Merge "Update FileObserver to be able to watch multiple files."

3 files changed, 116 insertions, 37 deletions

diff --git a/api/current.txt b/api/current.txt
index 0544b27bb903..361ee74becdd 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -34408,8 +34408,12 @@ package android.os {
   }
 
   public abstract class FileObserver {
-    ctor public FileObserver(String);
-    ctor public FileObserver(String, int);
+    ctor @Deprecated public FileObserver(String);
+    ctor public FileObserver(@NonNull java.io.File);
+    ctor public FileObserver(@NonNull java.util.List<java.io.File>);
+    ctor @Deprecated public FileObserver(String, int);
+    ctor public FileObserver(@NonNull java.io.File, int);
+    ctor public FileObserver(@NonNull java.util.List<java.io.File>, int);
     method protected void finalize();
     method public abstract void onEvent(int, @Nullable String);
     method public void startWatching();
diff --git a/core/java/android/os/FileObserver.java b/core/java/android/os/FileObserver.java
index dd85e1584f0e..da0389578e15 100644
--- a/core/java/android/os/FileObserver.java
+++ b/core/java/android/os/FileObserver.java
@@ -16,11 +16,15 @@
 
 package android.os;
 
+import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.util.Log;
 
+import java.io.File;
 import java.lang.ref.WeakReference;
+import java.util.Arrays;
 import java.util.HashMap;
+import java.util.List;
 
 /**
  * Monitors files (using <a href="http://en.wikipedia.org/wiki/Inotify">inotify</a>)
@@ -28,7 +32,7 @@ import java.util.HashMap;
  * the device (including this one).  FileObserver is an abstract class;
  * subclasses must implement the event handler {@link #onEvent(int, String)}.
  *
- * <p>Each FileObserver instance monitors a single file or directory.
+ * <p>Each FileObserver instance can monitor multiple files or directories.
  * If a directory is monitored, events will be triggered for all files and
  * subdirectories inside the monitored directory.</p>
  *
@@ -86,21 +90,32 @@ public abstract class FileObserver {
             observe(m_fd);
         }
 
-        public int startWatching(String path, int mask, FileObserver observer) {
-            int wfd = startWatching(m_fd, path, mask);
+        public int[] startWatching(List<File> files, int mask, FileObserver observer) {
+            final int count = files.size();
+            final String[] paths = new String[count];
+            for (int i = 0; i < count; ++i) {
+                paths[i] = files.get(i).getAbsolutePath();
+            }
+            final int[] wfds = new int[count];
+            Arrays.fill(wfds, -1);
+
+            startWatching(m_fd, paths, mask, wfds);
 
-            Integer i = new Integer(wfd);
-            if (wfd >= 0) {
-                synchronized (m_observers) {
-                    m_observers.put(i, new WeakReference(observer));
+            final WeakReference<FileObserver> fileObserverWeakReference =
+                    new WeakReference<>(observer);
+            synchronized (m_observers) {
+                for (int wfd : wfds) {
+                    if (wfd >= 0) {
+                        m_observers.put(wfd, fileObserverWeakReference);
+                    }
                 }
             }
 
-            return i;
+            return wfds;
         }
 
-        public void stopWatching(int descriptor) {
-            stopWatching(m_fd, descriptor);
+        public void stopWatching(int[] descriptors) {
+            stopWatching(m_fd, descriptors);
         }
 
         public void onEvent(int wfd, int mask, String path) {
@@ -129,8 +144,8 @@ public abstract class FileObserver {
 
         private native int init();
         private native void observe(int fd);
-        private native int startWatching(int fd, String path, int mask);
-        private native void stopWatching(int fd, int wfd);
+        private native void startWatching(int fd, String[] paths, int mask, int[] wfds);
+        private native void stopWatching(int fd, int[] wfds);
     }
 
     private static ObserverThread s_observerThread;
@@ -141,15 +156,34 @@ public abstract class FileObserver {
     }
 
     // instance
-    private String m_path;
-    private Integer m_descriptor;
-    private int m_mask;
+    private final List<File> mFiles;
+    private int[] mDescriptors;
+    private final int mMask;
 
     /**
      * Equivalent to FileObserver(path, FileObserver.ALL_EVENTS).
+     *
+     * @deprecated use {@link #FileObserver(File)} instead.
      */
+    @Deprecated
     public FileObserver(String path) {
-        this(path, ALL_EVENTS);
+        this(new File(path));
+    }
+
+    /**
+     * Equivalent to FileObserver(file, FileObserver.ALL_EVENTS).
+     */
+    public FileObserver(@NonNull File file) {
+        this(Arrays.asList(file));
+    }
+
+    /**
+     * Equivalent to FileObserver(paths, FileObserver.ALL_EVENTS).
+     *
+     * @param files The files or directories to monitor
+     */
+    public FileObserver(@NonNull List<File> files) {
+        this(files, ALL_EVENTS);
     }
 
     /**
@@ -159,11 +193,36 @@ public abstract class FileObserver {
      *
      * @param path The file or directory to monitor
      * @param mask The event or events (added together) to watch for
+     *
+     * @deprecated use {@link #FileObserver(File, int)} instead.
      */
+    @Deprecated
     public FileObserver(String path, int mask) {
-        m_path = path;
-        m_mask = mask;
-        m_descriptor = -1;
+        this(new File(path), mask);
+    }
+
+    /**
+     * Create a new file observer for a certain file or directory.
+     * Monitoring does not start on creation!  You must call
+     * {@link #startWatching()} before you will receive events.
+     *
+     * @param file The file or directory to monitor
+     * @param mask The event or events (added together) to watch for
+     */
+    public FileObserver(@NonNull File file, int mask) {
+        this(Arrays.asList(file), mask);
+    }
+
+    /**
+     * Version of {@link #FileObserver(File, int)} that allows callers to monitor
+     * multiple files or directories.
+     *
+     * @param files The files or directories to monitor
+     * @param mask The event or events (added together) to watch for
+     */
+    public FileObserver(@NonNull List<File> files, int mask) {
+        mFiles = files;
+        mMask = mask;
     }
 
     protected void finalize() {
@@ -176,8 +235,8 @@ public abstract class FileObserver {
      * If monitoring is already started, this call has no effect.
      */
     public void startWatching() {
-        if (m_descriptor < 0) {
-            m_descriptor = s_observerThread.startWatching(m_path, m_mask, this);
+        if (mDescriptors == null) {
+            mDescriptors = s_observerThread.startWatching(mFiles, mMask, this);
         }
     }
 
@@ -187,9 +246,9 @@ public abstract class FileObserver {
      * monitoring is already stopped, this call has no effect.
      */
     public void stopWatching() {
-        if (m_descriptor >= 0) {
-            s_observerThread.stopWatching(m_descriptor);
-            m_descriptor = -1;
+        if (mDescriptors != null) {
+            s_observerThread.stopWatching(mDescriptors);
+            mDescriptors = null;
         }
     }
 
diff --git a/core/jni/android_util_FileObserver.cpp b/core/jni/android_util_FileObserver.cpp
index 6f975b23e5bd..d25192a57228 100644
--- a/core/jni/android_util_FileObserver.cpp
+++ b/core/jni/android_util_FileObserver.cpp
@@ -16,6 +16,8 @@
 */
 
 #include <nativehelper/JNIHelp.h>
+#include <nativehelper/ScopedPrimitiveArray.h>
+#include <nativehelper/ScopedUtfChars.h>
 #include "jni.h"
 #include "utils/Log.h"
 #include "utils/misc.h"
@@ -98,31 +100,45 @@ static void android_os_fileobserver_observe(JNIEnv* env, jobject object, jint fd
 #endif
 }
 
-static jint android_os_fileobserver_startWatching(JNIEnv* env, jobject object, jint fd, jstring pathString, jint mask)
+static void android_os_fileobserver_startWatching(JNIEnv* env, jobject object, jint fd,
+                                                       jobjectArray pathStrings, jint mask,
+                                                       jintArray wfdArray)
 {
-    int res = -1;
+    ScopedIntArrayRW wfds(env, wfdArray);
+    if (wfds.get() == nullptr) {
+        jniThrowException(env, "java/lang/IllegalStateException", "Failed to get ScopedIntArrayRW");
+    }
 
 #if defined(__linux__)
 
     if (fd >= 0)
     {
-        const char* path = env->GetStringUTFChars(pathString, NULL);
+        size_t count = wfds.size();
+        for (jsize i = 0; i < count; ++i) {
+            jstring pathString = (jstring) env->GetObjectArrayElement(pathStrings, i);
 
-        res = inotify_add_watch(fd, path, mask);
+            ScopedUtfChars path(env, pathString);
 
-        env->ReleaseStringUTFChars(pathString, path);
+            wfds[i] = inotify_add_watch(fd, path.c_str(), mask);
+        }
     }
 
 #endif
-
-    return res;
 }
 
-static void android_os_fileobserver_stopWatching(JNIEnv* env, jobject object, jint fd, jint wfd)
+static void android_os_fileobserver_stopWatching(JNIEnv* env, jobject object,
+                                                 jint fd, jintArray wfdArray)
 {
 #if defined(__linux__)
 
-    inotify_rm_watch((int)fd, (uint32_t)wfd);
+    ScopedIntArrayRO wfds(env, wfdArray);
+    if (wfds.get() == nullptr) {
+        jniThrowException(env, "java/lang/IllegalStateException", "Failed to get ScopedIntArrayRO");
+    }
+    size_t count = wfds.size();
+    for (size_t i = 0; i < count; ++i) {
+        inotify_rm_watch((int)fd, (uint32_t)wfds[i]);
+    }
 
 #endif
 }
@@ -131,8 +147,8 @@ static const JNINativeMethod sMethods[] = {
      /* name, signature, funcPtr */
     { "init", "()I", (void*)android_os_fileobserver_init },
     { "observe", "(I)V", (void*)android_os_fileobserver_observe },
-    { "startWatching", "(ILjava/lang/String;I)I", (void*)android_os_fileobserver_startWatching },
-    { "stopWatching", "(II)V", (void*)android_os_fileobserver_stopWatching }
+    { "startWatching", "(I[Ljava/lang/String;I[I)V", (void*)android_os_fileobserver_startWatching },
+    { "stopWatching", "(I[I)V", (void*)android_os_fileobserver_stopWatching }
 
 };