com.google.inject.spi.ModuleSource Maven / Gradle / Ivy
/*
* Copyright (C) 2013 Google Inc.
*
* 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.google.inject.spi;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;
import com.google.inject.Module;
import com.google.inject.internal.util.StackTraceElements;
import com.google.inject.internal.util.StackTraceElements.InMemoryStackTraceElement;
import java.util.List;
/**
* Associated to a {@link Module module}, provides the module class name, the parent module {@link
* ModuleSource source}, and the call stack that ends just before the module {@link
* Module#configure(Binder) configure(Binder)} method invocation.
*/
final class ModuleSource {
/** The class name of module that this {@link ModuleSource} associated to. */
private final String moduleClassName;
/** The parent {@link ModuleSource module source}. */
private final ModuleSource parent;
/**
* The chunk of call stack that starts from the parent module {@link Module#configure(Binder)
* configure(Binder)} call and ends just before the module {@link Module#configure(Binder)
* configure(Binder)} method invocation. For a module without a parent module the chunk starts
* from the bottom of call stack. The array is non-empty if stack trace collection is on.
*/
private final InMemoryStackTraceElement[] partialCallStack;
/**
* Creates a new {@link ModuleSource} with a {@literal null} parent.
*
* @param moduleClass the corresponding module
* @param partialCallStack the chunk of call stack that starts from the parent module {@link
* Module#configure(Binder) configure(Binder)} call and ends just before the module {@link
* Module#configure(Binder) configure(Binder)} method invocation
*/
ModuleSource(Class moduleClass, StackTraceElement[] partialCallStack) {
this(null, moduleClass, partialCallStack);
}
/**
* Creates a new {@link ModuleSource} Object.
*
* @param parent the parent module {@link ModuleSource source}
* @param moduleClass the corresponding module
* @param partialCallStack the chunk of call stack that starts from the parent module {@link
* Module#configure(Binder) configure(Binder)} call and ends just before the module {@link
* Module#configure(Binder) configure(Binder)} method invocation
*/
private ModuleSource(
/* @Nullable */ ModuleSource parent,
Class moduleClass,
StackTraceElement[] partialCallStack) {
Preconditions.checkNotNull(moduleClass, "module cannot be null.");
Preconditions.checkNotNull(partialCallStack, "partialCallStack cannot be null.");
this.parent = parent;
this.moduleClassName = moduleClass.getName();
this.partialCallStack = StackTraceElements.convertToInMemoryStackTraceElement(partialCallStack);
}
/**
* Returns the corresponding module class name.
*
* @see Class#getName()
*/
String getModuleClassName() {
return moduleClassName;
}
/**
* Returns the chunk of call stack that starts from the parent module {@link
* Module#configure(Binder) configure(Binder)} call and ends just before the module {@link
* Module#configure(Binder) configure(Binder)} method invocation. The return array is non-empty
* only if stack trace collection is on.
*/
StackTraceElement[] getPartialCallStack() {
return StackTraceElements.convertToStackTraceElement(partialCallStack);
}
/** Returns the size of partial call stack if stack trace collection is on otherwise zero. */
int getPartialCallStackSize() {
return partialCallStack.length;
}
/**
* Creates and returns a child {@link ModuleSource} corresponding to the {@link Module module}.
*
* @param moduleClass the corresponding module
* @param partialCallStack the chunk of call stack that starts from the parent module {@link
* Module#configure(Binder) configure(Binder)} call and ends just before the module {@link
* Module#configure(Binder) configure(Binder)} method invocation
*/
ModuleSource createChild(Class moduleClass, StackTraceElement[] partialCallStack) {
return new ModuleSource(this, moduleClass, partialCallStack);
}
/** Returns the parent module {@link ModuleSource source}. */
ModuleSource getParent() {
return parent;
}
/**
* Returns the class names of modules in this module source. The first element (index 0) is filled
* by this object {@link #getModuleClassName()}. The second element is filled by the parent's
* {@link #getModuleClassName()} and so on.
*/
List getModuleClassNames() {
ImmutableList.Builder classNames = ImmutableList.builder();
ModuleSource current = this;
while (current != null) {
String className = current.moduleClassName;
classNames.add(className);
current = current.parent;
}
return classNames.build();
}
/**
* Returns the size of {@link ModuleSource ModuleSources} chain (all parents) that ends at this
* object.
*/
int size() {
if (parent == null) {
return 1;
}
return parent.size() + 1;
}
/**
* Returns the size of call stack that ends just before the module {@link Module#configure(Binder)
* configure(Binder)} method invocation (see {@link #getStackTrace()}).
*/
int getStackTraceSize() {
if (parent == null) {
return partialCallStack.length;
}
return parent.getStackTraceSize() + partialCallStack.length;
}
/**
* Returns the full call stack that ends just before the module {@link Module#configure(Binder)
* configure(Binder)} method invocation. The return array is non-empty if stack trace collection
* on.
*/
StackTraceElement[] getStackTrace() {
int stackTraceSize = getStackTraceSize();
StackTraceElement[] callStack = new StackTraceElement[stackTraceSize];
int cursor = 0;
ModuleSource current = this;
while (current != null) {
StackTraceElement[] chunk =
StackTraceElements.convertToStackTraceElement(current.partialCallStack);
int chunkSize = chunk.length;
System.arraycopy(chunk, 0, callStack, cursor, chunkSize);
current = current.parent;
cursor = cursor + chunkSize;
}
return callStack;
}
}