SvyatoslavScherbina
71 lines
1.9 KiB
Kotlin
71 lines
1.9 KiB
Kotlin
import kotlinx.cinterop.*
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import sockets.*
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fun main(args: Array<String>) {
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if (args.size < 1) {
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println("Usage: ./echo_server <port>")
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return
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}
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val port = atoi(args[0]).toUShort()
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memScoped {
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val bufferLength = 100L
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val buffer = allocArray<ByteVar>(bufferLength)
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val serverAddr = alloc<sockaddr_in>()
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val listenFd = socket(AF_INET, SOCK_STREAM, 0)
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.ensureUnixCallResult { it >= 0 }
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with(serverAddr) {
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memset(this.ptr, 0, sockaddr_in.size.convert())
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sin_family = AF_INET.convert()
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sin_addr.s_addr = htons(0u).convert()
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sin_port = htons(port)
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}
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bind(listenFd, serverAddr.ptr.reinterpret(), sockaddr_in.size.toUInt())
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.ensureUnixCallResult { it == 0 }
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listen(listenFd, 10)
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.ensureUnixCallResult { it == 0 }
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val commFd = accept(listenFd, null, null)
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.ensureUnixCallResult { it >= 0 }
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while (true) {
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val length = read(commFd, buffer, bufferLength.convert())
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.ensureUnixCallResult { it >= 0 }
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if (length == 0L) {
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break
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}
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write(commFd, buffer, length.convert())
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.ensureUnixCallResult { it >= 0 }
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}
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}
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}
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// Not available through interop because declared as macro:
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fun htons(value: UShort) = ((value.toInt() ushr 8) or (value.toInt() shl 8)).toUShort()
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fun throwUnixError(): Nothing {
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perror(null) // TODO: store error message to exception instead.
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throw Error("UNIX call failed")
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}
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inline fun Int.ensureUnixCallResult(predicate: (Int) -> Boolean): Int {
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if (!predicate(this)) {
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throwUnixError()
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}
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return this
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}
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inline fun Long.ensureUnixCallResult(predicate: (Long) -> Boolean): Long {
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if (!predicate(this)) {
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throwUnixError()
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}
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return this
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} |