Introduce AttachmentConstraint (#1370)

Introduced attachment constraint interface to TransactionState as a base for extension.

core/src/main/kotlin/net/corda/core/contracts/AttachmentConstraint.kt

@@ -0,0 +1,15 @@
+package net.corda.core.contracts
+
+import net.corda.core.serialization.CordaSerializable
+
+/** Constrain which contract-code-containing attachments can be used with a [ContractState]. */
+interface AttachmentConstraint {
+    /** Returns whether the given contract attachments can be used with the [ContractState] associated with this constraint object. */
+    fun isSatisfiedBy(attachments: List<Attachment>): Boolean
+}
+
+/** An [AttachmentConstraint] where [isSatisfiedBy] always returns true. */
+@CordaSerializable
+object AlwaysAcceptAttachmentConstraint : AttachmentConstraint {
+    override fun isSatisfiedBy(attachments: List<Attachment>) = true
+}

core/src/main/kotlin/net/corda/core/contracts/TransactionState.kt

@@ -71,4 +71,8 @@ data class TransactionState<out T : ContractState> @JvmOverloads constructor(
          * Note that an encumbered state that is being consumed must have its encumbrance consumed in the same transaction,
          * otherwise the transaction is not valid.
          */
-        val encumbrance: Int? = null)
+        val encumbrance: Int? = null,
+        /**
+         * A validator for the contract attachments on the transaction.
+         */
+        val constraint: AttachmentConstraint = AlwaysAcceptAttachmentConstraint)

finance/src/main/kotlin/net/corda/finance/contracts/asset/Obligation.kt

@@ -1,6 +1,10 @@
 package net.corda.finance.contracts.asset
 
 import net.corda.core.contracts.*
+import net.corda.finance.contracts.NetCommand
+import net.corda.finance.contracts.NetType
+import net.corda.finance.contracts.NettableState
+import net.corda.finance.contracts.asset.Obligation.Lifecycle.NORMAL
 import net.corda.core.crypto.SecureHash
 import net.corda.core.crypto.entropyToKeyPair
 import net.corda.core.identity.AbstractParty
@@ -14,15 +18,10 @@ import net.corda.core.transactions.TransactionBuilder
 import net.corda.core.utilities.NonEmptySet
 import net.corda.core.utilities.getX500Name
 import net.corda.core.utilities.seconds
-import net.corda.finance.contracts.NetCommand
-import net.corda.finance.contracts.NetType
-import net.corda.finance.contracts.NettableState
-import net.corda.finance.contracts.asset.Obligation.Lifecycle.NORMAL
 import net.corda.finance.utils.sumFungibleOrNull
 import net.corda.finance.utils.sumObligations
 import net.corda.finance.utils.sumObligationsOrNull
 import net.corda.finance.utils.sumObligationsOrZero
-import org.bouncycastle.asn1.x500.X500Name
 import java.math.BigInteger
 import java.security.PublicKey
 import java.time.Duration
@@ -132,7 +131,7 @@ class Obligation<P : Any> : Contract {
             val quantity: Long,
             /** The public key of the entity the contract pays to */
             val beneficiary: AbstractParty
-    ) : FungibleAsset<Obligation.Terms<P>>, NettableState<State<P>, MultilateralNetState<P>> {
+    ) : FungibleAsset<Terms<P>>, NettableState<State<P>, MultilateralNetState<P>> {
         override val amount: Amount<Issued<Terms<P>>> = Amount(quantity, Issued(obligor.ref(0), template))
         override val exitKeys: Collection<PublicKey> = setOf(beneficiary.owningKey)
         val dueBefore: Instant = template.dueBefore

node/src/test/kotlin/net/corda/node/services/events/ScheduledFlowTests.kt

@@ -3,7 +3,6 @@ package net.corda.node.services.events
 import co.paralleluniverse.fibers.Suspendable
 import net.corda.core.concurrent.CordaFuture
 import net.corda.core.contracts.*
-import net.corda.core.crypto.containsAny
 import net.corda.core.flows.*
 import net.corda.core.identity.AbstractParty
 import net.corda.core.identity.Party
@@ -29,7 +28,6 @@ import org.junit.After
 import org.junit.Assert.assertTrue
 import org.junit.Before
 import org.junit.Test
-import java.security.PublicKey
 import java.time.Instant
 import kotlin.test.assertEquals
 

samples/simm-valuation-demo/src/main/kotlin/net/corda/vega/contracts/IRSState.kt

@@ -3,12 +3,10 @@ package net.corda.vega.contracts
 import net.corda.core.contracts.Command
 import net.corda.core.contracts.StateAndContract
 import net.corda.core.contracts.UniqueIdentifier
-import net.corda.core.crypto.keys
 import net.corda.core.identity.AbstractParty
 import net.corda.core.identity.Party
 import net.corda.core.transactions.TransactionBuilder
 import net.corda.finance.contracts.DealState
-import java.security.PublicKey
 
 val IRS_PROGRAM_ID = "net.corda.vega.contracts.OGTrade"
 

samples/simm-valuation-demo/src/main/kotlin/net/corda/vega/contracts/PortfolioState.kt

@@ -1,7 +1,6 @@
 package net.corda.vega.contracts
 
 import net.corda.core.contracts.*
-import net.corda.core.crypto.keys
 import net.corda.core.flows.FlowLogicRefFactory
 import net.corda.core.identity.AbstractParty
 import net.corda.core.identity.Party
@@ -9,7 +8,6 @@ import net.corda.core.serialization.CordaSerializable
 import net.corda.core.transactions.TransactionBuilder
 import net.corda.finance.contracts.DealState
 import net.corda.vega.flows.SimmRevaluation
-import java.security.PublicKey
 import java.time.LocalDate
 import java.time.ZoneOffset
 import java.time.temporal.ChronoUnit

testing/test-utils/src/main/kotlin/net/corda/testing/contracts/DummyContract.kt

@@ -28,7 +28,7 @@ data class DummyContract(val blank: Any? = null) : Contract {
      * in a different field, however this is a good example of a contract with multiple states.
      */
     data class MultiOwnerState(override val magicNumber: Int = 0,
-                               val owners: List<AbstractParty>) : ContractState, State {
+                               val owners: List<AbstractParty>) : State {
         override val participants: List<AbstractParty> get() = owners
     }
 

testing/test-utils/src/main/kotlin/net/corda/testing/contracts/DummyDealContract.kt

@@ -2,7 +2,6 @@ package net.corda.testing.contracts
 
 import net.corda.core.contracts.Contract
 import net.corda.core.contracts.UniqueIdentifier
-import net.corda.core.crypto.containsAny
 import net.corda.core.identity.AbstractParty
 import net.corda.core.identity.Party
 import net.corda.core.schemas.MappedSchema
@@ -12,7 +11,6 @@ import net.corda.core.transactions.LedgerTransaction
 import net.corda.core.transactions.TransactionBuilder
 import net.corda.finance.contracts.DealState
 import net.corda.testing.schemas.DummyDealStateSchemaV1
-import java.security.PublicKey
 
 val DUMMY_DEAL_PROGRAM_ID = "net.corda.testing.contracts.DummyDealContract"
 

testing/test-utils/src/main/kotlin/net/corda/testing/contracts/DummyLinearContract.kt

@@ -5,7 +5,6 @@ import net.corda.core.contracts.LinearState
 import net.corda.core.contracts.UniqueIdentifier
 import net.corda.core.contracts.requireThat
 import net.corda.core.crypto.SecureHash
-import net.corda.core.crypto.containsAny
 import net.corda.core.identity.AbstractParty
 import net.corda.core.schemas.MappedSchema
 import net.corda.core.schemas.PersistentState