RewInt

RewInt is a specialized integer data type introduced in 2015 for use in the Real-time Event Workflow (REW) software framework. The type is designed to support efficient replay of event logs and to provide deterministic integer values for scheduled tasks, ensuring consistent behavior across distributed nodes. RewInt extends the conventional 64‑bit signed integer by embedding a sequence hash that is automatically updated each time the value is modified, allowing automatic detection of duplicated or out-of-order updates within the event stream.

The RewInt type was implemented in the core of the REW framework by the Institute for Distributed Systems at the University of Berlin. Its design draws on concepts from versioned persistent data structures and journaling file systems. The main contributors to the initial release were Dr. L. Müller and Prof. S. Yang. Since its introduction, RewInt has been ported to several programming languages, including Java, C++, and Rust, with language bindings developed by the REW community.

In practice, RewInt is used to annotate timestamps, transaction IDs, and state machine counters in event‑driven architectures. By coupling each integer value to a cryptographic hash, the framework can replay or roll back events without the risk of inconsistent state, making RewInt particularly useful in financial trading systems, supply‑chain monitoring, and real‑time analytics pipelines. Benchmark studies released by the University of Berlin in 2018 show that using RewInt reduces arbitration time by up to 25 % compared to traditional integer types in distributed consensus protocols.

RewInt has been adopted in several commercial products from the fintech sector, including the LedgerSync platform by FinTech Innovations Inc. The type remains an open‑source component under the MIT license, with an active community managing its development on GitHub.

RewInt continues to be studied for potential applications in blockchain technology, where deterministic replay and tamper‑proof sequencing of events are critical to consensus mechanisms.