Camera: Collect capture latency histogram

For each camera session, collect capture latency histogram for all streams.

Test: Camera CTS, and observe statsd output
Bug: 154159000
Change-Id: I7741371ca8540cdf9c9a47246c0ef0f0f82df32a

core/java/android/hardware/CameraStreamStats.java

@@ -19,7 +19,6 @@ import android.os.Parcel;
 import android.os.Parcelable;
 import android.util.Log;
 
-import java.util.ArrayList;
 /**
  * The camera stream statistics used for passing camera stream information from
  * camera service to camera service proxy.
@@ -30,6 +29,8 @@ import java.util.ArrayList;
  * @hide
  */
 public class CameraStreamStats implements Parcelable {
+    public static final int HISTOGRAM_TYPE_UNKNOWN = 0;
+    public static final int HISTOGRAM_TYPE_CAPTURE_LATENCY = 1;
 
     private int mWidth;
     private int mHeight;
@@ -41,6 +42,9 @@ public class CameraStreamStats implements Parcelable {
     private int mStartLatencyMs;
     private int mMaxHalBuffers;
     private int mMaxAppBuffers;
+    private int mHistogramType;
+    private float[] mHistogramBins;
+    private long[] mHistogramCounts;
 
     private static final String TAG = "CameraStreamStats";
 
@@ -55,6 +59,7 @@ public class CameraStreamStats implements Parcelable {
         mStartLatencyMs = 0;
         mMaxHalBuffers = 0;
         mMaxAppBuffers = 0;
+        mHistogramType = HISTOGRAM_TYPE_UNKNOWN;
     }
 
     public CameraStreamStats(int width, int height, int format,
@@ -70,6 +75,7 @@ public class CameraStreamStats implements Parcelable {
         mStartLatencyMs = startLatencyMs;
         mMaxHalBuffers = maxHalBuffers;
         mMaxAppBuffers = maxAppBuffers;
+        mHistogramType = HISTOGRAM_TYPE_UNKNOWN;
     }
 
     public static final @android.annotation.NonNull Parcelable.Creator<CameraStreamStats> CREATOR =
@@ -112,6 +118,9 @@ public class CameraStreamStats implements Parcelable {
         dest.writeInt(mStartLatencyMs);
         dest.writeInt(mMaxHalBuffers);
         dest.writeInt(mMaxAppBuffers);
+        dest.writeInt(mHistogramType);
+        dest.writeFloatArray(mHistogramBins);
+        dest.writeLongArray(mHistogramCounts);
     }
 
     public void readFromParcel(Parcel in) {
@@ -125,6 +134,9 @@ public class CameraStreamStats implements Parcelable {
         mStartLatencyMs = in.readInt();
         mMaxHalBuffers = in.readInt();
         mMaxAppBuffers = in.readInt();
+        mHistogramType = in.readInt();
+        mHistogramBins = in.createFloatArray();
+        mHistogramCounts = in.createLongArray();
     }
 
     public int getWidth() {
@@ -166,4 +178,16 @@ public class CameraStreamStats implements Parcelable {
     public int getMaxAppBuffers() {
         return mMaxAppBuffers;
     }
+
+    public int getHistogramType() {
+        return mHistogramType;
+    }
+
+    public float[] getHistogramBins() {
+        return mHistogramBins;
+    }
+
+    public long[] getHistogramCounts() {
+        return mHistogramCounts;
+    }
 }

services/core/java/com/android/server/camera/CameraServiceProxy.java

@@ -57,6 +57,7 @@ import com.android.server.wm.WindowManagerInternal;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
@@ -466,8 +467,13 @@ public class CameraServiceProxy extends SystemService
                     streamProtos[i].firstCaptureLatencyMillis = streamStats.getStartLatencyMs();
                     streamProtos[i].maxHalBuffers = streamStats.getMaxHalBuffers();
                     streamProtos[i].maxAppBuffers = streamStats.getMaxAppBuffers();
+                    streamProtos[i].histogramType = streamStats.getHistogramType();
+                    streamProtos[i].histogramBins = streamStats.getHistogramBins();
+                    streamProtos[i].histogramCounts = streamStats.getHistogramCounts();
 
                     if (CameraServiceProxy.DEBUG) {
+                        String histogramTypeName =
+                                cameraHistogramTypeToString(streamProtos[i].histogramType);
                         Slog.v(TAG, "Stream " + i + ": width " + streamProtos[i].width
                                 + ", height " + streamProtos[i].height
                                 + ", format " + streamProtos[i].format
@@ -478,7 +484,12 @@ public class CameraServiceProxy extends SystemService
                                 + ", firstCaptureLatencyMillis "
                                 + streamProtos[i].firstCaptureLatencyMillis
                                 + ", maxHalBuffers " + streamProtos[i].maxHalBuffers
-                                + ", maxAppBuffers " + streamProtos[i].maxAppBuffers);
+                                + ", maxAppBuffers " + streamProtos[i].maxAppBuffers
+                                + ", histogramType " + histogramTypeName
+                                + ", histogramBins "
+                                + Arrays.toString(streamProtos[i].histogramBins)
+                                + ", histogramCounts "
+                                + Arrays.toString(streamProtos[i].histogramCounts));
                     }
                 }
             }
@@ -797,4 +808,14 @@ public class CameraServiceProxy extends SystemService
         return "CAMERA_FACING_UNKNOWN";
     }
 
+    private static String cameraHistogramTypeToString(int cameraHistogramType) {
+        switch (cameraHistogramType) {
+            case CameraStreamStats.HISTOGRAM_TYPE_CAPTURE_LATENCY:
+                return "HISTOGRAM_TYPE_CAPTURE_LATENCY";
+            default:
+                break;
+        }
+        return "HISTOGRAM_TYPE_UNKNOWN";
+    }
+
 }