[EG-503] Spent state audit tool (#6107)

* [EG-503] Spent state audit tool

Fixes

* Refinements to notary query interfaces. Feature complete.

* EG-503: Introduce optional `notaryService` in `ServiceHubCoreInternal`

* Remove redundant logic following change to use extensions API

Co-authored-by: Viktor Kolomeyko <viktor.kolomeyko@r3.com>

core/src/main/kotlin/net/corda/core/internal/ServiceHubCoreInternal.kt

@@ -2,6 +2,7 @@ package net.corda.core.internal
 
 import co.paralleluniverse.fibers.Suspendable
 import net.corda.core.DeleteForDJVM
+import net.corda.core.internal.notary.NotaryService
 import net.corda.core.node.ServiceHub
 import net.corda.core.node.StatesToRecord
 import java.util.concurrent.ExecutorService
@@ -14,6 +15,11 @@ interface ServiceHubCoreInternal : ServiceHub {
 
     val attachmentTrustCalculator: AttachmentTrustCalculator
 
+    /**
+     * Optional `NotaryService` which will be `null` for all non-Notary nodes.
+     */
+    val notaryService: NotaryService?
+
     fun createTransactionsResolver(flow: ResolveTransactionsFlow): TransactionsResolver
 }
 

core/src/main/kotlin/net/corda/core/internal/notary/NotaryService.kt

@@ -14,6 +14,19 @@ abstract class NotaryService : SingletonSerializeAsToken() {
     abstract val services: ServiceHub
     abstract val notaryIdentityKey: PublicKey
 
+    /**
+     * Interfaces for the request and result formats of queries supported by notary services. To
+     * implement a new query, you must:
+     *
+     * - Define data classes which implement the [Query.Request] and [Query.Result] interfaces
+     * - Add corresponding handling for the new classes within the notary service implementations
+     *   that you want to support the query.
+     */
+    interface Query {
+        interface Request
+        interface Result
+    }
+
     abstract fun start()
     abstract fun stop()
 
@@ -22,4 +35,18 @@ abstract class NotaryService : SingletonSerializeAsToken() {
      * @param otherPartySession client [Party] making the request
      */
     abstract fun createServiceFlow(otherPartySession: FlowSession): FlowLogic<Void?>
+
+    /**
+     * Processes a [Query.Request] and returns a [Query.Result].
+     *
+     * Note that this always throws an [UnsupportedOperationException] to handle notary
+     * implementations that do not support this functionality. This must be overridden by
+     * notary implementations wishing to support query functionality.
+     *
+     * Overrides of this function may themselves still throw an [UnsupportedOperationException],
+     * if they do not support specific query implementations
+     */
+    open fun processQuery(query: Query.Request): Query.Result {
+        throw UnsupportedOperationException("Notary has not implemented query support")
+    }
 }

node/src/main/kotlin/net/corda/node/internal/AbstractNode.kt

@@ -367,6 +367,8 @@ abstract class AbstractNode<S>(val configuration: NodeConfiguration,
 
     private val checkpointDumper = CheckpointDumperImpl(checkpointStorage, database, services, services.configuration.baseDirectory)
 
+    private var notaryService: NotaryService? = null
+
     private val nodeServicesContext = object : NodeServicesContext {
         override val platformVersion = versionInfo.platformVersion
         override val configurationWithOptions = configuration.configurationWithOptions
@@ -524,7 +526,7 @@ abstract class AbstractNode<S>(val configuration: NodeConfiguration,
             // the KMS is meant for derived temporary keys used in transactions, and we're not supposed to sign things with
             // the identity key. But the infrastructure to make that easy isn't here yet.
             keyManagementService.start(keyPairs)
-            val notaryService = maybeStartNotaryService(myNotaryIdentity)
+            notaryService = maybeStartNotaryService(myNotaryIdentity)
             installCordaServices()
             contractUpgradeService.start()
             vaultService.start()
@@ -1160,6 +1162,7 @@ abstract class AbstractNode<S>(val configuration: NodeConfiguration,
         override val attachmentTrustCalculator: AttachmentTrustCalculator get() = this@AbstractNode.attachmentTrustCalculator
         override val diagnosticsService: DiagnosticsService get() = this@AbstractNode.diagnosticsService
         override val externalOperationExecutor: ExecutorService get() = this@AbstractNode.externalOperationExecutor
+        override val notaryService: NotaryService? get() = this@AbstractNode.notaryService
 
         private lateinit var _myInfo: NodeInfo
         override val myInfo: NodeInfo get() = _myInfo

testing/test-utils/src/main/kotlin/net/corda/testing/dsl/TestDSL.kt

@@ -9,6 +9,7 @@ import net.corda.core.crypto.SecureHash
 import net.corda.core.flows.FlowException
 import net.corda.core.identity.Party
 import net.corda.core.internal.*
+import net.corda.core.internal.notary.NotaryService
 import net.corda.core.node.ServiceHub
 import net.corda.core.node.ServicesForResolution
 import net.corda.core.node.services.AttachmentId
@@ -127,6 +128,8 @@ data class TestTransactionDSLInterpreter private constructor(
 
         override val cordappProvider: CordappProvider =
             ledgerInterpreter.services.cordappProvider
+
+        override val notaryService: NotaryService? = null
     }
 
     private fun copy(): TestTransactionDSLInterpreter =