Random16.java
/**
* 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.
*/
package org.apache.hadoop.examples.terasort;
/**
* This class implements a 128-bit linear congruential generator.
* Specifically, if X0 is the most recently issued 128-bit random
* number (or a seed of 0 if no random number has already been generated,
* the next number to be generated, X1, is equal to:
* X1 = (a * X0 + c) mod 2**128
* where a is 47026247687942121848144207491837523525
* or 0x2360ed051fc65da44385df649fccf645
* and c is 98910279301475397889117759788405497857
* or 0x4a696d47726179524950202020202001
* The coefficient "a" is suggested by:
* Pierre L'Ecuyer, "Tables of linear congruential generators of different
* sizes and good lattice structure", Mathematics of Computation, 68
* pp. 249 - 260 (1999)
* http://www.ams.org/mcom/1999-68-225/S0025-5718-99-00996-5/S0025-5718-99-00996-5.pdf
* The constant "c" meets the simple suggestion by the same reference that
* it be odd.
*
* There is also a facility for quickly advancing the state of the
* generator by a fixed number of steps - this facilitates parallel
* generation.
*
* This is based on 1.0 of rand16.c from Chris Nyberg
* <chris.nyberg@ordinal.com>.
*/
class Random16 {
/**
* The "Gen" array contain powers of 2 of the linear congruential generator.
* The index 0 struct contain the "a" coefficient and "c" constant for the
* generator. That is, the generator is:
* f(x) = (Gen[0].a * x + Gen[0].c) mod 2**128
*
* All structs after the first contain an "a" and "c" that
* comprise the square of the previous function.
*
* f**2(x) = (Gen[1].a * x + Gen[1].c) mod 2**128
* f**4(x) = (Gen[2].a * x + Gen[2].c) mod 2**128
* f**8(x) = (Gen[3].a * x + Gen[3].c) mod 2**128
* ...
*/
private static class RandomConstant {
final Unsigned16 a;
final Unsigned16 c;
public RandomConstant(String left, String right) {
a = new Unsigned16(left);
c = new Unsigned16(right);
}
}
private static final RandomConstant[] genArray = new RandomConstant[]{
/* [ 0] */ new RandomConstant("2360ed051fc65da44385df649fccf645",
"4a696d47726179524950202020202001"),
/* [ 1] */ new RandomConstant("17bce35bdf69743c529ed9eb20e0ae99",
"95e0e48262b3edfe04479485c755b646"),
/* [ 2] */ new RandomConstant("f4dd417327db7a9bd194dfbe42d45771",
"882a02c315362b60765f100068b33a1c"),
/* [ 3] */ new RandomConstant("6347af777a7898f6d1a2d6f33505ffe1",
"5efc4abfaca23e8ca8edb1f2dfbf6478"),
/* [ 4] */ new RandomConstant("b6a4239f3b315f84f6ef6d3d288c03c1",
"f25bd15439d16af594c1b1bafa6239f0"),
/* [ 5] */ new RandomConstant("2c82901ad1cb0cd182b631ba6b261781",
"89ca67c29c9397d59c612596145db7e0"),
/* [ 6] */ new RandomConstant("dab03f988288676ee49e66c4d2746f01",
"8b6ae036713bd578a8093c8eae5c7fc0"),
/* [ 7] */ new RandomConstant("602167331d86cf5684fe009a6d09de01",
"98a2542fd23d0dbdff3b886cdb1d3f80"),
/* [ 8] */ new RandomConstant("61ecb5c24d95b058f04c80a23697bc01",
"954db923fdb7933e947cd1edcecb7f00"),
/* [ 9] */ new RandomConstant("4a5c31e0654c28aa60474e83bf3f7801",
"00be4a36657c98cd204e8c8af7dafe00"),
/* [ 10] */ new RandomConstant("ae4f079d54fbece1478331d3c6bef001",
"991965329dccb28d581199ab18c5fc00"),
/* [ 11] */ new RandomConstant("101b8cb830c7cb927ff1ed50ae7de001",
"e1a8705b63ad5b8cd6c3d268d5cbf800"),
/* [ 12] */ new RandomConstant("f54a27fc056b00e7563f3505e0fbc001",
"2b657bbfd6ed9d632079e70c3c97f000"),
/* [ 13] */ new RandomConstant("df8a6fc1a833d201f98d719dd1f78001",
"59b60ee4c52fa49e9fe90682bd2fe000"),
/* [ 14] */ new RandomConstant("5480a5015f101a4ea7e3f183e3ef0001",
"cc099c88030679464fe86aae8a5fc000"),
/* [ 15] */ new RandomConstant("a498509e76e5d7925f539c28c7de0001",
"06b9abff9f9f33dd30362c0154bf8000"),
/* [ 16] */ new RandomConstant("0798a3d8b10dc72e60121cd58fbc0001",
"e296707121688d5a0260b293a97f0000"),
/* [ 17] */ new RandomConstant("1647d1e78ec02e665fafcbbb1f780001",
"189ffc4701ff23cb8f8acf6b52fe0000"),
/* [ 18] */ new RandomConstant("a7c982285e72bf8c0c8ddfb63ef00001",
"5141110ab208fb9d61fb47e6a5fc0000"),
/* [ 19] */ new RandomConstant("3eb78ee8fb8c56dbc5d4e06c7de00001",
"3c97caa62540f2948d8d340d4bf80000"),
/* [ 20] */ new RandomConstant("72d03b6f4681f2f9fe8e44d8fbc00001",
"1b25cb9cfe5a0c963174f91a97f00000"),
/* [ 21] */ new RandomConstant("ea85f81e4f502c9bc8ae99b1f7800001",
"0c644570b4a487103c5436352fe00000"),
/* [ 22] */ new RandomConstant("629c320db08b00c6bfa57363ef000001",
"3d0589c28869472bde517c6a5fc00000"),
/* [ 23] */ new RandomConstant("c5c4b9ce268d074a386be6c7de000001",
"bc95e5ab36477e65534738d4bf800000"),
/* [ 24] */ new RandomConstant("f30bbbbed1596187555bcd8fbc000001",
"ddb02ff72a031c01011f71a97f000000"),
/* [ 25] */ new RandomConstant("4a1000fb26c9eeda3cc79b1f78000001",
"2561426086d9acdb6c82e352fe000000"),
/* [ 26] */ new RandomConstant("89fb5307f6bf8ce2c1cf363ef0000001",
"64a788e3c118ed1c8215c6a5fc000000"),
/* [ 27] */ new RandomConstant("830b7b3358a5d67ea49e6c7de0000001",
"e65ea321908627cfa86b8d4bf8000000"),
/* [ 28] */ new RandomConstant("fd8a51da91a69fe1cd3cd8fbc0000001",
"53d27225604d85f9e1d71a97f0000000"),
/* [ 29] */ new RandomConstant("901a48b642b90b55aa79b1f780000001",
"ca5ec7a3ed1fe55e07ae352fe0000000"),
/* [ 30] */ new RandomConstant("118cdefdf32144f394f363ef00000001",
"4daebb2e085330651f5c6a5fc0000000"),
/* [ 31] */ new RandomConstant("0a88c0a91cff430829e6c7de00000001",
"9d6f1a00a8f3f76e7eb8d4bf80000000"),
/* [ 32] */ new RandomConstant("433bef4314f16a9453cd8fbc00000001",
"158c62f2b31e496dfd71a97f00000000"),
/* [ 33] */ new RandomConstant("c294b02995ae6738a79b1f7800000001",
"290e84a2eb15fd1ffae352fe00000000"),
/* [ 34] */ new RandomConstant("913575e0da8b16b14f363ef000000001",
"e3dc1bfbe991a34ff5c6a5fc00000000"),
/* [ 35] */ new RandomConstant("2f61b9f871cf4e629e6c7de000000001",
"ddf540d020b9eadfeb8d4bf800000000"),
/* [ 36] */ new RandomConstant("78d26ccbd68320c53cd8fbc000000001",
"8ee4950177ce66bfd71a97f000000000"),
/* [ 37] */ new RandomConstant("8b7ebd037898518a79b1f78000000001",
"39e0f787c907117fae352fe000000000"),
/* [ 38] */ new RandomConstant("0b5507b61f78e314f363ef0000000001",
"659d2522f7b732ff5c6a5fc000000000"),
/* [ 39] */ new RandomConstant("4f884628f812c629e6c7de0000000001",
"9e8722938612a5feb8d4bf8000000000"),
/* [ 40] */ new RandomConstant("be896744d4a98c53cd8fbc0000000001",
"e941a65d66b64bfd71a97f0000000000"),
/* [ 41] */ new RandomConstant("daf63a553b6318a79b1f780000000001",
"7b50d19437b097fae352fe0000000000"),
/* [ 42] */ new RandomConstant("2d7a23d8bf06314f363ef00000000001",
"59d7b68e18712ff5c6a5fc0000000000"),
/* [ 43] */ new RandomConstant("392b046a9f0c629e6c7de00000000001",
"4087bab2d5225feb8d4bf80000000000"),
/* [ 44] */ new RandomConstant("eb30fbb9c218c53cd8fbc00000000001",
"b470abc03b44bfd71a97f00000000000"),
/* [ 45] */ new RandomConstant("b9cdc30594318a79b1f7800000000001",
"366630eaba897fae352fe00000000000"),
/* [ 46] */ new RandomConstant("014ab453686314f363ef000000000001",
"a2dfc77e8512ff5c6a5fc00000000000"),
/* [ 47] */ new RandomConstant("395221c7d0c629e6c7de000000000001",
"1e0d25a14a25feb8d4bf800000000000"),
/* [ 48] */ new RandomConstant("4d972813a18c53cd8fbc000000000001",
"9d50a5d3944bfd71a97f000000000000"),
/* [ 49] */ new RandomConstant("06f9e2374318a79b1f78000000000001",
"bf7ab5eb2897fae352fe000000000000"),
/* [ 50] */ new RandomConstant("bd220cae86314f363ef0000000000001",
"925b14e6512ff5c6a5fc000000000000"),
/* [ 51] */ new RandomConstant("36fd3a5d0c629e6c7de0000000000001",
"724cce0ca25feb8d4bf8000000000000"),
/* [ 52] */ new RandomConstant("60def8ba18c53cd8fbc0000000000001",
"1af42d1944bfd71a97f0000000000000"),
/* [ 53] */ new RandomConstant("8d500174318a79b1f780000000000001",
"0f529e32897fae352fe0000000000000"),
/* [ 54] */ new RandomConstant("48e842e86314f363ef00000000000001",
"844e4c6512ff5c6a5fc0000000000000"),
/* [ 55] */ new RandomConstant("4af185d0c629e6c7de00000000000001",
"9f40d8ca25feb8d4bf80000000000000"),
/* [ 56] */ new RandomConstant("7a670ba18c53cd8fbc00000000000001",
"9912b1944bfd71a97f00000000000000"),
/* [ 57] */ new RandomConstant("86de174318a79b1f7800000000000001",
"9c69632897fae352fe00000000000000"),
/* [ 58] */ new RandomConstant("55fc2e86314f363ef000000000000001",
"e1e2c6512ff5c6a5fc00000000000000"),
/* [ 59] */ new RandomConstant("ccf85d0c629e6c7de000000000000001",
"68058ca25feb8d4bf800000000000000"),
/* [ 60] */ new RandomConstant("1df0ba18c53cd8fbc000000000000001",
"610b1944bfd71a97f000000000000000"),
/* [ 61] */ new RandomConstant("4be174318a79b1f78000000000000001",
"061632897fae352fe000000000000000"),
/* [ 62] */ new RandomConstant("d7c2e86314f363ef0000000000000001",
"1c2c6512ff5c6a5fc000000000000000"),
/* [ 63] */ new RandomConstant("af85d0c629e6c7de0000000000000001",
"7858ca25feb8d4bf8000000000000000"),
/* [ 64] */ new RandomConstant("5f0ba18c53cd8fbc0000000000000001",
"f0b1944bfd71a97f0000000000000000"),
/* [ 65] */ new RandomConstant("be174318a79b1f780000000000000001",
"e1632897fae352fe0000000000000000"),
/* [ 66] */ new RandomConstant("7c2e86314f363ef00000000000000001",
"c2c6512ff5c6a5fc0000000000000000"),
/* [ 67] */ new RandomConstant("f85d0c629e6c7de00000000000000001",
"858ca25feb8d4bf80000000000000000"),
/* [ 68] */ new RandomConstant("f0ba18c53cd8fbc00000000000000001",
"0b1944bfd71a97f00000000000000000"),
/* [ 69] */ new RandomConstant("e174318a79b1f7800000000000000001",
"1632897fae352fe00000000000000000"),
/* [ 70] */ new RandomConstant("c2e86314f363ef000000000000000001",
"2c6512ff5c6a5fc00000000000000000"),
/* [ 71] */ new RandomConstant("85d0c629e6c7de000000000000000001",
"58ca25feb8d4bf800000000000000000"),
/* [ 72] */ new RandomConstant("0ba18c53cd8fbc000000000000000001",
"b1944bfd71a97f000000000000000000"),
/* [ 73] */ new RandomConstant("174318a79b1f78000000000000000001",
"632897fae352fe000000000000000000"),
/* [ 74] */ new RandomConstant("2e86314f363ef0000000000000000001",
"c6512ff5c6a5fc000000000000000000"),
/* [ 75] */ new RandomConstant("5d0c629e6c7de0000000000000000001",
"8ca25feb8d4bf8000000000000000000"),
/* [ 76] */ new RandomConstant("ba18c53cd8fbc0000000000000000001",
"1944bfd71a97f0000000000000000000"),
/* [ 77] */ new RandomConstant("74318a79b1f780000000000000000001",
"32897fae352fe0000000000000000000"),
/* [ 78] */ new RandomConstant("e86314f363ef00000000000000000001",
"6512ff5c6a5fc0000000000000000000"),
/* [ 79] */ new RandomConstant("d0c629e6c7de00000000000000000001",
"ca25feb8d4bf80000000000000000000"),
/* [ 80] */ new RandomConstant("a18c53cd8fbc00000000000000000001",
"944bfd71a97f00000000000000000000"),
/* [ 81] */ new RandomConstant("4318a79b1f7800000000000000000001",
"2897fae352fe00000000000000000000"),
/* [ 82] */ new RandomConstant("86314f363ef000000000000000000001",
"512ff5c6a5fc00000000000000000000"),
/* [ 83] */ new RandomConstant("0c629e6c7de000000000000000000001",
"a25feb8d4bf800000000000000000000"),
/* [ 84] */ new RandomConstant("18c53cd8fbc000000000000000000001",
"44bfd71a97f000000000000000000000"),
/* [ 85] */ new RandomConstant("318a79b1f78000000000000000000001",
"897fae352fe000000000000000000000"),
/* [ 86] */ new RandomConstant("6314f363ef0000000000000000000001",
"12ff5c6a5fc000000000000000000000"),
/* [ 87] */ new RandomConstant("c629e6c7de0000000000000000000001",
"25feb8d4bf8000000000000000000000"),
/* [ 88] */ new RandomConstant("8c53cd8fbc0000000000000000000001",
"4bfd71a97f0000000000000000000000"),
/* [ 89] */ new RandomConstant("18a79b1f780000000000000000000001",
"97fae352fe0000000000000000000000"),
/* [ 90] */ new RandomConstant("314f363ef00000000000000000000001",
"2ff5c6a5fc0000000000000000000000"),
/* [ 91] */ new RandomConstant("629e6c7de00000000000000000000001",
"5feb8d4bf80000000000000000000000"),
/* [ 92] */ new RandomConstant("c53cd8fbc00000000000000000000001",
"bfd71a97f00000000000000000000000"),
/* [ 93] */ new RandomConstant("8a79b1f7800000000000000000000001",
"7fae352fe00000000000000000000000"),
/* [ 94] */ new RandomConstant("14f363ef000000000000000000000001",
"ff5c6a5fc00000000000000000000000"),
/* [ 95] */ new RandomConstant("29e6c7de000000000000000000000001",
"feb8d4bf800000000000000000000000"),
/* [ 96] */ new RandomConstant("53cd8fbc000000000000000000000001",
"fd71a97f000000000000000000000000"),
/* [ 97] */ new RandomConstant("a79b1f78000000000000000000000001",
"fae352fe000000000000000000000000"),
/* [ 98] */ new RandomConstant("4f363ef0000000000000000000000001",
"f5c6a5fc000000000000000000000000"),
/* [ 99] */ new RandomConstant("9e6c7de0000000000000000000000001",
"eb8d4bf8000000000000000000000000"),
/* [100] */ new RandomConstant("3cd8fbc0000000000000000000000001",
"d71a97f0000000000000000000000000"),
/* [101] */ new RandomConstant("79b1f780000000000000000000000001",
"ae352fe0000000000000000000000000"),
/* [102] */ new RandomConstant("f363ef00000000000000000000000001",
"5c6a5fc0000000000000000000000000"),
/* [103] */ new RandomConstant("e6c7de00000000000000000000000001",
"b8d4bf80000000000000000000000000"),
/* [104] */ new RandomConstant("cd8fbc00000000000000000000000001",
"71a97f00000000000000000000000000"),
/* [105] */ new RandomConstant("9b1f7800000000000000000000000001",
"e352fe00000000000000000000000000"),
/* [106] */ new RandomConstant("363ef000000000000000000000000001",
"c6a5fc00000000000000000000000000"),
/* [107] */ new RandomConstant("6c7de000000000000000000000000001",
"8d4bf800000000000000000000000000"),
/* [108] */ new RandomConstant("d8fbc000000000000000000000000001",
"1a97f000000000000000000000000000"),
/* [109] */ new RandomConstant("b1f78000000000000000000000000001",
"352fe000000000000000000000000000"),
/* [110] */ new RandomConstant("63ef0000000000000000000000000001",
"6a5fc000000000000000000000000000"),
/* [111] */ new RandomConstant("c7de0000000000000000000000000001",
"d4bf8000000000000000000000000000"),
/* [112] */ new RandomConstant("8fbc0000000000000000000000000001",
"a97f0000000000000000000000000000"),
/* [113] */ new RandomConstant("1f780000000000000000000000000001",
"52fe0000000000000000000000000000"),
/* [114] */ new RandomConstant("3ef00000000000000000000000000001",
"a5fc0000000000000000000000000000"),
/* [115] */ new RandomConstant("7de00000000000000000000000000001",
"4bf80000000000000000000000000000"),
/* [116] */ new RandomConstant("fbc00000000000000000000000000001",
"97f00000000000000000000000000000"),
/* [117] */ new RandomConstant("f7800000000000000000000000000001",
"2fe00000000000000000000000000000"),
/* [118] */ new RandomConstant("ef000000000000000000000000000001",
"5fc00000000000000000000000000000"),
/* [119] */ new RandomConstant("de000000000000000000000000000001",
"bf800000000000000000000000000000"),
/* [120] */ new RandomConstant("bc000000000000000000000000000001",
"7f000000000000000000000000000000"),
/* [121] */ new RandomConstant("78000000000000000000000000000001",
"fe000000000000000000000000000000"),
/* [122] */ new RandomConstant("f0000000000000000000000000000001",
"fc000000000000000000000000000000"),
/* [123] */ new RandomConstant("e0000000000000000000000000000001",
"f8000000000000000000000000000000"),
/* [124] */ new RandomConstant("c0000000000000000000000000000001",
"f0000000000000000000000000000000"),
/* [125] */ new RandomConstant("80000000000000000000000000000001",
"e0000000000000000000000000000000"),
/* [126] */ new RandomConstant("00000000000000000000000000000001",
"c0000000000000000000000000000000"),
/* [127] */ new RandomConstant("00000000000000000000000000000001",
"80000000000000000000000000000000")};
/**
* generate the random number that is "advance" steps
* from an initial random number of 0. This is done by
* starting with 0, and then advancing the by the
* appropriate powers of 2 of the linear congruential
* generator.
*/
public static Unsigned16 skipAhead(Unsigned16 advance) {
Unsigned16 result = new Unsigned16();
long bit_map;
bit_map = advance.getLow8();
for (int i = 0; bit_map != 0 && i < 64; i++) {
if ((bit_map & (1L << i)) != 0) {
/* advance random number by f**(2**i) (x)
*/
result.multiply(genArray[i].a);
result.add(genArray[i].c);
bit_map &= ~(1L << i);
}
}
bit_map = advance.getHigh8();
for (int i = 0; bit_map != 0 && i < 64; i++)
{
if ((bit_map & (1L << i)) != 0) {
/* advance random number by f**(2**(i + 64)) (x)
*/
result.multiply(genArray[i+64].a);
result.add(genArray[i+64].c);
bit_map &= ~(1L << i);
}
}
return result;
}
/**
* Generate the next 16 byte random number.
*/
public static void nextRand(Unsigned16 rand) {
/* advance the random number forward once using the linear congruential
* generator, and then return the new random number
*/
rand.multiply(genArray[0].a);
rand.add(genArray[0].c);
}
}