First pass trivial wallet: basic tracking of relevant states.

src/main/kotlin/core/Services.kt

@@ -16,6 +16,7 @@ import java.io.InputStream
 import java.security.KeyPair
 import java.security.PrivateKey
 import java.security.PublicKey
+import java.util.*
 
 /**
  * This file defines various 'services' which are not currently fleshed out. A service is a module that provides
@@ -45,6 +46,25 @@ interface WalletService {
      * keys in this wallet, you must inform the wallet service so it can update its internal state.
      */
     val currentWallet: Wallet
+
+    /**
+     * Returns a snapshot of how much cash we have in each currency, ignoring details like issuer. Note: currencies for
+     * which we have no cash evaluate to null, not 0.
+     */
+    val cashBalances: Map<Currency, Amount>
+
+    /**
+     * Possibly update the wallet by marking as spent states that these transactions consume, and adding any relevant
+     * new states that they create. You should only insert transactions that have been successfully verified here!
+     *
+     * Returns the new wallet that resulted from applying the transactions (note: it may quickly become out of date).
+     *
+     * TODO: Consider if there's a good way to enforce the must-be-verified requirement in the type system.
+     */
+    fun notifyAll(txns: Iterable<WireTransaction>): Wallet
+
+    /** Same as notifyAll but with a single transaction. */
+    fun notify(tx: WireTransaction): Wallet = notifyAll(listOf(tx))
 }
 
 /**

src/main/kotlin/core/node/AbstractNode.kt

@@ -86,7 +86,7 @@ abstract class AbstractNode(val dir: Path, val configuration: NodeConfiguration,
         storage = makeStorageService(dir)
         net = makeMessagingService()
         smm = StateMachineManager(services, serverThread)
-        wallet = E2ETestWalletService(services)
+        wallet = NodeWalletService(services)
         keyManagement = E2ETestKeyManagementService()
 
         // Insert a network map entry for the timestamper: this is all temp scaffolding and will go away. If we are

src/main/kotlin/core/node/NodeWalletService.kt

@@ -10,6 +10,9 @@ package core.node
 
 import contracts.Cash
 import core.*
+import core.utilities.loggerFor
+import core.utilities.trace
+import java.security.PublicKey
 import java.util.*
 import javax.annotation.concurrent.ThreadSafe
 
@@ -19,7 +22,9 @@ import javax.annotation.concurrent.ThreadSafe
  * states relevant to us into a database and once such a wallet is implemented, this scaffolding can be removed.
  */
 @ThreadSafe
-class E2ETestWalletService(private val services: ServiceHub) : WalletService {
+class NodeWalletService(private val services: ServiceHub) : WalletService {
+    private val log = loggerFor<NodeWalletService>()
+
     // Variables inside InnerState are protected with a lock by the ThreadBox and aren't in scope unless you're
     // inside mutex.locked {} code block. So we can't forget to take the lock unless we accidentally leak a reference
     // to wallet somewhere.
@@ -30,6 +35,71 @@ class E2ETestWalletService(private val services: ServiceHub) : WalletService {
 
     override val currentWallet: Wallet get() = mutex.locked { wallet }
 
+    /**
+     * Returns a snapshot of how much cash we have in each currency, ignoring details like issuer. Note: currencies for
+     * which we have no cash evaluate to null, not 0.
+     */
+    override val cashBalances: Map<Currency, Amount>
+        get() = mutex.locked { wallet }.let { wallet ->
+            wallet.states.
+                // Select the states we own which are cash, ignore the rest, take the amounts.
+                mapNotNull { (it.state as? Cash.State)?.amount }.
+                // Turn into a Map<Currency, List<Amount>> like { GBP -> (£100, £500, etc), USD -> ($2000, $50) }
+                groupBy { it.currency }.
+                // Collapse to Map<Currency, Amount> by summing all the amounts of the same currency together.
+                mapValues { it.value.sumOrThrow() }
+        }
+
+    override fun notifyAll(txns: Iterable<WireTransaction>): Wallet {
+        val ourKeys = services.keyManagementService.keys.keys
+
+        // Note how terribly incomplete this all is!
+        //
+        // - We don't notify anyone of anything, there are no event listeners.
+        // - We don't handle or even notice invalidations due to double spends of things in our wallet.
+        // - We have no concept of confidence (for txns where there is no definite finality).
+        // - No notification that keys are used, for the case where we observe a spend of our own states.
+        // - No ability to create complex spends.
+        // - No logging or tracking of how the wallet got into this state.
+        // - No persistence.
+        // - Does tx relevancy calculation and key management need to be interlocked? Probably yes.
+        //
+        // ... and many other things .... (Wallet.java in bitcoinj is several thousand lines long)
+
+        mutex.locked {
+            // Starting from the current wallet, keep applying the transaction updates, calculating a new Wallet each
+            // time, until we get to the result (this is perhaps a bit inefficient, but it's functional and easily
+            // unit tested).
+            wallet = txns.fold(currentWallet) { current, tx -> current.update(tx, ourKeys) }
+            return wallet
+        }
+    }
+
+    private fun Wallet.update(tx: WireTransaction, ourKeys: Set<PublicKey>): Wallet {
+        val ourNewStates = tx.outputs.
+                filterIsInstance<OwnableState>().
+                filter { it.owner in ourKeys }.
+                map { tx.outRef<OwnableState>(it) }
+
+        // Now calculate the states that are being spent by this transaction.
+        val consumed: Set<StateRef> = states.map { it.ref }.intersect(tx.inputs)
+
+        // Is transaction irrelevant?
+        if (consumed.isEmpty() && ourNewStates.isEmpty()) {
+            log.trace { "tx ${tx.id} was irrelevant to this wallet, ignoring" }
+            return this
+        }
+
+        // And calculate the new wallet.
+        val newStates = states.filter { it.ref !in consumed } + ourNewStates
+
+        log.trace {
+            "Applied tx ${tx.id.prefixChars()} to the wallet: consumed ${consumed.size} states and added ${newStates.size}"
+        }
+
+        return Wallet(newStates)
+    }
+
     /**
      * Creates a random set of between (by default) 3 and 10 cash states that add up to the given amount and adds them
      * to the wallet.
@@ -37,8 +107,11 @@ class E2ETestWalletService(private val services: ServiceHub) : WalletService {
      * The cash is self issued with the current nodes identity, as fetched from the storage service. Thus it
      * would not be trusted by any sensible market participant and is effectively an IOU. If it had been issued by
      * the central bank, well ... that'd be a different story altogether.
+     *
+     * TODO: Move this out of NodeWalletService
      */
-    fun fillWithSomeTestCash(howMuch: Amount, atLeastThisManyStates: Int = 3, atMostThisManyStates: Int = 10, rng: Random = Random()) {
+    fun fillWithSomeTestCash(howMuch: Amount, atLeastThisManyStates: Int = 3, atMostThisManyStates: Int = 10,
+                             rng: Random = Random()): Wallet {
         val amounts = calculateRandomlySizedAmounts(howMuch, atLeastThisManyStates, atMostThisManyStates, rng)
 
         val myIdentity = services.storageService.myLegalIdentity
@@ -62,13 +135,7 @@ class E2ETestWalletService(private val services: ServiceHub) : WalletService {
         // TODO: Centralise the process of transaction acceptance and filtering into the wallet, then move this out.
         services.storageService.validatedTransactions.putAll(transactions.associateBy { it.id })
 
-        val statesAndRefs = transactions.map {
-            StateAndRef(it.tx.outputs[0] as OwnableState, StateRef(it.id, 0))
-        }
-
-        mutex.locked {
-            wallet = wallet.copy(wallet.states + statesAndRefs)
-        }
+        return notifyAll(transactions.map { it.tx })
     }
 
     private fun calculateRandomlySizedAmounts(howMuch: Amount, min: Int, max: Int, rng: Random): LongArray {

src/main/kotlin/core/node/TraderDemo.kt

@@ -123,7 +123,7 @@ class TraderDemoProtocolBuyer() : ProtocolLogic<Unit>() {
     override fun call() {
         // Give us some cash. Note that as nodes do not currently track forward pointers, we can spend the same cash over
         // and over again and the double spends will never be detected! Fixing that is the next step.
-        (serviceHub.walletService as E2ETestWalletService).fillWithSomeTestCash(1500.DOLLARS)
+        (serviceHub.walletService as NodeWalletService).fillWithSomeTestCash(1500.DOLLARS)
 
         while (true) {
             // Wait around until a node asks to start a trade with us. In a real system, this part would happen out of band

src/test/kotlin/core/MockServices.kt

@@ -75,6 +75,13 @@ class MockKeyManagementService(vararg initialKeys: KeyPair) : KeyManagementServi
 }
 
 class MockWalletService(val states: List<StateAndRef<OwnableState>>) : WalletService {
+    override val cashBalances: Map<Currency, Amount>
+        get() = TODO("Use NodeWalletService instead")
+
+    override fun notifyAll(txns: Iterable<WireTransaction>): Wallet {
+        TODO("Use NodeWalletService instead")
+    }
+
     override val currentWallet = Wallet(states)
 }
 

src/test/kotlin/core/node/E2ETestWalletServiceTest.kt

@@ -1,46 +0,0 @@
-/*
- * Copyright 2015 Distributed Ledger Group LLC.  Distributed as Licensed Company IP to DLG Group Members
- * pursuant to the August 7, 2015 Advisory Services Agreement and subject to the Company IP License terms
- * set forth therein.
- *
- * All other rights reserved.
- */
-
-package core.node
-
-import contracts.Cash
-import core.DOLLARS
-import core.MockKeyManagementService
-import core.MockServices
-import core.ServiceHub
-import core.testutils.ALICE
-import core.testutils.ALICE_KEY
-import org.junit.Test
-import java.util.*
-import kotlin.test.assertEquals
-
-class E2ETestWalletServiceTest {
-    val kms = MockKeyManagementService()
-    val services: ServiceHub = MockServices(
-        keyManagement = kms
-    )
-
-    @Test fun splits() {
-        val wallet = E2ETestWalletService(services)
-        kms.nextKeys += Array(3) { ALICE_KEY }
-        // Fix the PRNG so that we get the same splits every time.
-        wallet.fillWithSomeTestCash(100.DOLLARS, 3, 3, Random(0L))
-
-        val w = wallet.currentWallet
-        assertEquals(3, w.states.size)
-
-        val state = w.states[0].state as Cash.State
-        assertEquals(services.storageService.myLegalIdentity, state.deposit.party)
-        assertEquals(services.storageService.myLegalIdentityKey.public, state.deposit.party.owningKey)
-        assertEquals(29.01.DOLLARS, state.amount)
-        assertEquals(ALICE, state.owner)
-
-        assertEquals(33.34.DOLLARS, (w.states[2].state as Cash.State).amount)
-        assertEquals(35.61.DOLLARS, (w.states[1].state as Cash.State).amount)
-    }
-}

src/test/kotlin/core/node/NodeWalletServiceTest.kt

@@ -0,0 +1,90 @@
+/*
+ * Copyright 2015 Distributed Ledger Group LLC.  Distributed as Licensed Company IP to DLG Group Members
+ * pursuant to the August 7, 2015 Advisory Services Agreement and subject to the Company IP License terms
+ * set forth therein.
+ *
+ * All other rights reserved.
+ */
+
+package core.node
+
+import contracts.Cash
+import core.*
+import core.testutils.*
+import core.utilities.BriefLogFormatter
+import org.junit.After
+import org.junit.Before
+import org.junit.Test
+import java.util.*
+import kotlin.test.assertEquals
+import kotlin.test.assertNull
+
+class NodeWalletServiceTest {
+    val kms = MockKeyManagementService(ALICE_KEY)
+    val services: ServiceHub = MockServices(keyManagement = kms)
+
+    @Before
+    fun setUp() {
+        BriefLogFormatter.loggingOn(NodeWalletService::class)
+    }
+
+    @After
+    fun tearDown() {
+        BriefLogFormatter.loggingOff(NodeWalletService::class)
+    }
+
+    @Test
+    fun splits() {
+        val wallet = NodeWalletService(services)
+        kms.nextKeys += Array(3) { ALICE_KEY }
+        // Fix the PRNG so that we get the same splits every time.
+        wallet.fillWithSomeTestCash(100.DOLLARS, 3, 3, Random(0L))
+
+        val w = wallet.currentWallet
+        assertEquals(3, w.states.size)
+
+        val state = w.states[0].state as Cash.State
+        assertEquals(services.storageService.myLegalIdentity, state.deposit.party)
+        assertEquals(services.storageService.myLegalIdentityKey.public, state.deposit.party.owningKey)
+        assertEquals(29.01.DOLLARS, state.amount)
+        assertEquals(ALICE, state.owner)
+
+        assertEquals(33.34.DOLLARS, (w.states[2].state as Cash.State).amount)
+        assertEquals(35.61.DOLLARS, (w.states[1].state as Cash.State).amount)
+    }
+
+    @Test
+    fun basics() {
+        val wallet = NodeWalletService(services)
+
+        // A tx that sends us money.
+        val freshKey = services.keyManagementService.freshKey()
+        val usefulTX = TransactionBuilder().apply {
+            Cash().generateIssue(this, 100.DOLLARS, MEGA_CORP.ref(1), freshKey.public)
+            signWith(MEGA_CORP_KEY)
+        }.toSignedTransaction()
+        val myOutput = usefulTX.verifyToLedgerTransaction(MockIdentityService).outRef<Cash.State>(0)
+
+        // A tx that spends our money.
+        val spendTX = TransactionBuilder().apply {
+            Cash().generateSpend(this, 80.DOLLARS, BOB, listOf(myOutput))
+            signWith(freshKey)
+        }.toSignedTransaction()
+
+        // A tx that doesn't send us anything.
+        val irrelevantTX = TransactionBuilder().apply {
+            Cash().generateIssue(this, 100.DOLLARS, MEGA_CORP.ref(1), BOB_KEY.public)
+            signWith(MEGA_CORP_KEY)
+        }.toSignedTransaction()
+
+        assertNull(wallet.cashBalances[USD])
+        wallet.notify(usefulTX.tx)
+        assertEquals(100.DOLLARS, wallet.cashBalances[USD])
+        wallet.notify(irrelevantTX.tx)
+        assertEquals(100.DOLLARS, wallet.cashBalances[USD])
+        wallet.notify(spendTX.tx)
+        assertEquals(20.DOLLARS, wallet.cashBalances[USD])
+
+        // TODO: Flesh out these tests as needed.
+    }
+}