[TTS] Record CTR by week and 28-day intervals.

chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/CtrSuppression.java

Index: chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/CtrSuppression.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/CtrSuppression.java b/chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/CtrSuppression.java
new file mode 100644
index 0000000000000000000000000000000000000000..1e7e28970f283d5bcfd91faf3b5adbde644e3331
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/CtrSuppression.java
@@ -0,0 +1,151 @@
+// 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.content.Context;
+
+import org.chromium.base.annotations.CalledByNative;
+import org.chromium.chrome.browser.preferences.ChromePreferenceManager;
+
+/**
+ * Provides a ContextualSearchHeuristic for CTR Recording, logging, and eventually suppression.
+ * Records impressions and CTR when the Bar is dismissed.
+ * TODO(donnd): add suppression logic.
+ * Logs "impressions" and "CTR" per user in UMA for the previous week and 28-day period.
+ * An impression is a view of our UX (the Bar) and CTR is the "click-through rate" (user opens of
+ * the Bar).
+ * This class also implements the device-based native integer storage required by the
+ * native {@code CtrAggregator} class.
+ */
+public class CtrSuppression extends ContextualSearchHeuristic {
+    private long mNativePointer;
+
+    private static Integer sCurrentWeekNumberCache;
+
+    private final ChromePreferenceManager mPreferenceManager;
+
+    /**
+     * Constructs an object that tracks impressions and clicks per user to produce CTR and
+     * impression metrics.
+     * @param context An Android Context.
+     */
+    CtrSuppression(Context context) {
+        mPreferenceManager = ChromePreferenceManager.getInstance(context);
+
+        // This needs to be done last in this constructor because the native code may call
+        // into this object.
+        mNativePointer = nativeInit();
+    }
+
+    /**
+     * This method should be called to clean up storage when an instance of this class is
+     * no longer in use.
+     */
+    public void destroy() {
+        if (mNativePointer != 0L) {
+            nativeDestroy(mNativePointer);
+        }
+    }
+
+    // ============================================================================================
+    // ContextualSearchHeuristic overrides.
+    // ============================================================================================
+
+    @Override
+    protected boolean isConditionSatisfiedAndEnabled() {
+        return false;
+    }
+
+    @Override
+    protected boolean isConditionSatisfiedForAggregateLogging() {
+        return false;
+    }
+
+    @Override
+    protected void logConditionState() {
+        // Since the CTR for previous time periods never changes, we only need to write to the UMA
+        // log when we may have moved to a new week, or we have new persistent data.
+        // We cache the current week in persistent storage so we can tell when it changes.
+        boolean didWeekChange = didWeekChange(nativeGetCurrentWeekNumber(mNativePointer));
+        if (didWeekChange) {
+            if (nativeHasPreviousWeekData(mNativePointer)) {
+                int previousWeekImpressions = nativeGetPreviousWeekImpressions(mNativePointer);
+                int previousWeekCtr = (int) (100 * nativeGetPreviousWeekCtr(mNativePointer));
+                ContextualSearchUma.logPreviousWeekCtr(previousWeekImpressions, previousWeekCtr);
+            }
+
+            if (nativeHasPrevious28DayData(mNativePointer)) {
+                int previous28DayImpressions = nativeGetPrevious28DayImpressions(mNativePointer);
+                int previous28DayCtr = (int) (100 * nativeGetPrevious28DayCtr(mNativePointer));
+                ContextualSearchUma.logPrevious28DayCtr(previous28DayImpressions, previous28DayCtr);
+            }
+        }
+    }
+
+    @Override
+    protected void logResultsSeen(boolean wasSearchContentViewSeen, boolean wasActivatedByTap) {
+        if (wasActivatedByTap) {
+            nativeRecordImpression(mNativePointer, wasSearchContentViewSeen);
+        }
+    }
+
+    // ============================================================================================
+    // Device integer storage.
+    // ============================================================================================
+
+    @CalledByNative
+    void writeInt(String key, int value) {
+        mPreferenceManager.writeInt(key, value);
+    }
+
+    @CalledByNative
+    int readInt(String key) {
+        return mPreferenceManager.readInt(key);
+    }
+
+    // ============================================================================================
+    // Private helpers.
+    // ============================================================================================
+
+    /**
+     * Updates the "current week number" preference and returns whether the week has changed.
+     * @param currentWeekNumber The week number of the current week.
+     * @return {@code true} if the current week number is different from the last time we checked,
+     *         or we have never checked.
+     */
+    private boolean didWeekChange(int currentWeekNumber) {
+        if (mPreferenceManager.getContextualSearchCurrentWeekNumber() == currentWeekNumber) {
+            return false;
+        } else {
+            mPreferenceManager.setContextualSearchCurrentWeekNumber(currentWeekNumber);
+            return true;
+        }
+    }
+
+    // ============================================================================================
+    // Native callback support.
+    // ============================================================================================
+
+    @CalledByNative
+    private void clearNativePointer() {
+        assert mNativePointer != 0;
+        mNativePointer = 0;
+    }
+
+    // ============================================================================================
+    // Native methods.
+    // ============================================================================================
+    private native long nativeInit();
+    private native void nativeDestroy(long nativeCtrSuppression);
+
+    private native void nativeRecordImpression(long nativeCtrSuppression, boolean wasSeen);
+    private native int nativeGetCurrentWeekNumber(long nativeCtrSuppression);
+    private native boolean nativeHasPreviousWeekData(long nativeCtrSuppression);
+    private native int nativeGetPreviousWeekImpressions(long nativeCtrSuppression);
+    private native float nativeGetPreviousWeekCtr(long nativeCtrSuppression);
+    private native boolean nativeHasPrevious28DayData(long nativeCtrSuppression);
+    private native int nativeGetPrevious28DayImpressions(long nativeCtrSuppression);
+    private native float nativeGetPrevious28DayCtr(long nativeCtrSuppression);
+}