From dcd3644f224da72ec95c590394ed656915bba481 Mon Sep 17 00:00:00 2001
From: Tianjie Xu <xunchang@google.com>
Date: Fri, 13 May 2016 12:30:29 -0700
Subject: [PATCH] Report OTA time statistics

Read time and I/O for OTA update from last_install, and report the
statistics using MetricsLogger.histogram.

Bug: 28658632
Change-Id: I7fd06a82cbabd346d6d44f81ebad08f6baf4b8d0
---
 core/java/android/os/RecoverySystem.java      | 62 ++++++++++++++++++-
 .../java/com/android/server/BootReceiver.java |  2 +-
 2 files changed, 62 insertions(+), 2 deletions(-)

diff --git a/core/java/android/os/RecoverySystem.java b/core/java/android/os/RecoverySystem.java
index 403e06ca85531..4abbf0efc81da 100644
--- a/core/java/android/os/RecoverySystem.java
+++ b/core/java/android/os/RecoverySystem.java
@@ -25,8 +25,10 @@ import android.text.TextUtils;
 import android.util.Log;
 
 import java.io.ByteArrayInputStream;
+import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileNotFoundException;
+import java.io.FileReader;
 import java.io.FileWriter;
 import java.io.IOException;
 import java.io.InputStream;
@@ -45,6 +47,8 @@ import java.util.Locale;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipFile;
 
+import com.android.internal.logging.MetricsLogger;
+
 import sun.security.pkcs.PKCS7;
 import sun.security.pkcs.SignerInfo;
 
@@ -69,6 +73,7 @@ public class RecoverySystem {
     /** Used to communicate with recovery.  See bootable/recovery/recovery.cpp. */
     private static final File RECOVERY_DIR = new File("/cache/recovery");
     private static final File LOG_FILE = new File(RECOVERY_DIR, "log");
+    private static final File LAST_INSTALL_FILE = new File(RECOVERY_DIR, "last_install");
     private static final String LAST_PREFIX = "last_";
 
     /**
@@ -682,13 +687,64 @@ public class RecoverySystem {
         }
     }
 
+    // Read last_install; then report time for update and I/O to tron.
+    // Only report on the reboots immediately after an OTA update.
+    private static void parseLastInstallLog(Context context) {
+        try (BufferedReader in = new BufferedReader(new FileReader(LAST_INSTALL_FILE))) {
+            String line = null;
+            int bytesWritten = -1, bytesStashed = -1;
+            int timeTotal = -1;
+            while ((line = in.readLine()) != null) {
+                // Here is an example of lines in last_install:
+                // ...
+                // time_total: 101
+                // bytes_written_vendor: 51074
+                // bytes_stashed_vendor: 200
+                int numIndex = line.indexOf(':');
+                if (numIndex == -1 || numIndex + 1 >= line.length()) {
+                    continue;
+                }
+                String numString = line.substring(numIndex + 1).trim();
+                int parsedNum;
+                try {
+                    parsedNum = Integer.parseInt(numString);
+                } catch (NumberFormatException ignored) {
+                    Log.e(TAG, "Failed to parse numbers in " + line);
+                    continue;
+                }
+
+                if (line.startsWith("time")) {
+                    timeTotal = parsedNum;
+                } else if (line.startsWith("bytes_written")) {
+                    bytesWritten = (bytesWritten == -1) ? parsedNum : bytesWritten + parsedNum;
+                } else if (line.startsWith("bytes_stashed")) {
+                    bytesStashed = (bytesStashed == -1) ? parsedNum : bytesStashed + parsedNum;
+                }
+            }
+
+            // Don't report data to tron if corresponding entry isn't found in last_install.
+            if (timeTotal != -1) {
+                MetricsLogger.histogram(context, "ota_time_total", timeTotal);
+            }
+            if (bytesWritten != -1) {
+                MetricsLogger.histogram(context, "ota_bytes_written", bytesWritten);
+            }
+            if (bytesStashed != -1) {
+                MetricsLogger.histogram(context, "ota_bytes_stashed", bytesStashed);
+            }
+
+        } catch (IOException ignored) {
+            Log.e(TAG, "Failed to read lines in last_install", ignored);
+        }
+    }
+
     /**
      * Called after booting to process and remove recovery-related files.
      * @return the log file from recovery, or null if none was found.
      *
      * @hide
      */
-    public static String handleAftermath() {
+    public static String handleAftermath(Context context) {
         // Record the tail of the LOG_FILE
         String log = null;
         try {
@@ -699,6 +755,10 @@ public class RecoverySystem {
             Log.e(TAG, "Error reading recovery log", e);
         }
 
+        if (log != null) {
+            parseLastInstallLog(context);
+        }
+
         // Only remove the OTA package if it's partially processed (uncrypt'd).
         boolean reservePackage = BLOCK_MAP_FILE.exists();
         if (!reservePackage && UNCRYPT_PACKAGE_FILE.exists()) {
diff --git a/core/java/com/android/server/BootReceiver.java b/core/java/com/android/server/BootReceiver.java
index 6d6c1622e5c24..fbc51cdca6c22 100644
--- a/core/java/com/android/server/BootReceiver.java
+++ b/core/java/com/android/server/BootReceiver.java
@@ -127,7 +127,7 @@ public class BootReceiver extends BroadcastReceiver {
             .append("\n").toString();
         final String bootReason = SystemProperties.get("ro.boot.bootreason", null);
 
-        String recovery = RecoverySystem.handleAftermath();
+        String recovery = RecoverySystem.handleAftermath(ctx);
         if (recovery != null && db != null) {
             db.addText("SYSTEM_RECOVERY_LOG", headers + recovery);
         }