Hyperledger - An object-key-value mapper for Hyperledger Fabric

About the Organization

In Hyperledger Fabric, there can be a significant mismatch between the simple key-value ledger storage abstraction and the data representation style used for developing chaincode – i.e., Java has classes and objects, not keys and values. Currently, there aren’t really good tools for facilitating the “object-key-value mapping” (at least anything approaching classic Object-Relational Mapping – ORM). This not only complicates chaincode development, but a less than systematic approach with the mapping can lead to performance problems (through logically unnecessary MVCC conflict transaction invalidations). Additionally, an explicit object-oriented ledger data model would enable imposing data-centric constraints on the ledger content, either for runtime checking or development time verification and validation. The goal of the mentorship is to design and implement an object-key-value mapper with the following functionality: - Generating key-value storage models from UML ledger data models - Application of storage strategies during the mapping (as we explored in the report referenced below) - Generating a chaincode-internal Java data access/persistence layer, “parameterized” by the storage model - Demonstration on a representative example (e.g., our earlier work on faithfully implementing TPC-C to Fabric) - (If we have time): declaring OCL (Object Constraint Language) constraints on the models and enforcing them in the data access layer