| /* |
| * 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. |
| */ |
| |
| #include "Random.h" |
| |
| #include <decaf/lang/System.h> |
| |
| #include <decaf/lang/exceptions/NullPointerException.h> |
| #include <decaf/lang/exceptions/IllegalArgumentException.h> |
| |
| using namespace decaf; |
| using namespace decaf::util; |
| using namespace decaf::lang; |
| using namespace decaf::lang::exceptions; |
| |
| unsigned long long Random::multiplier = 0x5deece66dLL; |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| Random::Random() : haveNextNextGaussian(false), seed(0), nextNextGaussian(0) { |
| setSeed( System::currentTimeMillis() ); |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| Random::Random(unsigned long long seed) : haveNextNextGaussian(false), seed(0), nextNextGaussian(0) { |
| setSeed(seed); |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| Random::~Random() { |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| bool Random::nextBoolean() { |
| return next(1) != 0; |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| void Random::nextBytes(std::vector<unsigned char>& buf) { |
| |
| try { |
| |
| if (buf.empty()) { |
| return; |
| } |
| |
| this->nextBytes(&buf[0], (int) buf.size()); |
| } |
| DECAF_CATCH_RETHROW(NullPointerException) |
| DECAF_CATCH_RETHROW(IllegalArgumentException) |
| DECAF_CATCHALL_THROW(Exception) |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| void Random::nextBytes(unsigned char* buf, int size) { |
| |
| if (buf == NULL) { |
| throw NullPointerException(__FILE__, __LINE__, "Buffer passed cannot be NULL."); |
| } |
| |
| if (size < 0) { |
| throw IllegalArgumentException(__FILE__, __LINE__, "Specified buffer size was negative."); |
| } |
| |
| int rand = 0; |
| int count = 0, loop = 0; |
| while (count < size) { |
| if (loop == 0) { |
| rand = nextInt(); |
| loop = 3; |
| } else { |
| loop--; |
| } |
| buf[count++] = (unsigned char) rand; |
| rand >>= 8; |
| } |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| double Random::nextDouble() { |
| long long divisor = 1LL; |
| divisor <<= 31; |
| divisor <<= 22; |
| return ((double) (((long long) next(26) << 27) + next(27)) / (double) divisor); |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| float Random::nextFloat() { |
| return ((float) next(24) / 16777216.0f); |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| double Random::nextGaussian() { |
| |
| if (haveNextNextGaussian) { |
| // if X1 has been returned, return the second Gaussian |
| haveNextNextGaussian = false; |
| return nextNextGaussian; |
| } |
| |
| double v1, v2, s; |
| do { |
| // Generates two independent random variables U1, U2 |
| v1 = 2 * nextDouble() - 1; |
| v2 = 2 * nextDouble() - 1; |
| s = v1 * v1 + v2 * v2; |
| } while (s >= 1); |
| double norm = std::sqrt(-2 * std::log(s) / s); |
| // should that not be norm instead of multiplier ? |
| nextNextGaussian = v2 * norm; |
| haveNextNextGaussian = true; |
| // should that not be norm instead of multiplier ? |
| return v1 * norm; |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| int Random::nextInt() { |
| return next(32); |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| int Random::nextInt(int n) { |
| |
| if (n > 0) { |
| |
| if ((n & -n) == n) { |
| return (int) ((n * (long long) next(31)) >> 31); |
| } |
| |
| int bits, val; |
| |
| do { |
| bits = next(31); |
| val = bits % n; |
| } while (bits - val + (n - 1) < 0); |
| |
| return val; |
| } |
| |
| throw exceptions::IllegalArgumentException( |
| __FILE__, __LINE__, "Value passed cannot be less than or equal to zero."); |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| long long Random::nextLong() { |
| return ((long long) next(32) << 32) + next(32); |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| void Random::setSeed(unsigned long long seed) { |
| unsigned long long mask = 1ULL; |
| mask <<= 31; |
| mask <<= 17; |
| this->seed = (seed ^ multiplier) & (mask - 1); |
| haveNextNextGaussian = false; |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| int Random::next(int bits) { |
| long long mask = 1L; |
| mask <<= 31; |
| mask <<= 17; |
| seed = (seed * multiplier + 0xbL) & (mask - 1); |
| // was: return (int) (seed >>> (48 - bits)); |
| return (int) (seed >> (48 - bits)); |
| } |