RNG-192: Remove use of overriddable instance method for state

initialisation

Author: aherbert

commons-rng-core/pom.xml

@@ -56,6 +56,7 @@
     <commons.jacoco.instructionRatio>0.99</commons.jacoco.instructionRatio>
     <commons.jacoco.lineRatio>0.99</commons.jacoco.lineRatio>
     <!-- Change from commons-parent of 1.0 as method handles to JDK Math cannot always be executed -->
+    <commons.jacoco.branchRatio>0.99</commons.jacoco.branchRatio>
     <commons.jacoco.methodRatio>0.99</commons.jacoco.methodRatio>
     <commons.jacoco.complexityRatio>0.99</commons.jacoco.complexityRatio>
 

commons-rng-core/src/main/java/org/apache/commons/rng/core/BaseProvider.java

@@ -174,6 +174,10 @@ protected void setStateInternal(byte[] state) {
      *  </li>
      * </ol>
      *
+     * <p>Note: It is not recommended to use this method from a constructor
+     * as it can be overridden by subclasses possibly leading to unexpected behaviour.
+     * Future versions may remove this method, or change it to static.
+     *
      * @param state State. Must be allocated.
      * @param seed Seed. Cannot be null.
      */
@@ -185,7 +189,7 @@ protected void fillState(int[] state,
 
         if (seedSize < stateSize) {
             for (int i = seedSize; i < stateSize; i++) {
-                state[i] = (int) scrambleWell(state[i - seed.length], i);
+                state[i] = (int) scrambleWell(state[i - seedSize], i);
             }
         }
     }
@@ -205,6 +209,10 @@ protected void fillState(int[] state,
      *  </li>
      * </ol>
      *
+     * <p>Note: It is not recommended to use this method from a constructor
+     * as it can be overridden by subclasses possibly leading to unexpected behaviour.
+     * Future versions may remove this method, or change it to static.
+     *
      * @param state State. Must be allocated.
      * @param seed Seed. Cannot be null.
      */
@@ -216,7 +224,7 @@ protected void fillState(long[] state,
 
         if (seedSize < stateSize) {
             for (int i = seedSize; i < stateSize; i++) {
-                state[i] = scrambleWell(state[i - seed.length], i);
+                state[i] = scrambleWell(state[i - seedSize], i);
             }
         }
     }

commons-rng-core/src/main/java/org/apache/commons/rng/core/source32/AbstractPcg6432.java

@@ -94,13 +94,7 @@ abstract class AbstractPcg6432 extends IntProvider {
      * is discarded by left shift and the increment is set to odd.</p>
      */
     AbstractPcg6432(long[] seed) {
-        if (seed.length < SEED_SIZE) {
-            final long[] tmp = new long[SEED_SIZE];
-            fillState(tmp, seed);
-            setSeedInternal(tmp);
-        } else {
-            setSeedInternal(seed);
-        }
+        setSeedInternal(extendSeed(seed, SEED_SIZE));
     }
 
     /**

commons-rng-core/src/main/java/org/apache/commons/rng/core/source32/AbstractXoRoShiRo64.java

@@ -46,13 +46,7 @@ abstract class AbstractXoRoShiRo64 extends IntProvider {
      * set. A seed containing all zeros will create a non-functional generator.
      */
     AbstractXoRoShiRo64(int[] seed) {
-        if (seed.length < SEED_SIZE) {
-            final int[] state = new int[SEED_SIZE];
-            fillState(state, seed);
-            setState(state);
-        } else {
-            setState(seed);
-        }
+        setState(extendSeed(seed, SEED_SIZE));
     }
 
     /**

commons-rng-core/src/main/java/org/apache/commons/rng/core/source32/AbstractXoShiRo128.java

@@ -61,13 +61,7 @@ abstract class AbstractXoShiRo128 extends IntProvider implements LongJumpableUni
      * set. A seed containing all zeros will create a non-functional generator.
      */
     AbstractXoShiRo128(int[] seed) {
-        if (seed.length < SEED_SIZE) {
-            final int[] state = new int[SEED_SIZE];
-            fillState(state, seed);
-            setState(state);
-        } else {
-            setState(seed);
-        }
+        setState(extendSeed(seed, SEED_SIZE));
     }
 
     /**

commons-rng-core/src/main/java/org/apache/commons/rng/core/source32/DotyHumphreySmallFastCounting32.java

@@ -49,13 +49,7 @@ public class DotyHumphreySmallFastCounting32 extends IntProvider {
      * be used; if smaller, the remaining elements will be automatically set.
      */
     public DotyHumphreySmallFastCounting32(int[] seed) {
-        if (seed.length < SEED_SIZE) {
-            final int[] state = new int[SEED_SIZE];
-            fillState(state, seed);
-            setSeedInternal(state);
-        } else {
-            setSeedInternal(seed);
-        }
+        setSeedInternal(extendSeed(seed, SEED_SIZE));
     }
 
     /**

commons-rng-core/src/main/java/org/apache/commons/rng/core/source32/KISSRandom.java

@@ -81,8 +81,7 @@ protected void setStateInternal(byte[] s) {
     private void setSeedInternal(int[] seed) {
         // Reset the whole state of this RNG (i.e. the 4 state variables).
         // Filling procedure is not part of the reference code.
-        final int[] tmp = new int[SEED_SIZE];
-        fillState(tmp, seed);
+        final int[] tmp = extendSeed(seed, SEED_SIZE);
 
         z = tmp[0];
         w = tmp[1];

commons-rng-core/src/main/java/org/apache/commons/rng/core/source32/MultiplyWithCarry256.java

@@ -91,8 +91,7 @@ protected void setStateInternal(byte[] s) {
     private void setSeedInternal(int[] seed) {
         // Reset the whole state of this RNG (i.e. "state" and "index").
         // Filling procedure is not part of the reference code.
-        final int[] tmp = new int[SEED_SIZE];
-        fillState(tmp, seed);
+        final int[] tmp = extendSeed(seed, SEED_SIZE);
 
         // First element of the "seed" is the initial "carry".
         final int c = tmp[0];

commons-rng-core/src/main/java/org/apache/commons/rng/core/source64/AbstractXoRoShiRo1024.java

@@ -62,7 +62,8 @@ abstract class AbstractXoRoShiRo1024 extends LongProvider implements LongJumpabl
      * set. A seed containing all zeros will create a non-functional generator.
      */
     AbstractXoRoShiRo1024(long[] seed) {
-        setSeedInternal(seed);
+        final long[] tmp = extendSeed(seed, SEED_SIZE);
+        System.arraycopy(tmp, 0, state, 0, SEED_SIZE);
     }
 
     /**
@@ -98,18 +99,6 @@ protected void setStateInternal(byte[] s) {
         super.setStateInternal(c[1]);
     }
 
-    /**
-     * Seeds the RNG.
-     *
-     * @param seed Seed.
-     */
-    private void setSeedInternal(long[] seed) {
-        // Reset the whole state of this RNG (i.e. "state" and "index").
-        // Filling procedure is not part of the reference code.
-        fillState(state, seed);
-        index = 0;
-    }
-
     /** {@inheritDoc} */
     @Override
     public long next() {

commons-rng-core/src/main/java/org/apache/commons/rng/core/source64/AbstractXoRoShiRo128.java

@@ -57,13 +57,7 @@ abstract class AbstractXoRoShiRo128 extends LongProvider implements LongJumpable
      * set. A seed containing all zeros will create a non-functional generator.
      */
     AbstractXoRoShiRo128(long[] seed) {
-        if (seed.length < SEED_SIZE) {
-            final long[] state = new long[SEED_SIZE];
-            fillState(state, seed);
-            setState(state);
-        } else {
-            setState(seed);
-        }
+        setState(extendSeed(seed, SEED_SIZE));
     }
 
     /**