Java tutorial
/* * Copyright 2015 Ben Manes. All Rights Reserved. * * Licensed 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 com.github.benmanes.caffeine.cache; import java.lang.ref.ReferenceQueue; import javax.lang.model.element.Modifier; import com.google.common.base.CaseFormat; import com.squareup.javapoet.ClassName; import com.squareup.javapoet.FieldSpec; import com.squareup.javapoet.ParameterSpec; import com.squareup.javapoet.ParameterizedTypeName; import com.squareup.javapoet.TypeName; import com.squareup.javapoet.TypeVariableName; /** * Shared constants for a code generation specification. * * @author ben.manes@gmail.com (Ben Manes) */ public final class Specifications { public static final String PACKAGE_NAME = Specifications.class.getPackage().getName(); public static final String RETIRED_STRONG_KEY = "RETIRED_STRONG_KEY"; public static final String RETIRED_WEAK_KEY = "RETIRED_WEAK_KEY"; public static final String DEAD_STRONG_KEY = "DEAD_STRONG_KEY"; public static final String DEAD_WEAK_KEY = "DEAD_WEAK_KEY"; public static final TypeVariableName kTypeVar = TypeVariableName.get("K"); public static final TypeVariableName vTypeVar = TypeVariableName.get("V"); public static final TypeName kRefQueueType = ParameterizedTypeName.get(ClassName.get(ReferenceQueue.class), kTypeVar); public static final TypeName vRefQueueType = ParameterizedTypeName.get(ClassName.get(ReferenceQueue.class), vTypeVar); public static final ClassName nodeType = ClassName.get(PACKAGE_NAME, "Node"); public static final TypeName lookupKeyType = ParameterizedTypeName .get(ClassName.get(PACKAGE_NAME + ".References", "LookupKeyReference"), kTypeVar); public static final TypeName referenceKeyType = ParameterizedTypeName .get(ClassName.get(PACKAGE_NAME + ".References", "WeakKeyReference"), kTypeVar); public static final TypeName rawReferenceKeyType = ParameterizedTypeName .get(ClassName.get(PACKAGE_NAME + ".References", "WeakKeyReference"), ClassName.get(Object.class)); public static final ParameterSpec keySpec = ParameterSpec.builder(kTypeVar, "key").build(); public static final ParameterSpec keyRefSpec = ParameterSpec.builder(Object.class, "keyReference").build(); public static final ParameterSpec keyRefQueueSpec = ParameterSpec.builder(kRefQueueType, "keyReferenceQueue") .build(); public static final ParameterSpec valueSpec = ParameterSpec.builder(vTypeVar, "value").build(); public static final ParameterSpec valueRefQueueSpec = ParameterSpec .builder(vRefQueueType, "valueReferenceQueue").build(); public static final ParameterSpec weightSpec = ParameterSpec.builder(int.class, "weight").build(); public static final TypeName NODE = ParameterizedTypeName.get(nodeType, kTypeVar, vTypeVar); public static final TypeName UNSAFE_ACCESS = ClassName.get("com.github.benmanes.caffeine.base", "UnsafeAccess"); public static final TypeName BUILDER = ParameterizedTypeName.get(ClassName.get(PACKAGE_NAME, "Caffeine"), kTypeVar, vTypeVar); public static final ParameterSpec BUILDER_PARAM = ParameterSpec.builder(BUILDER, "builder").build(); public static final TypeName BOUNDED_LOCAL_CACHE = ParameterizedTypeName .get(ClassName.get(PACKAGE_NAME, "BoundedLocalCache"), kTypeVar, vTypeVar); public static final TypeName CACHE_LOADER = ParameterizedTypeName .get(ClassName.get(PACKAGE_NAME, "CacheLoader"), TypeVariableName.get("? super K"), vTypeVar); public static final ParameterSpec CACHE_LOADER_PARAM = ParameterSpec.builder(CACHE_LOADER, "cacheLoader") .build(); public static final TypeName REMOVAL_LISTENER = ParameterizedTypeName .get(ClassName.get(PACKAGE_NAME, "RemovalListener"), kTypeVar, vTypeVar); public static final TypeName STATS_COUNTER = ClassName.get(PACKAGE_NAME + ".stats", "StatsCounter"); public static final TypeName TICKER = ClassName.get(PACKAGE_NAME, "Ticker"); public static final TypeName WEIGHER = ParameterizedTypeName.get(ClassName.get(PACKAGE_NAME, "Weigher"), TypeVariableName.get("? super K"), TypeVariableName.get("? super V")); public static final TypeName ACCESS_ORDER_DEQUE = ParameterizedTypeName .get(ClassName.get(PACKAGE_NAME, "AccessOrderDeque"), NODE); public static final TypeName WRITE_ORDER_DEQUE = ParameterizedTypeName .get(ClassName.get(PACKAGE_NAME, "WriteOrderDeque"), NODE); public static final ClassName WRITE_QUEUE_TYPE = ClassName.get(PACKAGE_NAME, "WriteBuffer"); public static final TypeName WRITE_QUEUE = ParameterizedTypeName.get(WRITE_QUEUE_TYPE, ClassName.get(Runnable.class)); public static final TypeName FREQUENCY_SKETCH = ParameterizedTypeName .get(ClassName.get(PACKAGE_NAME, "FrequencySketch"), kTypeVar); private Specifications() { } /** Returns the offset constant to this variable. */ public static String offsetName(String varName) { return CaseFormat.LOWER_CAMEL.to(CaseFormat.UPPER_UNDERSCORE, varName) + "_OFFSET"; } /** Creates a public static field with an Unsafe address offset. */ public static FieldSpec newFieldOffset(String className, String varName) { String name = offsetName(varName); return FieldSpec.builder(long.class, name, Modifier.PROTECTED, Modifier.STATIC, Modifier.FINAL) .initializer("$T.objectFieldOffset($T.class, $S)", UNSAFE_ACCESS, ClassName.bestGuess(className), varName) .build(); } }