diff -r bfee08a31fdc -r 2179f13227f4 src/lib/AbstractParser.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/lib/AbstractParser.cpp	Sat Mar 13 17:58:09 2021 +0100
@@ -0,0 +1,95 @@
+/**
+ * Relational pipes
+ * Copyright © 2021 František Kučera (Frantovo.cz, GlobalCode.info)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "AbstractParser.h"
+
+namespace relpipe {
+namespace in {
+namespace asn1 {
+namespace lib {
+
+class AbstractParserImpl {
+private:
+	AbstractParser* interface;
+public:
+
+	AbstractParserImpl(AbstractParser* interface) : interface(interface) {
+	}
+
+	virtual ~AbstractParserImpl() {
+	}
+
+	void write(const char* buffer, const size_t length) {
+		// TODO: update pointers and positions
+		try {
+			// TODO: call an overridable method to get preferred minimum block size and run cycle only if we have enough data or EOF
+			interface->update();
+			commit();
+		} catch (const AbstractParser::ReadBufferUnderflowException& e) {
+			rollback();
+		} catch (const AbstractParser::ExplicitRollbackException& e) {
+			rollback();
+		}
+	}
+
+	void rollback() {
+		// FIXME: store content of the current buffer + update pointers and positions
+		// TODO: notify rollback listeners? (they can monitor the performance / frequency of rollbacks)
+	}
+
+	void commit() {
+	}
+
+	void read(char* buffer, const size_t length) {
+	}
+
+	void peek(char* buffer, const size_t length) {
+	}
+};
+
+AbstractParser::AbstractParser() {
+	implementation = new AbstractParserImpl(this);
+}
+
+AbstractParser::~AbstractParser() {
+	delete (AbstractParserImpl*) implementation;
+}
+
+void AbstractParser::write(const char* buffer, const size_t length) {
+	((AbstractParserImpl*) implementation)->write(buffer, length);
+}
+
+void AbstractParser::commit() {
+	((AbstractParserImpl*) implementation)->commit();
+}
+
+void AbstractParser::rollback() {
+	((AbstractParserImpl*) implementation)->rollback();
+}
+
+void AbstractParser::read(char* buffer, const size_t length) {
+	((AbstractParserImpl*) implementation)->read(buffer, length);
+}
+
+void AbstractParser::peek(char* buffer, const size_t length) {
+	((AbstractParserImpl*) implementation)->peek(buffer, length);
+}
+
+}
+}
+}
+}
\ No newline at end of file