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Revision df38c1ce660628f05b4686eeaf0b548295ce7967 authored by Mike Kolupaev on 22 April 2019, 15:17:45 UTC, committed by Facebook Github Bot on 22 April 2019, 15:20:35 UTC 
Add BlockBasedTableOptions::index_shortening (#5174)
 
Summary:
Introduce BlockBasedTableOptions::index_shortening to give users control on which key shortening techniques to be used in building index blocks. Before this patch, both separators and successor keys where shortened in indexes. With this patch, the default is set to kShortenSeparators to only shorten the separators. Since each index block has many separators and only one successor (last key), the change should not have negative impact on index block size. However it should prevent many unnecessary block loads where due to approximation introduced by shorted successor, seek would land us to the previous block and then fix it by moving to the next one.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5174

Differential Revision: D14884185

Pulled By: al13n321

fbshipit-source-id: 1b08bc8c03edcf09b6b8c16e9a7eea08ad4dd534
1 parent de76909
Raw File
timer_queue_test.cc 
//  Portions 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).

// borrowed from
// http://www.crazygaze.com/blog/2016/03/24/portable-c-timer-queue/
// Timer Queue
//
// License
//
// The source code in this article is licensed under the CC0 license, so feel
// free
// to copy, modify, share, do whatever you want with it.
// No attribution is required, but Ill be happy if you do.
// CC0 license

// The person who associated a work with this deed has dedicated the work to the
// public domain by waiving all of his or her rights to the work worldwide
// under copyright law, including all related and neighboring rights, to the
// extent allowed by law.  You can copy, modify, distribute and perform the
// work, even for
// commercial purposes, all without asking permission. See Other Information
// below.
//

#include "util/timer_queue.h"
#include <future>

namespace Timing {

using Clock = std::chrono::high_resolution_clock;
double now() {
  static auto start = Clock::now();
  return std::chrono::duration<double, std::milli>(Clock::now() - start)
      .count();
}

}  // namespace Timing

int main() {
  TimerQueue q;

  double tnow = Timing::now();

  q.add(10000, [tnow](bool aborted) mutable {
    printf("T 1: %d, Elapsed %4.2fms\n", aborted, Timing::now() - tnow);
    return std::make_pair(false, 0);
  });
  q.add(10001, [tnow](bool aborted) mutable {
    printf("T 2: %d, Elapsed %4.2fms\n", aborted, Timing::now() - tnow);
    return std::make_pair(false, 0);
  });

  q.add(1000, [tnow](bool aborted) mutable {
    printf("T 3: %d, Elapsed %4.2fms\n", aborted, Timing::now() - tnow);
    return std::make_pair(!aborted, 1000);
  });

  auto id = q.add(2000, [tnow](bool aborted) mutable {
    printf("T 4: %d, Elapsed %4.2fms\n", aborted, Timing::now() - tnow);
    return std::make_pair(!aborted, 2000);
  });

  (void)id;
  // auto ret = q.cancel(id);
  // assert(ret == 1);
  // q.cancelAll();

  return 0;
}
//////////////////////////////////////////
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