tmp-file-mgr.h

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// Copyright 2012 Cloudera 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 IMPALA_RUNTIME_TMP_FILE_MGR_H
#define IMPALA_RUNTIME_TMP_FILE_MGR_H

#include <common/status.h>
#include "gen-cpp/Types_types.h"  // for TUniqueId

namespace impala {

//
class TmpFileMgr {
 public:
  class File {
   public:
    Status AllocateSpace(int64_t write_size, int64_t* offset);

    Status Remove();

    const std::string& path() const { return path_; }
    int disk_id() const { return disk_id_; }

   private:
    friend class TmpFileMgr;

    const static std::string TMP_SUB_DIR_NAME;

    const static uint64_t AVAILABLE_SPACE_THRESHOLD_MB;

    File(const std::string& path);

    std::string path_;

    int disk_id_;

    int64_t current_offset_;

    int64_t current_size_;
  };

  static Status Init();

  static Status GetFile(int tmp_device_id, const TUniqueId& query_id,
      File** new_file);

  static int num_tmp_devices() { return tmp_dirs_.size(); }

 private:
  static bool initialized_;

  static std::vector<std::string> tmp_dirs_;
};

}

#endif