Add a nng_stream example paired with a socket server on win/linux

1 files changed, 109 insertions, 0 deletions

diff --git a/demo/stream/stream.c b/demo/stream/stream.c
new file mode 100644
index 00000000..c6cc9b23
--- /dev/null
+++ b/demo/stream/stream.c
@@ -0,0 +1,109 @@
+// Copyright 2020 Hugo Lindström <hugolm84@gmail.com>
+
+// This software is supplied under the terms of the MIT License, a
+// copy of which should be located in the distribution where this
+// file was obtained (LICENSE.txt).  A copy of the license may also be
+// found online at https://opensource.org/licenses/MIT.
+//
+
+// This program serves as an example for how to write async communication with
+// an arbitrary socket using nng_stream. The server receives a connection and
+// sends a hello message to the nng_stream iov.
+
+// To run this program, start the server as stream -s <portnumber>
+// Then connect to it with the client as stream -c <url>
+//
+//  For example:
+//
+//  % ./stream -s 5555 &
+//  % ./stream -c tcp://127.0.0.1:5555
+
+#include <nng/nng.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+void
+nng_fatal(const char *func, int rv)
+{
+	fprintf(stderr, "%s: %s\n", func, nng_strerror(rv));
+	exit(1);
+}
+
+int server(int port);
+int client(const char *url);
+
+int
+main(int argc, char **argv)
+{
+	int rc;
+
+	if (argc < 3) {
+		fprintf(stderr, "Usage: %s [-s port|-c url]\n", argv[0]);
+		exit(EXIT_FAILURE);
+	}
+
+	if (strcmp(argv[1], "-s") == 0) {
+		rc = server(atoi(argv[2]));
+	} else {
+		rc = client(argv[2]);
+	}
+	exit(rc == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
+}
+
+int
+client(const char *url)
+{
+	nng_stream_dialer *dialer;
+	nng_aio *          aio;
+	nng_iov            iov;
+	int                rv;
+
+	// Allocatate dialer and aio assoicated with this connection
+	if ((rv = nng_stream_dialer_alloc(&dialer, url)) != 0) {
+		nng_fatal("call to nng_stream_dialer_alloc failed", rv);
+	}
+
+	if ((rv = nng_aio_alloc(&aio, NULL, NULL)) != 0) {
+		nng_fatal("call to nng_aio_alloc", rv);
+	}
+	nng_aio_set_timeout(aio, 5000); // 5 sec
+
+	// Allocatate a buffer to recv
+	iov.iov_len = 100;
+	iov.iov_buf = (char *) malloc(sizeof(char) * iov.iov_len);
+	if ((rv = nng_aio_set_iov(aio, 1, &iov)) != 0) {
+		nng_fatal("call to nng_aio_alloc", rv);
+	}
+	// Connect to the socket via url provided to alloc
+	nng_stream_dialer_dial(dialer, aio);
+
+	// Wait for connection
+	nng_aio_wait(aio);
+	if ((rv = nng_aio_result(aio)) != 0) {
+		nng_fatal("waiting for ng_stream_dialer_dial failed", rv);
+	}
+
+	// Get the stream (connection) at position 0
+	nng_stream *c1 = (nng_stream *) nng_aio_get_output(aio, 0);
+	nng_stream_recv(c1, aio);
+	nng_aio_wait(aio);
+	if ((rv = nng_aio_result(aio)) != 0) {
+		nng_fatal("waiting for nng_stream_recv failed", rv);
+	}
+
+	size_t recv_count = nng_aio_count(aio);
+	if (recv_count <= 0) {
+		nng_fatal("Recv count was 0!", NNG_ECONNABORTED);
+	} else {
+		printf("received %zu bytes, message: '%s'\n", recv_count,
+		    (char *) iov.iov_buf);
+	}
+
+	// Send ELCOSE to send/recv associated wit this stream
+	free(iov.iov_buf);
+	nng_stream_free(c1);
+	nng_aio_free(aio);
+	nng_stream_dialer_free(dialer);
+	return 0;
+}