1 /** 2 * Copyright (C) 2013 Google Inc. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.google.inject.spi; 18 19 import com.google.common.base.Preconditions; 20 import com.google.common.collect.ImmutableList; 21 import com.google.inject.Module; 22 import com.google.inject.internal.util.StackTraceElements; 23 import com.google.inject.internal.util.StackTraceElements.InMemoryStackTraceElement; 24 25 import java.util.List; 26 27 /** 28 * Associated to a {@link Module module}, provides the module class name, the parent module {@link 29 * ModuleSource source}, and the call stack that ends just before the module {@link 30 * Module#configure(Binder) configure(Binder)} method invocation. 31 */ 32 final class ModuleSource { 33 34 /** 35 * The class name of module that this {@link ModuleSource} associated to. 36 */ 37 private final String moduleClassName; 38 39 /** 40 * The parent {@link ModuleSource module source}. 41 */ 42 private final ModuleSource parent; 43 44 /** 45 * The chunk of call stack that starts from the parent module {@link Module#configure(Binder) 46 * configure(Binder)} call and ends just before the module {@link Module#configure(Binder) 47 * configure(Binder)} method invocation. For a module without a parent module the chunk starts 48 * from the bottom of call stack. The array is non-empty if stack trace collection is on. 49 */ 50 private final InMemoryStackTraceElement[] partialCallStack; 51 52 /** 53 * Creates a new {@link ModuleSource} with a {@literal null} parent. 54 * @param module the corresponding module 55 * @param partialCallStack the chunk of call stack that starts from the parent module {@link 56 * Module#configure(Binder) configure(Binder)} call and ends just before the module {@link 57 * Module#configure(Binder) configure(Binder)} method invocation 58 */ 59 ModuleSource(Object module, StackTraceElement[] partialCallStack) { 60 this(null, module, partialCallStack); 61 } 62 63 /** 64 * Creates a new {@link ModuleSource} Object. 65 * @param parent the parent module {@link ModuleSource source} 66 * @param module the corresponding module 67 * @param partialCallStack the chunk of call stack that starts from the parent module {@link 68 * Module#configure(Binder) configure(Binder)} call and ends just before the module {@link 69 * Module#configure(Binder) configure(Binder)} method invocation 70 */ 71 private ModuleSource( 72 /* @Nullable */ ModuleSource parent, Object module, StackTraceElement[] partialCallStack) { 73 Preconditions.checkNotNull(module, "module cannot be null."); 74 Preconditions.checkNotNull(partialCallStack, "partialCallStack cannot be null."); 75 this.parent = parent; 76 this.moduleClassName = module.getClass().getName(); 77 this.partialCallStack = StackTraceElements.convertToInMemoryStackTraceElement(partialCallStack); 78 } 79 80 /** 81 * Returns the corresponding module class name. 82 * 83 * @see Class#getName() 84 */ 85 String getModuleClassName() { 86 return moduleClassName; 87 } 88 89 /** 90 * Returns the chunk of call stack that starts from the parent module {@link 91 * Module#configure(Binder) configure(Binder)} call and ends just before the module {@link 92 * Module#configure(Binder) configure(Binder)} method invocation. The return array is non-empty 93 * only if stack trace collection is on. 94 */ 95 StackTraceElement[] getPartialCallStack() { 96 return StackTraceElements.convertToStackTraceElement(partialCallStack); 97 } 98 99 /** 100 * Returns the size of partial call stack if stack trace collection is on otherwise zero. 101 */ 102 int getPartialCallStackSize() { 103 return partialCallStack.length; 104 } 105 106 /** 107 * Creates and returns a child {@link ModuleSource} corresponding to the {@link Module module}. 108 * @param module the corresponding module 109 * @param partialCallStack the chunk of call stack that starts from the parent module {@link 110 * Module#configure(Binder) configure(Binder)} call and ends just before the module {@link 111 * Module#configure(Binder) configure(Binder)} method invocation 112 */ 113 ModuleSource createChild(Object module, StackTraceElement[] partialCallStack) { 114 return new ModuleSource(this, module, partialCallStack); 115 } 116 117 /** 118 * Returns the parent module {@link ModuleSource source}. 119 */ 120 ModuleSource getParent() { 121 return parent; 122 } 123 124 /** 125 * Returns the class names of modules in this module source. The first element (index 0) is filled 126 * by this object {@link #getModuleClassName()}. The second element is filled by the parent's 127 * {@link #getModuleClassName()} and so on. 128 */ 129 List<String> getModuleClassNames() { 130 ImmutableList.Builder<String> classNames = ImmutableList.builder(); 131 ModuleSource current = this; 132 while (current != null) { 133 String className = current.moduleClassName; 134 classNames.add(className); 135 current = current.parent; 136 } 137 return classNames.build(); 138 } 139 140 /** 141 * Returns the size of {@link ModuleSource ModuleSources} chain (all parents) that ends at this 142 * object. 143 */ 144 int size() { 145 if (parent == null) { 146 return 1; 147 } 148 return parent.size() + 1; 149 } 150 151 /** 152 * Returns the size of call stack that ends just before the module {@link Module#configure(Binder) 153 * configure(Binder)} method invocation (see {@link #getStackTrace()}). 154 */ 155 int getStackTraceSize() { 156 if (parent == null) { 157 return partialCallStack.length; 158 } 159 return parent.getStackTraceSize() + partialCallStack.length; 160 } 161 162 /** 163 * Returns the full call stack that ends just before the module {@link Module#configure(Binder) 164 * configure(Binder)} method invocation. The return array is non-empty if stack trace collection 165 * on. 166 */ 167 StackTraceElement[] getStackTrace() { 168 int stackTraceSize = getStackTraceSize(); 169 StackTraceElement[] callStack = new StackTraceElement[stackTraceSize]; 170 int cursor = 0; 171 ModuleSource current = this; 172 while (current != null) { 173 StackTraceElement[] chunk = 174 StackTraceElements.convertToStackTraceElement(current.partialCallStack); 175 int chunkSize = chunk.length; 176 System.arraycopy(chunk, 0, callStack, cursor, chunkSize); 177 current = current.parent; 178 cursor = cursor + chunkSize; 179 } 180 return callStack; 181 } 182 } 183
