refactor(rest): improve response creation (#3)

Directly serialize JSON into ByteBuf.

Author: MukjepScarlet

src/main/kotlin/net/ccbluex/netty/http/HttpConductor.kt

@@ -19,14 +19,14 @@
  */
 package net.ccbluex.netty.http
 
-import io.netty.buffer.Unpooled
 import io.netty.handler.codec.http.*
 import net.ccbluex.netty.http.HttpServer.Companion.logger
 import net.ccbluex.netty.http.model.RequestContext
 import net.ccbluex.netty.http.util.httpBadRequest
 import net.ccbluex.netty.http.util.httpInternalServerError
 import net.ccbluex.netty.http.util.httpNotFound
 import net.ccbluex.netty.http.model.RequestObject
+import net.ccbluex.netty.http.util.httpNoContent
 
 internal class HttpConductor(private val server: HttpServer) {
 
@@ -48,22 +48,13 @@ internal class HttpConductor(private val server: HttpServer) {
             return@runCatching httpBadRequest("Incomplete request")
         }
 
-        if (method == HttpMethod.OPTIONS) {
-            val response = DefaultFullHttpResponse(
-                HttpVersion.HTTP_1_1,
-                HttpResponseStatus.OK,
-                Unpooled.wrappedBuffer(ByteArray(0))
-            )
-
-            val httpHeaders = response.headers()
-            httpHeaders[HttpHeaderNames.CONTENT_TYPE] = "text/plain"
-            httpHeaders[HttpHeaderNames.CONTENT_LENGTH] = response.content().readableBytes()
-            return@runCatching response
-        }
-
         val (node, params, remaining) = server.routeController.processPath(context.path, method) ?:
             return@runCatching httpNotFound(context.path, "Route not found")
 
+        if (method == HttpMethod.OPTIONS) {
+            return@runCatching httpNoContent()
+        }
+
         logger.debug("Found destination {}", node)
         val requestObject = RequestObject(
             uri = context.uri,

src/main/kotlin/net/ccbluex/netty/http/HttpServerHandler.kt

@@ -86,7 +86,7 @@ internal class HttpServerHandler(private val server: HttpServer) : ChannelInboun
                 } else {
                     val requestContext = RequestContext(
                         msg.method(),
-                        URLDecoder.decode(msg.uri(), "UTF-8"),
+                        URLDecoder.decode(msg.uri(), Charsets.UTF_8),
                         msg.headers().associate { it.key to it.value },
                     )
 
@@ -95,21 +95,20 @@ internal class HttpServerHandler(private val server: HttpServer) : ChannelInboun
             }
 
             is HttpContent -> {
-                if (localRequestContext.get() == null) {
+                val requestContext = localRequestContext.get() ?: run {
                     logger.warn("Received HttpContent without HttpRequest")
                     return
                 }
 
                 // Append content to the buffer
-                val requestContext = localRequestContext.get()
                 requestContext
                     .contentBuffer
                     .append(msg.content().toString(Charsets.UTF_8))
 
                 // If this is the last content, process the request
                 if (msg is LastHttpContent) {
                     localRequestContext.remove()
-                    
+
                     val httpConductor = HttpConductor(server)
                     val response = httpConductor.processRequestContext(requestContext)
                     val httpResponse = server.middlewares.fold(response) { acc, f -> f(requestContext, acc) }

src/main/kotlin/net/ccbluex/netty/http/model/RequestContext.kt

@@ -20,37 +20,32 @@
 package net.ccbluex.netty.http.model
 
 import io.netty.handler.codec.http.HttpMethod
-import java.util.*
-import java.util.stream.Collectors
 
 data class RequestContext(var httpMethod: HttpMethod, var uri: String, var headers: Map<String, String>) {
     val contentBuffer = StringBuilder()
-    val path = if (uri.contains("?")) uri.substring(0, uri.indexOf('?')) else uri
+    val path = uri.substringBefore('?', uri)
     val params = getUriParams(uri)
 }
 
 /**
  * The received uri should be like: '...?param1=value&param2=value'
  */
 private fun getUriParams(uri: String): Map<String, String> {
-    if (uri.contains("?")) {
-        val paramsString = uri.substring(uri.indexOf('?') + 1)
+    val queryString = uri.substringAfter('?', "")
 
-        // in case of duplicated params, will be used la last value
-        return Arrays.stream(
-            if (paramsString.contains("&")) paramsString.split("&".toRegex()).dropLastWhile { it.isEmpty() }
-                .toTypedArray() else arrayOf(paramsString))
-            .map { value: String ->
-                value.split("=".toRegex()).dropLastWhile { it.isEmpty() }
-                    .toTypedArray()
-            }
-            .collect(
-                Collectors.toMap(
-                    { paramValue: Array<String> -> paramValue[0] },
-                    { paramValue: Array<String> -> paramValue[1] },
-                    { v1: String?, v2: String -> v2 })
-            )
+    if (queryString.isEmpty()) {
+        return emptyMap()
     }
 
-    return emptyMap()
+    // in case of duplicated params, will be used the last value
+    return queryString.split('&')
+        .mapNotNull { param ->
+            val index = param.indexOf('=')
+            if (index == -1) null
+            else {
+                val key = param.substring(0, index)
+                val value = param.substring(index + 1)
+                if (key.isNotEmpty()) key to value else null
+            }
+        }.toMap()
 }

src/main/kotlin/net/ccbluex/netty/http/model/RequestObject.kt

@@ -19,8 +19,8 @@
  */
 package net.ccbluex.netty.http.model
 
-import com.google.gson.Gson
 import io.netty.handler.codec.http.HttpMethod
+import net.ccbluex.netty.http.util.gson
 
 /**
  * Represents an HTTP request object.
@@ -51,7 +51,12 @@ data class RequestObject(
      * @return The JSON object of the specified type.
      */
     inline fun <reified T> asJson(): T {
-        return Gson().fromJson(body, T::class.java)
+        return GSON_INSTANCE.fromJson(body, T::class.java)
+    }
+
+    companion object {
+        @JvmField
+        val GSON_INSTANCE = gson
     }
 
 }

src/main/kotlin/net/ccbluex/netty/http/rest/RouteControl.kt

@@ -55,7 +55,7 @@ class RouteController : Node("") {
      */
     internal fun processPath(path: String, method: HttpMethod): Destination? {
         val pathArray = path.asPathArray()
-            .also { if (it.isEmpty()) throw IllegalArgumentException("Path cannot be empty") }
+        require(pathArray.isNotEmpty()) { "Path cannot be empty" }
 
         return travelNode(this, pathArray, method, 0, mutableMapOf())
     }
@@ -282,4 +282,8 @@ class FileServant(part: String, private val baseFolder: File) : Node(part) {
  *
  * @return An array of path parts.
  */
-private fun String.asPathArray() = split("/").drop(1).toTypedArray()
+private fun String.asPathArray(): Array<String> {
+    val parts = split("/")
+    return if (parts.size <= 1) emptyArray()
+    else parts.subList(1, parts.size).toTypedArray()
+}

src/main/kotlin/net/ccbluex/netty/http/util/ByteBufExtensions.kt

@@ -0,0 +1,29 @@
+/*
+ * This file is part of Netty-Rest (https://github.com/CCBlueX/netty-rest)
+ *
+ * Copyright (c) 2024 CCBlueX
+ *
+ * LiquidBounce is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Netty-Rest is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Netty-Rest. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+@file:Suppress("NOTHING_TO_INLINE")
+package net.ccbluex.netty.http.util
+
+import io.netty.buffer.ByteBuf
+import io.netty.buffer.ByteBufInputStream
+import io.netty.buffer.ByteBufOutputStream
+
+inline fun ByteBuf.inputStream() = ByteBufInputStream(this)
+
+inline fun ByteBuf.outputStream() = ByteBufOutputStream(this)