chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchRankerLoggerImpl.java - chromium/src - Git at Google

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 package org.chromium.chrome.browser.contextualsearch;

 import android.support.annotation.Nullable;

 import org.chromium.base.VisibleForTesting;
 import org.chromium.chrome.browser.contextualsearch.ContextualSearchFieldTrial.ContextualSearchSwitch;
 import org.chromium.content_public.browser.WebContents;

 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;

 /**
  * Implements the UMA logging for Ranker that's used for Contextual Search Tap Suppression.
  */
 public class ContextualSearchRankerLoggerImpl implements ContextualSearchInteractionRecorder {
     // Names for all our features and labels.
     // Map keys should contain @Feature int values only.
     private static final Map<Integer, String> ALL_NAMES;
     @VisibleForTesting
     // Map keys should contain @Feature int values only.
     static final Map<Integer, String> OUTCOMES;
     @VisibleForTesting
     // Map keys should contain @Feature int values only.
     static final Map<Integer, String> FEATURES;
     static {
         // Map keys should contain @Feature int values only.
         Map<Integer, String> outcomes = new HashMap<Integer, String>();
         outcomes.put(Feature.OUTCOME_WAS_PANEL_OPENED, "OutcomeWasPanelOpened");
         outcomes.put(Feature.OUTCOME_WAS_QUICK_ACTION_CLICKED, "OutcomeWasQuickActionClicked");
         outcomes.put(Feature.OUTCOME_WAS_QUICK_ANSWER_SEEN, "OutcomeWasQuickAnswerSeen");
         // UKM CS v2 outcomes.
         outcomes.put(Feature.OUTCOME_WAS_CARDS_DATA_SHOWN, "OutcomeWasCardsDataShown");
         OUTCOMES = Collections.unmodifiableMap(outcomes);

         // NOTE: this list needs to be kept in sync with the white list in
         // predictor_config_definitions.cc and with ukm.xml!
         // Integer values should contain @Feature values only.
         Map<Integer, String> features = new HashMap<Integer, String>();
         features.put(Feature.DURATION_AFTER_SCROLL_MS, "DurationAfterScrollMs");
         features.put(Feature.SCREEN_TOP_DPS, "ScreenTopDps");
         features.put(Feature.WAS_SCREEN_BOTTOM, "WasScreenBottom");
         features.put(Feature.PREVIOUS_WEEK_IMPRESSIONS_COUNT, "PreviousWeekImpressionsCount");
         features.put(Feature.PREVIOUS_WEEK_CTR_PERCENT, "PreviousWeekCtrPercent");
         features.put(Feature.PREVIOUS_28DAY_IMPRESSIONS_COUNT, "Previous28DayImpressionsCount");
         features.put(Feature.PREVIOUS_28DAY_CTR_PERCENT, "Previous28DayCtrPercent");
         // UKM CS v2 features.
         features.put(Feature.DID_OPT_IN, "DidOptIn");
         features.put(Feature.IS_SHORT_WORD, "IsShortWord");
         features.put(Feature.IS_LONG_WORD, "IsLongWord");
         features.put(Feature.IS_WORD_EDGE, "IsWordEdge");
         features.put(Feature.IS_ENTITY, "IsEntity");
         features.put(Feature.TAP_DURATION_MS, "TapDurationMs");
         // UKM CS v3 features.
         features.put(Feature.FONT_SIZE, "FontSize");
         features.put(Feature.IS_HTTP, "IsHttp");
         features.put(Feature.IS_SECOND_TAP_OVERRIDE, "IsSecondTapOverride");
         features.put(Feature.IS_ENTITY_ELIGIBLE, "IsEntityEligible");
         features.put(Feature.IS_LANGUAGE_MISMATCH, "IsLanguageMismatch");
         features.put(Feature.PORTION_OF_ELEMENT, "PortionOfElement");
         // UKM CS v4 features.
         features.put(Feature.TAP_COUNT, "TapCount");
         features.put(Feature.OPEN_COUNT, "OpenCount");
         features.put(Feature.QUICK_ANSWER_COUNT, "QuickAnswerCount");
         features.put(Feature.ENTITY_IMPRESSIONS_COUNT, "EntityImpressionsCount");
         features.put(Feature.ENTITY_OPENS_COUNT, "EntityOpensCount");
         features.put(Feature.QUICK_ACTION_IMPRESSIONS_COUNT, "QuickActionImpressionsCount");
         features.put(Feature.QUICK_ACTIONS_TAKEN_COUNT, "QuickActionsTaken");
         features.put(Feature.QUICK_ACTIONS_IGNORED_COUNT, "QuickActionsIgnored");
         FEATURES = Collections.unmodifiableMap(features);

         // Map keys should contain @Feature int values only.
         Map<Integer, String> allNames = new HashMap<Integer, String>();
         allNames.putAll(outcomes);
         allNames.putAll(features);
         ALL_NAMES = Collections.unmodifiableMap(allNames);
     }

     // Pointer to the native instance of this class.
     private long mNativePointer;

     // Whether logging for the current page has been setup.
     private boolean mIsLoggingReadyForPage;

     // The WebContents of the base page that the log data is associated with.
     private WebContents mBasePageWebContents;

     // Whether inference has already occurred for this interaction (and calling #logFeature is no
     // longer allowed).
     private boolean mHasInferenceOccurred;

     // What kind of ML prediction we were able to get.
     private @AssistRankerPrediction int mAssistRankerPrediction =
             AssistRankerPrediction.UNDETERMINED;

     // Map that accumulates all of the Features to log for a specific user-interaction.
     // Map keys should contain @Feature int values only.
     private Map<Integer, Object> mFeaturesToLog;

     // A for-testing copy of all the features to log setup so that it will survive a {@link #reset}.
     // Map keys should contain @Feature int values only.
     private Map<Integer, Object> mFeaturesLoggedForTesting;
     private Map<Integer, Object> mOutcomesLoggedForTesting;

     private ContextualSearchInteractionPersister mInteractionPersister;

     private long mEventIdToPersist;

     /**
      * Constructs a Ranker Logger and associated native implementation to write Contextual Search
      * ML data to Ranker.
      */
     public ContextualSearchRankerLoggerImpl() {
         this(new ContextualSearchInteractionPersisterImpl());
     }

     /**
      * Constructs a Ranker Logger implementation for testing.
      * @param interactionPersister The {@link ContextualSearchInteractionPersister} to use for this
      *        instance.
      */
     public ContextualSearchRankerLoggerImpl(
             ContextualSearchInteractionPersister interactionPersister) {
         mInteractionPersister = interactionPersister;
         if (isEnabled()) mNativePointer = nativeInit();
     }

     /**
      * This method should be called to clean up storage when an instance of this class is
      * no longer in use.  The nativeDestroy will call the destructor on the native instance.
      */
     void destroy() {
         // TODO(donnd): looks like this is never being called.  Fix.
         if (isEnabled()) {
             assert mNativePointer != 0;
             writeLogAndReset();
             nativeDestroy(mNativePointer);
             mNativePointer = 0;
         }
         mIsLoggingReadyForPage = false;
     }

     @Override
     public void setupLoggingForPage(@Nullable WebContents basePageWebContents) {
         mIsLoggingReadyForPage = true;
         mBasePageWebContents = basePageWebContents;
         mHasInferenceOccurred = false;
         nativeSetupLoggingAndRanker(mNativePointer, basePageWebContents);
     }

     @Override
     public boolean isQueryEnabled() {
         return nativeIsQueryEnabled(mNativePointer);
     }

     @Override
     public void logFeature(@Feature int feature, Object value) {
         assert mIsLoggingReadyForPage : "mIsLoggingReadyForPage false.";
         assert !mHasInferenceOccurred;
         if (!isEnabled()) return;

         logInternal(feature, value);
     }

     @Override
     public void logOutcome(@Feature int feature, Object value) {
         assert mIsLoggingReadyForPage;
         assert mHasInferenceOccurred;
         if (!isEnabled()) return;

         logInternal(feature, value);
     }

     @Override
     public @AssistRankerPrediction int runPredictionForTapSuppression() {
         assert mIsLoggingReadyForPage;
         assert !mHasInferenceOccurred;
         mHasInferenceOccurred = true;
         if (isEnabled() && mBasePageWebContents != null && mFeaturesToLog != null
                 && !mFeaturesToLog.isEmpty()) {
             for (Map.Entry<Integer, Object> entry : mFeaturesToLog.entrySet()) {
                 logObject(entry.getKey(), entry.getValue());
             }
             mFeaturesLoggedForTesting = mFeaturesToLog;
             mFeaturesToLog = new HashMap<Integer, Object>();
             mAssistRankerPrediction = nativeRunInference(mNativePointer);
             ContextualSearchUma.logRecordedFeaturesToRanker();
         }
         return mAssistRankerPrediction;
     }

     @Override
     public @AssistRankerPrediction int getPredictionForTapSuppression() {
         return mAssistRankerPrediction;
     }

     @Override
     public void reset() {
         mIsLoggingReadyForPage = false;
         mHasInferenceOccurred = false;
         mFeaturesToLog = null;
         mBasePageWebContents = null;
         mAssistRankerPrediction = AssistRankerPrediction.UNDETERMINED;
     }

     @Override
     public void writeLogAndReset() {
         if (isEnabled()) {
             if (mBasePageWebContents != null && mFeaturesToLog != null
                     && !mFeaturesToLog.isEmpty()) {
                 assert mIsLoggingReadyForPage;
                 assert mHasInferenceOccurred;
                 // Only the outcomes will be present, since we logged inference features at
                 // inference time.
                 for (Map.Entry<Integer, Object> entry : mFeaturesToLog.entrySet()) {
                     logObject(entry.getKey(), entry.getValue());
                 }
                 mOutcomesLoggedForTesting = mFeaturesToLog;
                 ContextualSearchUma.logRecordedOutcomesToRanker();
                 // Also persist the outcomes if we are persisting this interaction.
                 if (mEventIdToPersist != 0) {
                     mInteractionPersister.persistInteractions(mEventIdToPersist, mFeaturesToLog);
                     mEventIdToPersist = 0;
                 }
             }
             nativeWriteLogAndReset(mNativePointer);
         }
         reset();
     }

     @Override
     public void persistInteraction(long eventId) {
         if (eventId != 0) mEventIdToPersist = eventId;
     }

     @Override
     public ContextualSearchInteractionPersister getInteractionPersister() {
         return mInteractionPersister;
     }

     /**
      * Logs the given feature/value to the internal map that accumulates an entire record (which can
      * be logged by calling writeLogAndReset).
      * @param feature The feature to log.
      * @param value The value to log.
      */
     private void logInternal(@Feature int feature, Object value) {
         if (mFeaturesToLog == null) mFeaturesToLog = new HashMap<Integer, Object>();
         mFeaturesToLog.put(feature, value);
     }

     /** Whether actually writing data is enabled.  If not, we may do nothing, or just print. */
     private boolean isEnabled() {
         return !ContextualSearchFieldTrial.getSwitch(
                 ContextualSearchSwitch.IS_UKM_RANKER_LOGGING_DISABLED);
     }

     /**
      * Logs the given {@link ContextualSearchInteractionRecorder.Feature} with the given value
      * {@link Object}.
      * @param feature The feature to log.
      * @param value An {@link Object} value to log (must be convertible to a {@code long}).
      */
     private void logObject(@Feature int feature, Object value) {
         if (value instanceof Boolean) {
             logToNative(feature, ((boolean) value ? 1 : 0));
         } else if (value instanceof Integer) {
             logToNative(feature, (int) value);
         } else if (value instanceof Character) {
             logToNative(feature, Character.getNumericValue((char) value));
         } else {
             assert false : "Could not log feature to Ranker: " + String.valueOf(feature)
                            + " of class "
                            + value.getClass();
         }
     }

     /**
      * Logs to the native instance.  All native logging must go through this bottleneck.
      * @param feature The feature to log.
      * @param value The value to log.
      */
     private void logToNative(@Feature int feature, int value) {
         String featureName = getFeatureName(feature);
         assert featureName != null : "No Name for feature " + feature;
         nativeLogInt32(mNativePointer, featureName, value);
     }

     /**
      * @return The name of the given feature.
      */
     private String getFeatureName(@Feature int feature) {
         return ALL_NAMES.get(feature);
     }

     /**
      * Gets the current set of features that have been logged.  Should only be used for testing
      * purposes!
      * @return The current set of features that have been logged, or {@code null}.
      */
     @VisibleForTesting
     @Nullable
     Map<Integer, Object> getFeaturesLogged() {
         return mFeaturesLoggedForTesting;
     }

     /**
      * Gets the current set of outcomes that have been logged.  Should only be used for
      * testing purposes!
      * @return The current set of outcomes that have been logged, or {@code null}.
      */
     @VisibleForTesting
     @Nullable
     Map<Integer, Object> getOutcomesLogged() {
         return mOutcomesLoggedForTesting;
     }

     // ============================================================================================
     // Native methods.
     // ============================================================================================
     private native long nativeInit();
     private native void nativeDestroy(long nativeContextualSearchRankerLoggerImpl);
     private native void nativeLogInt32(
             long nativeContextualSearchRankerLoggerImpl, String featureString, int value);
     private native void nativeSetupLoggingAndRanker(
             long nativeContextualSearchRankerLoggerImpl, WebContents basePageWebContents);
     // Returns an AssistRankerPrediction integer value.
     private native int nativeRunInference(long nativeContextualSearchRankerLoggerImpl);
     private native void nativeWriteLogAndReset(long nativeContextualSearchRankerLoggerImpl);
     private native boolean nativeIsQueryEnabled(long nativeContextualSearchRankerLoggerImpl);
 }
	// Copyright 2016 The Chromium Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	package org.chromium.chrome.browser.contextualsearch;

	import android.support.annotation.Nullable;

	import org.chromium.base.VisibleForTesting;
	import org.chromium.chrome.browser.contextualsearch.ContextualSearchFieldTrial.ContextualSearchSwitch;
	import org.chromium.content_public.browser.WebContents;

	import java.util.Collections;
	import java.util.HashMap;
	import java.util.Map;

	/**
	* Implements the UMA logging for Ranker that's used for Contextual Search Tap Suppression.
	*/
	public class ContextualSearchRankerLoggerImpl implements ContextualSearchInteractionRecorder {
	// Names for all our features and labels.
	// Map keys should contain @Feature int values only.
	private static final Map<Integer, String> ALL_NAMES;
	@VisibleForTesting
	// Map keys should contain @Feature int values only.
	static final Map<Integer, String> OUTCOMES;
	@VisibleForTesting
	// Map keys should contain @Feature int values only.
	static final Map<Integer, String> FEATURES;
	static {
	// Map keys should contain @Feature int values only.
	Map<Integer, String> outcomes = new HashMap<Integer, String>();
	outcomes.put(Feature.OUTCOME_WAS_PANEL_OPENED, "OutcomeWasPanelOpened");
	outcomes.put(Feature.OUTCOME_WAS_QUICK_ACTION_CLICKED, "OutcomeWasQuickActionClicked");
	outcomes.put(Feature.OUTCOME_WAS_QUICK_ANSWER_SEEN, "OutcomeWasQuickAnswerSeen");
	// UKM CS v2 outcomes.
	outcomes.put(Feature.OUTCOME_WAS_CARDS_DATA_SHOWN, "OutcomeWasCardsDataShown");
	OUTCOMES = Collections.unmodifiableMap(outcomes);

	// NOTE: this list needs to be kept in sync with the white list in
	// predictor_config_definitions.cc and with ukm.xml!
	// Integer values should contain @Feature values only.
	Map<Integer, String> features = new HashMap<Integer, String>();
	features.put(Feature.DURATION_AFTER_SCROLL_MS, "DurationAfterScrollMs");
	features.put(Feature.SCREEN_TOP_DPS, "ScreenTopDps");
	features.put(Feature.WAS_SCREEN_BOTTOM, "WasScreenBottom");
	features.put(Feature.PREVIOUS_WEEK_IMPRESSIONS_COUNT, "PreviousWeekImpressionsCount");
	features.put(Feature.PREVIOUS_WEEK_CTR_PERCENT, "PreviousWeekCtrPercent");
	features.put(Feature.PREVIOUS_28DAY_IMPRESSIONS_COUNT, "Previous28DayImpressionsCount");
	features.put(Feature.PREVIOUS_28DAY_CTR_PERCENT, "Previous28DayCtrPercent");
	// UKM CS v2 features.
	features.put(Feature.DID_OPT_IN, "DidOptIn");
	features.put(Feature.IS_SHORT_WORD, "IsShortWord");
	features.put(Feature.IS_LONG_WORD, "IsLongWord");
	features.put(Feature.IS_WORD_EDGE, "IsWordEdge");
	features.put(Feature.IS_ENTITY, "IsEntity");
	features.put(Feature.TAP_DURATION_MS, "TapDurationMs");
	// UKM CS v3 features.
	features.put(Feature.FONT_SIZE, "FontSize");
	features.put(Feature.IS_HTTP, "IsHttp");
	features.put(Feature.IS_SECOND_TAP_OVERRIDE, "IsSecondTapOverride");
	features.put(Feature.IS_ENTITY_ELIGIBLE, "IsEntityEligible");
	features.put(Feature.IS_LANGUAGE_MISMATCH, "IsLanguageMismatch");
	features.put(Feature.PORTION_OF_ELEMENT, "PortionOfElement");
	// UKM CS v4 features.
	features.put(Feature.TAP_COUNT, "TapCount");
	features.put(Feature.OPEN_COUNT, "OpenCount");
	features.put(Feature.QUICK_ANSWER_COUNT, "QuickAnswerCount");
	features.put(Feature.ENTITY_IMPRESSIONS_COUNT, "EntityImpressionsCount");
	features.put(Feature.ENTITY_OPENS_COUNT, "EntityOpensCount");
	features.put(Feature.QUICK_ACTION_IMPRESSIONS_COUNT, "QuickActionImpressionsCount");
	features.put(Feature.QUICK_ACTIONS_TAKEN_COUNT, "QuickActionsTaken");
	features.put(Feature.QUICK_ACTIONS_IGNORED_COUNT, "QuickActionsIgnored");
	FEATURES = Collections.unmodifiableMap(features);

	// Map keys should contain @Feature int values only.
	Map<Integer, String> allNames = new HashMap<Integer, String>();
	allNames.putAll(outcomes);
	allNames.putAll(features);
	ALL_NAMES = Collections.unmodifiableMap(allNames);
	}

	// Pointer to the native instance of this class.
	private long mNativePointer;

	// Whether logging for the current page has been setup.
	private boolean mIsLoggingReadyForPage;

	// The WebContents of the base page that the log data is associated with.
	private WebContents mBasePageWebContents;

	// Whether inference has already occurred for this interaction (and calling #logFeature is no
	// longer allowed).
	private boolean mHasInferenceOccurred;

	// What kind of ML prediction we were able to get.
	private @AssistRankerPrediction int mAssistRankerPrediction =
	AssistRankerPrediction.UNDETERMINED;

	// Map that accumulates all of the Features to log for a specific user-interaction.
	// Map keys should contain @Feature int values only.
	private Map<Integer, Object> mFeaturesToLog;

	// A for-testing copy of all the features to log setup so that it will survive a {@link #reset}.
	// Map keys should contain @Feature int values only.
	private Map<Integer, Object> mFeaturesLoggedForTesting;
	private Map<Integer, Object> mOutcomesLoggedForTesting;

	private ContextualSearchInteractionPersister mInteractionPersister;

	private long mEventIdToPersist;

	/**
	* Constructs a Ranker Logger and associated native implementation to write Contextual Search
	* ML data to Ranker.
	*/
	public ContextualSearchRankerLoggerImpl() {
	this(new ContextualSearchInteractionPersisterImpl());
	}

	/**
	* Constructs a Ranker Logger implementation for testing.
	* @param interactionPersister The {@link ContextualSearchInteractionPersister} to use for this
	* instance.
	*/
	public ContextualSearchRankerLoggerImpl(
	ContextualSearchInteractionPersister interactionPersister) {
	mInteractionPersister = interactionPersister;
	if (isEnabled()) mNativePointer = nativeInit();
	}

	/**
	* This method should be called to clean up storage when an instance of this class is
	* no longer in use. The nativeDestroy will call the destructor on the native instance.
	*/
	void destroy() {
	// TODO(donnd): looks like this is never being called. Fix.
	if (isEnabled()) {
	assert mNativePointer != 0;
	writeLogAndReset();
	nativeDestroy(mNativePointer);
	mNativePointer = 0;
	}
	mIsLoggingReadyForPage = false;
	}

	@Override
	public void setupLoggingForPage(@Nullable WebContents basePageWebContents) {
	mIsLoggingReadyForPage = true;
	mBasePageWebContents = basePageWebContents;
	mHasInferenceOccurred = false;
	nativeSetupLoggingAndRanker(mNativePointer, basePageWebContents);
	}

	@Override
	public boolean isQueryEnabled() {
	return nativeIsQueryEnabled(mNativePointer);
	}

	@Override
	public void logFeature(@Feature int feature, Object value) {
	assert mIsLoggingReadyForPage : "mIsLoggingReadyForPage false.";
	assert !mHasInferenceOccurred;
	if (!isEnabled()) return;

	logInternal(feature, value);
	}

	@Override
	public void logOutcome(@Feature int feature, Object value) {
	assert mIsLoggingReadyForPage;
	assert mHasInferenceOccurred;
	if (!isEnabled()) return;

	logInternal(feature, value);
	}

	@Override
	public @AssistRankerPrediction int runPredictionForTapSuppression() {
	assert mIsLoggingReadyForPage;
	assert !mHasInferenceOccurred;
	mHasInferenceOccurred = true;
	if (isEnabled() && mBasePageWebContents != null && mFeaturesToLog != null
	&& !mFeaturesToLog.isEmpty()) {
	for (Map.Entry<Integer, Object> entry : mFeaturesToLog.entrySet()) {
	logObject(entry.getKey(), entry.getValue());
	}
	mFeaturesLoggedForTesting = mFeaturesToLog;
	mFeaturesToLog = new HashMap<Integer, Object>();
	mAssistRankerPrediction = nativeRunInference(mNativePointer);
	ContextualSearchUma.logRecordedFeaturesToRanker();
	}
	return mAssistRankerPrediction;
	}

	@Override
	public @AssistRankerPrediction int getPredictionForTapSuppression() {
	return mAssistRankerPrediction;
	}

	@Override
	public void reset() {
	mIsLoggingReadyForPage = false;
	mHasInferenceOccurred = false;
	mFeaturesToLog = null;
	mBasePageWebContents = null;
	mAssistRankerPrediction = AssistRankerPrediction.UNDETERMINED;
	}

	@Override
	public void writeLogAndReset() {
	if (isEnabled()) {
	if (mBasePageWebContents != null && mFeaturesToLog != null
	&& !mFeaturesToLog.isEmpty()) {
	assert mIsLoggingReadyForPage;
	assert mHasInferenceOccurred;
	// Only the outcomes will be present, since we logged inference features at
	// inference time.
	for (Map.Entry<Integer, Object> entry : mFeaturesToLog.entrySet()) {
	logObject(entry.getKey(), entry.getValue());
	}
	mOutcomesLoggedForTesting = mFeaturesToLog;
	ContextualSearchUma.logRecordedOutcomesToRanker();
	// Also persist the outcomes if we are persisting this interaction.
	if (mEventIdToPersist != 0) {
	mInteractionPersister.persistInteractions(mEventIdToPersist, mFeaturesToLog);
	mEventIdToPersist = 0;
	}
	}
	nativeWriteLogAndReset(mNativePointer);
	}
	reset();
	}

	@Override
	public void persistInteraction(long eventId) {
	if (eventId != 0) mEventIdToPersist = eventId;
	}

	@Override
	public ContextualSearchInteractionPersister getInteractionPersister() {
	return mInteractionPersister;
	}

	/**
	* Logs the given feature/value to the internal map that accumulates an entire record (which can
	* be logged by calling writeLogAndReset).
	* @param feature The feature to log.
	* @param value The value to log.
	*/
	private void logInternal(@Feature int feature, Object value) {
	if (mFeaturesToLog == null) mFeaturesToLog = new HashMap<Integer, Object>();
	mFeaturesToLog.put(feature, value);
	}

	/** Whether actually writing data is enabled. If not, we may do nothing, or just print. */
	private boolean isEnabled() {
	return !ContextualSearchFieldTrial.getSwitch(
	ContextualSearchSwitch.IS_UKM_RANKER_LOGGING_DISABLED);
	}

	/**
	* Logs the given {@link ContextualSearchInteractionRecorder.Feature} with the given value
	* {@link Object}.
	* @param feature The feature to log.
	* @param value An {@link Object} value to log (must be convertible to a {@code long}).
	*/
	private void logObject(@Feature int feature, Object value) {
	if (value instanceof Boolean) {
	logToNative(feature, ((boolean) value ? 1 : 0));
	} else if (value instanceof Integer) {
	logToNative(feature, (int) value);
	} else if (value instanceof Character) {
	logToNative(feature, Character.getNumericValue((char) value));
	} else {
	assert false : "Could not log feature to Ranker: " + String.valueOf(feature)
	+ " of class "
	+ value.getClass();
	}
	}

	/**
	* Logs to the native instance. All native logging must go through this bottleneck.
	* @param feature The feature to log.
	* @param value The value to log.
	*/
	private void logToNative(@Feature int feature, int value) {
	String featureName = getFeatureName(feature);
	assert featureName != null : "No Name for feature " + feature;
	nativeLogInt32(mNativePointer, featureName, value);
	}

	/**
	* @return The name of the given feature.
	*/
	private String getFeatureName(@Feature int feature) {
	return ALL_NAMES.get(feature);
	}

	/**
	* Gets the current set of features that have been logged. Should only be used for testing
	* purposes!
	* @return The current set of features that have been logged, or {@code null}.
	*/
	@VisibleForTesting
	@Nullable
	Map<Integer, Object> getFeaturesLogged() {
	return mFeaturesLoggedForTesting;
	}

	/**
	* Gets the current set of outcomes that have been logged. Should only be used for
	* testing purposes!
	* @return The current set of outcomes that have been logged, or {@code null}.
	*/
	@VisibleForTesting
	@Nullable
	Map<Integer, Object> getOutcomesLogged() {
	return mOutcomesLoggedForTesting;
	}

	// ============================================================================================
	// Native methods.
	// ============================================================================================
	private native long nativeInit();
	private native void nativeDestroy(long nativeContextualSearchRankerLoggerImpl);
	private native void nativeLogInt32(
	long nativeContextualSearchRankerLoggerImpl, String featureString, int value);
	private native void nativeSetupLoggingAndRanker(
	long nativeContextualSearchRankerLoggerImpl, WebContents basePageWebContents);
	// Returns an AssistRankerPrediction integer value.
	private native int nativeRunInference(long nativeContextualSearchRankerLoggerImpl);
	private native void nativeWriteLogAndReset(long nativeContextualSearchRankerLoggerImpl);
	private native boolean nativeIsQueryEnabled(long nativeContextualSearchRankerLoggerImpl);
	}