/*
* Copyright (C) 2011 The Android Open Source Project
*
* 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 tests.io;
import android.system.ErrnoException;
import android.system.OsConstants;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.ArrayDeque;
import java.util.Deque;
import java.util.HashMap;
import java.util.Map;
import libcore.io.Libcore;
import libcore.io.Os;
/**
* A mocking interceptor that wraps another {@link Os} to add faults. This can
* be useful to test otherwise hard-to-test scenarios such as a full disk.
*/
public final class MockOs {
private final InheritableThreadLocal<Map<String, Deque<InvocationHandler>>> handlers
= new InheritableThreadLocal<Map<String, Deque<InvocationHandler>>>() {
@Override protected Map<String, Deque<InvocationHandler>> initialValue() {
return new HashMap<String, Deque<InvocationHandler>>();
}
};
private Os delegate;
private final InvocationHandler delegateHandler = new InvocationHandler() {
@Override public Object invoke(Object o, Method method, Object[] args) throws Throwable {
try {
return method.invoke(delegate, args);
} catch (InvocationTargetException e) {
throw e.getCause();
}
}
};
private final InvocationHandler invocationHandler = new InvocationHandler() {
@Override public Object invoke(Object proxy, Method method, Object[] args)
throws Throwable {
InvocationHandler handler = getHandlers(method.getName()).poll();
if (handler == null) {
handler = delegateHandler;
}
return handler.invoke(proxy, method, args);
}
};
private final Os mockOs = (Os) Proxy.newProxyInstance(MockOs.class.getClassLoader(),
new Class[] { Os.class }, invocationHandler);
public void install() {
if (delegate != null) {
throw new IllegalStateException("MockOs already installed!");
}
delegate = Libcore.os;
Libcore.os = mockOs;
}
public void uninstall() {
if (delegate == null) {
throw new IllegalStateException("MockOs not installed!");
}
Libcore.os = delegate;
}
/**
* Returns the invocation handlers to handle upcoming invocations of
* {@code methodName}. If empty, calls will be handled by the delegate.
*/
public Deque<InvocationHandler> getHandlers(String methodName) {
Map<String, Deque<InvocationHandler>> threadFaults = handlers.get();
Deque<InvocationHandler> result = threadFaults.get(methodName);
if (result == null) {
result = new ArrayDeque<InvocationHandler>();
threadFaults.put(methodName, result);
}
return result;
}
/**
* Enqueues the specified number of normal operations. Useful to delay
* faults.
*/
public void enqueueNormal(String methodName, int count) {
Deque<InvocationHandler> handlers = getHandlers(methodName);
for (int i = 0; i < count; i++) {
handlers.add(delegateHandler);
}
}
public void enqueueFault(String methodName) {
enqueueFault(methodName, OsConstants.EIO);
}
public void enqueueFault(String methodName, final int errno) {
getHandlers(methodName).add(new InvocationHandler() {
@Override public Object invoke(Object proxy, Method method, Object[] args) throws ErrnoException {
throw new ErrnoException(method.getName(), errno);
}
});
}
}