fabric-loom/src/main/java/net/fabricmc/loom/util/StaticPathWatcher.java

90 lines
2.8 KiB
Java

/*
* This file is part of fabric-loom, licensed under the MIT License (MIT).
*
* Copyright (c) 2016-2021 FabricMC
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package net.fabricmc.loom.util;
import java.io.IOException;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.StandardWatchEventKinds;
import java.nio.file.WatchEvent;
import java.nio.file.WatchKey;
import java.nio.file.WatchService;
import java.util.HashMap;
import java.util.Map;
public final class StaticPathWatcher {
public static final StaticPathWatcher INSTANCE = new StaticPathWatcher();
private final Map<Path, Boolean> changeCache = new HashMap<>();
private final WatchService service;
private final Map<Path, WatchKey> pathsObserved = new HashMap<>();
private StaticPathWatcher() {
try {
service = FileSystems.getDefault().newWatchService();
} catch (IOException e) {
throw new RuntimeException(e);
}
}
public boolean hasFileChanged(Path filePath) {
if (!Files.exists(filePath)) {
return true;
}
WatchKey key;
while ((key = service.poll()) != null) {
for (WatchEvent<?> event : key.pollEvents()) {
Object ctx = event.context();
if (ctx instanceof Path path) {
changeCache.put(path.toAbsolutePath(), true);
}
}
}
filePath = filePath.toAbsolutePath();
Path parentPath = filePath.getParent();
if (changeCache.containsKey(filePath)) {
return true;
} else {
if (!pathsObserved.containsKey(parentPath)) {
try {
pathsObserved.put(parentPath, parentPath.register(service, StandardWatchEventKinds.ENTRY_MODIFY, StandardWatchEventKinds.ENTRY_DELETE));
return true;
} catch (IOException e) {
throw new RuntimeException(e);
}
} else {
return false;
}
}
}
}