rocksdb/file/read_write_util.cc

//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
//  This source code is licensed under both the GPLv2 (found in the
//  COPYING file in the root directory) and Apache 2.0 License
//  (found in the LICENSE.Apache file in the root directory).
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.

#include "file/read_write_util.h"

#include <sstream>
#include "test_util/sync_point.h"

namespace rocksdb {
Status NewWritableFile(Env* env, const std::string& fname,
                       std::unique_ptr<WritableFile>* result,
                       const EnvOptions& options) {
  Status s = env->NewWritableFile(fname, result, options);
  TEST_KILL_RANDOM("NewWritableFile:0", rocksdb_kill_odds * REDUCE_ODDS2);
  return s;
}

bool ReadOneLine(std::istringstream* iss, SequentialFile* seq_file,
                 std::string* output, bool* has_data, Status* result) {
  const int kBufferSize = 8192;
  char buffer[kBufferSize + 1];
  Slice input_slice;

  std::string line;
  bool has_complete_line = false;
  while (!has_complete_line) {
    if (std::getline(*iss, line)) {
      has_complete_line = !iss->eof();
    } else {
      has_complete_line = false;
    }
    if (!has_complete_line) {
      // if we're not sure whether we have a complete line,
      // further read from the file.
      if (*has_data) {
        *result = seq_file->Read(kBufferSize, &input_slice, buffer);
      }
      if (input_slice.size() == 0) {
        // meaning we have read all the data
        *has_data = false;
        break;
      } else {
        iss->str(line + input_slice.ToString());
        // reset the internal state of iss so that we can keep reading it.
        iss->clear();
        *has_data = (input_slice.size() == kBufferSize);
        continue;
      }
    }
  }
  *output = line;
  return *has_data || has_complete_line;
}

}  // namespace rocksdb