SynchronousPortHandler

This commit is contained in:
Alexander Nozik 2020-08-27 21:04:11 +03:00
parent fed5d55512
commit 08982dcd3e
4 changed files with 78 additions and 39 deletions

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@ -4,13 +4,9 @@ import kotlinx.coroutines.CancellationException
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.cancel
import kotlinx.coroutines.channels.Channel
import kotlinx.coroutines.channels.ReceiveChannel
import kotlinx.coroutines.flow.Flow
import kotlinx.coroutines.flow.collect
import kotlinx.coroutines.flow.flow
import kotlinx.coroutines.flow.receiveAsFlow
import kotlinx.coroutines.launch
import kotlinx.io.ByteArrayOutput
import kotlinx.io.Closeable
import mu.KLogger
@ -20,7 +16,7 @@ abstract class Port(val scope: CoroutineScope) : Closeable {
private val outgoing = Channel<ByteArray>(100)
private val incoming = Channel<ByteArray>(Channel.CONFLATED)
val receiveChannel: ReceiveChannel<ByteArray> get() = incoming
//val receiveChannel: ReceiveChannel<ByteArray> get() = incoming
/**
* Internal method to synchronously send data
@ -56,9 +52,9 @@ abstract class Port(val scope: CoroutineScope) : Closeable {
/**
* Raw flow of incoming data chunks. The chunks are not guaranteed to be complete phrases.
* In order to form phrases some condition should used on top of it.
* For example [delimitedInput] generates phrases with fixed delimiter.
* For example [delimitedIncoming] generates phrases with fixed delimiter.
*/
fun input(): Flow<ByteArray> {
fun incoming(): Flow<ByteArray> {
return incoming.receiveAsFlow()
}
@ -73,32 +69,3 @@ abstract class Port(val scope: CoroutineScope) : Closeable {
* Send UTF-8 encoded string
*/
suspend fun Port.send(string: String) = send(string.encodeToByteArray())
fun Flow<ByteArray>.withDelimiter(delimiter: ByteArray, expectedMessageSize: Int = 32): Flow<ByteArray> = flow {
require(delimiter.isNotEmpty()) { "Delimiter must not be empty" }
var output = ByteArrayOutput(expectedMessageSize)
var matcherPosition = 0
collect { chunk ->
chunk.forEach { byte ->
output.writeByte(byte)
//matching current symbol in delimiter
if (byte == delimiter[matcherPosition]) {
matcherPosition++
if (matcherPosition == delimiter.size) {
//full match achieved, sending result
emit(output.toByteArray())
output = ByteArrayOutput(expectedMessageSize)
matcherPosition = 0
}
} else if (matcherPosition > 0) {
//Reset matcher since full match not achieved
matcherPosition = 0
}
}
}
}
fun Port.delimitedInput(delimiter: ByteArray, expectedMessageSize: Int = 32) =
input().withDelimiter(delimiter, expectedMessageSize)

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@ -0,0 +1,34 @@
package hep.dataforge.control.ports
import kotlinx.coroutines.flow.Flow
import kotlinx.coroutines.flow.first
import kotlinx.coroutines.sync.Mutex
import kotlinx.coroutines.sync.withLock
/**
* A port handler for synchronous (request-response) communication with a port. Only one request could be active at a time (others are suspended.
* The handler does not guarantee exclusive access to the port so the user mush ensure that no other controller handles port at the moment.
*
*/
class SynchronousPortHandler(val port: Port) {
private val mutex = Mutex()
/**
* Send a single message and wait for the flow of respond messages.
*/
suspend fun <R> respond(data: ByteArray, transform: suspend Flow<ByteArray>.() -> R): R {
return mutex.withLock {
port.send(data)
transform(port.incoming())
}
}
}
/**
* Send request and read incoming data blocks until the delimiter is encountered
*/
suspend fun SynchronousPortHandler.respondWithDelimiter(data: ByteArray, delimiter: ByteArray): ByteArray {
return respond(data) {
withDelimiter(delimiter).first()
}
}

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@ -0,0 +1,38 @@
package hep.dataforge.control.ports
import kotlinx.coroutines.flow.Flow
import kotlinx.coroutines.flow.collect
import kotlinx.coroutines.flow.flow
import kotlinx.io.ByteArrayOutput
fun Flow<ByteArray>.withDelimiter(delimiter: ByteArray, expectedMessageSize: Int = 32): Flow<ByteArray> = flow {
require(delimiter.isNotEmpty()) { "Delimiter must not be empty" }
var output = ByteArrayOutput(expectedMessageSize)
var matcherPosition = 0
collect { chunk ->
chunk.forEach { byte ->
output.writeByte(byte)
//matching current symbol in delimiter
if (byte == delimiter[matcherPosition]) {
matcherPosition++
if (matcherPosition == delimiter.size) {
//full match achieved, sending result
emit(output.toByteArray())
output = ByteArrayOutput(expectedMessageSize)
matcherPosition = 0
}
} else if (matcherPosition > 0) {
//Reset matcher since full match not achieved
matcherPosition = 0
}
}
}
}
/**
* A flow of delimited phrases
*/
fun Port.delimitedIncoming(delimiter: ByteArray, expectedMessageSize: Int = 32) =
incoming().withDelimiter(delimiter, expectedMessageSize)

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@ -58,7 +58,7 @@ class TcpPortTest {
val port = TcpPort.open("localhost", 22188)
val logJob = launch {
port.input().collect {
port.incoming().collect {
println("Flow: ${it.decodeToString()}")
}
}
@ -83,7 +83,7 @@ class TcpPortTest {
val port = KtorTcpPort.open("localhost", 22188)
val logJob = launch {
port.input().collect {
port.incoming().collect {
println("Flow: ${it.decodeToString()}")
}
}