/*
* Copyright (C) 2021 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 androidx.test.platform.io;
import static androidx.test.internal.util.Checks.checkNotNull;
import androidx.test.annotation.ExperimentalTestApi;
import androidx.test.internal.platform.ServiceLoaderWrapper;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
/**
* An exposed registry instance that holds a reference to an {@code PlatformTestStorage} instance.
*
* <p>{@code PlatformTestStorage} and {@code PlatformTestStorageRegistry} are low level APIs,
* typically used by higher level test frameworks. It is generally not recommended for direct use by
* most tests.
*
* <p>This API is experimental and is subject to change or removal in future releases.
*/
@ExperimentalTestApi
public final class PlatformTestStorageRegistry {
private static PlatformTestStorage testStorageInstance;
static {
// By default, uses the instance loaded by the service loader if available; otherwise, uses a
// default no_op implementation.
testStorageInstance =
ServiceLoaderWrapper.loadSingleService(
PlatformTestStorage.class, NoOpPlatformTestStorage::new);
}
private PlatformTestStorageRegistry() {}
/**
* Registers a new {@code PlatformTestStorage} instance. This will override any previously set
* instance.
*
* @param instance the instance to be registered. Cannot be null.
*/
public static synchronized void registerInstance(PlatformTestStorage instance) {
testStorageInstance = checkNotNull(instance);
}
/**
* Returns the registered {@code PlatformTestStorage} instance.
*
* <p>This method returns the instance last registered by the {@link
* #registerInstance(PlatformTestStorage)} method, or the default instance if none is ever
* registered.
*/
public static synchronized PlatformTestStorage getInstance() {
return testStorageInstance;
}
/** A test storage that does nothing. All the I/O operations in this class are ignored. */
static class NoOpPlatformTestStorage implements PlatformTestStorage {
@Override
public InputStream openInputFile(String pathname) {
return new NullInputStream();
}
@Override
public String getInputArg(String argName) {
return null;
}
@Override
public Map<String, String> getInputArgs() {
return new HashMap<>();
}
@Override
public OutputStream openOutputFile(String pathname) {
return new NullOutputStream();
}
@Override
public OutputStream openOutputFile(String pathname, boolean append) {
return new NullOutputStream();
}
@Override
public void addOutputProperties(Map<String, Serializable> properties) {}
@Override
public Map<String, Serializable> getOutputProperties() {
return new HashMap<>();
}
@Override
public InputStream openInternalInputFile(String pathname) throws IOException {
return new NullInputStream();
}
@Override
public OutputStream openInternalOutputFile(String pathname) throws IOException {
return new NullOutputStream();
}
static class NullInputStream extends InputStream {
@Override
public int read() {
return -1;
}
}
static class NullOutputStream extends OutputStream {
@Override
public void write(int b) {}
}
}
}