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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
util_merge_operators_test.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).

#include "util/testharness.h"
#include "util/testutil.h"
#include "utilities/merge_operators.h"

namespace rocksdb {

class UtilMergeOperatorTest : public testing::Test {
 public:
  UtilMergeOperatorTest() {}

  std::string FullMergeV2(std::string existing_value,
                          std::vector<std::string> operands,
                          std::string key = "") {
    std::string result;
    Slice result_operand(nullptr, 0);

    Slice existing_value_slice(existing_value);
    std::vector<Slice> operands_slice(operands.begin(), operands.end());

    const MergeOperator::MergeOperationInput merge_in(
        key, &existing_value_slice, operands_slice, nullptr);
    MergeOperator::MergeOperationOutput merge_out(result, result_operand);
    merge_operator_->FullMergeV2(merge_in, &merge_out);

    if (result_operand.data()) {
      result.assign(result_operand.data(), result_operand.size());
    }
    return result;
  }

  std::string FullMergeV2(std::vector<std::string> operands,
                          std::string key = "") {
    std::string result;
    Slice result_operand(nullptr, 0);

    std::vector<Slice> operands_slice(operands.begin(), operands.end());

    const MergeOperator::MergeOperationInput merge_in(key, nullptr,
                                                      operands_slice, nullptr);
    MergeOperator::MergeOperationOutput merge_out(result, result_operand);
    merge_operator_->FullMergeV2(merge_in, &merge_out);

    if (result_operand.data()) {
      result.assign(result_operand.data(), result_operand.size());
    }
    return result;
  }

  std::string PartialMerge(std::string left, std::string right,
                           std::string key = "") {
    std::string result;

    merge_operator_->PartialMerge(key, left, right, &result, nullptr);
    return result;
  }

  std::string PartialMergeMulti(std::deque<std::string> operands,
                                std::string key = "") {
    std::string result;
    std::deque<Slice> operands_slice(operands.begin(), operands.end());

    merge_operator_->PartialMergeMulti(key, operands_slice, &result, nullptr);
    return result;
  }

 protected:
  std::shared_ptr<MergeOperator> merge_operator_;
};

TEST_F(UtilMergeOperatorTest, MaxMergeOperator) {
  merge_operator_ = MergeOperators::CreateMaxOperator();

  EXPECT_EQ("B", FullMergeV2("B", {"A"}));
  EXPECT_EQ("B", FullMergeV2("A", {"B"}));
  EXPECT_EQ("", FullMergeV2({"", "", ""}));
  EXPECT_EQ("A", FullMergeV2({"A"}));
  EXPECT_EQ("ABC", FullMergeV2({"ABC"}));
  EXPECT_EQ("Z", FullMergeV2({"ABC", "Z", "C", "AXX"}));
  EXPECT_EQ("ZZZ", FullMergeV2({"ABC", "CC", "Z", "ZZZ"}));
  EXPECT_EQ("a", FullMergeV2("a", {"ABC", "CC", "Z", "ZZZ"}));

  EXPECT_EQ("z", PartialMergeMulti({"a", "z", "efqfqwgwew", "aaz", "hhhhh"}));

  EXPECT_EQ("b", PartialMerge("a", "b"));
  EXPECT_EQ("z", PartialMerge("z", "azzz"));
  EXPECT_EQ("a", PartialMerge("a", ""));
}

}  // namespace rocksdb

int main(int argc, char** argv) {
  ::testing::InitGoogleTest(&argc, argv);
  return RUN_ALL_TESTS();
}
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