Repeat the queries by 10000 times in db to test the overhead of Ver…

…t.x Web network protocol processing

The result shows that the number of queries has increased by about 50%, which roughly means Vert.x Web network protocol processing consumes about half the computing power of single db queries.

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

@@ -15,7 +15,8 @@ import io.vertx.sqlclient.PreparedQuery
 import io.vertx.sqlclient.Row
 import io.vertx.sqlclient.RowSet
 import io.vertx.sqlclient.Tuple
-import kotlinx.coroutines.*
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
 import kotlinx.html.*
 import kotlinx.html.stream.appendHTML
 import kotlinx.serialization.Serializable
@@ -125,13 +126,17 @@ class MainVerticle(val hasDb: Boolean) : CoroutineVerticle() {
         return rowSets.map { it.single().toWorld() }
     }
 
+    suspend inline fun selectRandomWorld() =
+        selectWorldQuery.execute(Tuple.of(randomIntBetween1And10000())).await()
+
     fun Router.routes() {
         get("/json").jsonResponseHandler {
             jsonSerializationMessage
         }
 
         get("/db").jsonResponseHandler {
-            val rowSet = selectWorldQuery.execute(Tuple.of(randomIntBetween1And10000())).await()
+            repeat(9999) { selectRandomWorld() }
+            val rowSet = selectRandomWorld()
             rowSet.single().toWorld()
         }