/*
* Copyright (C) 2013 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.documentsui;
import static com.android.documentsui.DocumentsActivity.TAG;
import static com.android.documentsui.DocumentsActivity.State.SORT_ORDER_LAST_MODIFIED;
import android.app.ActivityManager;
import android.content.AsyncTaskLoader;
import android.content.ContentProviderClient;
import android.content.Context;
import android.database.Cursor;
import android.database.MatrixCursor;
import android.database.MergeCursor;
import android.net.Uri;
import android.os.Bundle;
import android.provider.DocumentsContract;
import android.provider.DocumentsContract.Document;
import android.provider.DocumentsContract.Root;
import android.text.format.DateUtils;
import android.util.Log;
import com.android.documentsui.DocumentsActivity.State;
import com.android.documentsui.model.RootInfo;
import com.google.android.collect.Maps;
import com.google.common.collect.Lists;
import com.google.common.util.concurrent.AbstractFuture;
import libcore.io.IoUtils;
import java.io.Closeable;
import java.io.IOException;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;
public class RecentLoader extends AsyncTaskLoader<DirectoryResult> {
private static final boolean LOGD = true;
// TODO: clean up cursor ownership so background thread doesn't traverse
// previously returned cursors for filtering/sorting; this currently races
// with the UI thread.
private static final int MAX_OUTSTANDING_RECENTS = 4;
private static final int MAX_OUTSTANDING_RECENTS_SVELTE = 2;
/**
* Time to wait for first pass to complete before returning partial results.
*/
private static final int MAX_FIRST_PASS_WAIT_MILLIS = 500;
/** Maximum documents from a single root. */
private static final int MAX_DOCS_FROM_ROOT = 64;
/** Ignore documents older than this age. */
private static final long REJECT_OLDER_THAN = 45 * DateUtils.DAY_IN_MILLIS;
/** MIME types that should always be excluded from recents. */
private static final String[] RECENT_REJECT_MIMES = new String[] { Document.MIME_TYPE_DIR };
private final Semaphore mQueryPermits;
private final RootsCache mRoots;
private final State mState;
private final HashMap<RootInfo, RecentTask> mTasks = Maps.newHashMap();
private final int mSortOrder = State.SORT_ORDER_LAST_MODIFIED;
private CountDownLatch mFirstPassLatch;
private volatile boolean mFirstPassDone;
private DirectoryResult mResult;
// TODO: create better transfer of ownership around cursor to ensure its
// closed in all edge cases.
public class RecentTask extends AbstractFuture<Cursor> implements Runnable, Closeable {
public final String authority;
public final String rootId;
private Cursor mWithRoot;
public RecentTask(String authority, String rootId) {
this.authority = authority;
this.rootId = rootId;
}
@Override
public void run() {
if (isCancelled()) return;
try {
mQueryPermits.acquire();
} catch (InterruptedException e) {
return;
}
try {
runInternal();
} finally {
mQueryPermits.release();
}
}
public void runInternal() {
ContentProviderClient client = null;
try {
client = DocumentsApplication.acquireUnstableProviderOrThrow(
getContext().getContentResolver(), authority);
final Uri uri = DocumentsContract.buildRecentDocumentsUri(authority, rootId);
final Cursor cursor = client.query(
uri, null, null, null, DirectoryLoader.getQuerySortOrder(mSortOrder));
mWithRoot = new RootCursorWrapper(authority, rootId, cursor, MAX_DOCS_FROM_ROOT);
} catch (Exception e) {
Log.w(TAG, "Failed to load " + authority + ", " + rootId, e);
} finally {
ContentProviderClient.releaseQuietly(client);
}
set(mWithRoot);
mFirstPassLatch.countDown();
if (mFirstPassDone) {
onContentChanged();
}
}
@Override
public void close() throws IOException {
IoUtils.closeQuietly(mWithRoot);
}
}
public RecentLoader(Context context, RootsCache roots, State state) {
super(context);
mRoots = roots;
mState = state;
// Keep clients around on high-RAM devices, since we'd be spinning them
// up moments later to fetch thumbnails anyway.
final ActivityManager am = (ActivityManager) getContext().getSystemService(
Context.ACTIVITY_SERVICE);
mQueryPermits = new Semaphore(
am.isLowRamDevice() ? MAX_OUTSTANDING_RECENTS_SVELTE : MAX_OUTSTANDING_RECENTS);
}
@Override
public DirectoryResult loadInBackground() {
if (mFirstPassLatch == null) {
// First time through we kick off all the recent tasks, and wait
// around to see if everyone finishes quickly.
final Collection<RootInfo> roots = mRoots.getMatchingRootsBlocking(mState);
for (RootInfo root : roots) {
if ((root.flags & Root.FLAG_SUPPORTS_RECENTS) != 0) {
final RecentTask task = new RecentTask(root.authority, root.rootId);
mTasks.put(root, task);
}
}
mFirstPassLatch = new CountDownLatch(mTasks.size());
for (RecentTask task : mTasks.values()) {
ProviderExecutor.forAuthority(task.authority).execute(task);
}
try {
mFirstPassLatch.await(MAX_FIRST_PASS_WAIT_MILLIS, TimeUnit.MILLISECONDS);
mFirstPassDone = true;
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
}
final long rejectBefore = System.currentTimeMillis() - REJECT_OLDER_THAN;
// Collect all finished tasks
boolean allDone = true;
List<Cursor> cursors = Lists.newArrayList();
for (RecentTask task : mTasks.values()) {
if (task.isDone()) {
try {
final Cursor cursor = task.get();
if (cursor == null) continue;
final FilteringCursorWrapper filtered = new FilteringCursorWrapper(
cursor, mState.acceptMimes, RECENT_REJECT_MIMES, rejectBefore) {
@Override
public void close() {
// Ignored, since we manage cursor lifecycle internally
}
};
cursors.add(filtered);
} catch (InterruptedException e) {
throw new RuntimeException(e);
} catch (ExecutionException e) {
// We already logged on other side
}
} else {
allDone = false;
}
}
if (LOGD) {
Log.d(TAG, "Found " + cursors.size() + " of " + mTasks.size() + " recent queries done");
}
final DirectoryResult result = new DirectoryResult();
result.sortOrder = SORT_ORDER_LAST_MODIFIED;
// Hint to UI if we're still loading
final Bundle extras = new Bundle();
if (!allDone) {
extras.putBoolean(DocumentsContract.EXTRA_LOADING, true);
}
final Cursor merged;
if (cursors.size() > 0) {
merged = new MergeCursor(cursors.toArray(new Cursor[cursors.size()]));
} else {
// Return something when nobody is ready
merged = new MatrixCursor(new String[0]);
}
final SortingCursorWrapper sorted = new SortingCursorWrapper(merged, result.sortOrder) {
@Override
public Bundle getExtras() {
return extras;
}
};
result.cursor = sorted;
return result;
}
@Override
public void cancelLoadInBackground() {
super.cancelLoadInBackground();
}
@Override
public void deliverResult(DirectoryResult result) {
if (isReset()) {
IoUtils.closeQuietly(result);
return;
}
DirectoryResult oldResult = mResult;
mResult = result;
if (isStarted()) {
super.deliverResult(result);
}
if (oldResult != null && oldResult != result) {
IoUtils.closeQuietly(oldResult);
}
}
@Override
protected void onStartLoading() {
if (mResult != null) {
deliverResult(mResult);
}
if (takeContentChanged() || mResult == null) {
forceLoad();
}
}
@Override
protected void onStopLoading() {
cancelLoad();
}
@Override
public void onCanceled(DirectoryResult result) {
IoUtils.closeQuietly(result);
}
@Override
protected void onReset() {
super.onReset();
// Ensure the loader is stopped
onStopLoading();
for (RecentTask task : mTasks.values()) {
IoUtils.closeQuietly(task);
}
IoUtils.closeQuietly(mResult);
mResult = null;
}
}
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