src/kudu/util/random_util.cc

// Copyright 2014 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.

#include "kudu/util/random_util.h"

#include <cmath>
#include <cstdlib>
#include <cstring>
#include <sys/types.h>
#include <unistd.h>

#include "kudu/util/env.h"
#include "kudu/util/random.h"
#include "kudu/gutil/walltime.h"

namespace kudu {

void RandomString(void* dest, size_t n, Random* rng) {
  size_t i = 0;
  uint32_t random = rng->Next();
  char* cdest = static_cast<char*>(dest);
  static const size_t sz = sizeof(random);
  if (n >= sz) {
    for (i = 0; i <= n - sz; i += sz) {
      memcpy(&cdest[i], &random, sizeof(random));
      random = rng->Next();
    }
  }
  memcpy(cdest + i, &random, n - i);
}

uint32_t GetRandomSeed32() {
  uint32_t seed = static_cast<uint32_t>(GetCurrentTimeMicros());
  seed *= getpid();
  seed *= Env::Default()->gettid();
  return seed;
}

} // namespace kudu