Add a 2.5 MB size limit to the text file storing BMM Events.

Test: atest CtsBackupHostTestCases, GtsBackupHostTestCases
atest BackupManagerMonitorDumpsysUtilsTest, UserBackupManagerServiceTest
Bug: 297163567

Change-Id: Ia1fdc0b465b960337f5e5c626460e305d96f4eb2

2 files changed, 34 insertions, 1 deletions

diff --git a/services/backup/java/com/android/server/backup/UserBackupManagerService.java b/services/backup/java/com/android/server/backup/UserBackupManagerService.java
index 2d80af92eea5..38af61b16ef3 100644
--- a/services/backup/java/com/android/server/backup/UserBackupManagerService.java
+++ b/services/backup/java/com/android/server/backup/UserBackupManagerService.java
@@ -486,6 +486,13 @@ public class UserBackupManagerService {
             File baseStateDir,
             File dataDir,
             TransportManager transportManager) {
+        // check if we are past the retention period for BMM Events,
+        // if so delete expired events and do not print them to dumpsys
+        BackupManagerMonitorDumpsysUtils backupManagerMonitorDumpsysUtils =
+                new BackupManagerMonitorDumpsysUtils();
+        if (backupManagerMonitorDumpsysUtils.deleteExpiredBMMEvents() && DEBUG){
+            Slog.d(TAG, "BMM Events recorded for dumpsys have expired");
+        }
         return new UserBackupManagerService(
                 userId,
                 context,
@@ -4197,6 +4204,9 @@ public class UserBackupManagerService {
             // We have not recorded BMMEvents yet.
             pw.println("NO BACKUP MANAGER MONITOR EVENTS");
             return;
+        } else if (bm.isFileLargerThanSizeLimit(events)){
+            pw.println("BACKUP MANAGER MONITOR EVENTS FILE OVER SIZE LIMIT - "
+                    + "future events will not be recorded");
         }
         pw.println("START OF BACKUP MANAGER MONITOR EVENTS");
         try (BufferedReader reader = new BufferedReader(new FileReader(events))) {
diff --git a/services/backup/java/com/android/server/backup/utils/BackupManagerMonitorDumpsysUtils.java b/services/backup/java/com/android/server/backup/utils/BackupManagerMonitorDumpsysUtils.java
index 16da846a093a..4b0d5a4928b6 100644
--- a/services/backup/java/com/android/server/backup/utils/BackupManagerMonitorDumpsysUtils.java
+++ b/services/backup/java/com/android/server/backup/utils/BackupManagerMonitorDumpsysUtils.java
@@ -57,11 +57,17 @@ public class BackupManagerMonitorDumpsysUtils {
     // Retention period of 60 days (in millisec) for the BMM Events.
     // After tha time has passed the text file containing the BMM events will be emptied
     private static final long LOGS_RETENTION_PERIOD_MILLISEC = 60 * TimeUnit.DAYS.toMillis(1);
+    // Size limit for the text file containing the BMM events
+    private static final long BMM_FILE_SIZE_LIMIT_BYTES = 25 * 1024 * 1000; // 2.5 MB
+
     // We cache the value of IsAfterRetentionPeriod() to avoid unnecessary disk I/O
     // mIsAfterRetentionPeriodCached tracks if we have cached the value of IsAfterRetentionPeriod()
     private boolean mIsAfterRetentionPeriodCached = false;
-    // The cahched value of IsAfterRetentionPeriod()
+    // The cached value of IsAfterRetentionPeriod()
     private boolean mIsAfterRetentionPeriod;
+    // If isFileLargerThanSizeLimit(bmmEvents)  returns true we cache the value to avoid
+    // unnecessary disk I/O
+   private boolean mIsFileLargerThanSizeLimit = false;
 
     /**
      * Parses the BackupManagerMonitor bundle for a RESTORE event in a series of strings that
@@ -116,6 +122,11 @@ public class BackupManagerMonitorDumpsysUtils {
             recordSetUpTimestamp();
         }
 
+        if(isFileLargerThanSizeLimit(bmmEvents)){
+            // Do not write more events if the file is over size limit
+            return;
+        }
+
         try (FileOutputStream out = new FileOutputStream(bmmEvents, /*append*/ true);
              PrintWriter pw = new FastPrintWriter(out);) {
 
@@ -192,6 +203,13 @@ public class BackupManagerMonitorDumpsysUtils {
         return fname;
     }
 
+    public boolean isFileLargerThanSizeLimit(File events){
+        if (!mIsFileLargerThanSizeLimit) {
+            mIsFileLargerThanSizeLimit = events.length() > getBMMEventsFileSizeLimit();
+        }
+        return mIsFileLargerThanSizeLimit;
+    }
+
     private String timestamp() {
         long currentTime = System.currentTimeMillis();
         Date date = new Date(currentTime);
@@ -402,6 +420,11 @@ public class BackupManagerMonitorDumpsysUtils {
         return LOGS_RETENTION_PERIOD_MILLISEC;
     }
 
+    @VisibleForTesting
+    long getBMMEventsFileSizeLimit(){
+        return BMM_FILE_SIZE_LIMIT_BYTES;
+    }
+
     /**
      * Delete the BMM Events file after the retention period has passed.
      *