Crux Corda

A Crux library that allows you to pipe verified Corda transactions into a Crux node, to then query using Crux’s bitemporal Datalog query engine.

Things of interest:

crux-corda library

• crux-corda/src/main/kotlin/crux/corda/CruxCorda.kt - entry point for the Crux driver, adds extension functions to AppServiceHub

• crux-corda/src/main/clojure/crux/corda.clj - the implementation of the Crux driver

• crux-corda-state/src/main/kotlin/crux/corda/state/CruxState.kt - interface that Corda states should implement to be included in Crux

Example user app

• iou-contract/src/main/kotlin/com/example/contract/IOUState.kt - example of a Corda state with a Crux mapping

  @BelongsToContract(IOUContract::class)
  data class IOUState(val value: Int,
                      val lender: Party,
                      val borrower: Party,
                      override val linearId: UniqueIdentifier = UniqueIdentifier()) :
      LinearState, QueryableState, CruxState {
  
      override val cruxId = linearId.id
      override val cruxDoc: Map<String, Any> = mapOf(
          "iou-state/value" to value,
          "iou-state/lender" to lender.name.toString(),
          "iou-state/borrower" to borrower.name.toString())
  }

• iou-workflow/src/main/kotlin/com/example/service/CruxService.kt - example of a CordaService that starts a Crux node

  @CordaService
  class CruxService(private val serviceHub: AppServiceHub) : SingletonSerializeAsToken() {
  
      val node = serviceHub.startCruxNode {
          // configure node
      }
  }

  By default, Crux looks out for Corda states that implement CruxState, but you can manually specify this mapping thus:

val node = serviceHub.startCruxNode {
    withCordaTxLog {
        withDocumentMapping { doc ->
            // this is the default implementation,
            // replace it with your own mapping
            if (doc is CruxState) listOf(doc)
            else null
        }
    }

    // ...
}

• iou-workflow/src/test/kotlin/com/example/workflow/IOUFlowTests.kt - E2E test for the IOU app