AMashenkov commented on a change in pull request #64: URL: https://github.com/apache/ignite-3/pull/64#discussion_r592417345
########## File path: modules/metastorage-common/src/main/java/org/apache/ignite/metastorage/common/Condition.java ########## @@ -0,0 +1,357 @@ +/* + * 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.ignite.metastorage.common; + +import java.util.Arrays; + +/** + * Represents a condition for conditional update. + */ +public final class Condition { + /** Actual condition implementation. */ + private final InnerCondition cond; + + /** + * Constructs a condition which wraps the actual condition implementation. + * + * @param cond The actual condition implementation. + */ + Condition(InnerCondition cond) { + this.cond = cond; + } + + /** + * Tests the given entry on satisfaction of the condition. + * + * @param e Entry. + * @return The result of condition test. {@code true} - if the entry satisfies to the condition, + * otherwise - {@code false}. + */ + public boolean test(Entry e) { + return cond.test(e); + } + + /** + * Represents condition on entry revision. Only one type of condition could be applied to + * the one instance of condition. Subsequent invocations of any method which produces condition will throw + * {@link IllegalStateException}. + */ + public static final class RevisionCondition implements InnerCondition { + /** + * The type of condition. + * + * @see Type + */ + private Type type; + + /** + * The revision as the condition argument. + */ + private long rev; + + /** + * Default no-op constructor. + */ + RevisionCondition() { + // No-op. + } + + // TODO: eq, ne, lt, le, gt, ge + /** + * Produces the condition of type {@link Type#EQUAL}. This condition tests the given revision on equality with + * target entry revision. + * + * @param rev The revision. + * @return The condition of type {@link Type#EQUAL}. + * @throws IllegalStateException In case when the condition is already defined. + */ + public Condition eq(long rev) { + validate(type); + + this.type = Type.EQUAL; + this.rev = rev; + + return new Condition(this); + } + + /** + * Produces the condition of type {@link Type#NOT_EQUAL}. This condition tests the given revision on inequality + * with target entry revision. + * + * @param rev The revision. + * @return The condition of type {@link Type#NOT_EQUAL}. + * @throws IllegalStateException In case when the condition is already defined. + */ + public Condition ne(long rev) { + validate(type); + + this.type = Type.NOT_EQUAL; + this.rev = rev; + + return new Condition(this); + } + + /** + * Produces the condition of type {@link Type#GREATER}. This condition tests that the target entry revision + * is greater than given revision. + * + * @param rev The revision. + * @return The condition of type {@link Type#GREATER}. + * @throws IllegalStateException In case when the condition is already defined. + */ + public Condition gt(long rev) { + validate(type); + + this.type = Type.GREATER; + this.rev = rev; + + return new Condition(this); + } + + /** + * Produces the condition of type {@link Type#GREATER_OR_EQUAL}. This condition tests that the target entry + * revision is greater than or equal to given revision. + * + * @param rev The revision. + * @return The condition of type {@link Type#GREATER_OR_EQUAL}. + * @throws IllegalStateException In case when the condition is already defined. + */ + public Condition ge(long rev) { + validate(type); + + this.type = Type.GREATER_OR_EQUAL; + this.rev = rev; + + return new Condition(this); + } + + /** + * Produces the condition of type {@link Type#LESS}. This condition tests that target entry revision + * is less than the given revision. + * + * @param rev The revision. + * @return The condition of type {@link Type#LESS}. + * @throws IllegalStateException In case when the condition is already defined. + */ + public Condition lt(long rev) { + validate(type); + + this.type = Type.LESS; + this.rev = rev; + + return new Condition(this); + } + + /** + * Produces the condition of type {@link Type#LESS_OR_EQUAL}. This condition tests that target entry revision + * is less than or equal to the given revision. + * + * @param rev The revision. + * @return The condition of type {@link Type#LESS_OR_EQUAL}. + * @throws IllegalStateException In case when the condition is already defined. + */ + public Condition le(long rev) { + validate(type); + + this.type = Type.LESS_OR_EQUAL; + this.rev = rev; + + return new Condition(this); + } + + /** {@inheritDoc} */ + @Override public boolean test(Entry e) { + int res = Long.compare(e.revision(), rev); + + return type.test(res); + } + + /** + * Defines possible condition types which can be applied to the revision. + */ + enum Type { + /** Equality condition type. */ + EQUAL { + @Override public boolean test(long res) { + return res == 0; + } + }, + + /** Inequality condition type. */ + NOT_EQUAL { + @Override public boolean test(long res) { + return res != 0; + } + }, + + /** Greater than condition type. */ + GREATER { + @Override public boolean test(long res) { + return res > 0; + } + }, + + /** Less than condition type. */ + LESS { + @Override public boolean test(long res) { + return res < 0; + } + }, + + /** Less than or equal to condition type. */ + LESS_OR_EQUAL { + @Override public boolean test(long res) { + return res <= 0; + } + }, + + /** Greater than or equal to condition type. */ + GREATER_OR_EQUAL { + @Override public boolean test(long res) { + return res >= 0; + } + }; + + /** + * Interprets comparison result. + * + * @param res The result of comparison. + * @return The interpretation of the comparison result. + */ + public abstract boolean test(long res); + } + } + + /** + * Represents condition on entry value. Only one type of condition could be applied to + * the one instance of condition. Subsequent invocations of any method which produces condition will throw + * {@link IllegalStateException}. + */ + public static final class ValueCondition implements InnerCondition { + /** + * The type of condition. + * + * @see Type + */ + private Type type; + + /** + * The value as the condition argument. + */ + private byte[] val; + + /** + * Default no-op constructor. + */ + ValueCondition() { + // No-op. + } + + /** + * Produces the condition of type {@link Type#EQUAL}. This condition tests the given value on equality with + * target entry value. + * + * @param val The value. + * @return The condition of type {@link Type#EQUAL}. + * @throws IllegalStateException In case when the condition is already defined. + */ + public Condition eq(byte[] val) { + validate(type); + + this.type = Type.EQUAL; + this.val = val; + + return new Condition(this); + } + + /** + * Produces the condition of type {@link Type#NOT_EQUAL}. This condition tests the given мфдгу on inequality + * with target entry мфдгу. Review comment: ```suggestion * Produces the condition of type {@link Type#NOT_EQUAL}. This condition tests the given value on inequality * with target entry value. ``` ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
