/*
* Copyright (c) 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017 David Berkman
*
* This file is part of the SmallMind Code Project.
*
* The SmallMind Code Project is free software, you can redistribute
* it and/or modify it under either, at your discretion...
*
* 1) The terms of GNU Affero General Public License as published by the
* Free Software Foundation, either version 3 of the License, or (at
* your option) any later version.
*
* ...or...
*
* 2) The terms of the Apache License, Version 2.0.
*
* The SmallMind Code Project is distributed in the hope that it will
* be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License or Apache License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* and the Apache License along with the SmallMind Code Project. If not, see
* <http://www.gnu.org/licenses/> or <http://www.apache.org/licenses/LICENSE-2.0>.
*
* Additional permission under the GNU Affero GPL version 3 section 7
* ------------------------------------------------------------------
* If you modify this Program, or any covered work, by linking or
* combining it with other code, such other code is not for that reason
* alone subject to any of the requirements of the GNU Affero GPL
* version 3.
*/
package org.smallmind.nutsnbolts.context;
import java.lang.reflect.Array;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.Map;
public class ContextFactory {
private static final InheritableThreadLocal<Map<Class<? extends Context>, ContextStack>> CONTEXT_MAP_LOCAL = new InheritableThreadLocal<Map<Class<? extends Context>, ContextStack>>() {
@Override
protected Map<Class<? extends Context>, ContextStack> initialValue () {
return new HashMap<>();
}
@Override
protected Map<Class<? extends Context>, ContextStack> childValue (Map<Class<? extends Context>, ContextStack> parentValue) {
return new HashMap<>(parentValue);
}
};
public static <C extends Context> void importContextTrace (Class<C> contextClass, Context... contexts) {
ContextStack<C> contextStack;
if ((contexts != null) && (contexts.length > 0)) {
if ((contextStack = CONTEXT_MAP_LOCAL.get().get(contextClass)) == null) {
CONTEXT_MAP_LOCAL.get().put(contextClass, contextStack = new ContextStack<C>());
}
for (Context context : contexts) {
contextStack.push(contextClass.cast(context));
}
}
}
public static <C extends Context> C[] exportContextTrace (Class<C> contextClass) {
C[] contexts;
C context;
LinkedList<C> contextList;
ContextStack<C> contextStack;
contextList = new LinkedList<>();
if ((contextStack = CONTEXT_MAP_LOCAL.get().get(contextClass)) != null) {
while ((context = contextStack.pop()) != null) {
contextList.addFirst(context);
}
}
contexts = (C[])Array.newInstance(contextClass, contextList.size());
contextList.toArray(contexts);
return contexts;
}
public static <C extends Context> void clearContextTrace (Class<C> contextClass) {
C context;
ContextStack<C> contextStack;
if ((contextStack = CONTEXT_MAP_LOCAL.get().get(contextClass)) != null) {
do {
context = contextStack.pop();
} while (context != null);
}
}
public static <C extends Context> boolean exists (Class<C> contextClass) {
ContextStack<C> contextStack;
return ((contextStack = CONTEXT_MAP_LOCAL.get().get(contextClass)) != null) && (!contextStack.isEmpty());
}
public static <C extends Context> C getContext (Class<C> contextClass)
throws ContextException {
ContextStack<C> contextStack;
C context;
if (((contextStack = CONTEXT_MAP_LOCAL.get().get(contextClass)) == null) || ((context = contextStack.peek()) == null)) {
return null;
}
return context;
}
public static Context[] getContextsOn (Method method) {
return getContextsOn(method, Context.class);
}
public static Context[] getContextsOn (Method method, Class<? extends Context>... baseContextClasses)
throws ContextException {
Context[] contexts;
ExpectedContexts expectedContexts;
HashSet<Class<? extends Context>> requiredClasses = new HashSet<>();
LinkedList<Context> contextList = new LinkedList<>();
if ((expectedContexts = method.getAnnotation(ExpectedContexts.class)) != null) {
requiredClasses.addAll(Arrays.asList(expectedContexts.value()));
}
for (Map.Entry<Class<? extends Context>, ContextStack> contextEntry : CONTEXT_MAP_LOCAL.get().entrySet()) {
Context context;
for (Class<? extends Context> baseContextClass : baseContextClasses) {
if (baseContextClass.isAssignableFrom(contextEntry.getKey())) {
if ((context = contextEntry.getValue().peek()) != null) {
requiredClasses.remove(contextEntry.getKey());
contextList.add(context);
}
break;
}
}
}
if (!requiredClasses.isEmpty()) {
throw new ContextException("Context(%s) has not been instantiated", requiredClasses.iterator().next());
}
contexts = new Context[contextList.size()];
contextList.toArray(contexts);
return contexts;
}
public static <C extends Context> void pushContext (C context) {
ContextStack<C> contextStack;
if ((contextStack = CONTEXT_MAP_LOCAL.get().get(context.getClass())) == null) {
CONTEXT_MAP_LOCAL.get().put(context.getClass(), contextStack = new ContextStack<>());
}
contextStack.push(context);
}
public static Context popContext (Context context) {
return popContext(context.getClass());
}
public static <C extends Context> C popContext (Class<C> contextClass) {
ContextStack<C> contextStack;
if ((contextStack = CONTEXT_MAP_LOCAL.get().get(contextClass)) != null) {
return contextStack.pop();
}
return null;
}
}