From bbc22e6924cfd6a7b46b5e9ddc8d502e530111be Mon Sep 17 00:00:00 2001 From: PiggyPiglet Date: Sat, 18 Jul 2020 00:33:40 +0800 Subject: [PATCH 1/2] Added ij to gitignore --- .gitignore | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/.gitignore b/.gitignore index 00fe968..d11dd98 100644 --- a/.gitignore +++ b/.gitignore @@ -1,5 +1,7 @@ -/target/ +target/ .classpath .project *.settings -.editorconfig \ No newline at end of file +.editorconfig +.idea/ +*.iml \ No newline at end of file From d7bb2f35f6175e0f2bbbedf9e821cba932bc29ca Mon Sep 17 00:00:00 2001 From: PiggyPiglet Date: Sat, 18 Jul 2020 00:48:04 +0800 Subject: [PATCH 2/2] Use annotations instead of null checks Remove redundant method modifiers Use final where appropriate Fix bad javadocs --- pom.xml | 9 + .../probabilitylib/ProbabilityCollection.java | 423 ++++++++---------- .../ProbabilityCollectionTest.java | 29 +- 3 files changed, 211 insertions(+), 250 deletions(-) diff --git a/pom.xml b/pom.xml index f1fe868..08f03ef 100644 --- a/pom.xml +++ b/pom.xml @@ -18,6 +18,15 @@ + + org.jetbrains + annotations + 19.0.0 + compile + + + org.junit.jupiter junit-jupiter-engine diff --git a/src/main/java/com/lewdev/probabilitylib/ProbabilityCollection.java b/src/main/java/com/lewdev/probabilitylib/ProbabilityCollection.java index 98bd9b1..0faa8f9 100644 --- a/src/main/java/com/lewdev/probabilitylib/ProbabilityCollection.java +++ b/src/main/java/com/lewdev/probabilitylib/ProbabilityCollection.java @@ -1,32 +1,30 @@ /* -* Copyright (c) 2020 Lewys Davies -* -* Permission is hereby granted, free of charge, to any person obtaining a copy -* of this software and associated documentation files (the "Software"), to deal -* in the Software without restriction, including without limitation the rights -* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell -* copies of the Software, and to permit persons to whom the Software is -* furnished to do so, subject to the following conditions: -* -* The above copyright notice and this permission notice shall be included in all -* copies or substantial portions of the Software. -* -* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR -* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, -* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE -* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER -* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, -* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE -* SOFTWARE. -*/ + * Copyright (c) 2020 Lewys Davies + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in all + * copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ package com.lewdev.probabilitylib; -import java.util.Comparator; -import java.util.Iterator; -import java.util.NavigableSet; -import java.util.Objects; -import java.util.SplittableRandom; -import java.util.TreeSet; +import org.jetbrains.annotations.NotNull; +import org.jetbrains.annotations.Nullable; + +import java.util.*; /** * ProbabilityCollection for retrieving random elements based on probability. @@ -43,214 +41,187 @@ * selected than those with smaller probability. *

* - * - * @author Lewys Davies - * @version 0.8 * * @param Type of elements + * @author Lewys Davies + * @version 0.8 */ public class ProbabilityCollection { - - private final NavigableSet> collection; - private final SplittableRandom random = new SplittableRandom(); + private final NavigableSet> collection = + new TreeSet<>(Comparator.comparingInt(ProbabilitySetElement::getIndex)); + private final SplittableRandom random = new SplittableRandom(); + + private int totalProbability = 0; + + /** + * @return Number of objects inside the collection + */ + public int size() { + return this.collection.size(); + } + + /** + * @return True if collection contains no elements, else False + */ + public boolean isEmpty() { + return this.collection.isEmpty(); + } + + /** + * @param object Object to test against + * @return True if collection contains the object, else False + * @throws IllegalArgumentException if object is null + */ + public boolean contains(@NotNull E object) { + return this.collection.stream() + .anyMatch(entry -> entry.getObject().equals(object)); + } + + /** + * @return Iterator over this collection + */ + @NotNull + public Iterator> iterator() { + return this.collection.iterator(); + } + + /** + * Add an object to this collection + * + * @param object Non-null object to add. + * @param probability share. Must be greater than 0. + * @throws IllegalArgumentException if probability <= 0 + */ + public void add(@NotNull E object, int probability) { + if (probability <= 0) { + throw new IllegalArgumentException("Probability must be greater than 0"); + } + + final ProbabilitySetElement entry = new ProbabilitySetElement<>(object, probability); + entry.setIndex(this.totalProbability + 1); + + this.collection.add(entry); + this.totalProbability += probability; + } + + /** + * Remove a object from this collection + * + * @param object Object to remove + * @return True if object was removed, else False. + */ + public boolean remove(@NotNull E object) { + final Iterator> it = this.iterator(); + boolean removed = false; + + while (it.hasNext()) { + ProbabilitySetElement entry = it.next(); + + if (entry.getObject().equals(object)) { + this.totalProbability -= entry.getProbability(); + it.remove(); + removed = true; + } + } + + this.updateIndexes(); + + return removed; + } + + /** + * Remove all objects from this collection + */ + public void clear() { + this.collection.clear(); + this.totalProbability = 0; + } + + /** + * Get a random object from this collection, based on probability. + * + * @return Random object + * @throws IllegalStateException if this collection is empty + */ + @NotNull + public E get() { + if (this.isEmpty()) { + throw new IllegalStateException("Cannot get an object out of a empty collection"); + } + + final ProbabilitySetElement toFind = new ProbabilitySetElement<>(null, 0); + toFind.setIndex(this.random.nextInt(1, this.totalProbability + 1)); + + return Objects.requireNonNull(Objects.requireNonNull(this.collection.floor(toFind)).getObject()); + } + + /** + * @return Sum of all element's probability + */ + public final int getTotalProbability() { + return this.totalProbability; + } + + /* + * Calculate the size of all element's "block" of space: + * i.e 1-5, 6-10, 11-14, 15, 16 + * + * We then only need to store the start index of each element, + * as we make use of the TreeSet#floor + */ + private void updateIndexes() { + int previousIndex = 0; + + for (final ProbabilitySetElement entry : this.collection) { + previousIndex = entry.setIndex(previousIndex + 1) + (entry.getProbability() - 1); + } + } - private int totalProbability; - - /** - * Construct a new Probability Collection - */ - public ProbabilityCollection() { - this.collection = new TreeSet<>(Comparator.comparingInt(ProbabilitySetElement::getIndex)); - this.totalProbability = 0; - } + /** + * Used internally to store information about a object's + * state in a collection. Specifically, the probability + * and index within the collection. + *

+ * Indexes refer to the start position of this element's "block" of space. + * The space between element "block"s represents their probability of being selected + * + * @param Type of element + * @author Lewys Davies + */ + private static final class ProbabilitySetElement { + private final T object; + private final int probability; + private int index; - /** - * @return Number of objects inside the collection - */ - public int size() { - return this.collection.size(); - } - - /** - * @return True if collection contains no elements, else False - */ - public boolean isEmpty() { - return this.collection.isEmpty(); - } - - /** - * @param object - * @return True if collection contains the object, else False - * @throws IllegalArgumentException if object is null - */ - public boolean contains(E object) { - if(object == null) { - throw new IllegalArgumentException("Cannot check if null object is contained in this collection"); - } - - return this.collection.stream() - .anyMatch(entry -> entry.getObject().equals(object)); - } + protected ProbabilitySetElement(T object, int probability) { + this.object = object; + this.probability = probability; + } - /** - * @return Iterator over this collection - */ - public Iterator> iterator() { - return this.collection.iterator(); - } - - /** - * Add an object to this collection - * - * @param object. Not null. - * @param probability share. Must be greater than 0. - * - * @throws IllegalArgumentException if object is null - * @throws IllegalArgumentException if probability <= 0 - */ - public void add(E object, int probability) { - if(object == null) { - throw new IllegalArgumentException("Cannot add null object"); - } - - if(probability <= 0) { - throw new IllegalArgumentException("Probability must be greater than 0"); - } - - ProbabilitySetElement entry = new ProbabilitySetElement(object, probability); - entry.setIndex(this.totalProbability + 1); - - this.collection.add(entry); - this.totalProbability += probability; - } + /** + * @return The actual object + */ + @Nullable + public T getObject() { + return this.object; + } - /** - * Remove a object from this collection - * - * @param object - * @return True if object was removed, else False. - * - * @throws IllegalArgumentException if object is null - */ - public boolean remove(E object) { - if(object == null) { - throw new IllegalArgumentException("Cannot remove null object"); - } - - Iterator> it = this.iterator(); - boolean removed = false; - - while(it.hasNext()) { - ProbabilitySetElement entry = it.next(); - if(entry.getObject().equals(object)) { - this.totalProbability -= entry.getProbability(); - it.remove(); - removed = true; - } - } - - this.updateIndexes(); - - return removed; - } - - /** - * Remove all objects from this collection - */ - public void clear() { - this.collection.clear(); - this.totalProbability = 0; - } - - /** - * Get a random object from this collection, based on probability. - * - * @return Random object - * - * @throws IllegalStateException if this collection is empty - */ - public E get() { - if(this.isEmpty()) { - throw new IllegalStateException("Cannot get an object out of a empty collection"); - } - - ProbabilitySetElement toFind = new ProbabilitySetElement<>(null, 0); - toFind.setIndex(this.random.nextInt(1, this.totalProbability + 1)); - - return Objects.requireNonNull(this.collection.floor(toFind).getObject()); - } - - /** - * @return Sum of all element's probability - */ - public final int getTotalProbability() { - return this.totalProbability; - } - - /* - * Calculate the size of all element's "block" of space: - * i.e 1-5, 6-10, 11-14, 15, 16 - * - * We then only need to store the start index of each element, - * as we make use of the TreeSet#floor - */ - private final void updateIndexes() { - int previousIndex = 0; - - for(ProbabilitySetElement entry : this.collection) { - previousIndex = entry.setIndex(previousIndex + 1) + (entry.getProbability() - 1); - } - } - - /** - * Used internally to store information about a object's - * state in a collection. Specifically, the probability - * and index within the collection. - * - * Indexes refer to the start position of this element's "block" of space. - * The space between element "block"s represents their probability of being selected - * - * @author Lewys Davies - * - * @param Type of element - */ - final static class ProbabilitySetElement { - private final T object; - private final int probability; - private int index; - - /** - * @param object - * @param probability - */ - protected ProbabilitySetElement(T object, int probability) { - this.object = object; - this.probability = probability; - } + /** + * @return Probability share in this collection + */ + public int getProbability() { + return this.probability; + } - /** - * @return The actual object - */ - public final T getObject() { - return this.object; - } + // Used internally, see this class's documentation + private int getIndex() { + return this.index; + } - /** - * @return Probability share in this collection - */ - public final int getProbability() { - return this.probability; - } - - // Used internally, see this class's documentation - private final int getIndex() { - return this.index; - } - - // Used Internally, see this class's documentation - private final int setIndex(int index) { - this.index = index; - return this.index; - } - } + // Used Internally, see this class's documentation + private int setIndex(int index) { + this.index = index; + return this.index; + } + } } diff --git a/src/test/java/com/lewdev/probabilitylib/ProbabilityCollectionTest.java b/src/test/java/com/lewdev/probabilitylib/ProbabilityCollectionTest.java index 5bd0aae..277aeb4 100644 --- a/src/test/java/com/lewdev/probabilitylib/ProbabilityCollectionTest.java +++ b/src/test/java/com/lewdev/probabilitylib/ProbabilityCollectionTest.java @@ -1,10 +1,10 @@ package com.lewdev.probabilitylib; -import static org.junit.jupiter.api.Assertions.*; - import org.junit.jupiter.api.RepeatedTest; import org.junit.jupiter.api.Test; +import static org.junit.jupiter.api.Assertions.*; + /** * @author Lewys Davies */ @@ -250,48 +250,29 @@ public void test_Errors() { assertEquals(0, collection.size()); assertTrue(collection.isEmpty()); assertEquals(0, collection.getTotalProbability()); - + // Cannot get from empty collection - assertThrows(IllegalStateException.class, () -> { - collection.get(); - }); + assertThrows(IllegalStateException.class, collection::get); assertEquals(0, collection.size()); assertTrue(collection.isEmpty()); assertEquals(0, collection.getTotalProbability()); - // Cannot add null object - assertThrows(IllegalArgumentException.class, () -> { - collection.add(null, 1); - }); - assertEquals(0, collection.size()); assertTrue(collection.isEmpty()); assertEquals(0, collection.getTotalProbability()); // Cannot add prob 0 - assertThrows(IllegalArgumentException.class, () -> { - collection.add("A", 0); - }); + assertThrows(IllegalArgumentException.class, () -> collection.add("A", 0)); assertEquals(0, collection.size()); assertTrue(collection.isEmpty()); assertEquals(0, collection.getTotalProbability()); - // Cannot remove null - assertThrows(IllegalArgumentException.class, () -> { - collection.remove(null); - }); - assertEquals(0, collection.size()); assertTrue(collection.isEmpty()); assertEquals(0, collection.getTotalProbability()); - // Cannot contains null - assertThrows(IllegalArgumentException.class, () -> { - collection.contains(null); - }); - assertEquals(0, collection.size()); assertTrue(collection.isEmpty()); assertEquals(0, collection.getTotalProbability());