From 52ced669dd4d3efa1fe0af8d5a1eb871cab27861 Mon Sep 17 00:00:00 2001
From: Zlatin Balevsky <zlatinb@gmail.com>
Date: Mon, 17 Jun 2019 16:36:12 +0100
Subject: [PATCH] basic watching of directories

---
 .../main/groovy/com/muwire/core/Core.groovy   |  7 ++
 .../muwire/core/files/DirectoryWatcher.groovy | 65 +++++++++++++++++++
 .../muwire/core/files/HasherService.groovy    |  2 +-
 3 files changed, 73 insertions(+), 1 deletion(-)

diff --git a/core/src/main/groovy/com/muwire/core/Core.groovy b/core/src/main/groovy/com/muwire/core/Core.groovy
index e77548c5..4dd272a5 100644
--- a/core/src/main/groovy/com/muwire/core/Core.groovy
+++ b/core/src/main/groovy/com/muwire/core/Core.groovy
@@ -23,6 +23,7 @@ import com.muwire.core.files.FileSharedEvent
 import com.muwire.core.files.FileUnsharedEvent
 import com.muwire.core.files.HasherService
 import com.muwire.core.files.PersisterService
+import com.muwire.core.files.DirectoryWatcher
 import com.muwire.core.hostcache.CacheClient
 import com.muwire.core.hostcache.HostCache
 import com.muwire.core.hostcache.HostDiscoveredEvent
@@ -70,6 +71,7 @@ public class Core {
     private final ConnectionEstablisher connectionEstablisher
     private final HasherService hasherService
     private final DownloadManager downloadManager
+    private final DirectoryWatcher directoryWatcher
         
     public Core(MuWireSettings props, File home, String myVersion) {
         this.home = home		
@@ -213,6 +215,9 @@ public class Core {
 		connectionAcceptor = new ConnectionAcceptor(eventBus, connectionManager, props, 
             i2pAcceptor, hostCache, trustService, searchManager, uploadManager, connectionEstablisher)
 		
+        log.info("initializing directory watcher")
+        directoryWatcher = new DirectoryWatcher(eventBus)
+        eventBus.register(FileSharedEvent.class, directoryWatcher)
         
         log.info("initializing hasher service")
         hasherService = new HasherService(new FileHasher(), eventBus, fileManager)
@@ -221,6 +226,7 @@ public class Core {
     
     public void startServices() {
         hasherService.start()
+        directoryWatcher.start()
         trustService.start()
         trustService.waitForLoad()
         persisterService.start()
@@ -242,6 +248,7 @@ public class Core {
         connectionEstablisher.stop()
         log.info("shutting down connection manager")
         connectionManager.shutdown()
+        directoryWatcher.stop()
     }
 
     static main(args) {
diff --git a/core/src/main/groovy/com/muwire/core/files/DirectoryWatcher.groovy b/core/src/main/groovy/com/muwire/core/files/DirectoryWatcher.groovy
index 1410786a..295e7557 100644
--- a/core/src/main/groovy/com/muwire/core/files/DirectoryWatcher.groovy
+++ b/core/src/main/groovy/com/muwire/core/files/DirectoryWatcher.groovy
@@ -1,4 +1,69 @@
 package com.muwire.core.files
 
+import java.nio.file.FileSystem
+import java.nio.file.FileSystems
+import java.nio.file.Path
+import java.nio.file.Paths
+import java.nio.file.StandardWatchEventKinds
+import java.nio.file.WatchEvent
+import java.nio.file.WatchKey
+import java.nio.file.WatchService
+
+import com.muwire.core.EventBus
+
+import groovy.util.logging.Log
+
+@Log
 class DirectoryWatcher {
+    
+    private final EventBus eventBus
+    private final Thread watcherThread
+    private WatchService watchService
+    
+    DirectoryWatcher(EventBus eventBus) {
+        this.eventBus = eventBus
+        this.watcherThread = new Thread({watch() } as Runnable, "directory-watcher")
+    }
+    
+    void start() {
+        watchService = FileSystems.getDefault().newWatchService()
+        watcherThread.start()
+    }
+    
+    void stop() {
+        watcherThread.interrupt()
+        watchService.close()
+    }
+    
+    void onFileSharedEvent(FileSharedEvent e) {
+        if (!e.file.isDirectory())
+            return
+        Path path = e.file.getCanonicalFile().toPath()
+        path.register(watchService, 
+            StandardWatchEventKinds.ENTRY_MODIFY, 
+            StandardWatchEventKinds.ENTRY_DELETE)
+        
+    }
+    
+    private void watch() {
+        while(true) {
+            WatchKey key = watchService.take()
+            key.pollEvents().each {
+                if (it.kind() == StandardWatchEventKinds.ENTRY_MODIFY)
+                    processModified(key.watchable(), it.context()) 
+            }
+            key.reset()
+        }
+    }
+    
+    
+    private void processModified(Path parent, Path path) {
+        File f = join(parent, path)
+        eventBus.publish(new FileSharedEvent(file : f))
+    }
+    
+    private static File join(Path parent, Path path) {
+        File parentFile = parent.toFile().getCanonicalFile()
+        new File(parentFile, path.toFile().getName())
+    }
 }
diff --git a/core/src/main/groovy/com/muwire/core/files/HasherService.groovy b/core/src/main/groovy/com/muwire/core/files/HasherService.groovy
index 9607b1ea..b3701a30 100644
--- a/core/src/main/groovy/com/muwire/core/files/HasherService.groovy
+++ b/core/src/main/groovy/com/muwire/core/files/HasherService.groovy
@@ -32,7 +32,7 @@ class HasherService {
 	private void process(File f) {
 		f = f.getCanonicalFile()
 		if (f.isDirectory()) {
-			f.listFiles().each {onFileSharedEvent new FileSharedEvent(file: it) }
+			f.listFiles().each {eventBus.publish new FileSharedEvent(file: it) }
 		} else {
 			if (f.length() == 0) {
 				eventBus.publish new FileHashedEvent(error: "Not sharing empty file $f")