Avoid code duplication.
Project: http://git-wip-us.apache.org/repos/asf/commons-rng/repo Commit: http://git-wip-us.apache.org/repos/asf/commons-rng/commit/2471de81 Tree: http://git-wip-us.apache.org/repos/asf/commons-rng/tree/2471de81 Diff: http://git-wip-us.apache.org/repos/asf/commons-rng/diff/2471de81 Branch: refs/heads/master Commit: 2471de8168ec158749fd7e3febfde146405f6559 Parents: fe6ec47 Author: Gilles <[email protected]> Authored: Sat Sep 10 16:25:44 2016 +0200 Committer: Gilles <[email protected]> Committed: Sat Sep 10 16:25:44 2016 +0200 ---------------------------------------------------------------------- .../rng/internal/source32/KISSRandom.java | 15 ++------ .../internal/source32/MultiplyWithCarry256.java | 15 ++------ .../commons/rng/internal/util/SeedFactory.java | 36 ++++++++++++++++++++ 3 files changed, 40 insertions(+), 26 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/commons-rng/blob/2471de81/src/main/java/org/apache/commons/rng/internal/source32/KISSRandom.java ---------------------------------------------------------------------- diff --git a/src/main/java/org/apache/commons/rng/internal/source32/KISSRandom.java b/src/main/java/org/apache/commons/rng/internal/source32/KISSRandom.java index 674d803..62ae60b 100644 --- a/src/main/java/org/apache/commons/rng/internal/source32/KISSRandom.java +++ b/src/main/java/org/apache/commons/rng/internal/source32/KISSRandom.java @@ -17,6 +17,7 @@ package org.apache.commons.rng.internal.source32; import org.apache.commons.rng.internal.util.NumberFactory; +import org.apache.commons.rng.internal.util.SeedFactory; /** * Port from Marsaglia's <a href="http://www.cse.yorku.ca/~oz/marsaglia-rng.html";> @@ -78,20 +79,8 @@ public class KISSRandom extends IntProvider { private void setSeedInternal(int[] seed) { // Reset the whole state of this RNG (i.e. the 4 state variables). // Seeding procedure is not part of the reference code. - final int[] tmp = new int[SEED_SIZE]; - System.arraycopy(seed, 0, tmp, 0, Math.min(seed.length, tmp.length)); - - if (seed.length < SEED_SIZE) { - for (int i = seed.length; i < SEED_SIZE; i++) { - tmp[i] = 26021969 * i; - } - for (int i = SEED_SIZE - 1; i > seed.length; i--) { - tmp[i] ^= tmp[SEED_SIZE - i - 1]; - } - - tmp[seed.length] = 0x80000000; // Ensuring non-zero initial array. - } + SeedFactory.fillState(tmp, seed); z = tmp[0]; w = tmp[1]; http://git-wip-us.apache.org/repos/asf/commons-rng/blob/2471de81/src/main/java/org/apache/commons/rng/internal/source32/MultiplyWithCarry256.java ---------------------------------------------------------------------- diff --git a/src/main/java/org/apache/commons/rng/internal/source32/MultiplyWithCarry256.java b/src/main/java/org/apache/commons/rng/internal/source32/MultiplyWithCarry256.java index 8ed0331..58b48d1 100644 --- a/src/main/java/org/apache/commons/rng/internal/source32/MultiplyWithCarry256.java +++ b/src/main/java/org/apache/commons/rng/internal/source32/MultiplyWithCarry256.java @@ -18,6 +18,7 @@ package org.apache.commons.rng.internal.source32; import java.util.Arrays; import org.apache.commons.rng.internal.util.NumberFactory; +import org.apache.commons.rng.internal.util.SeedFactory; /** * Port from Marsaglia's <a href="https://en.wikipedia.org/wiki/Multiply-with-carry";> @@ -87,20 +88,8 @@ public class MultiplyWithCarry256 extends IntProvider { private void setSeedInternal(int[] seed) { // Reset the whole state of this RNG (i.e. "state" and "index"). // Seeding procedure is not part of the reference code. - final int[] tmp = new int[SEED_SIZE]; - System.arraycopy(seed, 0, tmp, 0, Math.min(seed.length, tmp.length)); - - if (seed.length < SEED_SIZE) { - for (int i = seed.length; i < SEED_SIZE; i++) { - tmp[i] = 26021969 * i; - } - for (int i = SEED_SIZE - 1; i > seed.length; i--) { - tmp[i] ^= tmp[SEED_SIZE - i - 1]; - } - - tmp[seed.length] = 0x80000000; // Ensuring non-zero initial array. - } + SeedFactory.fillState(tmp, seed); // First element of the "seed" is the initial "carry". final int c = tmp[0]; http://git-wip-us.apache.org/repos/asf/commons-rng/blob/2471de81/src/main/java/org/apache/commons/rng/internal/util/SeedFactory.java ---------------------------------------------------------------------- diff --git a/src/main/java/org/apache/commons/rng/internal/util/SeedFactory.java b/src/main/java/org/apache/commons/rng/internal/util/SeedFactory.java index fe9e66c..047e9f0 100644 --- a/src/main/java/org/apache/commons/rng/internal/util/SeedFactory.java +++ b/src/main/java/org/apache/commons/rng/internal/util/SeedFactory.java @@ -98,6 +98,42 @@ public class SeedFactory { } /** + * Simple filling procedure. + * It will + * <ol> + * <li> + * fill the beginning of {@code state} by copying + * {@code min(seed.length, state.length)} elements from + * {@code seed}, + * </li> + * <li> + * set all remaining elements of {@code state} with non-zero + * values (even if {@code seed.length < state.length}). + * </li> + * </ol> + * + * @param state State. Must be allocated. + * @param seed Seed. Cannot be null. + */ + public static void fillState(int[] state, + int[] seed) { + final int stateSize = state.length; + final int seedSize = seed.length; + System.arraycopy(seed, 0, state, 0, Math.min(seedSize, stateSize)); + + if (seedSize < stateSize) { + for (int i = seedSize; i < stateSize; i++) { + state[i] = 26021969 * i; + } + for (int i = stateSize - 1; i > seedSize; i--) { + state[i] ^= state[stateSize - i - 1]; + } + + state[seedSize] = 0x80000000; // Ensuring non-zero initial array. + } + } + + /** * Creates an array of numbers for use as a seed. * * @param n Size of the array to create.
