From 0a368b2c391dd3ebaf6b8917c16c41b65c1d5ab7 Mon Sep 17 00:00:00 2001
From: David Chen <dwchen@google.com>
Date: Wed, 6 Dec 2017 16:28:16 -0800
Subject: [PATCH] Adds API for apps to push events to statsd.

This API allows app to construct custom metrics based on labels
chosen by the app developers. Also added some buttons to manually
test this functionality in the dogfood app.

Test: Verified that Android can be built and tested with custom app.
Bug: 69522276
Change-Id: Ifb7abea4c1d62fb435a9cb6f32df12bc2234d82f
---
 Android.bp                                    |  2 +-
 api/current.txt                               |  6 ++
 cmds/statsd/src/atoms.proto                   | 24 +++++++
 .../dogfood/res/layout/activity_main.xml      | 17 +++++
 .../tools/dogfood/res/values/strings.xml      |  3 +
 .../android/statsd/dogfood/MainActivity.java  | 14 ++++
 core/java/android/util/StatsLog.java          | 70 +++++++++++++++++++
 tools/stats_log_api_gen/main.cpp              |  2 +-
 8 files changed, 136 insertions(+), 2 deletions(-)
 create mode 100644 core/java/android/util/StatsLog.java

diff --git a/Android.bp b/Android.bp
index 015e59fe9d08..773bf76da80d 100644
--- a/Android.bp
+++ b/Android.bp
@@ -624,7 +624,7 @@ genrule {
     name: "framework-statslog-gen",
     tools: ["stats-log-api-gen"],
     cmd: "$(location stats-log-api-gen) --java $(out)",
-    out: ["android/util/StatsLog.java"],
+    out: ["android/util/StatsLogInternal.java"],
 }
 
 gensrcs {
diff --git a/api/current.txt b/api/current.txt
index 66a577c17de5..455cb7db1264 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -44575,6 +44575,12 @@ package android.util {
     field public static final int[] WILD_CARD;
   }
 
+  public final class StatsLog {
+    method public static boolean logEvent(int);
+    method public static boolean logStart(int);
+    method public static boolean logStop(int);
+  }
+
   public class StringBuilderPrinter implements android.util.Printer {
     ctor public StringBuilderPrinter(java.lang.StringBuilder);
     method public void println(java.lang.String);
diff --git a/cmds/statsd/src/atoms.proto b/cmds/statsd/src/atoms.proto
index 716fee6bb1fb..3471737e7dd9 100644
--- a/cmds/statsd/src/atoms.proto
+++ b/cmds/statsd/src/atoms.proto
@@ -79,6 +79,7 @@ message Atom {
         IsolatedUidChanged isolated_uid_changed = 43;
         PacketWakeupOccurred packet_wakeup_occurred = 44;
         DropboxErrorChanged dropbox_error_changed = 45;
+        AppHook app_hook = 46;
         // TODO: Reorder the numbering so that the most frequent occur events occur in the first 15.
     }
 
@@ -801,6 +802,29 @@ message DropboxErrorChanged {
     optional int32 is_foreground = 7;
 }
 
+/*
+ * Allows other apps to push events into statsd.
+ * Logged from:
+ *      frameworks/base/core/java/android/util/StatsLog.java
+ */
+message AppHook {
+    // The uid of the application that sent this custom atom.
+    optional int32 uid = 1;
+
+    // An arbitrary label chosen by the developer. For Android P, the label should be in [0, 16).
+    optional int32 label = 2;
+
+    // Allows applications to easily use a custom event as start/stop boundaries (ie, define custom
+    // predicates for the metrics).
+    enum State {
+        UNKNOWN = 0;
+        UNSPECIFIED = 1;  // For events that are known to not represent START/STOP.
+        STOP = 2;
+        START = 3;
+    }
+    optional State state = 3;
+}
+
 /**
  * Pulls bytes transferred via wifi (Sum of foreground and background usage).
  *
diff --git a/cmds/statsd/tools/dogfood/res/layout/activity_main.xml b/cmds/statsd/tools/dogfood/res/layout/activity_main.xml
index 39978971d6b4..5d35c291f365 100644
--- a/cmds/statsd/tools/dogfood/res/layout/activity_main.xml
+++ b/cmds/statsd/tools/dogfood/res/layout/activity_main.xml
@@ -111,6 +111,23 @@
                 android:text="@string/screen_off"/>
         </LinearLayout>
 
+        <LinearLayout android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:orientation="horizontal">
+
+            <Button
+                android:id="@+id/custom_start"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/custom_start" />
+
+            <Button
+                android:id="@+id/custom_stop"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/custom_stop" />
+        </LinearLayout>
+
         <Button android:id="@+id/dump"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
diff --git a/cmds/statsd/tools/dogfood/res/values/strings.xml b/cmds/statsd/tools/dogfood/res/values/strings.xml
index 7690df616ca5..0eab0f4d0725 100644
--- a/cmds/statsd/tools/dogfood/res/values/strings.xml
+++ b/cmds/statsd/tools/dogfood/res/values/strings.xml
@@ -47,6 +47,9 @@
     <string name="screen_on">Screen On</string>
     <string name="screen_off">Screen Off</string>
 
+    <string name="custom_start">App hook start</string>
+    <string name="custom_stop">App hook stop</string>
+
     <string name="dump">DumpReport</string>
     <string name="report_header">Report details</string>
 </resources>
diff --git a/cmds/statsd/tools/dogfood/src/com/android/statsd/dogfood/MainActivity.java b/cmds/statsd/tools/dogfood/src/com/android/statsd/dogfood/MainActivity.java
index c83802e58cd9..70dd6347e1a4 100644
--- a/cmds/statsd/tools/dogfood/src/com/android/statsd/dogfood/MainActivity.java
+++ b/cmds/statsd/tools/dogfood/src/com/android/statsd/dogfood/MainActivity.java
@@ -140,6 +140,20 @@ public class MainActivity extends Activity {
             }
         });
 
+        findViewById(R.id.custom_start).setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View view) {
+                StatsLog.logStart(8);
+            }
+        });
+
+        findViewById(R.id.custom_stop).setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View view) {
+                StatsLog.logStop(8);
+            }
+        });
+
         mReportText = (TextView) findViewById(R.id.report_text);
 
         findViewById(R.id.dump).setOnClickListener(new View.OnClickListener() {
diff --git a/core/java/android/util/StatsLog.java b/core/java/android/util/StatsLog.java
new file mode 100644
index 000000000000..4805318385d5
--- /dev/null
+++ b/core/java/android/util/StatsLog.java
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.util;
+
+/**
+ * StatsLog provides an API for developers to send events to statsd. The events can be used to
+ * define custom metrics inside statsd. We will rate-limit how often the calls can be made inside
+ * statsd.
+ */
+public final class StatsLog extends StatsLogInternal {
+    private static final String TAG = "StatsManager";
+
+    private StatsLog() {}
+
+    /**
+     * Logs a start event.
+     *
+     * @param label developer-chosen label that is from [0, 16).
+     * @return True if the log request was sent to statsd.
+     */
+    public static boolean logStart(int label) {
+        if (label >= 0 && label < 16) {
+            StatsLog.write(APP_HOOK, label, APP_HOOK__STATE__START);
+            return true;
+        }
+        return false;
+    }
+
+    /**
+     * Logs a stop event.
+     *
+     * @param label developer-chosen label that is from [0, 16).
+     * @return True if the log request was sent to statsd.
+     */
+    public static boolean logStop(int label) {
+        if (label >= 0 && label < 16) {
+            StatsLog.write(APP_HOOK, label, APP_HOOK__STATE__STOP);
+            return true;
+        }
+        return false;
+    }
+
+    /**
+     * Logs an event that does not represent a start or stop boundary.
+     *
+     * @param label developer-chosen label that is from [0, 16).
+     * @return True if the log request was sent to statsd.
+     */
+    public static boolean logEvent(int label) {
+        if (label >= 0 && label < 16) {
+            StatsLog.write(APP_HOOK, label, APP_HOOK__STATE__UNSPECIFIED);
+            return true;
+        }
+        return false;
+    }
+}
diff --git a/tools/stats_log_api_gen/main.cpp b/tools/stats_log_api_gen/main.cpp
index 423d0285e96f..9a2082d55b58 100644
--- a/tools/stats_log_api_gen/main.cpp
+++ b/tools/stats_log_api_gen/main.cpp
@@ -247,7 +247,7 @@ write_stats_log_java(FILE* out, const Atoms& atoms)
     fprintf(out, " * API For logging statistics events.\n");
     fprintf(out, " * @hide\n");
     fprintf(out, " */\n");
-    fprintf(out, "public final class StatsLog {\n");
+    fprintf(out, "public class StatsLogInternal {\n");
     fprintf(out, "    // Constants for atom codes.\n");
 
     // Print constants for the atom codes.