Update FileObserver to be able to watch multiple files. (f7c79b4f) · Commits · e / os / android_frameworks_base

api/current.txt

+6 −2

Original line number	Diff line number	Diff line
		@@ -34405,8 +34405,12 @@ 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();

core/java/android/os/FileObserver.java

+83 −24

Original line number	Diff line number	Diff line
		@@ -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);

		Integer i = new Integer(wfd);
		if (wfd >= 0) {
		startWatching(m_fd, paths, mask, wfds);

		final WeakReference<FileObserver> fileObserverWeakReference =
		new WeakReference<>(observer);
		synchronized (m_observers) {
		m_observers.put(i, new WeakReference(observer));
		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;
		}
		}

core/jni/android_util_FileObserver.cpp

+27 −11

Original line number	Diff line number	Diff line
		@@ -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 }

		};