Refactoring TLV's code

2025-09-21 18:50:47 +02:00 · 2023-08-15 11:13:01 -04:00
parent 52687a48df
commit 1ad1d233cd
5 changed files with 143 additions and 146 deletions
--- a/app/src/main/java/com/vitorpamplona/amethyst/service/model/ATag.kt
+++ b/app/src/main/java/com/vitorpamplona/amethyst/service/model/ATag.kt
@@ -2,11 +2,9 @@ package com.vitorpamplona.amethyst.service.model

 import android.util.Log
 import androidx.compose.runtime.Immutable
-import com.vitorpamplona.amethyst.model.hexToByteArray
-import com.vitorpamplona.amethyst.model.toHexKey
 import com.vitorpamplona.amethyst.service.bechToBytes
 import com.vitorpamplona.amethyst.service.nip19.Tlv
-import com.vitorpamplona.amethyst.service.nip19.toByteArray
+import com.vitorpamplona.amethyst.service.nip19.TlvBuilder
 import com.vitorpamplona.amethyst.service.toNAddress
 import fr.acinq.secp256k1.Hex

@@ -15,22 +13,12 @@ data class ATag(val kind: Int, val pubKeyHex: String, val dTag: String, val rela
    fun toTag() = "$kind:$pubKeyHex:$dTag"

    fun toNAddr(): String {
-        val kind = kind.toByteArray()
-        val author = pubKeyHex.hexToByteArray()
-        val dTag = dTag.toByteArray(Charsets.UTF_8)
-        val relay = relay?.toByteArray(Charsets.UTF_8)
-
-        var fullArray = byteArrayOf(Tlv.Type.SPECIAL.id, dTag.size.toByte()) + dTag
-
-        if (relay != null) {
-            fullArray = fullArray + byteArrayOf(Tlv.Type.RELAY.id, relay.size.toByte()) + relay
-        }
-
-        fullArray = fullArray +
-            byteArrayOf(Tlv.Type.AUTHOR.id, author.size.toByte()) + author +
-            byteArrayOf(Tlv.Type.KIND.id, kind.size.toByte()) + kind
-
-        return fullArray.toNAddress()
+        return TlvBuilder().apply {
+            addString(Tlv.Type.SPECIAL, dTag)
+            addStringIfNotNull(Tlv.Type.RELAY, relay)
+            addHex(Tlv.Type.AUTHOR, pubKeyHex)
+            addInt(Tlv.Type.KIND, kind)
+        }.build().toNAddress()
    }

    companion object {
@@ -63,10 +51,11 @@ data class ATag(val kind: Int, val pubKeyHex: String, val dTag: String, val rela

                if (key.startsWith("naddr")) {
                    val tlv = Tlv.parse(key.bechToBytes())
-                    val d = tlv.get(Tlv.Type.SPECIAL.id)?.get(0)?.toString(Charsets.UTF_8) ?: ""
-                    val relay = tlv.get(Tlv.Type.RELAY.id)?.get(0)?.toString(Charsets.UTF_8)
-                    val author = tlv.get(Tlv.Type.AUTHOR.id)?.get(0)?.toHexKey()
-                    val kind = tlv.get(Tlv.Type.KIND.id)?.get(0)?.let { Tlv.toInt32(it) }
+
+                    val d = tlv.firstAsString(Tlv.Type.SPECIAL) ?: ""
+                    val relay = tlv.firstAsString(Tlv.Type.RELAY)
+                    val author = tlv.firstAsHex(Tlv.Type.AUTHOR)
+                    val kind = tlv.firstAsInt(Tlv.Type.KIND)

                    if (kind != null && author != null) {
                        return ATag(kind, author, d, relay)
--- a/app/src/main/java/com/vitorpamplona/amethyst/service/nip19/Nip19.kt
+++ b/app/src/main/java/com/vitorpamplona/amethyst/service/nip19/Nip19.kt
@@ -2,7 +2,6 @@ package com.vitorpamplona.amethyst.service.nip19

 import android.util.Log
 import androidx.compose.runtime.Immutable
-import com.vitorpamplona.amethyst.model.hexToByteArray
 import com.vitorpamplona.amethyst.model.toHexKey
 import com.vitorpamplona.amethyst.service.bechToBytes
 import com.vitorpamplona.amethyst.service.toNEvent
@@ -82,13 +81,8 @@ object Nip19 {
    private fun nprofile(bytes: ByteArray): Return? {
        val tlv = Tlv.parse(bytes)

-        val hex = tlv.get(Tlv.Type.SPECIAL.id)
-            ?.get(0)
-            ?.toHexKey() ?: return null
-
-        val relay = tlv.get(Tlv.Type.RELAY.id)
-            ?.get(0)
-            ?.toString(Charsets.UTF_8)
+        val hex = tlv.firstAsHex(Tlv.Type.SPECIAL) ?: return null
+        val relay = tlv.firstAsString(Tlv.Type.RELAY)

        return Return(Type.USER, hex, relay)
    }
@@ -96,30 +90,16 @@ object Nip19 {
    private fun nevent(bytes: ByteArray): Return? {
        val tlv = Tlv.parse(bytes)

-        val hex = tlv.get(Tlv.Type.SPECIAL.id)
-            ?.get(0)
-            ?.toHexKey() ?: return null
-
-        val relay = tlv.get(Tlv.Type.RELAY.id)
-            ?.get(0)
-            ?.toString(Charsets.UTF_8)
-
-        val author = tlv.get(Tlv.Type.AUTHOR.id)
-            ?.get(0)
-            ?.toHexKey()
-
-        val kind = tlv.get(Tlv.Type.KIND.id)
-            ?.get(0)
-            ?.let { Tlv.toInt32(it) }
+        val hex = tlv.firstAsHex(Tlv.Type.SPECIAL) ?: return null
+        val relay = tlv.firstAsString(Tlv.Type.RELAY)
+        val author = tlv.firstAsHex(Tlv.Type.AUTHOR)
+        val kind = tlv.firstAsInt(Tlv.Type.KIND.id)

        return Return(Type.EVENT, hex, relay, author, kind)
    }

    private fun nrelay(bytes: ByteArray): Return? {
-        val relayUrl = Tlv.parse(bytes)
-            .get(Tlv.Type.SPECIAL.id)
-            ?.get(0)
-            ?.toString(Charsets.UTF_8) ?: return null
+        val relayUrl = Tlv.parse(bytes).firstAsString(Tlv.Type.SPECIAL.id) ?: return null

        return Return(Type.RELAY, relayUrl)
    }
@@ -127,53 +107,20 @@ object Nip19 {
    private fun naddr(bytes: ByteArray): Return? {
        val tlv = Tlv.parse(bytes)

-        val d = tlv.get(Tlv.Type.SPECIAL.id)
-            ?.get(0)
-            ?.toString(Charsets.UTF_8) ?: return null
-
-        val relay = tlv.get(Tlv.Type.RELAY.id)
-            ?.get(0)
-            ?.toString(Charsets.UTF_8)
-
-        val author = tlv.get(Tlv.Type.AUTHOR.id)
-            ?.get(0)
-            ?.toHexKey()
-
-        val kind = tlv.get(Tlv.Type.KIND.id)
-            ?.get(0)
-            ?.let { Tlv.toInt32(it) }
+        val d = tlv.firstAsString(Tlv.Type.SPECIAL.id) ?: ""
+        val relay = tlv.firstAsString(Tlv.Type.RELAY.id)
+        val author = tlv.firstAsHex(Tlv.Type.AUTHOR.id) ?: return null
+        val kind = tlv.firstAsInt(Tlv.Type.KIND.id) ?: return null

        return Return(Type.ADDRESS, "$kind:$author:$d", relay, author, kind)
    }

    public fun createNEvent(idHex: String, author: String?, kind: Int?, relay: String?): String {
-        val kind = kind?.toByteArray()
-        val author = author?.hexToByteArray()
-        val idHex = idHex.hexToByteArray()
-        val relay = relay?.toByteArray(Charsets.UTF_8)
-
-        var fullArray = byteArrayOf(Tlv.Type.SPECIAL.id, idHex.size.toByte()) + idHex
-
-        if (relay != null) {
-            fullArray = fullArray + byteArrayOf(Tlv.Type.RELAY.id, relay.size.toByte()) + relay
-        }
-
-        if (author != null) {
-            fullArray = fullArray + byteArrayOf(Tlv.Type.AUTHOR.id, author.size.toByte()) + author
-        }
-
-        if (kind != null) {
-            fullArray = fullArray + byteArrayOf(Tlv.Type.KIND.id, kind.size.toByte()) + kind
-        }
-
-        return fullArray.toNEvent()
+        return TlvBuilder().apply {
+            addHex(Tlv.Type.SPECIAL, idHex)
+            addStringIfNotNull(Tlv.Type.RELAY, relay)
+            addHexIfNotNull(Tlv.Type.AUTHOR, author)
+            addIntIfNotNull(Tlv.Type.KIND, kind)
+        }.build().toNEvent()
    }
 }
-
-fun Int.toByteArray(): ByteArray {
-    val bytes = ByteArray(4)
-    (0..3).forEach {
-        bytes[3 - it] = ((this ushr (8 * it)) and 0xFFFF).toByte()
-    }
-    return bytes
-}
--- a/app/src/main/java/com/vitorpamplona/amethyst/service/nip19/Tlv.kt
+++ b/app/src/main/java/com/vitorpamplona/amethyst/service/nip19/Tlv.kt
@@ -1,9 +1,67 @@
 package com.vitorpamplona.amethyst.service.nip19

+import com.vitorpamplona.amethyst.model.HexKey
+import com.vitorpamplona.amethyst.model.hexToByteArray
+import com.vitorpamplona.amethyst.model.toHexKey
+import java.io.ByteArrayOutputStream
 import java.nio.ByteBuffer
 import java.nio.ByteOrder

-object Tlv {
+class TlvBuilder() {
+    val outputStream = ByteArrayOutputStream()
+
+    private fun add(type: Byte, byteArray: ByteArray) {
+        outputStream.write(byteArrayOf(type, byteArray.size.toByte()))
+        outputStream.write(byteArray)
+    }
+
+    fun addString(type: Byte, string: String) = add(type, string.toByteArray(Charsets.UTF_8))
+    fun addHex(type: Byte, key: HexKey) = add(type, key.hexToByteArray())
+    fun addInt(type: Byte, data: Int) = add(type, data.toByteArray())
+
+    fun addStringIfNotNull(type: Byte, data: String?) = data?.let { addString(type, it) }
+    fun addHexIfNotNull(type: Byte, data: HexKey?) = data?.let { addHex(type, it) }
+    fun addIntIfNotNull(type: Byte, data: Int?) = data?.let { addInt(type, it) }
+
+    fun addString(type: Tlv.Type, string: String) = addString(type.id, string)
+    fun addHex(type: Tlv.Type, key: HexKey) = addHex(type.id, key)
+    fun addInt(type: Tlv.Type, data: Int) = addInt(type.id, data)
+
+    fun addStringIfNotNull(type: Tlv.Type, data: String?) = addStringIfNotNull(type.id, data)
+    fun addHexIfNotNull(type: Tlv.Type, data: HexKey?) = addHexIfNotNull(type.id, data)
+    fun addIntIfNotNull(type: Tlv.Type, data: Int?) = addIntIfNotNull(type.id, data)
+
+    fun build(): ByteArray {
+        return outputStream.toByteArray()
+    }
+}
+
+fun Int.toByteArray(): ByteArray {
+    val bytes = ByteArray(4)
+    (0..3).forEach {
+        bytes[3 - it] = ((this ushr (8 * it)) and 0xFFFF).toByte()
+    }
+    return bytes
+}
+
+fun ByteArray.toInt32(): Int? {
+    if (size != 4) return null
+    return ByteBuffer.wrap(this, 0, 4).order(ByteOrder.BIG_ENDIAN).int
+}
+
+class Tlv(val data: Map<Byte, List<ByteArray>>) {
+    fun asInt(type: Byte) = data[type]?.mapNotNull { it.toInt32() }
+    fun asHex(type: Byte) = data[type]?.map { it.toHexKey().intern() }
+    fun asString(type: Byte) = data[type]?.map { it.toString(Charsets.UTF_8) }
+
+    fun firstAsInt(type: Byte) = data[type]?.firstOrNull()?.toInt32()
+    fun firstAsHex(type: Byte) = data[type]?.firstOrNull()?.toHexKey()?.intern()
+    fun firstAsString(type: Byte) = data[type]?.firstOrNull()?.toString(Charsets.UTF_8)
+
+    fun firstAsInt(type: Type) = firstAsInt(type.id)
+    fun firstAsHex(type: Type) = firstAsHex(type.id)
+    fun firstAsString(type: Type) = firstAsString(type.id)
+
    enum class Type(val id: Byte) {
        SPECIAL(0),
        RELAY(1),
@@ -11,26 +69,24 @@ object Tlv {
        KIND(3);
    }

-    fun toInt32(bytes: ByteArray): Int {
-        require(bytes.size == 4) { "length must be 4, got: ${bytes.size}" }
-        return ByteBuffer.wrap(bytes, 0, 4).order(ByteOrder.BIG_ENDIAN).int
-    }
+    companion object {

-    fun parse(data: ByteArray): Map<Byte, List<ByteArray>> {
-        val result = mutableMapOf<Byte, MutableList<ByteArray>>()
-        var rest = data
-        while (rest.isNotEmpty()) {
-            val t = rest[0]
-            val l = rest[1].toUByte().toInt()
-            val v = rest.sliceArray(IntRange(2, (2 + l) - 1))
-            rest = rest.sliceArray(IntRange(2 + l, rest.size - 1))
-            if (v.size < l) continue
+        fun parse(data: ByteArray): Tlv {
+            val result = mutableMapOf<Byte, MutableList<ByteArray>>()
+            var rest = data
+            while (rest.isNotEmpty()) {
+                val t = rest[0]
+                val l = rest[1].toUByte().toInt()
+                val v = rest.sliceArray(IntRange(2, (2 + l) - 1))
+                rest = rest.sliceArray(IntRange(2 + l, rest.size - 1))
+                if (v.size < l) continue

-            if (!result.containsKey(t)) {
-                result[t] = mutableListOf()
+                if (!result.containsKey(t)) {
+                    result[t] = mutableListOf()
+                }
+                result[t]?.add(v)
            }
-            result[t]?.add(v)
+            return Tlv(result)
        }
-        return result
    }
 }
--- a/app/src/test/java/com/vitorpamplona/amethyst/service/TlvIntegerTest.kt
+++ b/app/src/test/java/com/vitorpamplona/amethyst/service/TlvIntegerTest.kt
@@ -0,0 +1,40 @@
+package com.vitorpamplona.amethyst.service
+
+import com.vitorpamplona.amethyst.service.nip19.toByteArray
+import com.vitorpamplona.amethyst.service.nip19.toInt32
+import org.junit.Assert
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class TlvIntegerTest {
+    fun to_int_32_length_smaller_than_4() {
+        Assert.assertNull(byteArrayOfInts(1, 2, 3).toInt32())
+    }
+
+    fun to_int_32_length_bigger_than_4() {
+        Assert.assertNull(byteArrayOfInts(1, 2, 3, 4, 5).toInt32())
+    }
+
+    @Test()
+    fun to_int_32_length_4() {
+        val actual = byteArrayOfInts(1, 2, 3, 4).toInt32()
+
+        assertEquals(16909060, actual)
+    }
+
+    @Test()
+    fun backAndForth() {
+        assertEquals(234, 234.toByteArray().toInt32())
+        assertEquals(1, 1.toByteArray().toInt32())
+        assertEquals(0, 0.toByteArray().toInt32())
+        assertEquals(1000, 1000.toByteArray().toInt32())
+
+        assertEquals(-234, (-234).toByteArray().toInt32())
+        assertEquals(-1, (-1).toByteArray().toInt32())
+        assertEquals(-0, (-0).toByteArray().toInt32())
+        assertEquals(-1000, (-1000).toByteArray().toInt32())
+    }
+
+    private fun byteArrayOfInts(vararg ints: Int) =
+        ByteArray(ints.size) { pos -> ints[pos].toByte() }
+}
--- a/app/src/test/java/com/vitorpamplona/amethyst/service/TlvTest.kt
+++ b/app/src/test/java/com/vitorpamplona/amethyst/service/TlvTest.kt
@@ -1,35 +0,0 @@
-package com.vitorpamplona.amethyst.service
-
-import com.vitorpamplona.amethyst.service.nip19.Tlv
-import org.junit.Assert
-import org.junit.Ignore
-import org.junit.Test
-
-class TlvTest {
-
-    @Test(expected = IllegalArgumentException::class)
-    fun to_int_32_length_smaller_than_4() {
-        Tlv.toInt32(byteArrayOfInts(1, 2, 3))
-    }
-
-    @Test(expected = IllegalArgumentException::class)
-    fun to_int_32_length_bigger_than_4() {
-        Tlv.toInt32(byteArrayOfInts(1, 2, 3, 4, 5))
-    }
-
-    @Test()
-    fun to_int_32_length_4() {
-        val actual = Tlv.toInt32(byteArrayOfInts(1, 2, 3, 4))
-
-        Assert.assertEquals(16909060, actual)
-    }
-
-    @Ignore("Test not implemented yet")
-    @Test()
-    fun parse_TLV() {
-        // TODO: I don't know how to test this (?)
-    }
-
-    private fun byteArrayOfInts(vararg ints: Int) =
-        ByteArray(ints.size) { pos -> ints[pos].toByte() }
-}