Replace Okio with kotlinx-io and remove unneeded code

The "JSON serialization" performance seems to be slightly less.

frameworks/Kotlin/vertx-web-kotlinx/README.md

@@ -27,6 +27,7 @@ The tests were run with:
 * [Vert.x Reactive PostgreSQL Client](https://vertx.io/docs/vertx-pg-client/java/)
 * [kotlinx.coroutines](https://github.com/Kotlin/kotlinx.coroutines)
 * [kotlinx.serialization](https://github.com/Kotlin/kotlinx.serialization)
+* [kotlinx-io](https://github.com/Kotlin/kotlinx-io)
 * [kotlinx.html](https://github.com/Kotlin/kotlinx.html)
 
 ## Test URLs

frameworks/Kotlin/vertx-web-kotlinx/build.gradle.kts

@@ -29,9 +29,8 @@ dependencies {
     implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.9.0")
 
     implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:$kotlinxSerializationVersion")
-    //implementation("org.jetbrains.kotlinx:kotlinx-serialization-json-io:$kotlinxSerializationVersion")
-    implementation("org.jetbrains.kotlinx:kotlinx-serialization-json-okio:$kotlinxSerializationVersion")
-    implementation("com.squareup.okio:okio:3.9.1")
+    implementation("org.jetbrains.kotlinx:kotlinx-serialization-json-io:$kotlinxSerializationVersion")
+    implementation("org.jetbrains.kotlinx:kotlinx-io-core:0.5.4")
 
     implementation("org.jetbrains.kotlinx:kotlinx-html:0.11.0")
     //implementation("org.jetbrains.kotlinx:kotlinx-datetime:0.4.0") // the latest version is 0.6.1

frameworks/Kotlin/vertx-web-kotlinx/src/main/kotlin/KotlinxIo.kt

@@ -0,0 +1,49 @@
+import io.vertx.core.streams.WriteStream
+import io.vertx.kotlin.coroutines.coAwait
+import kotlinx.coroutines.runBlocking
+import kotlinx.io.RawSink
+import kotlinx.io.readByteArray
+import io.vertx.core.buffer.Buffer as VertxBuffer
+import kotlinx.io.Buffer as KotlinxIoBuffer
+
+@Suppress("NOTHING_TO_INLINE")
+private inline fun Long.toIntOrThrow(): Int {
+    require(this in Int.MIN_VALUE.toLong()..Int.MAX_VALUE.toLong())
+    return toInt()
+}
+
+@JvmInline
+value class VertxBufferWriteStreamSink(val writeStream: WriteStream<VertxBuffer>) : RawSink {
+    override fun write(source: KotlinxIoBuffer, byteCount: Long) {
+        runBlocking {
+            // `source` is temporarily converted to a byte array because wrapping it as a Vert.x `Buffer` is too complicated to implement.
+            writeStream.write(VertxBuffer.buffer(source.readByteArray(byteCount.toIntOrThrow()))).coAwait()
+        }
+    }
+
+    override fun flush() {}
+
+    override fun close() {
+        writeStream.end()
+    }
+}
+
+// not used currently
+fun WriteStream<VertxBuffer>.toRawSink(): RawSink =
+    VertxBufferWriteStreamSink(this)
+
+
+@JvmInline
+value class VertxBufferSink(val vertxBuffer: VertxBuffer) : RawSink {
+    override fun write(source: KotlinxIoBuffer, byteCount: Long) {
+        // same problem as above
+        vertxBuffer.appendBytes(source.readByteArray(byteCount.toIntOrThrow()))
+    }
+
+    override fun flush() {}
+
+    override fun close() {}
+}
+
+fun VertxBuffer.toRawSink(): RawSink =
+    VertxBufferSink(this)

frameworks/Kotlin/vertx-web-kotlinx/src/main/kotlin/MainVerticle.kt

@@ -20,12 +20,12 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 import kotlinx.html.*
 import kotlinx.html.stream.appendHTML
+import kotlinx.io.buffered
 import kotlinx.serialization.ExperimentalSerializationApi
 import kotlinx.serialization.Serializable
 import kotlinx.serialization.SerializationStrategy
 import kotlinx.serialization.json.Json
-import kotlinx.serialization.json.okio.encodeToBufferedSink
-import okio.buffer
+import kotlinx.serialization.json.io.encodeToSink
 import java.time.ZonedDateTime
 import java.time.format.DateTimeFormatter
 
@@ -133,17 +133,17 @@ class MainVerticle(val hasDb: Boolean) : CoroutineVerticle() {
                 /*
                 // approach 2
                 // java.lang.IllegalStateException: You must set the Content-Length header to be the total size of the message body BEFORE sending any data if you are not using HTTP chunked encoding.
-                toSink().buffer().use { bufferedSink ->
+                toRawSink().buffered().use { bufferedSink ->
                     @OptIn(ExperimentalSerializationApi::class)
-                    Json.encodeToBufferedSink(serializer, requestHandler(it), bufferedSink)
+                    Json.encodeToSink(serializer, requestHandler(it), bufferedSink)
                 }
                 */
 
                 // approach 3
                 end(Buffer.buffer().apply {
-                    toSink().buffer().use { bufferedSink ->
+                    toRawSink().buffered().use { bufferedSink ->
                         @OptIn(ExperimentalSerializationApi::class)
-                        Json.encodeToBufferedSink(serializer, requestHandler(it), bufferedSink)
+                        Json.encodeToSink(serializer, requestHandler(it), bufferedSink)
                     }
                 })
             }