test: Add XmlStringBuilderPerfTest.

src/test/kotlin/org/jitsi/xmpp/extensions/XmlStringBuilderPerfTest.kt

@@ -0,0 +1,114 @@
+/*
+ * Jicofo, the Jitsi Conference Focus.
+ *
+ * Copyright @ 2024-Present 8x8, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jitsi.xmpp.extensions
+
+import io.kotest.core.spec.style.ShouldSpec
+import org.jitsi.utils.logging2.createLogger
+import org.jivesoftware.smack.util.Supplier
+import org.jivesoftware.smack.util.XmlStringBuilder
+
+/**
+ * A test for the performance of XmlStringBuilder serialization. See https://github.com/igniterealtime/Smack/pull/569
+ */
+class XmlStringBuilderPerfTest : ShouldSpec() {
+    val countOuter: Int = 500
+    val countInner: Int = 50
+    val logger = createLogger()
+
+    init {
+        xcontext("XmlStringBuilder.toString() performance") {
+            test1()
+            test2()
+            test3()
+        }
+    }
+
+    private fun test1() {
+        logger.info("Test 1")
+        val parent = XmlStringBuilder()
+        val child = XmlStringBuilder()
+        val child2 = XmlStringBuilder()
+
+        for (i in 1 until countOuter) {
+            val cs = XmlStringBuilder()
+            for (j in 0 until countInner) {
+                cs.append("abc")
+            }
+            child2.append(cs as CharSequence)
+        }
+
+        child.append(child2 as CharSequence)
+        parent.append(child as CharSequence)
+
+        time("test1: parent") { "len=" + parent.toString().length }
+        time("test1: child") { "len=" + child.toString().length }
+        time("test1: child2") { "len=" + child2.toString().length }
+    }
+
+    private fun test2() {
+        logger.info("Test 2: evaluate children first")
+        val parent = XmlStringBuilder()
+        val child = XmlStringBuilder()
+        val child2 = XmlStringBuilder()
+
+        for (i in 1 until countOuter) {
+            val cs = XmlStringBuilder()
+            for (j in 0 until countInner) {
+                cs.append("abc")
+            }
+            child2.append(cs as CharSequence)
+        }
+
+        child.append(child2 as CharSequence)
+        parent.append(child as CharSequence)
+
+        time("test2: child2") { "len=" + child2.toString().length }
+        time("test2: child") { "len=" + child.toString().length }
+        time("test2: parent") { "len=" + parent.toString().length }
+    }
+
+    private fun test3() {
+        logger.info("Test 3: use append(XmlStringBuilder)")
+        val parent = XmlStringBuilder()
+        val child = XmlStringBuilder()
+        val child2 = XmlStringBuilder()
+
+        for (i in 1 until countOuter) {
+            val cs = XmlStringBuilder()
+            for (j in 0 until countInner) {
+                cs.append("abc")
+            }
+            child2.append(cs)
+        }
+
+        child.append(child2)
+        parent.append(child)
+
+        time("test3: parent") { "len=" + parent.toString().length }
+        time("test3: child") { "len=" + child.toString().length }
+        time("test3: child2") { "len=" + child2.toString().length }
+    }
+
+    fun time(name: String, block: Supplier<String>) {
+        val start = System.currentTimeMillis()
+        val result = block.get()
+        val end = System.currentTimeMillis()
+
+        logger.info(name + " took " + (end - start) + "ms: " + result)
+    }
+}