YugabyteDB (2.13.0.0-b42, bfc6a6643e7399ac8a0e81d06a3ee6d6571b33ab)

// 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.

//

// The following only applies to changes made to this file as part of YugaByte development.

//

// Portions Copyright (c) YugaByte, Inc.

//

// Licensed 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 YB_UTIL_ENV_UTIL_H

#define YB_UTIL_ENV_UTIL_H

#include <memory>

#include <string>

#include "yb/gutil/macros.h"

#include "yb/util/env.h"

namespace yb {

namespace env_util {

// Searches for the suitable "YugaByte distribution root" directory that contains the given

// subdirectory. If the YB_HOME environment variable is specified, the value of that variable is

// immediately returned. Otherwise, we start walking up from the directory of the current executable

// until we are in a directory that has a subdirectory with the given name. Then we return the path

// of that directory (not of the subdirectory).

std::string GetRootDir(const std::string& search_for_dir);

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 = WritableFileOptions());

// 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();

  ScopedFileDeleter(ScopedFileDeleter&& other) = default;

  // Do not delete the file when this object goes out of scope.

  void Cancel() {

    should_delete_ = false;

  }

  const std::string& path() {

    return path_;

  }

 private:

  Env* const env_;

  const std::string path_;

  bool should_delete_;

  DISALLOW_COPY_AND_ASSIGN(ScopedFileDeleter);

};

} // namespace env_util

} // namespace yb

#endif  // YB_UTIL_ENV_UTIL_H