YugabyteDB (2.13.1.0-b60, 21121d69985fbf76aa6958d8f04a9bfa936293b5)

//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.

//  This source code is licensed under the BSD-style license found in the

//  LICENSE file in the root directory of this source tree. An additional grant

//  of patent rights can be found in the PATENTS file in the same directory.

//

// 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/rocksdb/util/random.h"

#include <stdint.h>

#include <string.h>

#include <thread>

#include <utility>

#include "yb/rocksdb/port/likely.h"

#include "yb/rocksdb/util/thread_local.h" // For ROCKSDB_SUPPORT_THREAD_LOCAL

#if ROCKSDB_SUPPORT_THREAD_LOCAL

#define STORAGE_DECL static __thread

#else

#define STORAGE_DECL static

#endif

namespace rocksdb {

Random* Random::GetTLSInstance() {

  STORAGE_DECL Random* tls_instance;

  STORAGE_DECL std::aligned_storage<sizeof(Random)>::type tls_instance_bytes;

  auto rv = tls_instance;

  if (UNLIKELY(rv == nullptr)) {

    size_t seed = std::hash<std::thread::id>()(std::this_thread::get_id());

    rv = new (&tls_instance_bytes) Random((uint32_t)seed);

    tls_instance = rv;

  }

  return rv;

}

Slice RandomString(Random* rnd, int len, std::string* dst) {

  dst->resize(len);

  for (int i = 0; i < len; 
i++3.87G
) {

    (*dst)[i] = static_cast<char>(' ' + rnd->Uniform(95));   // ' ' .. '~'

  }

  return Slice(*dst);

}

Slice CompressibleString(Random* rnd, double compressed_fraction, int len, std::string* dst) {

  int raw = static_cast<int>(len * compressed_fraction);

  if (raw < 1) 
raw = 10
;

  std::string raw_data;

  RandomString(rnd, raw, &raw_data);

  // Duplicate the random data until we have filled "len" bytes

  dst->clear();

  while (dst->size() < (unsigned int)len) {

    dst->append(raw_data);

  }

  dst->resize(len);

  return Slice(*dst);

}

}  // namespace rocksdb