- }
-
- virtual Status NewLogger(const std::string& fname, Logger** result) {
- FILE* f = fopen(fname.c_str(), "w");
- if (f == NULL) {
- *result = NULL;
- return IOError(fname, errno);
- } else {
- *result = new PosixLogger(f, &PosixEnv::gettid);
- return Status::OK();
- }
- }
-
- virtual uint64_t NowMicros() {
- struct timeval tv;
- gettimeofday(&tv, NULL);
- return static_cast<uint64_t>(tv.tv_sec) * 1000000 + tv.tv_usec;
- }
-
- virtual void SleepForMicroseconds(int micros) {
- usleep(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;
- }
-
- size_t page_size_;
- pthread_mutex_t mu_;
- pthread_cond_t bgsignal_;
- pthread_t bgthread_;
- bool started_bgthread_;
-
- // Entry per Schedule() call
- struct BGItem { void* arg; void (*function)(void*); };
- typedef std::deque<BGItem> BGQueue;
- BGQueue queue_;
-
- PosixLockTable locks_;
- MmapLimiter mmap_limit_;
-};
-
-PosixEnv::PosixEnv() : page_size_(getpagesize()),
- started_bgthread_(false) {
- PthreadCall("mutex_init", pthread_mutex_init(&mu_, NULL));
- PthreadCall("cvar_init", pthread_cond_init(&bgsignal_, NULL));
-}
-
-void PosixEnv::Schedule(void (*function)(void*), void* arg) {
- PthreadCall("lock", pthread_mutex_lock(&mu_));
-
- // Start background thread if necessary
- if (!started_bgthread_) {
- started_bgthread_ = true;
- PthreadCall(
- "create thread",
- pthread_create(&bgthread_, NULL, &PosixEnv::BGThreadWrapper, this));
- }
-
- // If the queue is currently empty, the background thread may currently be
- // waiting.
- if (queue_.empty()) {
- PthreadCall("signal", pthread_cond_signal(&bgsignal_));
- }
-
- // Add to priority queue
- queue_.push_back(BGItem());
- queue_.back().function = function;
- queue_.back().arg = arg;
-
- PthreadCall("unlock", pthread_mutex_unlock(&mu_));
-}
-
-void PosixEnv::BGThread() {
- while (true) {
- // Wait until there is an item that is ready to run
- PthreadCall("lock", pthread_mutex_lock(&mu_));
- while (queue_.empty()) {
- PthreadCall("wait", pthread_cond_wait(&bgsignal_, &mu_));
- }
-
- void (*function)(void*) = queue_.front().function;
- void* arg = queue_.front().arg;
- queue_.pop_front();
-
- PthreadCall("unlock", pthread_mutex_unlock(&mu_));
- (*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) {
- pthread_t t;
- StartThreadState* state = new StartThreadState;
- state->user_function = function;
- state->arg = arg;
- PthreadCall("start thread",
- pthread_create(&t, NULL, &StartThreadWrapper, state));
-}
-
-} // namespace
-
-static pthread_once_t once = PTHREAD_ONCE_INIT;
-static Env* default_env;
-static void InitDefaultEnv() { default_env = new PosixEnv; }
-
-Env* Env::Default() {
- pthread_once(&once, InitDefaultEnv);
- return default_env;
-}
-
-} // namespace leveldb
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