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.

//

#include "yb/util/random_util.h"

#include <algorithm>

#include <cmath>

#include "yb/util/random.h"

#include "yb/util/test_util.h"

namespace yb {

class RandomUtilTest : public YBTest {

 protected:

  RandomUtilTest() : rng_(SeedRandom()) {}

  Random rng_;

  static const int kLenMax = 100;

  static const int kNumTrials = 100;

};

namespace {

// Checks string defined at start is set to \0 everywhere but [from, to)

void CheckEmpty(char* start, int from, int to, int stop) {

  DCHECK_LE(0, from);

  DCHECK_LE(from, to);

  DCHECK_LE(to, stop);

  for (int j = 0; (j == from ? j = to : j) < stop; ++j) {

    CHECK_EQ(start[j], '\0') << "Index " << j << " not null after defining"

                             << "indices [" << from << "," << to << ") of "

                             << "a nulled string [0," << stop << ").";

  }

}

} // anonymous namespace

// Makes sure that RandomString only writes the specified amount

TEST_F(RandomUtilTest, TestRandomString) {

  char start[kLenMax];

  for (int i = 0; i < kNumTrials; ++i) {

    memset(start, '\0', kLenMax);

    int to = rng_.Uniform(kLenMax + 1);

    int from = rng_.Uniform(to + 1);

    RandomString(start + from, to - from, &rng_);

    CheckEmpty(start, from, to, kLenMax);

  }

  // Corner case

  memset(start, '\0', kLenMax);

  RandomString(start, 0, &rng_);

  CheckEmpty(start, 0, 0, kLenMax);

}

} // namespace yb