Move SharedPreferencesImpl out of ContextImpl.java (d3da4403) · Commits · e / os / android_frameworks_base

core/java/android/app/ContextImpl.java

+3 −484

Original line number	Diff line number	Diff line
		@@ -18,7 +18,6 @@ package android.app;

		import com.android.internal.policy.PolicyManager;
		import com.android.internal.util.XmlUtils;
		import com.google.android.collect.Maps;

		import org.xmlpull.v1.XmlPullParserException;

		@@ -114,11 +113,9 @@ import java.io.InputStream;
		import java.lang.ref.WeakReference;
		import java.util.ArrayList;
		import java.util.HashMap;
		import java.util.HashSet;
		import java.util.Iterator;
		import java.util.List;
		import java.util.Map;
		import java.util.Map.Entry;
		import java.util.Set;
		import java.util.WeakHashMap;
		import java.util.concurrent.CountDownLatch;
		@@ -315,7 +312,7 @@ class ContextImpl extends Context {
		throw new RuntimeException("Not supported in system context");
		}

		private static File makeBackupFile(File prefsFile) {
		static File makeBackupFile(File prefsFile) {
		return new File(prefsFile.getPath() + ".bak");
		}

		@@ -363,7 +360,7 @@ class ContextImpl extends Context {
		FileInputStream str = new FileInputStream(prefsFile);
		map = XmlUtils.readMapXml(str);
		str.close();
		} catch (org.xmlpull.v1.XmlPullParserException e) {
		} catch (XmlPullParserException e) {
		Log.w(TAG, "getSharedPreferences", e);
		} catch (FileNotFoundException e) {
		Log.w(TAG, "getSharedPreferences", e);
		@@ -1593,7 +1590,7 @@ class ContextImpl extends Context {
		return mActivityToken;
		}

		private static void setFilePermissionsFromMode(String name, int mode,
		static void setFilePermissionsFromMode(String name, int mode,
		int extraPermissions) {
		int perms = FileUtils.S_IRUSR\|FileUtils.S_IWUSR
		\|FileUtils.S_IRGRP\|FileUtils.S_IWGRP
		@@ -2727,482 +2724,4 @@ class ContextImpl extends Context {
		private static HashMap<ResourceName, WeakReference<CharSequence> > sStringCache
		= new HashMap<ResourceName, WeakReference<CharSequence> >();
		}

		// ----------------------------------------------------------------------
		// ----------------------------------------------------------------------
		// ----------------------------------------------------------------------

		private static final class SharedPreferencesImpl implements SharedPreferences {

		// Lock ordering rules:
		// - acquire SharedPreferencesImpl.this before EditorImpl.this
		// - acquire mWritingToDiskLock before EditorImpl.this

		private final File mFile;
		private final File mBackupFile;
		private final int mMode;

		private Map<String, Object> mMap; // guarded by 'this'
		private int mDiskWritesInFlight = 0; // guarded by 'this'
		private boolean mLoaded = false; // guarded by 'this'
		private long mStatTimestamp; // guarded by 'this'
		private long mStatSize; // guarded by 'this'

		private final Object mWritingToDiskLock = new Object();
		private static final Object mContent = new Object();
		private final WeakHashMap<OnSharedPreferenceChangeListener, Object> mListeners;

		SharedPreferencesImpl(
		File file, int mode, Map initialContents) {
		mFile = file;
		mBackupFile = makeBackupFile(file);
		mMode = mode;
		mLoaded = initialContents != null;
		mMap = initialContents != null ? initialContents : new HashMap<String, Object>();
		FileStatus stat = new FileStatus();
		if (FileUtils.getFileStatus(file.getPath(), stat)) {
		mStatTimestamp = stat.mtime;
		}
		mListeners = new WeakHashMap<OnSharedPreferenceChangeListener, Object>();
		}

		// Has this SharedPreferences ever had values assigned to it?
		boolean isLoaded() {
		synchronized (this) {
		return mLoaded;
		}
		}

		// Has the file changed out from under us? i.e. writes that
		// we didn't instigate.
		public boolean hasFileChangedUnexpectedly() {
		synchronized (this) {
		if (mDiskWritesInFlight > 0) {
		// If we know we caused it, it's not unexpected.
		if (DEBUG) Log.d(TAG, "disk write in flight, not unexpected.");
		return false;
		}
		}
		FileStatus stat = new FileStatus();
		if (!FileUtils.getFileStatus(mFile.getPath(), stat)) {
		return true;
		}
		synchronized (this) {
		return mStatTimestamp != stat.mtime \|\| mStatSize != stat.size;
		}
		}

		public void replace(Map newContents) {
		synchronized (this) {
		mLoaded = true;
		if (newContents != null) {
		mMap = newContents;
		}
		}
		}

		public void registerOnSharedPreferenceChangeListener(OnSharedPreferenceChangeListener listener) {
		synchronized(this) {
		mListeners.put(listener, mContent);
		}
		}

		public void unregisterOnSharedPreferenceChangeListener(OnSharedPreferenceChangeListener listener) {
		synchronized(this) {
		mListeners.remove(listener);
		}
		}

		public Map<String, ?> getAll() {
		synchronized(this) {
		//noinspection unchecked
		return new HashMap<String, Object>(mMap);
		}
		}

		public String getString(String key, String defValue) {
		synchronized (this) {
		String v = (String)mMap.get(key);
		return v != null ? v : defValue;
		}
		}

		public Set<String> getStringSet(String key, Set<String> defValues) {
		synchronized (this) {
		Set<String> v = (Set<String>) mMap.get(key);
		return v != null ? v : defValues;
		}
		}

		public int getInt(String key, int defValue) {
		synchronized (this) {
		Integer v = (Integer)mMap.get(key);
		return v != null ? v : defValue;
		}
		}
		public long getLong(String key, long defValue) {
		synchronized (this) {
		Long v = (Long)mMap.get(key);
		return v != null ? v : defValue;
		}
		}
		public float getFloat(String key, float defValue) {
		synchronized (this) {
		Float v = (Float)mMap.get(key);
		return v != null ? v : defValue;
		}
		}
		public boolean getBoolean(String key, boolean defValue) {
		synchronized (this) {
		Boolean v = (Boolean)mMap.get(key);
		return v != null ? v : defValue;
		}
		}

		public boolean contains(String key) {
		synchronized (this) {
		return mMap.containsKey(key);
		}
		}

		public Editor edit() {
		return new EditorImpl();
		}

		// Return value from EditorImpl#commitToMemory()
		private static class MemoryCommitResult {
		public boolean changesMade; // any keys different?
		public List<String> keysModified; // may be null
		public Set<OnSharedPreferenceChangeListener> listeners; // may be null
		public Map<?, ?> mapToWriteToDisk;
		public final CountDownLatch writtenToDiskLatch = new CountDownLatch(1);
		public volatile boolean writeToDiskResult = false;

		public void setDiskWriteResult(boolean result) {
		writeToDiskResult = result;
		writtenToDiskLatch.countDown();
		}
		}

		public final class EditorImpl implements Editor {
		private final Map<String, Object> mModified = Maps.newHashMap();
		private boolean mClear = false;

		public Editor putString(String key, String value) {
		synchronized (this) {
		mModified.put(key, value);
		return this;
		}
		}
		public Editor putStringSet(String key, Set<String> values) {
		synchronized (this) {
		mModified.put(key, values);
		return this;
		}
		}
		public Editor putInt(String key, int value) {
		synchronized (this) {
		mModified.put(key, value);
		return this;
		}
		}
		public Editor putLong(String key, long value) {
		synchronized (this) {
		mModified.put(key, value);
		return this;
		}
		}
		public Editor putFloat(String key, float value) {
		synchronized (this) {
		mModified.put(key, value);
		return this;
		}
		}
		public Editor putBoolean(String key, boolean value) {
		synchronized (this) {
		mModified.put(key, value);
		return this;
		}
		}

		public Editor remove(String key) {
		synchronized (this) {
		mModified.put(key, this);
		return this;
		}
		}

		public Editor clear() {
		synchronized (this) {
		mClear = true;
		return this;
		}
		}

		public void apply() {
		final MemoryCommitResult mcr = commitToMemory();
		final Runnable awaitCommit = new Runnable() {
		public void run() {
		try {
		mcr.writtenToDiskLatch.await();
		} catch (InterruptedException ignored) {
		}
		}
		};

		QueuedWork.add(awaitCommit);

		Runnable postWriteRunnable = new Runnable() {
		public void run() {
		awaitCommit.run();
		QueuedWork.remove(awaitCommit);
		}
		};

		SharedPreferencesImpl.this.enqueueDiskWrite(mcr, postWriteRunnable);

		// Okay to notify the listeners before it's hit disk
		// because the listeners should always get the same
		// SharedPreferences instance back, which has the
		// changes reflected in memory.
		notifyListeners(mcr);
		}

		// Returns true if any changes were made
		private MemoryCommitResult commitToMemory() {
		MemoryCommitResult mcr = new MemoryCommitResult();
		synchronized (SharedPreferencesImpl.this) {
		// We optimistically don't make a deep copy until
		// a memory commit comes in when we're already
		// writing to disk.
		if (mDiskWritesInFlight > 0) {
		// We can't modify our mMap as a currently
		// in-flight write owns it. Clone it before
		// modifying it.
		// noinspection unchecked
		mMap = new HashMap<String, Object>(mMap);
		}
		mcr.mapToWriteToDisk = mMap;
		mDiskWritesInFlight++;

		boolean hasListeners = mListeners.size() > 0;
		if (hasListeners) {
		mcr.keysModified = new ArrayList<String>();
		mcr.listeners =
		new HashSet<OnSharedPreferenceChangeListener>(mListeners.keySet());
		}

		synchronized (this) {
		if (mClear) {
		if (!mMap.isEmpty()) {
		mcr.changesMade = true;
		mMap.clear();
		}
		mClear = false;
		}

		for (Entry<String, Object> e : mModified.entrySet()) {
		String k = e.getKey();
		Object v = e.getValue();
		if (v == this) { // magic value for a removal mutation
		if (!mMap.containsKey(k)) {
		continue;
		}
		mMap.remove(k);
		} else {
		boolean isSame = false;
		if (mMap.containsKey(k)) {
		Object existingValue = mMap.get(k);
		if (existingValue != null && existingValue.equals(v)) {
		continue;
		}
		}
		mMap.put(k, v);
		}

		mcr.changesMade = true;
		if (hasListeners) {
		mcr.keysModified.add(k);
		}
		}

		mModified.clear();
		}
		}
		return mcr;
		}

		public boolean commit() {
		MemoryCommitResult mcr = commitToMemory();
		SharedPreferencesImpl.this.enqueueDiskWrite(
		mcr, null /* sync write on this thread okay */);
		try {
		mcr.writtenToDiskLatch.await();
		} catch (InterruptedException e) {
		return false;
		}
		notifyListeners(mcr);
		return mcr.writeToDiskResult;
		}

		private void notifyListeners(final MemoryCommitResult mcr) {
		if (mcr.listeners == null \|\| mcr.keysModified == null \|\|
		mcr.keysModified.size() == 0) {
		return;
		}
		if (Looper.myLooper() == Looper.getMainLooper()) {
		for (int i = mcr.keysModified.size() - 1; i >= 0; i--) {
		final String key = mcr.keysModified.get(i);
		for (OnSharedPreferenceChangeListener listener : mcr.listeners) {
		if (listener != null) {
		listener.onSharedPreferenceChanged(SharedPreferencesImpl.this, key);
		}
		}
		}
		} else {
		// Run this function on the main thread.
		ActivityThread.sMainThreadHandler.post(new Runnable() {
		public void run() {
		notifyListeners(mcr);
		}
		});
		}
		}
		}

		/**
		* Enqueue an already-committed-to-memory result to be written
		* to disk.
		*
		* They will be written to disk one-at-a-time in the order
		* that they're enqueued.
		*
		* @param postWriteRunnable if non-null, we're being called
		* from apply() and this is the runnable to run after
		* the write proceeds. if null (from a regular commit()),
		* then we're allowed to do this disk write on the main
		* thread (which in addition to reducing allocations and
		* creating a background thread, this has the advantage that
		* we catch them in userdebug StrictMode reports to convert
		* them where possible to apply() ...)
		*/
		private void enqueueDiskWrite(final MemoryCommitResult mcr,
		final Runnable postWriteRunnable) {
		final Runnable writeToDiskRunnable = new Runnable() {
		public void run() {
		synchronized (mWritingToDiskLock) {
		writeToFile(mcr);
		}
		synchronized (SharedPreferencesImpl.this) {
		mDiskWritesInFlight--;
		}
		if (postWriteRunnable != null) {
		postWriteRunnable.run();
		}
		}
		};

		final boolean isFromSyncCommit = (postWriteRunnable == null);

		// Typical #commit() path with fewer allocations, doing a write on
		// the current thread.
		if (isFromSyncCommit) {
		boolean wasEmpty = false;
		synchronized (SharedPreferencesImpl.this) {
		wasEmpty = mDiskWritesInFlight == 1;
		}
		if (wasEmpty) {
		writeToDiskRunnable.run();
		return;
		}
		}

		QueuedWork.singleThreadExecutor().execute(writeToDiskRunnable);
		}

		private static FileOutputStream createFileOutputStream(File file) {
		FileOutputStream str = null;
		try {
		str = new FileOutputStream(file);
		} catch (FileNotFoundException e) {
		File parent = file.getParentFile();
		if (!parent.mkdir()) {
		Log.e(TAG, "Couldn't create directory for SharedPreferences file " + file);
		return null;
		}
		FileUtils.setPermissions(
		parent.getPath(),
		FileUtils.S_IRWXU\|FileUtils.S_IRWXG\|FileUtils.S_IXOTH,
		-1, -1);
		try {
		str = new FileOutputStream(file);
		} catch (FileNotFoundException e2) {
		Log.e(TAG, "Couldn't create SharedPreferences file " + file, e2);
		}
		}
		return str;
		}

		// Note: must hold mWritingToDiskLock
		private void writeToFile(MemoryCommitResult mcr) {
		// Rename the current file so it may be used as a backup during the next read
		if (mFile.exists()) {
		if (!mcr.changesMade) {
		// If the file already exists, but no changes were
		// made to the underlying map, it's wasteful to
		// re-write the file. Return as if we wrote it
		// out.
		mcr.setDiskWriteResult(true);
		return;
		}
		if (!mBackupFile.exists()) {
		if (!mFile.renameTo(mBackupFile)) {
		Log.e(TAG, "Couldn't rename file " + mFile
		+ " to backup file " + mBackupFile);
		mcr.setDiskWriteResult(false);
		return;
		}
		} else {
		mFile.delete();
		}
		}

		// Attempt to write the file, delete the backup and return true as atomically as
		// possible. If any exception occurs, delete the new file; next time we will restore
		// from the backup.
		try {
		FileOutputStream str = createFileOutputStream(mFile);
		if (str == null) {
		mcr.setDiskWriteResult(false);
		return;
		}
		XmlUtils.writeMapXml(mcr.mapToWriteToDisk, str);
		FileUtils.sync(str);
		str.close();
		setFilePermissionsFromMode(mFile.getPath(), mMode, 0);
		FileStatus stat = new FileStatus();
		if (FileUtils.getFileStatus(mFile.getPath(), stat)) {
		synchronized (this) {
		mStatTimestamp = stat.mtime;
		mStatSize = stat.size;
		}
		}
		// Writing was successful, delete the backup file if there is one.
		mBackupFile.delete();
		mcr.setDiskWriteResult(true);
		return;
		} catch (XmlPullParserException e) {
		Log.w(TAG, "writeToFile: Got exception:", e);
		} catch (IOException e) {
		Log.w(TAG, "writeToFile: Got exception:", e);
		}
		// Clean up an unsuccessfully written file
		if (mFile.exists()) {
		if (!mFile.delete()) {
		Log.e(TAG, "Couldn't clean up partially-written file " + mFile);
		}
		}
		mcr.setDiskWriteResult(false);
		}
		}
		}

core/java/android/app/SharedPreferencesImpl.java

0 → 100644

+518 −0

File added.

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