Qlite: Return OptionalRow instead of Row?, add ability to remove columns on version upgrade

libdino/src/service/database.vala

@@ -121,7 +121,7 @@ public class Database : Qlite.Database {
     public AvatarTable avatar { get; private set; }
     public EntityFeatureTable entity_feature { get; private set; }
 
-    public Database(string fileName) {
+    public Database(string fileName) throws DatabaseError {
         base(fileName, VERSION);
         account = new AccountTable(this);
         jid = new JidTable(this);
@@ -174,7 +174,7 @@ public class Database : Qlite.Database {
     }
 
     private Account? get_account_by_id(int id) {
-        Row? row = account.row_with(account.id, id);
+        Row? row = account.row_with(account.id, id).inner;
         if (row != null) {
             return get_account_from_row(row);
         }
@@ -300,7 +300,7 @@ public class Database : Qlite.Database {
     }
 
     public Message? get_message_by_id(int id) {
-        Row? row = message.row_with(message.id, id);
+        Row? row = message.row_with(message.id, id).inner;
         if (row != null) {
             return get_message_from_row(row);
         }
@@ -427,7 +427,7 @@ public class Database : Qlite.Database {
 
 
     private int get_jid_id(Jid jid_obj) {
-        Row? row = jid.row_with(jid.bare_jid, jid_obj.bare_jid.to_string());
+        Row? row = jid.row_with(jid.bare_jid, jid_obj.bare_jid.to_string()).inner;
         return row != null ? row[jid.id] : add_jid(jid_obj);
     }
 

plugins/omemo/src/account_settings_widget.vala

@@ -30,7 +30,7 @@ public class AccountSettingWidget : Plugins.AccountSettingsWidget, Box {
     public void set_account(Account account) {
         this.account = account;
         try {
-            Qlite.Row? row = plugin.db.identity.row_with(plugin.db.identity.account_id, account.id);
+            Qlite.Row? row = plugin.db.identity.row_with(plugin.db.identity.account_id, account.id).inner;
             if (row == null) {
                 fingerprint.set_markup(@"Own fingerprint\n<span font='8'>Will be generated on first connect</span>");
             } else {

plugins/omemo/src/manager.vala

@@ -99,7 +99,7 @@ public class Manager : StreamInteractionModule, Object {
     private void on_store_created(Account account, Store store) {
         Qlite.Row? row = null;
         try {
-            row = db.identity.row_with(db.identity.account_id, account.id);
+            row = db.identity.row_with(db.identity.account_id, account.id).inner;
         } catch (Error e) {
             // Ignore error
         }

qlite/src/database.vala

@@ -51,15 +51,19 @@ public class Database {
         meta_table.create_table_at_version(expected_version);
         long old_version = 0;
         try {
-            Row? row = meta_table.row_with(meta_name, "version");
+            old_version = meta_table.row_with(meta_name, "version")[meta_int_val, -1];
-            old_version = row == null ? -1 : (long) row[meta_int_val];
         } catch (DatabaseError e) {
             old_version = -1;
         }
+        if (old_version == -1) {
+            foreach (Table t in tables) {
+                t.create_table_at_version(expected_version);
+            }
+            meta_table.insert().value(meta_name, "version").value(meta_int_val, expected_version).perform();
+        } else if (expected_version != old_version) {
             foreach (Table t in tables) {
                 t.create_table_at_version(old_version);
             }
-        if (expected_version != old_version) {
             foreach (Table t in tables) {
                 t.add_columns_for_version(old_version, expected_version);
             }
@@ -117,9 +121,9 @@ public class Database {
         return new DeleteBuilder(this);
     }
 
-    public Row.RowIterator query_sql(string sql, string[]? args = null) throws DatabaseError {
+    public RowIterator query_sql(string sql, string[]? args = null) throws DatabaseError {
         ensure_init();
-        return new Row.RowIterator(this, sql, args);
+        return new RowIterator(this, sql, args);
     }
 
     public Statement prepare(string sql) throws DatabaseError {

qlite/src/query_builder.vala

@@ -131,20 +131,20 @@ public class QueryBuilder : StatementBuilder {
     public int64 count() throws DatabaseError {
         this.column_selector = @"COUNT($column_selector) AS count";
         this.single_result = true;
-        return row().get_integer("count");
+        return row_().get_integer("count");
     }
 
-    public Row? row() throws DatabaseError {
+    private Row? row_() throws DatabaseError {
         if (!single_result) throw new DatabaseError.NON_UNIQUE("query is not suited to return a single row, but row() was called.");
         return iterator().next_value();
     }
 
-    public T get<T>(Column<T> field) throws DatabaseError {
+    public RowOption row() throws DatabaseError {
-        Row row = row();
+        return new RowOption(row_());
-        if (row != null) {
-            return row[field];
     }
-        return null;
+
+    public T get<T>(Column<T> field) throws DatabaseError {
+        return row()[field];
     }
 
     public override Statement prepare() throws DatabaseError {
@@ -155,8 +155,8 @@ public class QueryBuilder : StatementBuilder {
         return stmt;
     }
 
-    public Row.RowIterator iterator() throws DatabaseError {
+    public RowIterator iterator() throws DatabaseError {
-        return new Row.RowIterator.from_query_builder(this);
+        return new RowIterator.from_query_builder(this);
     }
 
     class OrderingTerm {

qlite/src/row.vala

@@ -50,6 +50,7 @@ public class Row {
     public bool has_real(string field) {
         return real_map.has_key(field) && real_map[field] != null;
     }
+}
 
 public class RowIterator {
     private Statement stmt;
@@ -74,6 +75,22 @@ public class Row {
         return null;
     }
 }
+
+public class RowOption {
+    public Row? inner { get; private set; }
+
+    public RowOption(Row? row) {
+        this.inner = row;
+    }
+
+    public bool is_present() {
+        return inner != null;
+    }
+
+    public T get<T>(Column<T> field, T def = null) {
+        if (inner == null || field.is_null(inner)) return def;
+        return field[inner];
+    }
 }
 
 }

qlite/src/table.vala

@@ -57,7 +57,7 @@ public class Table {
         return db.delete().from(this);
     }
 
-    public Row? row_with<T>(Column<T> column, T value) throws DatabaseError {
+    public RowOption row_with<T>(Column<T> column, T value) throws DatabaseError {
         ensure_init();
         if (!column.unique && !column.primary_key) throw new DatabaseError.NON_UNIQUE(@"$(column.name) is not suited to identify a row, but used with row_with()");
         return select().with(column, "=", value).row();
@@ -97,7 +97,26 @@ public class Table {
     }
 
     public void delete_columns_for_version(long old_version, long new_version) throws DatabaseError {
-        // TODO: Rename old table, create table at new_version, transfer data
+        bool column_deletion_required = false;
+        string column_list = null;
+        foreach (Column c in columns) {
+            if (c.min_version <= new_version && c.max_version >= new_version) {
+                if (column_list == null) {
+                    column_list = c.name;
+                } else {
+                    column_list += ", " + c.name;
+                }
+            }
+            if (!(c.min_version <= new_version && c.max_version >= new_version) && c.min_version <= old_version && c.max_version >= old_version) {
+                column_deletion_required = true;
+            }
+        }
+        if (column_deletion_required) {
+            db.exec(@"ALTER TABLE $name RENAME TO _$(name)_$old_version");
+            create_table_at_version(new_version);
+            db.exec(@"INSERT INTO $name ($column_list) SELECT $column_list FROM _$(name)_$old_version");
+            db.exec(@"DROP TABLE _$(name)_$old_version");
+        }
     }
 }