Refactor to utilize Kotlin features

core/src/main/kotlin/ch/dissem/bitmessage/entity/valueobject/extended/Message.kt

@@ -37,33 +37,33 @@ import java.util.*
 data class Message constructor(
     val subject: String,
     val body: String,
-    val parents: List<InventoryVector>,
+    val parents: List<InventoryVector> = emptyList(),
-    val files: List<Attachment>
+    val files: List<Attachment> = emptyList()
 ) : ExtendedEncoding.ExtendedType {
 
     override val type: String = TYPE
 
     override fun pack(): MPMap<MPString, MPType<*>> {
         val result = MPMap<MPString, MPType<*>>()
-        result.put("".mp, TYPE.mp)
+        result["".mp] = TYPE.mp
-        result.put("subject".mp, subject.mp)
+        result["subject".mp] = subject.mp
-        result.put("body".mp, body.mp)
+        result["body".mp] = body.mp
 
         if (!files.isEmpty()) {
             val items = MPArray<MPMap<MPString, MPType<*>>>()
-            result.put("files".mp, items)
+            result["files".mp] = items
             for (file in files) {
                 val item = MPMap<MPString, MPType<*>>()
-                item.put("name".mp, file.name.mp)
+                item["name".mp] = file.name.mp
-                item.put("data".mp, file.data.mp)
+                item["data".mp] = file.data.mp
-                item.put("type".mp, file.type.mp)
+                item["type".mp] = file.type.mp
-                item.put("disposition".mp, file.disposition.name.mp)
+                item["disposition".mp] = file.disposition.name.mp
                 items.add(item)
             }
         }
         if (!parents.isEmpty()) {
             val items = MPArray<MPBinary>()
-            result.put("parents".mp, items)
+            result["parents".mp] = items
             for ((hash) in parents) {
                 items.add(mp(*hash))
             }
@@ -179,6 +179,6 @@ data class Message constructor(
     companion object {
         private val LOG = LoggerFactory.getLogger(Message::class.java)
 
-        val TYPE = "message"
+        const val TYPE = "message"
     }
 }

core/src/main/kotlin/ch/dissem/bitmessage/ports/Cryptography.kt

@@ -156,6 +156,16 @@ interface Cryptography {
     fun doProofOfWork(objectMessage: ObjectMessage, nonceTrialsPerByte: Long,
                       extraBytes: Long, callback: ProofOfWorkEngine.Callback)
 
+    @JvmSynthetic
+    fun doProofOfWork(objectMessage: ObjectMessage, nonceTrialsPerByte: Long,
+                      extraBytes: Long, callback: (ByteArray, ByteArray) -> Unit) {
+        doProofOfWork(objectMessage, nonceTrialsPerByte, extraBytes, object : ProofOfWorkEngine.Callback {
+            override fun onNonceCalculated(initialHash: ByteArray, nonce: ByteArray) {
+                callback.invoke(initialHash, nonce)
+            }
+        })
+    }
+
     /**
      * @param objectMessage      to be checked
      * *

core/src/main/kotlin/ch/dissem/bitmessage/ports/ProofOfWorkEngine.kt

@@ -23,16 +23,32 @@ interface ProofOfWorkEngine {
     /**
      * Returns a nonce, such that the first 8 bytes from sha512(sha512(nonce||initialHash)) represent a unsigned long
      * smaller than target.
-
+     *
      * @param initialHash the SHA-512 hash of the object to send, sans nonce
-     * *
      * @param target      the target, representing an unsigned long
-     * *
+     * @param callback    called with the initial hash and the calculated nonce as argument. The ProofOfWorkEngine
-     * @param callback    called with the calculated nonce as argument. The ProofOfWorkEngine implementation must make
+     *                    implementation must make sure this is only called once.
-     * *                    sure this is only called once.
      */
     fun calculateNonce(initialHash: ByteArray, target: ByteArray, callback: Callback)
 
+    /**
+     * Returns a nonce, such that the first 8 bytes from sha512(sha512(nonce||initialHash)) represent a unsigned long
+     * smaller than target.
+     *
+     * @param initialHash the SHA-512 hash of the object to send, sans nonce
+     * @param target      the target, representing an unsigned long
+     * @param callback    called with the initial hash and the calculated nonce as argument. The ProofOfWorkEngine
+     *                    implementation must make sure this is only called once.
+     */
+    @JvmSynthetic
+    fun calculateNonce(initialHash: ByteArray, target: ByteArray, callback: (ByteArray, ByteArray) -> Unit) {
+        calculateNonce(initialHash, target, object : Callback {
+            override fun onNonceCalculated(initialHash: ByteArray, nonce: ByteArray) {
+                callback.invoke(initialHash, nonce)
+            }
+        })
+    }
+
     interface Callback {
         /**
          * @param nonce 8 bytes nonce

core/src/test/kotlin/ch/dissem/bitmessage/BitmessageContextTest.kt

@@ -126,7 +126,7 @@ class BitmessageContextTest {
         ctx.addContact(contact)
 
         verify(ctx.addresses, timeout(1000).atLeastOnce()).save(eq(contact))
-        verify(testPowEngine, timeout(1000)).calculateNonce(any(), any(), any())
+        verify(testPowEngine, timeout(1000)).calculateNonce(any(), any(), any<ProofOfWorkEngine.Callback>())
     }
 
     @Test
@@ -139,7 +139,7 @@ class BitmessageContextTest {
         ctx.addContact(contact)
 
         verify(ctx.addresses, times(1)).save(contact)
-        verify(testPowEngine, never()).calculateNonce(any(), any(), any())
+        verify(testPowEngine, never()).calculateNonce(any(), any(), any<ProofOfWorkEngine.Callback>())
     }
 
     @Test
@@ -162,7 +162,7 @@ class BitmessageContextTest {
         ctx.addContact(contact)
 
         verify(ctx.addresses, atLeastOnce()).save(contact)
-        verify(testPowEngine, never()).calculateNonce(any(), any(), any())
+        verify(testPowEngine, never()).calculateNonce(any(), any(), any<ProofOfWorkEngine.Callback>())
     }
 
     @Test
@@ -186,7 +186,7 @@ class BitmessageContextTest {
         ctx.addContact(contact)
 
         verify(ctx.addresses, atLeastOnce()).save(any())
-        verify(testPowEngine, never()).calculateNonce(any(), any(), any())
+        verify(testPowEngine, never()).calculateNonce(any(), any(), any<ProofOfWorkEngine.Callback>())
     }
 
     @Test
@@ -245,7 +245,7 @@ class BitmessageContextTest {
             "Subject", "Message")
         verify(ctx.internals.proofOfWorkRepository, timeout(1000).atLeastOnce())
             .putObject(argThat { payload.type == ObjectType.BROADCAST }, eq(1000L), eq(1000L))
-        verify(testPowEngine).calculateNonce(any(), any(), any())
+        verify(testPowEngine).calculateNonce(any(), any(), any<ProofOfWorkEngine.Callback>())
         verify(ctx.messages, timeout(10000).atLeastOnce()).save(argThat<Plaintext> { type == Type.BROADCAST })
     }
 

core/src/test/kotlin/ch/dissem/bitmessage/ProofOfWorkServiceTest.kt

@@ -23,6 +23,7 @@ import ch.dissem.bitmessage.entity.Plaintext.Type.MSG
 import ch.dissem.bitmessage.entity.payload.GenericPayload
 import ch.dissem.bitmessage.entity.payload.Msg
 import ch.dissem.bitmessage.ports.Cryptography
+import ch.dissem.bitmessage.ports.ProofOfWorkEngine
 import ch.dissem.bitmessage.ports.ProofOfWorkRepository
 import ch.dissem.bitmessage.utils.Singleton
 import ch.dissem.bitmessage.utils.TestUtils
@@ -65,11 +66,11 @@ class ProofOfWorkServiceTest {
     fun `ensure missing proof of work is done`() {
         whenever(ctx.proofOfWorkRepository.getItems()).thenReturn(Arrays.asList<ByteArray>(ByteArray(64)))
         whenever(ctx.proofOfWorkRepository.getItem(any())).thenReturn(ProofOfWorkRepository.Item(obj, 1001, 1002))
-        doNothing().whenever(cryptography).doProofOfWork(any(), any(), any(), any())
+        doNothing().whenever(cryptography).doProofOfWork(any(), any(), any(), any<ProofOfWorkEngine.Callback>())
 
         ctx.proofOfWorkService.doMissingProofOfWork(10)
 
-        verify(cryptography, timeout(1000)).doProofOfWork(eq(obj), eq(1001L), eq(1002L), any())
+        verify(cryptography, timeout(1000)).doProofOfWork(eq(obj), eq(1001L), eq(1002L), any<ProofOfWorkEngine.Callback>())
     }
 
     @Test

cryptography-bc/src/test/kotlin/ch/dissem/bitmessage/security/CryptographyTest.kt

@@ -89,12 +89,7 @@ class CryptographyTest {
             stream = 1
         )
         val waiter = CallbackWaiter<ByteArray>()
-        crypto.doProofOfWork(objectMessage, 1000, 1000,
+        crypto.doProofOfWork(objectMessage, 1000, 1000) { _, nonce -> waiter.setValue(nonce) }
-            object : ProofOfWorkEngine.Callback {
-                override fun onNonceCalculated(initialHash: ByteArray, nonce: ByteArray) {
-                    waiter.setValue(nonce)
-                }
-            })
         objectMessage.nonce = waiter.waitForValue()
         try {
             crypto.checkProofOfWork(objectMessage, 1000, 1000)

extensions/src/main/kotlin/ch/dissem/bitmessage/extensions/CryptoCustomMessage.kt

@@ -42,19 +42,21 @@ import java.io.OutputStream
  */
 class CryptoCustomMessage<T : Streamable> : CustomMessage {
 
-    private val dataReader: Reader<T>?
+    private val dataReader: (BitmessageAddress, InputStream) -> T
     private var container: CryptoBox? = null
     var sender: BitmessageAddress? = null
         private set
     private var data: T? = null
-        private set
 
     constructor(data: T) : super(COMMAND, null) {
         this.data = data
-        this.dataReader = null
+        this.dataReader = { _, _ -> data }
     }
 
-    private constructor(container: CryptoBox, dataReader: Reader<T>) : super(COMMAND, null) {
+    private constructor(container: CryptoBox, dataReader: (BitmessageAddress, InputStream) -> T) : super(
+        COMMAND,
+        null
+    ) {
         this.container = container
         this.dataReader = dataReader
     }
@@ -81,8 +83,9 @@ class CryptoCustomMessage<T : Streamable> : CustomMessage {
 
     @Throws(DecryptionFailedException::class)
     fun decrypt(privateKey: ByteArray): T {
-        val input = SignatureCheckingInputStream(container?.decrypt(privateKey) ?: throw IllegalStateException("no encrypted data available"))
+        val input = SignatureCheckingInputStream(
-        if (dataReader == null) throw IllegalStateException("no data reader available")
+            container?.decrypt(privateKey) ?: throw IllegalStateException("no encrypted data available")
+        )
 
         val addressVersion = varInt(input)
         val stream = varInt(input)
@@ -92,7 +95,8 @@ class CryptoCustomMessage<T : Streamable> : CustomMessage {
         val nonceTrialsPerByte = if (addressVersion >= 3) varInt(input) else 0
         val extraBytes = if (addressVersion >= 3) varInt(input) else 0
 
-        val sender = BitmessageAddress(Factory.createPubkey(
+        val sender = BitmessageAddress(
+            Factory.createPubkey(
                 addressVersion,
                 stream,
                 publicSigningKey,
@@ -100,10 +104,11 @@ class CryptoCustomMessage<T : Streamable> : CustomMessage {
                 nonceTrialsPerByte,
                 extraBytes,
                 behaviorBitfield
-        ))
+            )
+        )
         this.sender = sender
 
-        data = dataReader.read(sender, input)
+        data = dataReader.invoke(sender, input)
 
         input.checkSignature(sender.pubkey!!)
 
@@ -127,7 +132,8 @@ class CryptoCustomMessage<T : Streamable> : CustomMessage {
         fun read(sender: BitmessageAddress, input: InputStream): T
     }
 
-    private inner class SignatureCheckingInputStream internal constructor(private val wrapped: InputStream) : InputStream() {
+    private inner class SignatureCheckingInputStream internal constructor(private val wrapped: InputStream) :
+        InputStream() {
         private val out = ByteArrayOutputStream()
 
         override fun read(): Int {
@@ -145,13 +151,24 @@ class CryptoCustomMessage<T : Streamable> : CustomMessage {
     }
 
     companion object {
-        @JvmField
+        const val COMMAND = "ENCRYPTED"
-        val COMMAND = "ENCRYPTED"
 
         @JvmStatic
-        fun <T : Streamable> read(data: CustomMessage, dataReader: Reader<T>): CryptoCustomMessage<T> {
+        fun <T : Streamable> read(data: CustomMessage, dataReader: Reader<T>): CryptoCustomMessage<T> =
-            val cryptoBox = CryptoBox.read(ByteArrayInputStream(data.getData()), data.getData().size)
+            CryptoCustomMessage(
-            return CryptoCustomMessage(cryptoBox, dataReader)
+                CryptoBox.read(ByteArrayInputStream(data.getData()), data.getData().size)
+            ) { address, input ->
+                dataReader.read(address, input)
             }
+
+        @JvmSynthetic
+        fun <T : Streamable> read(
+            data: CustomMessage,
+            dataReader: (BitmessageAddress, InputStream) -> T
+        ): CryptoCustomMessage<T> =
+            CryptoCustomMessage(
+                CryptoBox.read(ByteArrayInputStream(data.getData()), data.getData().size),
+                dataReader
+            )
     }
 }