[SettingsProvider] use per-prefix caches for Config.getStrings queries (d05c0ff6) · Commits · e / os / android_frameworks_base

core/java/android/provider/Settings.java

+42 −51

Original line number	Diff line number	Diff line
		@@ -3238,9 +3238,17 @@ public final class Settings {

		private static final String NAME_EQ_PLACEHOLDER = "name=?";

		// Cached values of queried settings.
		// Key is the setting's name, value is the setting's value.
		// Must synchronize on 'this' to access mValues and mValuesVersion.
		private final ArrayMap<String, String> mValues = new ArrayMap<>();

		// Cached values for queried prefixes.
		// Key is the prefix, value is all of the settings under the prefix, mapped from a setting's
		// name to a setting's value. The name string doesn't include the prefix.
		// Must synchronize on 'this' to access.
		private final ArrayMap<String, ArrayMap<String, String>> mPrefixToValues = new ArrayMap<>();

		private final Uri mUri;
		@UnsupportedAppUsage
		private final ContentProviderHolder mProviderHolder;
		@@ -3585,15 +3593,13 @@ public final class Settings {
		\|\| applicationInfo.isSignedWithPlatformKey();
		}

		private ArrayMap<String, String> getStringsForPrefixStripPrefix(
		ContentResolver cr, String prefix, String[] names) {
		private Map<String, String> getStringsForPrefixStripPrefix(
		ContentResolver cr, String prefix, List<String> names) {
		String namespace = prefix.substring(0, prefix.length() - 1);
		ArrayMap<String, String> keyValues = new ArrayMap<>();
		int substringLength = prefix.length();

		int currentGeneration = -1;
		boolean needsGenerationTracker = false;

		synchronized (NameValueCache.this) {
		final GenerationTracker generationTracker = mGenerationTrackers.get(prefix);
		if (generationTracker != null) {
		@@ -3607,40 +3613,22 @@ public final class Settings {
		// generation tracker and request a new one
		generationTracker.destroy();
		mGenerationTrackers.remove(prefix);
		for (int i = mValues.size() - 1; i >= 0; i--) {
		String key = mValues.keyAt(i);
		if (key.startsWith(prefix)) {
		mValues.remove(key);
		}
		}
		mPrefixToValues.remove(prefix);
		needsGenerationTracker = true;
		} else {
		boolean prefixCached = mValues.containsKey(prefix);
		if (prefixCached) {
		if (DEBUG) {
		Log.i(TAG, "Cache hit for prefix:" + prefix);
		}
		if (names.length > 0) {
		final ArrayMap<String, String> cachedSettings = mPrefixToValues.get(prefix);
		if (cachedSettings != null) {
		if (!names.isEmpty()) {
		for (String name : names) {
		// mValues can contain "null" values, need to use containsKey.
		if (mValues.containsKey(name)) {
		// The cache can contain "null" values, need to use containsKey.
		if (cachedSettings.containsKey(name)) {
		keyValues.put(
		name.substring(substringLength),
		mValues.get(name));
		name,
		cachedSettings.get(name));
		}
		}
		} else {
		for (int i = 0; i < mValues.size(); ++i) {
		String key = mValues.keyAt(i);
		// Explicitly exclude the prefix as it is only there to
		// signal that the prefix has been cached.
		if (key.startsWith(prefix) && !key.equals(prefix)) {
		String value = mValues.valueAt(i);
		keyValues.put(
		key.substring(substringLength),
		value);
		}
		}
		keyValues.putAll(cachedSettings);
		}
		return keyValues;
		}
		@@ -3650,7 +3638,6 @@ public final class Settings {
		needsGenerationTracker = true;
		}
		}

		if (mCallListCommand == null) {
		// No list command specified, return empty map
		return keyValues;
		@@ -3695,20 +3682,23 @@ public final class Settings {
		}

		// All flags for the namespace
		Map<String, String> flagsToValues =
		HashMap<String, String> flagsToValues =
		(HashMap) b.getSerializable(Settings.NameValueTable.VALUE, java.util.HashMap.class);
		if (flagsToValues == null) {
		return keyValues;
		}
		// Only the flags requested by the caller
		if (names.length > 0) {
		if (!names.isEmpty()) {
		for (String name : names) {
		// flagsToValues can contain "null" values, need to use containsKey.
		if (flagsToValues.containsKey(name)) {
		final String key = Config.createCompositeName(namespace, name);
		if (flagsToValues.containsKey(key)) {
		keyValues.put(
		name.substring(substringLength),
		flagsToValues.get(name));
		name,
		flagsToValues.get(key));
		}
		}
		} else {
		keyValues.ensureCapacity(keyValues.size() + flagsToValues.size());
		for (Map.Entry<String, String> flag : flagsToValues.entrySet()) {
		keyValues.put(
		flag.getKey().substring(substringLength),
		@@ -3742,10 +3732,18 @@ public final class Settings {
		if (DEBUG) {
		Log.i(TAG, "Updating cache for prefix:" + prefix);
		}
		// cache the complete list of flags for the namespace
		mValues.putAll(flagsToValues);
		// Adding the prefix as a signal that the prefix is cached.
		mValues.put(prefix, null);
		// Cache the complete list of flags for the namespace for bulk queries.
		// In this cached list, the setting's name doesn't include the prefix.
		ArrayMap<String, String> namesToValues =
		new ArrayMap<>(flagsToValues.size() + 1);
		for (Map.Entry<String, String> flag : flagsToValues.entrySet()) {
		namesToValues.put(
		flag.getKey().substring(substringLength),
		flag.getValue());
		}
		// Legacy behavior, we return <"", null> when queried with name = ""
		namesToValues.put("", null);
		mPrefixToValues.put(prefix, namesToValues);
		}
		}
		return keyValues;
		@@ -19909,16 +19907,9 @@ public final class Settings {
		@RequiresPermission(Manifest.permission.READ_DEVICE_CONFIG)
		public static Map<String, String> getStrings(@NonNull ContentResolver resolver,
		@NonNull String namespace, @NonNull List<String> names) {
		String[] compositeNames = new String[names.size()];
		for (int i = 0, size = names.size(); i < size; ++i) {
		compositeNames[i] = createCompositeName(namespace, names.get(i));
		}

		String prefix = createPrefix(namespace);

		ArrayMap<String, String> keyValues = sNameValueCache.getStringsForPrefixStripPrefix(
		resolver, prefix, compositeNames);
		return keyValues;
		return sNameValueCache.getStringsForPrefixStripPrefix(resolver, prefix, names);
		}

		/**
		@@ -20240,7 +20231,7 @@ public final class Settings {
		}
		}

		private static String createCompositeName(@NonNull String namespace, @NonNull String name) {
		static String createCompositeName(@NonNull String namespace, @NonNull String name) {
		Preconditions.checkNotNull(namespace);
		Preconditions.checkNotNull(name);
		var sb = new StringBuilder(namespace.length() + 1 + name.length());