Merge "[LayoutInflater] Use precompiled layouts if available" (cb5f54e2) · Commits · e / os / android_frameworks_base

core/java/android/view/LayoutInflater.java

+182 −79

Original line number	Diff line number	Diff line
		@@ -28,6 +28,7 @@ import android.content.res.XmlResourceParser;
		import android.graphics.Canvas;
		import android.os.Handler;
		import android.os.Message;
		import android.os.SystemProperties;
		import android.os.Trace;
		import android.util.AttributeSet;
		import android.util.Log;
		@@ -37,6 +38,9 @@ import android.widget.FrameLayout;

		import com.android.internal.R;

		import dalvik.system.PathClassLoader;
		import java.io.File;
		import java.lang.reflect.Method;
		import org.xmlpull.v1.XmlPullParser;
		import org.xmlpull.v1.XmlPullParserException;

		@@ -71,6 +75,10 @@ public abstract class LayoutInflater {
		private static final String TAG = LayoutInflater.class.getSimpleName();
		private static final boolean DEBUG = false;

		private static final String USE_PRECOMPILED_LAYOUT_SYSTEM_PROPERTY
		= "view.precompiled_layout_enabled";
		private static final String COMPILED_VIEW_DEX_FILE_NAME = "/compiled_view.dex";

		/** Empty stack trace used to avoid log spam in re-throw exceptions. */
		private static final StackTraceElement[] EMPTY_STACK_TRACE = new StackTraceElement[0];

		@@ -92,6 +100,13 @@ public abstract class LayoutInflater {
		private Factory2 mPrivateFactory;
		private Filter mFilter;

		// Indicates whether we should try to inflate layouts using a precompiled layout instead of
		// inflating from the XML resource.
		private boolean mUseCompiledView;
		// This variable holds the classloader that will be used to look for precompiled layouts. The
		// The classloader includes the generated compiled_view.dex file.
		private ClassLoader mPrecompiledClassLoader;

		@UnsupportedAppUsage
		final Object[] mConstructorArgs = new Object[2];

		@@ -214,6 +229,7 @@ public abstract class LayoutInflater {
		*/
		protected LayoutInflater(Context context) {
		mContext = context;
		initPrecompiledViews();
		}

		/**
		@@ -230,6 +246,7 @@ public abstract class LayoutInflater {
		mFactory2 = original.mFactory2;
		mPrivateFactory = original.mPrivateFactory;
		setFilter(original.mFilter);
		initPrecompiledViews();
		}

		/**
		@@ -371,6 +388,29 @@ public abstract class LayoutInflater {
		}
		}

		private void initPrecompiledViews() {
		try {
		mUseCompiledView =
		SystemProperties.getBoolean(USE_PRECOMPILED_LAYOUT_SYSTEM_PROPERTY, false);
		if (mUseCompiledView) {
		mPrecompiledClassLoader = mContext.getClassLoader();
		String dexFile = mContext.getCodeCacheDir() + COMPILED_VIEW_DEX_FILE_NAME;
		if (new File(dexFile).exists()) {
		mPrecompiledClassLoader = new PathClassLoader(dexFile, mPrecompiledClassLoader);
		} else {
		// If the precompiled layout file doesn't exist, then disable precompiled
		// layouts.
		mUseCompiledView = false;
		}
		}
		} catch (Throwable e) {
		if (DEBUG) {
		Log.e(TAG, "Failed to initialized precompiled views layouts", e);
		}
		mUseCompiledView = false;
		}
		}

		/**
		* Inflate a new view hierarchy from the specified xml resource. Throws
		* {@link InflateException} if there is an error.
		@@ -430,7 +470,11 @@ public abstract class LayoutInflater {
		+ Integer.toHexString(resource) + ")");
		}

		final XmlResourceParser parser = res.getLayout(resource);
		View view = tryInflatePrecompiled(resource, res, root, attachToRoot);
		if (view != null) {
		return view;
		}
		XmlResourceParser parser = res.getLayout(resource);
		try {
		return inflate(parser, root, attachToRoot);
		} finally {
		@@ -438,6 +482,73 @@ public abstract class LayoutInflater {
		}
		}

		private @Nullable
		View tryInflatePrecompiled(@LayoutRes int resource, Resources res, @Nullable ViewGroup root,
		boolean attachToRoot) {
		if (!mUseCompiledView) {
		return null;
		}

		Trace.traceBegin(Trace.TRACE_TAG_VIEW, "inflate (precompiled)");

		// Try to inflate using a precompiled layout.
		String pkg = res.getResourcePackageName(resource);
		String layout = res.getResourceEntryName(resource);

		try {
		Class clazz = mPrecompiledClassLoader.loadClass("" + pkg + ".CompiledView");
		Method inflater = clazz.getMethod(layout, Context.class, int.class);
		View view = (View) inflater.invoke(null, mContext, resource);

		if (view != null && root != null) {
		// We were able to use the precompiled inflater, but now we need to do some work to
		// attach the view to the root correctly.
		XmlResourceParser parser = res.getLayout(resource);
		try {
		AttributeSet attrs = Xml.asAttributeSet(parser);
		advanceToRootNode(parser);
		ViewGroup.LayoutParams params = root.generateLayoutParams(attrs);

		if (attachToRoot) {
		root.addView(view, params);
		} else {
		view.setLayoutParams(params);
		}
		} finally {
		parser.close();
		}
		}

		return view;
		} catch (Throwable e) {
		if (DEBUG) {
		Log.e(TAG, "Failed to use precompiled view", e);
		}
		} finally {
		Trace.traceEnd(Trace.TRACE_TAG_VIEW);
		}
		return null;
		}

		/**
		* Advances the given parser to the first START_TAG. Throws InflateException if no start tag is
		* found.
		*/
		private void advanceToRootNode(XmlPullParser parser)
		throws InflateException, IOException, XmlPullParserException {
		// Look for the root node.
		int type;
		while ((type = parser.next()) != XmlPullParser.START_TAG &&
		type != XmlPullParser.END_DOCUMENT) {
		// Empty
		}

		if (type != XmlPullParser.START_TAG) {
		throw new InflateException(parser.getPositionDescription()
		+ ": No start tag found!");
		}
		}

		/**
		* Inflate a new view hierarchy from the specified XML node. Throws
		* {@link InflateException} if there is an error.
		@@ -471,18 +582,7 @@ public abstract class LayoutInflater {
		View result = root;

		try {
		// Look for the root node.
		int type;
		while ((type = parser.next()) != XmlPullParser.START_TAG &&
		type != XmlPullParser.END_DOCUMENT) {
		// Empty
		}

		if (type != XmlPullParser.START_TAG) {
		throw new InflateException(parser.getPositionDescription()
		+ ": No start tag found!");
		}

		advanceToRootNode(parser);
		final String name = parser.getName();

		if (DEBUG) {
		@@ -985,6 +1085,9 @@ public abstract class LayoutInflater {
		+ "reference. The layout ID " + value + " is not valid.");
		}

		final View precompiled = tryInflatePrecompiled(layout, context.getResources(),
		(ViewGroup) parent, /attachToRoot=/true);
		if (precompiled == null) {
		final XmlResourceParser childParser = context.getResources().getLayout(layout);

		try {
		@@ -1060,7 +1163,7 @@ public abstract class LayoutInflater {
		} finally {
		childParser.close();
		}

		}
		LayoutInflater.consumeChildElements(parser);
		}