Implement TextClassifierImpl.detectLanguage()

- Includes some fixes to handle null ParcelFileDescriptors.
- Closes fds immediately after the model has been loaded.

Bug: 116020587
Test: atest android.view.textclassifier.TextClassificationManagerTest
Change-Id: Ieb05d081847ac218d2a5b46db95cd512838f67ab

2 files changed, 168 insertions, 41 deletions

diff --git a/core/java/android/view/textclassifier/TextClassifierImpl.java b/core/java/android/view/textclassifier/TextClassifierImpl.java
index 3e240cfdb69f..7f1e443f4aa5 100644
--- a/core/java/android/view/textclassifier/TextClassifierImpl.java
+++ b/core/java/android/view/textclassifier/TextClassifierImpl.java
@@ -31,6 +31,7 @@ import android.content.Intent;
 import android.content.pm.PackageManager;
 import android.content.pm.ResolveInfo;
 import android.graphics.drawable.Icon;
+import android.icu.util.ULocale;
 import android.net.Uri;
 import android.os.Bundle;
 import android.os.LocaleList;
@@ -45,6 +46,7 @@ import com.android.internal.util.IndentingPrintWriter;
 import com.android.internal.util.Preconditions;
 
 import com.google.android.textclassifier.AnnotatorModel;
+import com.google.android.textclassifier.LangIdModel;
 
 import java.io.File;
 import java.io.FileNotFoundException;
@@ -83,6 +85,9 @@ public final class TextClassifierImpl implements TextClassifier {
     private static final String MODEL_FILE_REGEX = "textclassifier\\.(.*)\\.model";
     private static final String UPDATED_MODEL_FILE_PATH =
             "/data/misc/textclassifier/textclassifier.model";
+    private static final String LANG_ID_MODEL_FILE_PATH = "/etc/textclassifier/lang_id.model";
+    private static final String UPDATED_LANG_ID_MODEL_FILE_PATH =
+            "/data/misc/textclassifier/lang_id.model";
 
     private final Context mContext;
     private final TextClassifier mFallback;
@@ -94,7 +99,9 @@ public final class TextClassifierImpl implements TextClassifier {
     @GuardedBy("mLock") // Do not access outside this lock.
     private ModelFile mModel;
     @GuardedBy("mLock") // Do not access outside this lock.
-    private AnnotatorModel mNative;
+    private AnnotatorModel mAnnotatorImpl;
+    @GuardedBy("mLock") // Do not access outside this lock.
+    private LangIdModel mLangIdImpl;
 
     private final Object mLoggerLock = new Object();
     @GuardedBy("mLoggerLock") // Do not access outside this lock.
@@ -127,14 +134,15 @@ public final class TextClassifierImpl implements TextClassifier {
                     && rangeLength <= mSettings.getSuggestSelectionMaxRangeLength()) {
                 final String localesString = concatenateLocales(request.getDefaultLocales());
                 final ZonedDateTime refTime = ZonedDateTime.now();
-                final AnnotatorModel nativeImpl = getNative(request.getDefaultLocales());
+                final AnnotatorModel annotatorImpl =
+                        getAnnotatorImpl(request.getDefaultLocales());
                 final int start;
                 final int end;
                 if (mSettings.isModelDarkLaunchEnabled() && !request.isDarkLaunchAllowed()) {
                     start = request.getStartIndex();
                     end = request.getEndIndex();
                 } else {
-                    final int[] startEnd = nativeImpl.suggestSelection(
+                    final int[] startEnd = annotatorImpl.suggestSelection(
                             string, request.getStartIndex(), request.getEndIndex(),
                             new AnnotatorModel.SelectionOptions(localesString));
                     start = startEnd[0];
@@ -145,7 +153,7 @@ public final class TextClassifierImpl implements TextClassifier {
                         && start <= request.getStartIndex() && end >= request.getEndIndex()) {
                     final TextSelection.Builder tsBuilder = new TextSelection.Builder(start, end);
                     final AnnotatorModel.ClassificationResult[] results =
-                            nativeImpl.classifyText(
+                            annotatorImpl.classifyText(
                                     string, start, end,
                                     new AnnotatorModel.ClassificationOptions(
                                             refTime.toInstant().toEpochMilli(),
@@ -187,7 +195,7 @@ public final class TextClassifierImpl implements TextClassifier {
                 final ZonedDateTime refTime = request.getReferenceTime() != null
                         ? request.getReferenceTime() : ZonedDateTime.now();
                 final AnnotatorModel.ClassificationResult[] results =
-                        getNative(request.getDefaultLocales())
+                        getAnnotatorImpl(request.getDefaultLocales())
                                 .classifyText(
                                         string, request.getStartIndex(), request.getEndIndex(),
                                         new AnnotatorModel.ClassificationOptions(
@@ -230,10 +238,10 @@ public final class TextClassifierImpl implements TextClassifier {
                     ? request.getEntityConfig().resolveEntityListModifications(
                             getEntitiesForHints(request.getEntityConfig().getHints()))
                     : mSettings.getEntityListDefault();
-            final AnnotatorModel nativeImpl =
-                    getNative(request.getDefaultLocales());
+            final AnnotatorModel annotatorImpl =
+                    getAnnotatorImpl(request.getDefaultLocales());
             final AnnotatorModel.AnnotatedSpan[] annotations =
-                    nativeImpl.annotate(
+                    annotatorImpl.annotate(
                         textString,
                         new AnnotatorModel.AnnotationOptions(
                                 refTime.toInstant().toEpochMilli(),
@@ -288,6 +296,7 @@ public final class TextClassifierImpl implements TextClassifier {
         }
     }
 
+    /** @inheritDoc */
     @Override
     public void onSelectionEvent(SelectionEvent event) {
         Preconditions.checkNotNull(event);
@@ -299,7 +308,29 @@ public final class TextClassifierImpl implements TextClassifier {
         }
     }
 
-    private AnnotatorModel getNative(LocaleList localeList)
+    /** @inheritDoc */
+    @Override
+    public TextLanguage detectLanguage(@NonNull TextLanguage.Request request) {
+        Preconditions.checkNotNull(request);
+        Utils.checkMainThread();
+        try {
+            final TextLanguage.Builder builder = new TextLanguage.Builder();
+            final LangIdModel.LanguageResult[] langResults =
+                    getLangIdImpl().detectLanguages(request.getText().toString());
+            for (int i = 0; i < langResults.length; i++) {
+                builder.putLocale(
+                        ULocale.forLanguageTag(langResults[i].getLanguage()),
+                        langResults[i].getScore());
+            }
+            return builder.build();
+        } catch (Throwable t) {
+            // Avoid throwing from this method. Log the error.
+            Log.e(LOG_TAG, "Error detecting text language.", t);
+        }
+        return mFallback.detectLanguage(request);
+    }
+
+    private AnnotatorModel getAnnotatorImpl(LocaleList localeList)
             throws FileNotFoundException {
         synchronized (mLock) {
             localeList = localeList == null ? LocaleList.getEmptyLocaleList() : localeList;
@@ -307,31 +338,79 @@ public final class TextClassifierImpl implements TextClassifier {
             if (bestModel == null) {
                 throw new FileNotFoundException("No model for " + localeList.toLanguageTags());
             }
-            if (mNative == null || !Objects.equals(mModel, bestModel)) {
+            if (mAnnotatorImpl == null || !Objects.equals(mModel, bestModel)) {
                 Log.d(DEFAULT_LOG_TAG, "Loading " + bestModel);
-                destroyNativeIfExistsLocked();
+                destroyAnnotatorImplIfExistsLocked();
                 final ParcelFileDescriptor fd = ParcelFileDescriptor.open(
                         new File(bestModel.getPath()), ParcelFileDescriptor.MODE_READ_ONLY);
-                mNative = new AnnotatorModel(fd.getFd());
-                closeAndLogError(fd);
-                mModel = bestModel;
+                try {
+                    if (fd != null) {
+                        mAnnotatorImpl = new AnnotatorModel(fd.getFd());
+                        mModel = bestModel;
+                    }
+                } finally {
+                    maybeCloseAndLogError(fd);
+                }
             }
-            return mNative;
+            return mAnnotatorImpl;
         }
     }
 
-    private String createId(String text, int start, int end) {
+    @GuardedBy("mLock") // Do not call outside this lock.
+    private void destroyAnnotatorImplIfExistsLocked() {
+        if (mAnnotatorImpl != null) {
+            mAnnotatorImpl.close();
+            mAnnotatorImpl = null;
+        }
+    }
+
+    private LangIdModel getLangIdImpl() throws FileNotFoundException {
         synchronized (mLock) {
-            return SelectionSessionLogger.createId(text, start, end, mContext, mModel.getVersion(),
-                    mModel.getSupportedLocales());
+            if (mLangIdImpl == null) {
+                ParcelFileDescriptor factoryFd = null;
+                ParcelFileDescriptor updateFd = null;
+                try {
+                    int factoryVersion = -1;
+                    int updateVersion = factoryVersion;
+                    final File factoryFile = new File(LANG_ID_MODEL_FILE_PATH);
+                    if (factoryFile.exists()) {
+                        factoryFd = ParcelFileDescriptor.open(
+                                factoryFile, ParcelFileDescriptor.MODE_READ_ONLY);
+                        // TODO: Uncomment when method is implemented:
+                        // if (factoryFd != null) {
+                        //     factoryVersion = LangIdModel.getVersion(factoryFd.getFd());
+                        // }
+                    }
+                    final File updateFile = new File(UPDATED_LANG_ID_MODEL_FILE_PATH);
+                    if (updateFile.exists()) {
+                        updateFd = ParcelFileDescriptor.open(
+                                updateFile, ParcelFileDescriptor.MODE_READ_ONLY);
+                        // TODO: Uncomment when method is implemented:
+                        // if (updateFd != null) {
+                        //     updateVersion = LangIdModel.getVersion(updateFd.getFd());
+                        // }
+                    }
+
+                    if (updateVersion > factoryVersion) {
+                        mLangIdImpl = new LangIdModel(updateFd.getFd());
+                    } else if (factoryFd != null) {
+                        mLangIdImpl = new LangIdModel(factoryFd.getFd());
+                    } else {
+                        throw new FileNotFoundException("Language detection model not found");
+                    }
+                } finally {
+                    maybeCloseAndLogError(factoryFd);
+                    maybeCloseAndLogError(updateFd);
+                }
+            }
+            return mLangIdImpl;
         }
     }
 
-    @GuardedBy("mLock") // Do not call outside this lock.
-    private void destroyNativeIfExistsLocked() {
-        if (mNative != null) {
-            mNative.close();
-            mNative = null;
+    private String createId(String text, int start, int end) {
+        synchronized (mLock) {
+            return SelectionSessionLogger.createId(text, start, end, mContext, mModel.getVersion(),
+                    mModel.getSupportedLocales());
         }
     }
 
@@ -407,20 +486,19 @@ public final class TextClassifierImpl implements TextClassifier {
                 .setText(classifiedText);
 
         final int size = classifications.length;
-        AnnotatorModel.ClassificationResult highestScoringResult = null;
-        float highestScore = Float.MIN_VALUE;
+        AnnotatorModel.ClassificationResult highestScoringResult =
+                size > 0 ? classifications[0] : null;
         for (int i = 0; i < size; i++) {
             builder.setEntityType(classifications[i].getCollection(),
                                   classifications[i].getScore());
-            if (classifications[i].getScore() > highestScore) {
+            if (classifications[i].getScore() > highestScoringResult.getScore()) {
                 highestScoringResult = classifications[i];
-                highestScore = classifications[i].getScore();
             }
         }
 
         boolean isPrimaryAction = true;
         for (LabeledIntent labeledIntent : IntentFactory.create(
-                mContext, referenceTime, highestScoringResult, classifiedText)) {
+                mContext, classifiedText, referenceTime, highestScoringResult)) {
             final RemoteAction action = labeledIntent.asRemoteAction(mContext);
             if (action == null) {
                 continue;
@@ -461,9 +539,13 @@ public final class TextClassifierImpl implements TextClassifier {
     }
 
     /**
-     * Closes the ParcelFileDescriptor and logs any errors that occur.
+     * Closes the ParcelFileDescriptor, if non-null, and logs any errors that occur.
      */
-    private static void closeAndLogError(ParcelFileDescriptor fd) {
+    private static void maybeCloseAndLogError(@Nullable ParcelFileDescriptor fd) {
+        if (fd == null) {
+            return;
+        }
+
         try {
             fd.close();
         } catch (IOException e) {
@@ -485,12 +567,17 @@ public final class TextClassifierImpl implements TextClassifier {
         /** Returns null if the path did not point to a compatible model. */
         static @Nullable ModelFile fromPath(String path) {
             final File file = new File(path);
+            if (!file.exists()) {
+                return null;
+            }
+            ParcelFileDescriptor modelFd = null;
             try {
-                final ParcelFileDescriptor modelFd = ParcelFileDescriptor.open(
-                        file, ParcelFileDescriptor.MODE_READ_ONLY);
+                modelFd = ParcelFileDescriptor.open(file, ParcelFileDescriptor.MODE_READ_ONLY);
+                if (modelFd == null) {
+                    return null;
+                }
                 final int version = AnnotatorModel.getVersion(modelFd.getFd());
-                final String supportedLocalesStr =
-                        AnnotatorModel.getLocales(modelFd.getFd());
+                final String supportedLocalesStr = AnnotatorModel.getLocales(modelFd.getFd());
                 if (supportedLocalesStr.isEmpty()) {
                     Log.d(DEFAULT_LOG_TAG, "Ignoring " + file.getAbsolutePath());
                     return null;
@@ -500,12 +587,13 @@ public final class TextClassifierImpl implements TextClassifier {
                 for (String langTag : supportedLocalesStr.split(",")) {
                     supportedLocales.add(Locale.forLanguageTag(langTag));
                 }
-                closeAndLogError(modelFd);
                 return new ModelFile(path, file.getName(), version, supportedLocales,
                                      languageIndependent);
             } catch (FileNotFoundException e) {
                 Log.e(DEFAULT_LOG_TAG, "Failed to peek " + file.getAbsolutePath(), e);
                 return null;
+            } finally {
+                maybeCloseAndLogError(modelFd);
             }
         }
 
@@ -557,12 +645,12 @@ public final class TextClassifierImpl implements TextClassifier {
         public boolean equals(Object other) {
             if (this == other) {
                 return true;
-            } else if (other == null || !ModelFile.class.isAssignableFrom(other.getClass())) {
-                return false;
-            } else {
+            }
+            if (other instanceof ModelFile) {
                 final ModelFile otherModel = (ModelFile) other;
                 return mPath.equals(otherModel.mPath);
             }
+            return false;
         }
 
         @Override
@@ -677,10 +765,12 @@ public final class TextClassifierImpl implements TextClassifier {
         @NonNull
         public static List<LabeledIntent> create(
                 Context context,
+                String text,
                 @Nullable Instant referenceTime,
-                AnnotatorModel.ClassificationResult classification,
-                String text) {
-            final String type = classification.getCollection().trim().toLowerCase(Locale.ENGLISH);
+                @Nullable AnnotatorModel.ClassificationResult classification) {
+            final String type = classification != null
+                    ? classification.getCollection().trim().toLowerCase(Locale.ENGLISH)
+                    : null;
             text = text.trim();
             switch (type) {
                 case TextClassifier.TYPE_EMAIL:
diff --git a/core/tests/coretests/src/android/view/textclassifier/TextClassificationManagerTest.java b/core/tests/coretests/src/android/view/textclassifier/TextClassificationManagerTest.java
index e891fc9d6134..8646c685c998 100644
--- a/core/tests/coretests/src/android/view/textclassifier/TextClassificationManagerTest.java
+++ b/core/tests/coretests/src/android/view/textclassifier/TextClassificationManagerTest.java
@@ -307,6 +307,24 @@ public class TextClassificationManagerTest {
     }
 
     @Test
+    public void testDetectLanguage() {
+        if (isTextClassifierDisabled()) return;
+        String text = "This is English text";
+        TextLanguage.Request request = new TextLanguage.Request.Builder(text).build();
+        TextLanguage textLanguage = mClassifier.detectLanguage(request);
+        assertThat(textLanguage, isTextLanguage("en"));
+    }
+
+    @Test
+    public void testDetectLanguage_japanese() {
+        if (isTextClassifierDisabled()) return;
+        String text = "これは日本語のテキストです";
+        TextLanguage.Request request = new TextLanguage.Request.Builder(text).build();
+        TextLanguage textLanguage = mClassifier.detectLanguage(request);
+        assertThat(textLanguage, isTextLanguage("ja"));
+    }
+
+    @Test
     public void testSetTextClassifier() {
         TextClassifier classifier = mock(TextClassifier.class);
         mTcm.setTextClassifier(classifier);
@@ -444,4 +462,23 @@ public class TextClassificationManagerTest {
             }
         };
     }
+
+    private static Matcher<TextLanguage> isTextLanguage(final String languageTag) {
+        return new BaseMatcher<TextLanguage>() {
+            @Override
+            public boolean matches(Object o) {
+                if (o instanceof TextLanguage) {
+                    TextLanguage result = (TextLanguage) o;
+                    return result.getLocaleHypothesisCount() > 0
+                            && languageTag.equals(result.getLocale(0).toLanguageTag());
+                }
+                return false;
+            }
+
+            @Override
+            public void describeTo(Description description) {
+                description.appendText("locale=").appendValue(languageTag);
+            }
+        };
+    }
 }