| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you under the Apache License, Version 2.0 (the |
| // "License"); you may not use this file except in compliance |
| // with the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, |
| // software distributed under the License is distributed on an |
| // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| // KIND, either express or implied. See the License for the |
| // specific language governing permissions and limitations |
| // under the License. |
| #ifndef KUDU_UTIL_ENV_UTIL_H |
| #define KUDU_UTIL_ENV_UTIL_H |
| |
| #include <memory> |
| #include <string> |
| |
| #include "kudu/gutil/macros.h" |
| #include "kudu/util/env.h" |
| |
| namespace kudu { |
| namespace env_util { |
| |
| Status OpenFileForWrite(Env *env, const std::string &path, |
| std::shared_ptr<WritableFile> *file); |
| |
| Status OpenFileForWrite(const WritableFileOptions& opts, |
| Env *env, const std::string &path, |
| std::shared_ptr<WritableFile> *file); |
| |
| Status OpenFileForRandom(Env *env, const std::string &path, |
| std::shared_ptr<RandomAccessFile> *file); |
| |
| Status OpenFileForSequential(Env *env, const std::string &path, |
| std::shared_ptr<SequentialFile> *file); |
| |
| // Read exactly 'n' bytes from the given file. If fewer than 'n' bytes |
| // are read, returns an IOError. This differs from the underlying |
| // RandomAccessFile::Read(), which may return a "short read". |
| // |
| // Similar to RandomAccessFile::Read(), '*result' is modified to point |
| // to the bytes which were read. These bytes may be a copy placed in |
| // the 'scratch' buffer, or result may point into the underlying file |
| // (e.g. via mmap or other zero-copy mechanism). |
| // |
| // NOTE: even if this returns an error, some data _may_ be read into |
| // the provided scratch buffer, but no guarantee that that will be the |
| // case. |
| Status ReadFully(RandomAccessFile* file, uint64_t offset, size_t n, |
| Slice* result, uint8_t* scratch); |
| |
| // Creates the directory given by 'path', unless it already exists. |
| // |
| // If 'created' is not NULL, sets it to true if the directory was |
| // created, false otherwise. |
| Status CreateDirIfMissing(Env* env, const std::string& path, |
| bool* created = NULL); |
| |
| // Copy the contents of file source_path to file dest_path. |
| // This is not atomic, and if there is an error while reading or writing, |
| // a partial copy may be left in 'dest_path'. Does not fsync the parent |
| // directory of dest_path -- if you need durability then do that yourself. |
| Status CopyFile(Env* env, const std::string& source_path, const std::string& dest_path, |
| WritableFileOptions opts); |
| |
| // Deletes a file or directory when this object goes out of scope. |
| // |
| // The deletion may be cancelled by calling .Cancel(). |
| // This is typically useful for cleaning up temporary files if the |
| // creation of the tmp file may fail. |
| class ScopedFileDeleter { |
| public: |
| ScopedFileDeleter(Env* env, std::string path); |
| ~ScopedFileDeleter(); |
| |
| // Do not delete the file when this object goes out of scope. |
| void Cancel() { |
| should_delete_ = false; |
| } |
| |
| private: |
| Env* const env_; |
| const std::string path_; |
| bool should_delete_; |
| |
| DISALLOW_COPY_AND_ASSIGN(ScopedFileDeleter); |
| }; |
| |
| } // namespace env_util |
| } // namespace kudu |
| |
| #endif |