Smart Contract Design Pattern for Processing Logically Coherent Transaction Types

Recent research shows that the source code of smart contracts is often cloned. The processing of related types of transactions in blockchain networks results in the implementation of many similar smart contracts. The rules verifying transactions are therefore duplicated many times. The article introduces the AdapT v2.0 smart contract design pattern. The design pattern employs a distinct configuration for each transaction type, and verification rule objects are shared among configurations. The redundancy of logical conditions was eliminated at two levels. Firstly, it is possible to combine similar smart contracts into one. Secondly, a configuration in a smart contract reuses verification rule objects at runtime. As a result, only one object is instantiated for each verification rule. It allows for the effective use of operating memory by the smart contract. The article presents the implementation of the pattern using object-oriented and functional programming mechanisms. Applying the pattern ensures the self-adaptability of a smart contract to any number of transaction types. The performance tests were carried out for various numbers of verification rules in a smart contract and a different number of checked transactions. The obtained evaluation time of 10,000,000 transactions is less than 0.25 s.