/*
* Copyright (C) 2015 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 com.android.statementservice;
import android.app.Service;
import android.content.Intent;
import android.net.http.HttpResponseCache;
import android.os.Bundle;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.IBinder;
import android.os.Looper;
import android.os.ResultReceiver;
import android.util.Log;
import com.android.statementservice.retriever.AbstractAsset;
import com.android.statementservice.retriever.AbstractAssetMatcher;
import com.android.statementservice.retriever.AbstractStatementRetriever;
import com.android.statementservice.retriever.AbstractStatementRetriever.Result;
import com.android.statementservice.retriever.AssociationServiceException;
import com.android.statementservice.retriever.Relation;
import com.android.statementservice.retriever.Statement;
import org.json.JSONException;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Callable;
/**
* Handles com.android.statementservice.service.CHECK_ALL_ACTION intents.
*/
public final class DirectStatementService extends Service {
private static final String TAG = DirectStatementService.class.getSimpleName();
/**
* Returns true if every asset in {@code SOURCE_ASSET_DESCRIPTORS} is associated with {@code
* EXTRA_TARGET_ASSET_DESCRIPTOR} for {@code EXTRA_RELATION} relation.
*
* <p>Takes parameter {@code EXTRA_RELATION}, {@code SOURCE_ASSET_DESCRIPTORS}, {@code
* EXTRA_TARGET_ASSET_DESCRIPTOR}, and {@code EXTRA_RESULT_RECEIVER}.
*/
public static final String CHECK_ALL_ACTION =
"com.android.statementservice.service.CHECK_ALL_ACTION";
/**
* Parameter for {@link #CHECK_ALL_ACTION}.
*
* <p>A relation string.
*/
public static final String EXTRA_RELATION =
"com.android.statementservice.service.RELATION";
/**
* Parameter for {@link #CHECK_ALL_ACTION}.
*
* <p>An array of asset descriptors in JSON.
*/
public static final String EXTRA_SOURCE_ASSET_DESCRIPTORS =
"com.android.statementservice.service.SOURCE_ASSET_DESCRIPTORS";
/**
* Parameter for {@link #CHECK_ALL_ACTION}.
*
* <p>An asset descriptor in JSON.
*/
public static final String EXTRA_TARGET_ASSET_DESCRIPTOR =
"com.android.statementservice.service.TARGET_ASSET_DESCRIPTOR";
/**
* Parameter for {@link #CHECK_ALL_ACTION}.
*
* <p>A {@code ResultReceiver} instance that will be used to return the result. If the request
* failed, return {@link #RESULT_FAIL} and an empty {@link android.os.Bundle}. Otherwise, return
* {@link #RESULT_SUCCESS} and a {@link android.os.Bundle} with the result stored in {@link
* #IS_ASSOCIATED}.
*/
public static final String EXTRA_RESULT_RECEIVER =
"com.android.statementservice.service.RESULT_RECEIVER";
/**
* A boolean bundle entry that stores the result of {@link #CHECK_ALL_ACTION}.
* This is set only if the service returns with {@code RESULT_SUCCESS}.
* {@code IS_ASSOCIATED} is true if and only if {@code FAILED_SOURCES} is empty.
*/
public static final String IS_ASSOCIATED = "is_associated";
/**
* A String ArrayList bundle entry that stores sources that can't be verified.
*/
public static final String FAILED_SOURCES = "failed_sources";
/**
* Returned by the service if the request is successfully processed. The caller should check
* the {@code IS_ASSOCIATED} field to determine if the association exists or not.
*/
public static final int RESULT_SUCCESS = 0;
/**
* Returned by the service if the request failed. The request will fail if, for example, the
* input is not well formed, or the network is not available.
*/
public static final int RESULT_FAIL = 1;
private static final long HTTP_CACHE_SIZE_IN_BYTES = 1 * 1024 * 1024; // 1 MBytes
private static final String CACHE_FILENAME = "request_cache";
private AbstractStatementRetriever mStatementRetriever;
private Handler mHandler;
private HandlerThread mThread;
private HttpResponseCache mHttpResponseCache;
@Override
public void onCreate() {
mThread = new HandlerThread("DirectStatementService thread",
android.os.Process.THREAD_PRIORITY_BACKGROUND);
mThread.start();
onCreate(AbstractStatementRetriever.createDirectRetriever(this), mThread.getLooper(),
getCacheDir());
}
/**
* Creates a DirectStatementService with the dependencies passed in for easy testing.
*/
public void onCreate(AbstractStatementRetriever statementRetriever, Looper looper,
File cacheDir) {
super.onCreate();
mStatementRetriever = statementRetriever;
mHandler = new Handler(looper);
try {
File httpCacheDir = new File(cacheDir, CACHE_FILENAME);
mHttpResponseCache = HttpResponseCache.install(httpCacheDir, HTTP_CACHE_SIZE_IN_BYTES);
} catch (IOException e) {
Log.i(TAG, "HTTPS response cache installation failed:" + e);
}
}
@Override
public void onDestroy() {
super.onDestroy();
if (mThread != null) {
mThread.quit();
}
try {
if (mHttpResponseCache != null) {
mHttpResponseCache.delete();
}
} catch (IOException e) {
Log.i(TAG, "HTTP(S) response cache deletion failed:" + e);
}
}
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
super.onStartCommand(intent, flags, startId);
if (intent == null) {
Log.e(TAG, "onStartCommand called with null intent");
return START_STICKY;
}
if (intent.getAction().equals(CHECK_ALL_ACTION)) {
Bundle extras = intent.getExtras();
List<String> sources = extras.getStringArrayList(EXTRA_SOURCE_ASSET_DESCRIPTORS);
String target = extras.getString(EXTRA_TARGET_ASSET_DESCRIPTOR);
String relation = extras.getString(EXTRA_RELATION);
ResultReceiver resultReceiver = extras.getParcelable(EXTRA_RESULT_RECEIVER);
if (resultReceiver == null) {
Log.e(TAG, " Intent does not have extra " + EXTRA_RESULT_RECEIVER);
return START_STICKY;
}
if (sources == null) {
Log.e(TAG, " Intent does not have extra " + EXTRA_SOURCE_ASSET_DESCRIPTORS);
resultReceiver.send(RESULT_FAIL, Bundle.EMPTY);
return START_STICKY;
}
if (target == null) {
Log.e(TAG, " Intent does not have extra " + EXTRA_TARGET_ASSET_DESCRIPTOR);
resultReceiver.send(RESULT_FAIL, Bundle.EMPTY);
return START_STICKY;
}
if (relation == null) {
Log.e(TAG, " Intent does not have extra " + EXTRA_RELATION);
resultReceiver.send(RESULT_FAIL, Bundle.EMPTY);
return START_STICKY;
}
mHandler.post(new ExceptionLoggingFutureTask<Void>(
new IsAssociatedCallable(sources, target, relation, resultReceiver), TAG));
} else {
Log.e(TAG, "onStartCommand called with unsupported action: " + intent.getAction());
}
return START_STICKY;
}
private class IsAssociatedCallable implements Callable<Void> {
private List<String> mSources;
private String mTarget;
private String mRelation;
private ResultReceiver mResultReceiver;
public IsAssociatedCallable(List<String> sources, String target, String relation,
ResultReceiver resultReceiver) {
mSources = sources;
mTarget = target;
mRelation = relation;
mResultReceiver = resultReceiver;
}
private boolean verifyOneSource(AbstractAsset source, AbstractAssetMatcher target,
Relation relation) throws AssociationServiceException {
Result statements = mStatementRetriever.retrieveStatements(source);
for (Statement statement : statements.getStatements()) {
if (relation.matches(statement.getRelation())
&& target.matches(statement.getTarget())) {
return true;
}
}
return false;
}
@Override
public Void call() {
Bundle result = new Bundle();
ArrayList<String> failedSources = new ArrayList<String>();
AbstractAssetMatcher target;
Relation relation;
try {
target = AbstractAssetMatcher.createMatcher(mTarget);
relation = Relation.create(mRelation);
} catch (AssociationServiceException | JSONException e) {
Log.e(TAG, "isAssociatedCallable failed with exception", e);
mResultReceiver.send(RESULT_FAIL, Bundle.EMPTY);
return null;
}
boolean allSourcesVerified = true;
for (String sourceString : mSources) {
AbstractAsset source;
try {
source = AbstractAsset.create(sourceString);
} catch (AssociationServiceException e) {
mResultReceiver.send(RESULT_FAIL, Bundle.EMPTY);
return null;
}
try {
if (!verifyOneSource(source, target, relation)) {
failedSources.add(source.toJson());
allSourcesVerified = false;
}
} catch (AssociationServiceException e) {
failedSources.add(source.toJson());
allSourcesVerified = false;
}
}
result.putBoolean(IS_ASSOCIATED, allSourcesVerified);
result.putStringArrayList(FAILED_SOURCES, failedSources);
mResultReceiver.send(RESULT_SUCCESS, result);
return null;
}
}
}