add frequent restart detection

1 files changed, 23 insertions, 1 deletions

diff --git a/src/main/java/eu/siacs/conversations/persistance/DatabaseBackend.java b/src/main/java/eu/siacs/conversations/persistance/DatabaseBackend.java
index 5f625ebe..ad8dc62c 100644
--- a/src/main/java/eu/siacs/conversations/persistance/DatabaseBackend.java
+++ b/src/main/java/eu/siacs/conversations/persistance/DatabaseBackend.java
@@ -54,7 +54,7 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 	private static DatabaseBackend instance = null;
 
 	private static final String DATABASE_NAME = "history";
-	private static final int DATABASE_VERSION = 29;
+	private static final int DATABASE_VERSION = 30;
 
 	private static String CREATE_CONTATCS_STATEMENT = "create table "
 			+ Contact.TABLENAME + "(" + Contact.ACCOUNT + " TEXT, "
@@ -139,6 +139,8 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 			+ ") ON CONFLICT IGNORE"
 			+ ");";
 
+	private static String CREATE_START_TIMES_TABLE = "create table start_times (timestamp NUMBER);";
+
 	private DatabaseBackend(Context context) {
 		super(context, DATABASE_NAME, null, DATABASE_VERSION);
 	}
@@ -194,6 +196,7 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 		db.execSQL(CREATE_SIGNED_PREKEYS_STATEMENT);
 		db.execSQL(CREATE_IDENTITIES_STATEMENT);
 		db.execSQL(CREATE_PRESENCE_TEMPLATES_STATEMENT);
+		db.execSQL(CREATE_START_TIMES_TABLE);
 	}
 
 	@Override
@@ -338,6 +341,9 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 		if (oldVersion < 29 && newVersion >= 29) {
 			db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN " + Message.ERROR_MESSAGE + " TEXT");
 		}
+		if (oldVersion < 30 && newVersion >= 30) {
+			db.execSQL(CREATE_START_TIMES_TABLE);
+		}
 	}
 
 	private void canonicalizeJids(SQLiteDatabase db) {
@@ -1222,4 +1228,20 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 				SQLiteAxolotlStore.ACCOUNT + " = ?",
 				deleteArgs);
 	}
+
+	public boolean startTimeCountExceedsThreshold() {
+		SQLiteDatabase db = this.getWritableDatabase();
+		long cleanBeforeTimestamp = System.currentTimeMillis() - Config.FREQUENT_RESTARTS_DETECTION_WINDOW;
+		db.execSQL("delete from start_times where timestamp < "+cleanBeforeTimestamp);
+		ContentValues values = new ContentValues();
+		values.put("timestamp",System.currentTimeMillis());
+		db.insert("start_times",null,values);
+		String[] columns = new String[]{"count(timestamp)"};
+		Cursor cursor = db.query("start_times",columns,null,null,null,null,null);
+		if (cursor.moveToFirst()) {
+			return cursor.getInt(0) >= Config.FREQUENT_RESTARTS_THRESHOLD;
+		} else {
+			return false;
+		}
+	}
 }