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Diffstat (limited to 'src/leveldb/helpers/memenv/memenv.cc')
-rw-r--r--src/leveldb/helpers/memenv/memenv.cc203
1 files changed, 98 insertions, 105 deletions
diff --git a/src/leveldb/helpers/memenv/memenv.cc b/src/leveldb/helpers/memenv/memenv.cc
index 68c0614a59..47e4481f7c 100644
--- a/src/leveldb/helpers/memenv/memenv.cc
+++ b/src/leveldb/helpers/memenv/memenv.cc
@@ -4,14 +4,18 @@
#include "helpers/memenv/memenv.h"
+#include <string.h>
+
+#include <limits>
+#include <map>
+#include <string>
+#include <vector>
+
#include "leveldb/env.h"
#include "leveldb/status.h"
#include "port/port.h"
+#include "port/thread_annotations.h"
#include "util/mutexlock.h"
-#include <map>
-#include <string.h>
-#include <string>
-#include <vector>
namespace leveldb {
@@ -23,6 +27,10 @@ class FileState {
// and the caller must call Ref() at least once.
FileState() : refs_(0), size_(0) {}
+ // No copying allowed.
+ FileState(const FileState&) = delete;
+ FileState& operator=(const FileState&) = delete;
+
// Increase the reference count.
void Ref() {
MutexLock lock(&refs_mutex_);
@@ -47,9 +55,22 @@ class FileState {
}
}
- uint64_t Size() const { return size_; }
+ uint64_t Size() const {
+ MutexLock lock(&blocks_mutex_);
+ return size_;
+ }
+
+ void Truncate() {
+ MutexLock lock(&blocks_mutex_);
+ for (char*& block : blocks_) {
+ delete[] block;
+ }
+ blocks_.clear();
+ size_ = 0;
+ }
Status Read(uint64_t offset, size_t n, Slice* result, char* scratch) const {
+ MutexLock lock(&blocks_mutex_);
if (offset > size_) {
return Status::IOError("Offset greater than file size.");
}
@@ -62,16 +83,9 @@ class FileState {
return Status::OK();
}
- assert(offset / kBlockSize <= SIZE_MAX);
+ assert(offset / kBlockSize <= std::numeric_limits<size_t>::max());
size_t block = static_cast<size_t>(offset / kBlockSize);
size_t block_offset = offset % kBlockSize;
-
- if (n <= kBlockSize - block_offset) {
- // The requested bytes are all in the first block.
- *result = Slice(blocks_[block] + block_offset, n);
- return Status::OK();
- }
-
size_t bytes_to_copy = n;
char* dst = scratch;
@@ -96,6 +110,7 @@ class FileState {
const char* src = data.data();
size_t src_len = data.size();
+ MutexLock lock(&blocks_mutex_);
while (src_len > 0) {
size_t avail;
size_t offset = size_ % kBlockSize;
@@ -122,28 +137,17 @@ class FileState {
}
private:
- // Private since only Unref() should be used to delete it.
- ~FileState() {
- for (std::vector<char*>::iterator i = blocks_.begin(); i != blocks_.end();
- ++i) {
- delete [] *i;
- }
- }
+ enum { kBlockSize = 8 * 1024 };
- // No copying allowed.
- FileState(const FileState&);
- void operator=(const FileState&);
+ // Private since only Unref() should be used to delete it.
+ ~FileState() { Truncate(); }
port::Mutex refs_mutex_;
- int refs_; // Protected by refs_mutex_;
+ int refs_ GUARDED_BY(refs_mutex_);
- // The following fields are not protected by any mutex. They are only mutable
- // while the file is being written, and concurrent access is not allowed
- // to writable files.
- std::vector<char*> blocks_;
- uint64_t size_;
-
- enum { kBlockSize = 8 * 1024 };
+ mutable port::Mutex blocks_mutex_;
+ std::vector<char*> blocks_ GUARDED_BY(blocks_mutex_);
+ uint64_t size_ GUARDED_BY(blocks_mutex_);
};
class SequentialFileImpl : public SequentialFile {
@@ -152,11 +156,9 @@ class SequentialFileImpl : public SequentialFile {
file_->Ref();
}
- ~SequentialFileImpl() {
- file_->Unref();
- }
+ ~SequentialFileImpl() override { file_->Unref(); }
- virtual Status Read(size_t n, Slice* result, char* scratch) {
+ Status Read(size_t n, Slice* result, char* scratch) override {
Status s = file_->Read(pos_, n, result, scratch);
if (s.ok()) {
pos_ += result->size();
@@ -164,7 +166,7 @@ class SequentialFileImpl : public SequentialFile {
return s;
}
- virtual Status Skip(uint64_t n) {
+ Status Skip(uint64_t n) override {
if (pos_ > file_->Size()) {
return Status::IOError("pos_ > file_->Size()");
}
@@ -176,7 +178,7 @@ class SequentialFileImpl : public SequentialFile {
return Status::OK();
}
- virtual std::string GetName() const { return "[memenv]"; }
+ virtual std::string GetName() const override { return "[memenv]"; }
private:
FileState* file_;
uint64_t pos_;
@@ -184,68 +186,58 @@ class SequentialFileImpl : public SequentialFile {
class RandomAccessFileImpl : public RandomAccessFile {
public:
- explicit RandomAccessFileImpl(FileState* file) : file_(file) {
- file_->Ref();
- }
+ explicit RandomAccessFileImpl(FileState* file) : file_(file) { file_->Ref(); }
- ~RandomAccessFileImpl() {
- file_->Unref();
- }
+ ~RandomAccessFileImpl() override { file_->Unref(); }
- virtual Status Read(uint64_t offset, size_t n, Slice* result,
- char* scratch) const {
+ Status Read(uint64_t offset, size_t n, Slice* result,
+ char* scratch) const override {
return file_->Read(offset, n, result, scratch);
}
- virtual std::string GetName() const { return "[memenv]"; }
+ virtual std::string GetName() const override { return "[memenv]"; }
private:
FileState* file_;
};
class WritableFileImpl : public WritableFile {
public:
- WritableFileImpl(FileState* file) : file_(file) {
- file_->Ref();
- }
+ WritableFileImpl(FileState* file) : file_(file) { file_->Ref(); }
- ~WritableFileImpl() {
- file_->Unref();
- }
+ ~WritableFileImpl() override { file_->Unref(); }
- virtual Status Append(const Slice& data) {
- return file_->Append(data);
- }
+ Status Append(const Slice& data) override { return file_->Append(data); }
- virtual Status Close() { return Status::OK(); }
- virtual Status Flush() { return Status::OK(); }
- virtual Status Sync() { return Status::OK(); }
+ Status Close() override { return Status::OK(); }
+ Status Flush() override { return Status::OK(); }
+ Status Sync() override { return Status::OK(); }
- virtual std::string GetName() const { return "[memenv]"; }
+ virtual std::string GetName() const override { return "[memenv]"; }
private:
FileState* file_;
};
class NoOpLogger : public Logger {
public:
- virtual void Logv(const char* format, va_list ap) { }
+ void Logv(const char* format, va_list ap) override {}
};
class InMemoryEnv : public EnvWrapper {
public:
- explicit InMemoryEnv(Env* base_env) : EnvWrapper(base_env) { }
+ explicit InMemoryEnv(Env* base_env) : EnvWrapper(base_env) {}
- virtual ~InMemoryEnv() {
- for (FileSystem::iterator i = file_map_.begin(); i != file_map_.end(); ++i){
- i->second->Unref();
+ ~InMemoryEnv() override {
+ for (const auto& kvp : file_map_) {
+ kvp.second->Unref();
}
}
// Partial implementation of the Env interface.
- virtual Status NewSequentialFile(const std::string& fname,
- SequentialFile** result) {
+ Status NewSequentialFile(const std::string& fname,
+ SequentialFile** result) override {
MutexLock lock(&mutex_);
if (file_map_.find(fname) == file_map_.end()) {
- *result = NULL;
+ *result = nullptr;
return Status::IOError(fname, "File not found");
}
@@ -253,11 +245,11 @@ class InMemoryEnv : public EnvWrapper {
return Status::OK();
}
- virtual Status NewRandomAccessFile(const std::string& fname,
- RandomAccessFile** result) {
+ Status NewRandomAccessFile(const std::string& fname,
+ RandomAccessFile** result) override {
MutexLock lock(&mutex_);
if (file_map_.find(fname) == file_map_.end()) {
- *result = NULL;
+ *result = nullptr;
return Status::IOError(fname, "File not found");
}
@@ -265,27 +257,32 @@ class InMemoryEnv : public EnvWrapper {
return Status::OK();
}
- virtual Status NewWritableFile(const std::string& fname,
- WritableFile** result) {
+ Status NewWritableFile(const std::string& fname,
+ WritableFile** result) override {
MutexLock lock(&mutex_);
- if (file_map_.find(fname) != file_map_.end()) {
- DeleteFileInternal(fname);
- }
+ FileSystem::iterator it = file_map_.find(fname);
- FileState* file = new FileState();
- file->Ref();
- file_map_[fname] = file;
+ FileState* file;
+ if (it == file_map_.end()) {
+ // File is not currently open.
+ file = new FileState();
+ file->Ref();
+ file_map_[fname] = file;
+ } else {
+ file = it->second;
+ file->Truncate();
+ }
*result = new WritableFileImpl(file);
return Status::OK();
}
- virtual Status NewAppendableFile(const std::string& fname,
- WritableFile** result) {
+ Status NewAppendableFile(const std::string& fname,
+ WritableFile** result) override {
MutexLock lock(&mutex_);
FileState** sptr = &file_map_[fname];
FileState* file = *sptr;
- if (file == NULL) {
+ if (file == nullptr) {
file = new FileState();
file->Ref();
}
@@ -293,18 +290,18 @@ class InMemoryEnv : public EnvWrapper {
return Status::OK();
}
- virtual bool FileExists(const std::string& fname) {
+ bool FileExists(const std::string& fname) override {
MutexLock lock(&mutex_);
return file_map_.find(fname) != file_map_.end();
}
- virtual Status GetChildren(const std::string& dir,
- std::vector<std::string>* result) {
+ Status GetChildren(const std::string& dir,
+ std::vector<std::string>* result) override {
MutexLock lock(&mutex_);
result->clear();
- for (FileSystem::iterator i = file_map_.begin(); i != file_map_.end(); ++i){
- const std::string& filename = i->first;
+ for (const auto& kvp : file_map_) {
+ const std::string& filename = kvp.first;
if (filename.size() >= dir.size() + 1 && filename[dir.size()] == '/' &&
Slice(filename).starts_with(Slice(dir))) {
@@ -315,7 +312,8 @@ class InMemoryEnv : public EnvWrapper {
return Status::OK();
}
- void DeleteFileInternal(const std::string& fname) {
+ void DeleteFileInternal(const std::string& fname)
+ EXCLUSIVE_LOCKS_REQUIRED(mutex_) {
if (file_map_.find(fname) == file_map_.end()) {
return;
}
@@ -324,7 +322,7 @@ class InMemoryEnv : public EnvWrapper {
file_map_.erase(fname);
}
- virtual Status DeleteFile(const std::string& fname) {
+ Status DeleteFile(const std::string& fname) override {
MutexLock lock(&mutex_);
if (file_map_.find(fname) == file_map_.end()) {
return Status::IOError(fname, "File not found");
@@ -334,15 +332,11 @@ class InMemoryEnv : public EnvWrapper {
return Status::OK();
}
- virtual Status CreateDir(const std::string& dirname) {
- return Status::OK();
- }
+ Status CreateDir(const std::string& dirname) override { return Status::OK(); }
- virtual Status DeleteDir(const std::string& dirname) {
- return Status::OK();
- }
+ Status DeleteDir(const std::string& dirname) override { return Status::OK(); }
- virtual Status GetFileSize(const std::string& fname, uint64_t* file_size) {
+ Status GetFileSize(const std::string& fname, uint64_t* file_size) override {
MutexLock lock(&mutex_);
if (file_map_.find(fname) == file_map_.end()) {
return Status::IOError(fname, "File not found");
@@ -352,8 +346,8 @@ class InMemoryEnv : public EnvWrapper {
return Status::OK();
}
- virtual Status RenameFile(const std::string& src,
- const std::string& target) {
+ Status RenameFile(const std::string& src,
+ const std::string& target) override {
MutexLock lock(&mutex_);
if (file_map_.find(src) == file_map_.end()) {
return Status::IOError(src, "File not found");
@@ -365,22 +359,22 @@ class InMemoryEnv : public EnvWrapper {
return Status::OK();
}
- virtual Status LockFile(const std::string& fname, FileLock** lock) {
+ Status LockFile(const std::string& fname, FileLock** lock) override {
*lock = new FileLock;
return Status::OK();
}
- virtual Status UnlockFile(FileLock* lock) {
+ Status UnlockFile(FileLock* lock) override {
delete lock;
return Status::OK();
}
- virtual Status GetTestDirectory(std::string* path) {
+ Status GetTestDirectory(std::string* path) override {
*path = "/test";
return Status::OK();
}
- virtual Status NewLogger(const std::string& fname, Logger** result) {
+ Status NewLogger(const std::string& fname, Logger** result) override {
*result = new NoOpLogger;
return Status::OK();
}
@@ -388,14 +382,13 @@ class InMemoryEnv : public EnvWrapper {
private:
// Map from filenames to FileState objects, representing a simple file system.
typedef std::map<std::string, FileState*> FileSystem;
+
port::Mutex mutex_;
- FileSystem file_map_; // Protected by mutex_.
+ FileSystem file_map_ GUARDED_BY(mutex_);
};
} // namespace
-Env* NewMemEnv(Env* base_env) {
- return new InMemoryEnv(base_env);
-}
+Env* NewMemEnv(Env* base_env) { return new InMemoryEnv(base_env); }
} // namespace leveldb