0.3.2: UDP timeout support, fix #4

.idea/artifacts/kiloparsec_js_0_3_2.xml

@@ -0,0 +1,8 @@
+<component name="ArtifactManager">
+  <artifact type="jar" name="kiloparsec-js-0.3.2">
+    <output-path>$PROJECT_DIR$/build/libs</output-path>
+    <root id="archive" name="kiloparsec-js-0.3.2.jar">
+      <element id="module-output" name="kiloparsec.jsMain" />
+    </root>
+  </artifact>
+</component>

.idea/artifacts/kiloparsec_js_0_3_3.xml

@@ -0,0 +1,8 @@
+<component name="ArtifactManager">
+  <artifact type="jar" name="kiloparsec-js-0.3.3">
+    <output-path>$PROJECT_DIR$/build/libs</output-path>
+    <root id="archive" name="kiloparsec-js-0.3.3.jar">
+      <element id="module-output" name="kiloparsec.jsMain" />
+    </root>
+  </artifact>
+</component>

.idea/artifacts/kiloparsec_jvm_0_3_2.xml

@@ -0,0 +1,8 @@
+<component name="ArtifactManager">
+  <artifact type="jar" name="kiloparsec-jvm-0.3.2">
+    <output-path>$PROJECT_DIR$/build/libs</output-path>
+    <root id="archive" name="kiloparsec-jvm-0.3.2.jar">
+      <element id="module-output" name="kiloparsec.jvmMain" />
+    </root>
+  </artifact>
+</component>

.idea/artifacts/kiloparsec_jvm_0_3_3.xml

@@ -0,0 +1,8 @@
+<component name="ArtifactManager">
+  <artifact type="jar" name="kiloparsec-jvm-0.3.3">
+    <output-path>$PROJECT_DIR$/build/libs</output-path>
+    <root id="archive" name="kiloparsec-jvm-0.3.3.jar">
+      <element id="module-output" name="kiloparsec.jvmMain" />
+    </root>
+  </artifact>
+</component>

.idea/markdown.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="MarkdownSettings">
+    <option name="showProblemsInCodeBlocks" value="false" />
+  </component>
+</project>

README.md

@@ -1,6 +1,6 @@
 # Kiloparsec
 
-__Recommended version is `0.3.2`: to keep the code compatible with current and further versions we
+__Recommended version is `0.3.3`: to keep the code compatible with current and further versions we
 ask to upgrade to `0.3.2` at least.__ Starting from this version some pacakage names are changed for
 better clarity and fast UDP endpoints are added.
 
@@ -183,6 +183,8 @@ Is very much straightforward, same as with TCP/IP:
 
 ### UDP specifics
 
+#### Command size
+
 Each command invocation and result are packed in a separate UDP diagram using effective binary packing. 
 Thus for the best results commands and results should be relatively short, best to fit into 240 bytes. While bigger datagrams are often transmitted successfully, the probability of the effective transmission drops with the size.
 
@@ -190,6 +192,14 @@ Kiloparsec UDP transport does not retransmits not delivered packets. Use TCP/IP
 
 For the best results we recommend using [push](https://code.sergeych.net/docs/kiloparsec/kiloparsec/net.sergeych.kiloparsec/-remote-interface/index.html#1558240250%2FFunctions%2F788909594) for remote interfaces with UDP.
 
+#### Timeouts
+
+As Datagrams do not form protocol itself, kiloparsec issues pings when no data is circulated between parties.
+When no pings are received long enough, kiloparsec connection is closed. There are `maxInactivityTimeout` in all
+relevant functions and constructors.
+
+Client shoudl not issue pings manually.
+
 ## Reusing code between servers
 
 The same instance of the [KiloInterface](https://code.sergeych.net/docs/kiloparsec/kiloparsec/net.sergeych.kiloparsec/-kilo-interface/index.html?query=open%20class%20KiloInterface%3CS%3E%20:%20LocalInterface%3CKiloScope%3CS%3E%3E) could easily be reused with all instances of servers with different protocols.

build.gradle.kts

@@ -6,7 +6,7 @@ plugins {
 }
 
 group = "net.sergeych"
-version = "0.3.2"
+version = "0.3.3"
 
 repositories {
     mavenCentral()

src/ktorSocketMain/kotlin/net/sergeych/kiloparsec/adapter/TcpProvider.kt

@@ -27,7 +27,7 @@ private val logCounter = AtomicCounter(0)
 class ProtocolException(text: String, cause: Throwable? = null) : RuntimeException(text, cause)
 
 const val MAX_TCP_BLOCK_SIZE = 16776216
-val PING_INACTIVITY_TIME = 30.seconds
+internal val PING_INACTIVITY_TIME = 30.seconds
 
 /**
  * Listen for incoming TCP/IP connections on all local interfaces and the specified [port]

src/ktorSocketMain/kotlin/net/sergeych/kiloparsec/adapter/UdpProvider.kt

@@ -10,6 +10,8 @@ import net.sergeych.kiloparsec.KiloServer
 import net.sergeych.kiloparsec.RemoteInterface
 import net.sergeych.mp_tools.globalLaunch
 import net.sergeych.tools.AtomicCounter
+import kotlin.time.Duration
+import kotlin.time.Duration.Companion.minutes
 
 internal val udpCounter = AtomicCounter(0)
 
@@ -55,9 +57,40 @@ class UdpTransportException(override val message: String) : RemoteInterface.Inva
  * See [connectUdpDevice] for the client sample.
  *
  * When it is necessary to stop listening to some port, use [UdpServer] instead.
+ *
+ * @param port port to listen
+ * @param localInterface string form local interface to listen
+ * @param maxInactivityTimeout maximum silence time after which the connection is supposed to be lost.
+ *          the module automatically issues pings on inactivity when there is no data often enough
+ *          to maintain the connection open.
  */
-fun acceptUdpDevice(port: Int, localInterface: String = "0.0.0.0"): Flow<InetTransportDevice> =
-    UdpServer(port, localInterface).transportFlow
+fun acceptUdpDevice(
+    port: Int,
+    localInterface: String = "0.0.0.0",
+    maxInactivityTimeout: Duration = 2.minutes,
+): Flow<InetTransportDevice> =
+    UdpServer(port, localInterface,maxInactivityTimeout).transportFlow
+
+/**
+ * Connect to UDP server (see [acceptUdpDevice] or [UdpServer]) and return a [InetTransportDevice] for it. It
+ * should be used with [KiloClient] as connection provider:
+ * ```kotlin
+ * val client = KiloClient<Unit>() {
+ *     connect { connectUdpDevice("localhost:$port") }
+ * }
+ * // now we can execute remote commands:
+ * assertEquals("start", client.call(cmdLoad))
+ * ```
+ *
+ * @param hostPort "host:port" string address of the remote UDP port to connect to
+ * @param maxInactivityTimeout maximum silence time after which the connection is supposed to be lost.
+ *          the module automatically issues pings on inactivity when there is no data often enough
+ *          to maintain the connection open.
+ */
+fun connectUdpDevice(
+    hostPort: String,
+    maxInactivityTimeout: Duration = 2.minutes,
+) = connectUdpDevice(hostPort.toNetworkAddress(), maxInactivityTimeout)
 
 /**
  * Connect to UDP server (see [acceptUdpDevice]) and return a [InetTransportDevice] for it. It
@@ -69,21 +102,15 @@ fun acceptUdpDevice(port: Int, localInterface: String = "0.0.0.0"): Flow<InetTra
  * // now we can execute remote commands:
  * assertEquals("start", client.call(cmdLoad))
  * ```
+ * @param addr the network address where to connect to
+ * @param maxInactivityTimeout maximum silence time after which the connection is supposed to be lost.
+ *          the module automatically issues pings on inactivity when there is no data often enough
+ *          to maintain the connection open.
  */
-fun connectUdpDevice(hostPort: String) = connectUdpDevice(hostPort.toNetworkAddress())
-
-/**
- * Connect to UDP server (see [acceptUdpDevice]) and return a [InetTransportDevice] for it. It
- * should be used with [KiloClient] as connection provider:
- * ```kotlin
- * val client = KiloClient<Unit>() {
- *     connect { connectUdpDevice("localhost:$port") }
- * }
- * // now we can execute remote commands:
- * assertEquals("start", client.call(cmdLoad))
- * ```
- */
-fun connectUdpDevice(addr: NetworkAddress): InetTransportDevice {
+fun connectUdpDevice(
+    addr: NetworkAddress,
+    maxInactivityTimeout: Duration = 2.minutes,
+): InetTransportDevice {
     val selectorManager = SelectorManager(Dispatchers.IO)
     val remoteAddress = InetSocketAddress(addr.host, addr.port)
     val socket = aSocket(selectorManager).udp().connect(remoteAddress)
@@ -99,7 +126,7 @@ fun connectUdpDevice(addr: NetworkAddress): InetTransportDevice {
             done.complete(Unit)
         }
 
-    }, remoteAddress, false)
+    }, remoteAddress, false, maxInactivityTimeout)
 
     globalLaunch {
         launch {

src/ktorSocketMain/kotlin/net/sergeych/kiloparsec/adapter/UdpServer.kt

@@ -14,6 +14,8 @@ import net.sergeych.mp_logger.LogTag
 import net.sergeych.mp_logger.Loggable
 import net.sergeych.mp_logger.debug
 import net.sergeych.mp_logger.exception
+import kotlin.time.Duration
+import kotlin.time.Duration.Companion.minutes
 
 /**
  * UDP server for kiloparsec. Unlike [acceptUdpDevice], it allow stopping listening
@@ -34,8 +36,15 @@ import net.sergeych.mp_logger.exception
  * ```
  *
  * See [acceptUdpDevice] for more information.
+ *
+ * @param port port to listen to
+ * @param localInterface string form of local interface to listen to
+ * @param maxInactivityTimeout maximum silence time after which the connection is supposed to be lost.
+ *          the module automatically issues pings on inactivity when there is no data often enough
+ *          to maintain the connection open.
+
  */
-class UdpServer(val port: Int,localInterface: String = "0.0.0.0") :
+class UdpServer(val port: Int, localInterface: String = "0.0.0.0", maxInactivityTimeout: Duration = 2.minutes) :
     Loggable by LogTag("UDPS${udpCounter.incrementAndGet()}"), UdpConnector {
 
     private val sessions = mutableMapOf<SocketAddress, UdpSocketTransport>()
@@ -68,18 +77,17 @@ class UdpServer(val port: Int,localInterface: String = "0.0.0.0") :
                             sessions.getOrPut(remoteAddress) {
                                 // new connection: create transport
                                 debug { "Creating new connection to $remoteAddress" }
-                                UdpSocketTransport(this@UdpServer, remoteAddress, true)
+                                UdpSocketTransport(this@UdpServer, remoteAddress, true, maxInactivityTimeout)
                                     // and emit it:
                                     .also { emit(it.transportDevice) }
                             }.processIncoming(block)
                         }
                     }
-                }
-                catch(_: CancellationException) { break }
-                catch(_: ClosedReceiveChannelException) {
+                } catch (_: CancellationException) {
                     break
-                }
-                catch(e: Exception) {
+                } catch (_: ClosedReceiveChannelException) {
+                    break
+                } catch (e: Exception) {
                     exception { "unexpected exception in incoming datagram processing" to e }
                     close()
                     break

src/ktorSocketMain/kotlin/net/sergeych/kiloparsec/adapter/UdpSocketTransport.kt

@@ -16,14 +16,19 @@ import net.sergeych.mp_logger.Loggable
 import net.sergeych.mp_logger.debug
 import net.sergeych.mp_logger.exception
 import net.sergeych.mp_tools.globalLaunch
-import kotlin.time.Duration.Companion.seconds
+import kotlin.time.Duration
 
 /**
  * This is a common part of UDP transport shared between client and server connections.
  * It should not be used directly but bu the [UdpServer], [acceptUdpDevice] and [connectUdpDevice]
  * respectively.
  */
-internal class UdpSocketTransport(private val server: UdpConnector, val socketAddress: SocketAddress, val isServer: Boolean) :
+internal class UdpSocketTransport(
+    private val server: UdpConnector,
+    val socketAddress: SocketAddress,
+    val isServer: Boolean,
+    val maxInactivityTimeout: Duration
+) :
     Loggable {
 
     // IMPORTANT! Log stuff must be the first (or you shot your leg):
@@ -34,12 +39,10 @@ internal class UdpSocketTransport(private val server: UdpConnector, val socketAd
     // Pinger params: keep them first!
     private var lastSendAt = Clock.System.now()
     private var lastReceived = Clock.System.now()
-    private val pingTimeout = 30.seconds
+    private val pingTimeout = maxInactivityTimeout / 3
     private val pingSleep = pingTimeout / 3
-    private val pingMinTimeout = pingTimeout / 2
+    private val pingMinTimeout = pingTimeout * 2 / 3
 
-    // TODO: break on inactivity
-    private val inactivityBreakTimeout = 30.seconds
     val inputDataBlocks = Channel<UByteArray>(256, onBufferOverflow = BufferOverflow.DROP_OLDEST)
     val outputDataBlocks = Channel<UByteArray>(256, onBufferOverflow = BufferOverflow.DROP_OLDEST)
 
@@ -142,7 +145,12 @@ internal class UdpSocketTransport(private val server: UdpConnector, val socketAd
     private suspend fun pinger() {
         while (!isClosed) {
             delay(pingSleep)
-            if (Clock.System.now() - lastSendAt >= pingTimeout) {
+            val inactivity = Clock.System.now() - lastSendAt
+            if( inactivity > maxInactivityTimeout) {
+                debug { "inactivity timout: closing the connection" }
+                close()
+            }
+            if (inactivity >= pingTimeout) {
                 debug { "pinger sends a ping on timeout" }
                 send(UdpBlock.Ping)
             }

src/ktorSocketTest/kotlin/net/sergeych/kiloparsec/adapter/InternetTest.kt

@@ -1,7 +1,9 @@
+package net.sergeych.kiloparsec.adapter
+
+import assertThrows
 import kotlinx.coroutines.test.runTest
 import net.sergeych.crypto2.initCrypto
 import net.sergeych.kiloparsec.*
-import net.sergeych.kiloparsec.adapter.*
 import net.sergeych.mp_logger.Log
 import kotlin.random.Random
 import kotlin.test.Test