anotherim/src/main/java/eu/siacs/conversations/utils/ConversationsFileObserver.java
2021-01-23 09:25:34 +01:00

139 lines
4.3 KiB
Java

package eu.siacs.conversations.utils;
import android.os.FileObserver;
import android.util.Log;
import java.io.File;
import java.util.ArrayList;
import java.util.List;
import java.util.Stack;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicBoolean;
import eu.siacs.conversations.Config;
/**
* Copyright (C) 2012 Bartek Przybylski
* Copyright (C) 2015 ownCloud Inc.
* Copyright (C) 2016 Daniel Gultsch
*/
public abstract class ConversationsFileObserver {
private static final Executor EVENT_EXECUTOR = Executors.newSingleThreadExecutor();
private static final int MASK = FileObserver.DELETE | FileObserver.MOVED_FROM | FileObserver.CREATE;
private final String path;
private final List<SingleFileObserver> mObservers = new ArrayList<>();
private final AtomicBoolean shouldStop = new AtomicBoolean(true);
protected ConversationsFileObserver(String path) {
this.path = path;
}
public void startWatching() {
shouldStop.set(false);
startWatchingInternal();
}
private synchronized void startWatchingInternal() {
final Stack<String> stack = new Stack<>();
stack.push(path);
while (!stack.empty()) {
if (shouldStop.get()) {
Log.d(Config.LOGTAG, "file observer received command to stop");
return;
}
final String parent = stack.pop();
final File path = new File(parent);
mObservers.add(new SingleFileObserver(path, MASK));
final File[] files = path.listFiles();
for (final File file : (files == null ? new File[0] : files)) {
if (shouldStop.get()) {
Log.d(Config.LOGTAG, "file observer received command to stop");
return;
}
if (file.isDirectory() && file.getName().charAt(0) != '.') {
final String currentPath = file.getAbsolutePath();
if (depth(file) <= 8 && !stack.contains(currentPath) && !observing(file)) {
stack.push(currentPath);
}
}
}
}
for (FileObserver observer : mObservers) {
observer.startWatching();
}
}
private static int depth(File file) {
int depth = 0;
while ((file = file.getParentFile()) != null) {
depth++;
}
return depth;
}
private boolean observing(final File path) {
for (final SingleFileObserver observer : mObservers) {
if (path.equals(observer.path)) {
return true;
}
}
return false;
}
public void stopWatching() {
shouldStop.set(true);
stopWatchingInternal();
}
private synchronized void stopWatchingInternal() {
for (FileObserver observer : mObservers) {
observer.stopWatching();
}
mObservers.clear();
}
abstract public void onEvent(final int event, File path);
public void restartWatching() {
stopWatching();
startWatching();
}
private class SingleFileObserver extends FileObserver {
private final File path;
SingleFileObserver(final File path, final int mask) {
super(path.getAbsolutePath(), mask);
this.path = path;
}
@Override
public void onEvent(final int event, final String filename) {
if (filename == null) {
Log.d(Config.LOGTAG, "ignored file event with NULL filename (event=" + event + ")");
return;
}
EVENT_EXECUTOR.execute(() -> {
final File file = new File(this.path, filename);
if ((event & FileObserver.ALL_EVENTS) == FileObserver.CREATE) {
if (file.isDirectory()) {
Log.d(Config.LOGTAG, "file observer observed new directory creation " + file);
if (!observing(file)) {
final SingleFileObserver observer = new SingleFileObserver(file, MASK);
observer.startWatching();
}
}
return;
}
ConversationsFileObserver.this.onEvent(event, file);
});
}
}
}