belliottsmith commented on code in PR #50: URL: https://github.com/apache/cassandra-accord/pull/50#discussion_r1262812000
########## accord-core/src/test/java/accord/utils/SimpleBitSetTest.java: ########## @@ -0,0 +1,203 @@ +/* + * 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 accord.utils; + +import java.util.ArrayList; +import java.util.BitSet; +import java.util.List; +import java.util.Random; +import java.util.function.BiConsumer; +import java.util.function.IntConsumer; + +import com.google.common.collect.Lists; +import org.junit.jupiter.api.Test; + +import static org.junit.jupiter.api.Assertions.assertEquals; + +public class SimpleBitSetTest +{ + private static final int NOT_FOUND = Integer.MAX_VALUE; + + private static class Check + { + final SimpleBitSet test; + final BitSet canon; + final int size; + + private Check(SimpleBitSet test, BitSet canon, int size) + { + this.test = test; + this.canon = canon; + this.size = size; + } + + void check(Random random) + { + assertEquals(canon.cardinality(), test.setBitCount()); + assertEquals(canon.nextSetBit(0), test.firstSetBit()); + assertEquals(normaliseNotFound(canon.nextSetBit(0)), test.firstSetBit(NOT_FOUND)); + assertEquals(canon.previousSetBit(size), test.lastSetBit()); + assertEquals(normaliseNotFound(canon.previousSetBit(size)), test.lastSetBit(NOT_FOUND)); + + forIndices(random, i -> assertEquals(canon.nextSetBit(i), test.nextSetBit(i))); + forIndices(random, i -> assertEquals(normaliseBefore(canon.nextSetBit(0), i), test.firstSetBitBefore(i))); + forIndices(random, i -> assertEquals(normaliseNotFoundBefore(canon.nextSetBit(0), i), test.firstSetBitBefore(i, NOT_FOUND))); + forRanges(random, (i, j) -> assertEquals(normaliseBefore(canon.nextSetBit(i), j), test.nextSetBitBefore(i, j))); + forRanges(random, (i, j) -> assertEquals(normaliseNotFoundBefore(canon.nextSetBit(i), j), test.nextSetBitBefore(i, j, NOT_FOUND))); + + forIndices(random, i -> assertEquals(i == 0 ? -1 : canon.previousSetBit(i - 1), test.prevSetBit(i))); + forIndices(random, i -> assertEquals(normaliseNotBefore(size == 0 ? -1 : canon.previousSetBit(size - 1), i), test.lastSetBitNotBefore(i))); + forIndices(random, i -> assertEquals(normaliseNotFoundNotBefore(size == 0 ? -1 : canon.previousSetBit(size - 1), i), test.lastSetBitNotBefore(i, NOT_FOUND))); + forRanges(random, (i, j) -> assertEquals(normaliseNotBefore(j == 0 ? -1 : canon.previousSetBit(j - 1), i), test.prevSetBitNotBefore(j, i))); + forRanges(random, (i, j) -> assertEquals(normaliseNotFoundNotBefore(j == 0 ? -1 : canon.previousSetBit(j - 1), i), test.prevSetBitNotBefore(j, i, NOT_FOUND))); + + List<Integer> canonCollect = new ArrayList<>(), testCollect = new ArrayList<>(); + canon.stream().forEachOrdered(canonCollect::add); + test.forEach(testCollect, List::add); + assertEquals(canonCollect, testCollect); + + canonCollect = Lists.reverse(canonCollect); + testCollect.clear(); + test.reverseForEach(testCollect, List::add); + assertEquals(canonCollect, testCollect); + } + + void forIndices(Random random, IntConsumer consumer) + { + for (int c = 0 ; c < 100 ; ++c) + { + int i = random.nextInt(size + 1); + consumer.accept(i); + } + } + + void forRanges(Random random, BiConsumer<Integer, Integer> consumer) + { + for (int c = 0 ; c < 100 ; ++c) + { + int i = random.nextInt(size + 1); + int j = random.nextInt(size + 1); + if (i > j) { int t = i; i = j; j = t; } + consumer.accept(i, j); + } + } + + static Check generate(Random random, int maxSize, int modCount, int runLength, float runChance, float clearChance) + { + int size = random.nextInt(maxSize); + runLength = Math.min(size, runLength); + BitSet canon = new BitSet(size); + SimpleBitSet test = new SimpleBitSet(size); + if (size > 0) + { + while (modCount-- > 0) + { + boolean set = random.nextFloat() >= clearChance; + boolean run = runLength > 1 && random.nextFloat() < runChance; + if (run) + { + int i = random.nextInt(size); + int j = random.nextInt(size); + if (j < i) { int t = i; i = j; j = t; } + j = Math.min(i + 1 + random.nextInt(runLength - 1), j); + + if (set) + { + canon.set(i, j); + test.setRange(i, j); + } + else + { + canon.clear(i, j); + while (i < j) + test.unset(i++); + } + } + else + { + int i = random.nextInt(size); + if (set) + { + assertEquals(!canon.get(i), test.set(i)); + canon.set(i); + } + else + { + assertEquals(canon.get(i), test.unset(i)); + canon.clear(i); + } + } + assertEquals(canon.cardinality(), test.setBitCount()); + } + } + return new Check(test, canon, size); + } + } + + @Test + public void testRandomBitSets() + { + Random random = new Random(); + long seed = random.nextLong(); + System.err.println("Seed: " + seed); + random.setSeed(seed); + testRandomBitSets(random, 100000); Review Comment: > I strongly feel duplication is a waste and a drag on the code What duplication are we discussing here? Because most of this is micro boiler plate. I am relatively neutral on avoiding modest amounts of boilerplate. Everything comes with a cost, including de-duplication, so unless it is a significant saving of duplication I don't see _significant_ value. > this is what qt does... Could you show me how? Because I do not see it doing this. It very much looks to me like you ask it for uniformly generated values. Now, you _can_ layer your own distributions on top of this, as you can with any source of randomness and Turing complete language. But I do not see any facilities provided by the QT style, and today it would make your declarations much more complex and harder to read, to the point where the API would probably be counter-productive IMO. > This 100% depends on the author; you can write very narrow tests, or very complex ones... I do not see what in the API makes this harder than hand rolling? APIs encourage and discourage certain behaviours. Declarative interfaces like the `qt` one are a bit like streams - they make it feel very easy to write certain kinds of simple things, but other things become much harder - particularly in comparison. So it discourages things that are too complex to express in this declarative way. Of course, you _can_ do it, but it is no longer very nice to read. Since the simpler tests are pleasing to look at, and more easily arrived at with the API, this tends to be what gets produced. In particular, past a certain point you have to switch back to imperative programming, and I personally find layering complex imperative work _inside_ declarative frameworks makes code much harder to understand. > for this ticket you can solve this problem by throws I have for now already adopted your use of `qt()`. Although I would perhaps prefer to have a separate `Fuzzing.run(count, LongConsumer)` that is separate from the `qt()` tooling. -- This is an automated message from the Apache Git Service. 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