Examples - Adding ping / pong examples (#310)

* Examples - Adding ping / pong examples

* Examples - using countdown latch on ZPong

examples/build.gradle.kts

@@ -37,6 +37,8 @@ tasks {
         "ZGetLiveliness",
         "ZInfo",
         "ZLiveliness",
+        "ZPing",
+        "ZPong",
         "ZPub",
         "ZPubThr",
         "ZPut",

examples/src/main/kotlin/io.zenoh/ZLiveliness.kt

@@ -40,8 +40,8 @@ class ZLiveliness(private val emptyArgs: Boolean) : CliktCommand(
 
     private val configFile by option("-c", "--config", help = "A configuration file.", metavar = "config")
     private val key by option(
-        "-k", "--key", help = "The key expression to subscribe to [default: group1/**]", metavar = "key"
-    ).default("group1/**")
+        "-k", "--key", help = "The key expression to subscribe to [default: group1/zenoh-kotlin]", metavar = "key"
+    ).default("group1/zenoh-kotlin")
     private val connect: List<String> by option(
         "-e", "--connect", help = "Endpoints to connect to.", metavar = "connect"
     ).multiple()

examples/src/main/kotlin/io.zenoh/ZPing.kt

@@ -0,0 +1,113 @@
+//
+// Copyright (c) 2023 ZettaScale Technology
+//
+// This program and the accompanying materials are made available under the
+// terms of the Eclipse Public License 2.0 which is available at
+// http://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+// which is available at https://www.apache.org/licenses/LICENSE-2.0.
+//
+// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+//
+// Contributors:
+//   ZettaScale Zenoh Team, <zenoh@zettascale.tech>
+//
+
+package io.zenoh
+
+import com.github.ajalt.clikt.core.CliktCommand
+import com.github.ajalt.clikt.parameters.arguments.argument
+import com.github.ajalt.clikt.parameters.arguments.default
+import com.github.ajalt.clikt.parameters.options.*
+import com.github.ajalt.clikt.parameters.types.double
+import com.github.ajalt.clikt.parameters.types.int
+import io.zenoh.bytes.ZBytes
+import io.zenoh.keyexpr.intoKeyExpr
+import io.zenoh.qos.CongestionControl
+import io.zenoh.qos.QoS
+import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.runBlocking
+
+class ZPing(private val emptyArgs: Boolean) : CliktCommand(
+    help = "Zenoh Ping example"
+) {
+    override fun run() {
+        val config = loadConfig(emptyArgs, configFile, connect, listen, noMulticastScouting, mode)
+
+        Zenoh.initLogFromEnvOr("error")
+
+        println("Opening session...")
+        val session = Zenoh.open(config).getOrThrow()
+        val keyExprPing = "test/ping".intoKeyExpr().getOrThrow()
+        val keyExprPong = "test/pong".intoKeyExpr().getOrThrow()
+
+        val sub = session.declareSubscriber(keyExprPong, Channel()).getOrThrow()
+        val publisher = session.declarePublisher(keyExprPing, qos = QoS(CongestionControl.BLOCK, express = !noExpress)).getOrThrow()
+
+        val data = ByteArray(payloadSize)
+        for (i in 0..<payloadSize) {
+            data[i] = (i % 10).toByte()
+        }
+        val payload = ZBytes.from(data)
+        val samples = arrayListOf<Long>()
+
+        // -- warmup --
+        println("Warming up for $warmup...")
+        val startTime = System.currentTimeMillis()
+        while (System.currentTimeMillis() - startTime < warmup) {
+            publisher.put(payload).getOrThrow()
+            runBlocking { sub.receiver.receive() }
+        }
+
+        for (x in 0..n ) {
+            val writeTime = System.nanoTime()
+            publisher.put(payload).getOrThrow()
+            runBlocking { sub.receiver.receive() }
+            val ts = (System.nanoTime() - writeTime) / 1_000 //convert to microseconds
+            samples.add(ts)
+        }
+
+        for (x in samples.withIndex()) {
+            println("$payloadSize bytes: seq=${x.index} rtt=${x.value}µs lat=${x.value / 2}µs")
+        }
+    }
+
+
+    private val payloadSize by argument(
+        "payload_size",
+        help = "Sets the size of the payload to publish [Default: 8]"
+    ).int().default(8)
+    private val noExpress: Boolean by option(
+        "--no-express", help = "Express for sending data."
+    ).flag(default = false)
+    private val warmup: Double by option(
+        "-w",
+        "--warmup",
+        metavar = "warmup",
+        help = "The number of seconds to warm up (double) [default: 1]"
+    ).double().default(1.0)
+    private val n: Int by option(
+        "-n",
+        "--samples",
+        metavar = "samples",
+        help = "The number of round-trips to measure [default: 100]"
+    ).int().default(100)
+
+    private val configFile by option("-c", "--config", help = "A configuration file.", metavar = "config")
+    private val connect: List<String> by option(
+        "-e", "--connect", help = "Endpoints to connect to.", metavar = "connect"
+    ).multiple()
+    private val listen: List<String> by option(
+        "-l", "--listen", help = "Endpoints to listen on.", metavar = "listen"
+    ).multiple()
+    private val mode by option(
+        "-m",
+        "--mode",
+        help = "The session mode. Default: peer. Possible values: [peer, client, router]",
+        metavar = "mode"
+    ).default("peer")
+    private val noMulticastScouting: Boolean by option(
+        "--no-multicast-scouting", help = "Disable the multicast-based scouting mechanism."
+    ).flag(default = false)
+}
+
+fun main(args: Array<String>) = ZPing(args.isEmpty()).main(args)

examples/src/main/kotlin/io.zenoh/ZPong.kt

@@ -0,0 +1,72 @@
+//
+// Copyright (c) 2023 ZettaScale Technology
+//
+// This program and the accompanying materials are made available under the
+// terms of the Eclipse Public License 2.0 which is available at
+// http://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+// which is available at https://www.apache.org/licenses/LICENSE-2.0.
+//
+// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+//
+// Contributors:
+//   ZettaScale Zenoh Team, <zenoh@zettascale.tech>
+//
+
+package io.zenoh
+
+import com.github.ajalt.clikt.core.CliktCommand
+import com.github.ajalt.clikt.parameters.options.*
+import io.zenoh.keyexpr.intoKeyExpr
+import io.zenoh.qos.CongestionControl
+import io.zenoh.qos.QoS
+import io.zenoh.sample.Sample
+import java.util.concurrent.CountDownLatch
+
+class ZPong(private val emptyArgs: Boolean) : CliktCommand(
+    help = "Zenoh ZPong example"
+) {
+    val latch = CountDownLatch(1)
+
+    override fun run() {
+        val config = loadConfig(emptyArgs, configFile, connect, listen, noMulticastScouting, mode)
+
+        Zenoh.initLogFromEnvOr("error")
+
+        println("Opening session...")
+        val session = Zenoh.open(config).getOrThrow()
+        val keyExprPing = "test/ping".intoKeyExpr().getOrThrow()
+        val keyExprPong = "test/pong".intoKeyExpr().getOrThrow()
+
+        val publisher = session.declarePublisher(keyExprPong, qos = QoS(CongestionControl.BLOCK, express = !noExpress)).getOrThrow()
+        session.declareSubscriber(keyExprPing, callback = { sample: Sample -> publisher.put(sample.payload).getOrThrow() }).getOrThrow()
+
+        latch.await()
+    }
+
+
+    private val noExpress: Boolean by option(
+        "--no-express", help = "Express for sending data."
+    ).flag(default = false)
+
+    private val configFile by option("-c", "--config", help = "A configuration file.", metavar = "config")
+    private val connect: List<String> by option(
+        "-e", "--connect", help = "Endpoints to connect to.", metavar = "connect"
+    ).multiple()
+    private val listen: List<String> by option(
+        "-l", "--listen", help = "Endpoints to listen on.", metavar = "listen"
+    ).multiple()
+    private val mode by option(
+        "-m",
+        "--mode",
+        help = "The session mode. Default: peer. Possible values: [peer, client, router]",
+        metavar = "mode"
+    ).default("peer")
+    private val noMulticastScouting: Boolean by option(
+        "--no-multicast-scouting", help = "Disable the multicast-based scouting mechanism."
+    ).flag(default = false)
+}
+
+fun main(args: Array<String>) {
+    val zPong = ZPong(args.isEmpty())
+    zPong.main(args)
+}