diff options
Diffstat (limited to 'src/leveldb/helpers/memenv/memenv.cc')
| -rw-r--r-- | src/leveldb/helpers/memenv/memenv.cc | 203 |
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 |