Batch delete log entries

app/src/main/java/eu/faircode/email/DaoLog.java

@@ -42,6 +42,7 @@ public interface DaoLog {
     long insertLog(EntityLog log);
 
     @Query("DELETE FROM log" +
-            " WHERE time < :before")
-    int deleteLogs(long before);
+            " WHERE id IN (SELECT id FROM log" +
+            " WHERE time < :before ORDER BY time LIMIT :limit)")
+    int deleteLogs(long before, int limit);
 }

app/src/main/java/eu/faircode/email/FragmentLogs.java

@@ -136,7 +136,13 @@ public class FragmentLogs extends FragmentBase {
             protected Void onExecute(Context context, Bundle args) {
                 DB db = DB.getInstance(context);
 
-                db.log().deleteLogs(new Date().getTime());
+                long before = new Date().getTime();
+                while (true) {
+                    int logs = db.log().deleteLogs(before, WorkerCleanup.LOG_DELETE_BATCH_SIZE);
+                    Log.i("Deleted logs=" + logs);
+                    if (logs < WorkerCleanup.LOG_DELETE_BATCH_SIZE)
+                        break;
+                }
 
                 return null;
             }

app/src/main/java/eu/faircode/email/WorkerCleanup.java

@@ -53,6 +53,8 @@ public class WorkerCleanup extends Worker {
     private static final long KEEP_CONTACTS_DURATION = 180 * 24 * 3600 * 1000L; // milliseconds
     private static final long KEEP_LOG_DURATION = 24 * 3600 * 1000L; // milliseconds
 
+    static final int LOG_DELETE_BATCH_SIZE = 100;
+
     public WorkerCleanup(@NonNull Context context, @NonNull WorkerParameters workerParams) {
         super(context, workerParams);
         Log.i("Instance " + getName());
@@ -297,8 +299,13 @@ public class WorkerCleanup extends Worker {
             Log.i("Deleted contacts=" + contacts);
 
             Log.i("Cleanup log");
-            int logs = db.log().deleteLogs(now - KEEP_LOG_DURATION);
-            Log.i("Deleted logs=" + logs);
+            long before = now - KEEP_LOG_DURATION;
+            while (true) {
+                int logs = db.log().deleteLogs(before, LOG_DELETE_BATCH_SIZE);
+                Log.i("Deleted logs=" + logs + " before=" + new Date(before));
+                if (logs < LOG_DELETE_BATCH_SIZE)
+                    break;
+            }
 
             if (BuildConfig.DEBUG) {
                 // https://sqlite.org/lang_analyze.html