1 files changed, 404 insertions, 0 deletions
diff --git a/src/protocol/pubsub0/sub.c b/src/protocol/pubsub0/sub.c
new file mode 100644
index 00000000..6c504d75
--- /dev/null
+++ b/src/protocol/pubsub0/sub.c
@@ -0,0 +1,404 @@
+//
+// Copyright 2017 Garrett D'Amore <garrett@damore.org>
+// Copyright 2017 Capitar IT Group BV <info@capitar.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.
+//
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "core/nng_impl.h"
+#include "protocol/pubsub0/sub.h"
+
+// Subscriber protocol.  The SUB protocol receives messages sent to
+// it from publishers, and filters out those it is not interested in,
+// only passing up ones that match known subscriptions.
+
+#ifndef NNI_PROTO_SUB_V0
+#define NNI_PROTO_SUB_V0 NNI_PROTO(2, 1)
+#endif
+
+#ifndef NNI_PROTO_PUB_V0
+#define NNI_PROTO_PUB_V0 NNI_PROTO(2, 0)
+#endif
+
+typedef struct sub0_pipe  sub0_pipe;
+typedef struct sub0_sock  sub0_sock;
+typedef struct sub0_topic sub0_topic;
+
+static void sub0_recv_cb(void *);
+static void sub0_putq_cb(void *);
+static void sub0_pipe_fini(void *);
+
+struct sub0_topic {
+	nni_list_node node;
+	size_t        len;
+	void *        buf;
+};
+
+// sub0_sock is our per-socket protocol private structure.
+struct sub0_sock {
+	nni_list  topics;
+	nni_msgq *urq;
+	int       raw;
+	nni_mtx   lk;
+};
+
+// sub0_pipe is our per-pipe protocol private structure.
+struct sub0_pipe {
+	nni_pipe * pipe;
+	sub0_sock *sub;
+	nni_aio *  aio_recv;
+	nni_aio *  aio_putq;
+};
+
+static int
+sub0_sock_init(void **sp, nni_sock *sock)
+{
+	sub0_sock *s;
+
+	if ((s = NNI_ALLOC_STRUCT(s)) == NULL) {
+		return (NNG_ENOMEM);
+	}
+	nni_mtx_init(&s->lk);
+	NNI_LIST_INIT(&s->topics, sub0_topic, node);
+	s->raw = 0;
+
+	s->urq = nni_sock_recvq(sock);
+	*sp    = s;
+	return (0);
+}
+
+static void
+sub0_sock_fini(void *arg)
+{
+	sub0_sock * s = arg;
+	sub0_topic *topic;
+
+	while ((topic = nni_list_first(&s->topics)) != NULL) {
+		nni_list_remove(&s->topics, topic);
+		nni_free(topic->buf, topic->len);
+		NNI_FREE_STRUCT(topic);
+	}
+	nni_mtx_fini(&s->lk);
+	NNI_FREE_STRUCT(s);
+}
+
+static void
+sub0_sock_open(void *arg)
+{
+	NNI_ARG_UNUSED(arg);
+}
+
+static void
+sub0_sock_close(void *arg)
+{
+	NNI_ARG_UNUSED(arg);
+}
+
+static void
+sub0_pipe_fini(void *arg)
+{
+	sub0_pipe *p = arg;
+
+	nni_aio_fini(p->aio_putq);
+	nni_aio_fini(p->aio_recv);
+	NNI_FREE_STRUCT(p);
+}
+
+static int
+sub0_pipe_init(void **pp, nni_pipe *pipe, void *s)
+{
+	sub0_pipe *p;
+	int        rv;
+
+	if ((p = NNI_ALLOC_STRUCT(p)) == NULL) {
+		return (NNG_ENOMEM);
+	}
+	if (((rv = nni_aio_init(&p->aio_putq, sub0_putq_cb, p)) != 0) ||
+	    ((rv = nni_aio_init(&p->aio_recv, sub0_recv_cb, p)) != 0)) {
+		sub0_pipe_fini(p);
+		return (rv);
+	}
+
+	p->pipe = pipe;
+	p->sub  = s;
+	*pp     = p;
+	return (0);
+}
+
+static int
+sub0_pipe_start(void *arg)
+{
+	sub0_pipe *p = arg;
+
+	nni_pipe_recv(p->pipe, p->aio_recv);
+	return (0);
+}
+
+static void
+sub0_pipe_stop(void *arg)
+{
+	sub0_pipe *p = arg;
+
+	nni_aio_stop(p->aio_putq);
+	nni_aio_stop(p->aio_recv);
+}
+
+static void
+sub0_recv_cb(void *arg)
+{
+	sub0_pipe *p   = arg;
+	sub0_sock *s   = p->sub;
+	nni_msgq * urq = s->urq;
+	nni_msg *  msg;
+
+	if (nni_aio_result(p->aio_recv) != 0) {
+		nni_pipe_stop(p->pipe);
+		return;
+	}
+
+	msg = nni_aio_get_msg(p->aio_recv);
+	nni_aio_set_msg(p->aio_recv, NULL);
+	nni_msg_set_pipe(msg, nni_pipe_id(p->pipe));
+	nni_aio_set_msg(p->aio_putq, msg);
+	nni_msgq_aio_put(urq, p->aio_putq);
+}
+
+static void
+sub0_putq_cb(void *arg)
+{
+	sub0_pipe *p = arg;
+
+	if (nni_aio_result(p->aio_putq) != 0) {
+		nni_msg_free(nni_aio_get_msg(p->aio_putq));
+		nni_aio_set_msg(p->aio_putq, NULL);
+		nni_pipe_stop(p->pipe);
+		return;
+	}
+
+	nni_pipe_recv(p->pipe, p->aio_recv);
+}
+
+// For now we maintain subscriptions on a sorted linked list.  As we do not
+// expect to have huge numbers of subscriptions, and as the operation is
+// really O(n), we think this is acceptable.  In the future we might decide
+// to replace this with a patricia trie, like old nanomsg had.
+
+static int
+sub0_subscribe(void *arg, const void *buf, size_t sz)
+{
+	sub0_sock * s = arg;
+	sub0_topic *topic;
+	sub0_topic *newtopic;
+
+	nni_mtx_lock(&s->lk);
+	NNI_LIST_FOREACH (&s->topics, topic) {
+		int rv;
+
+		if (topic->len >= sz) {
+			rv = memcmp(topic->buf, buf, sz);
+		} else {
+			rv = memcmp(topic->buf, buf, topic->len);
+		}
+		if (rv == 0) {
+			if (topic->len == sz) {
+				// Already inserted.
+				nni_mtx_unlock(&s->lk);
+				return (0);
+			}
+			if (topic->len > sz) {
+				break;
+			}
+		} else if (rv > 0) {
+			break;
+		}
+	}
+
+	if ((newtopic = NNI_ALLOC_STRUCT(newtopic)) == NULL) {
+		nni_mtx_unlock(&s->lk);
+		return (NNG_ENOMEM);
+	}
+	if ((newtopic->buf = nni_alloc(sz)) == NULL) {
+		nni_mtx_unlock(&s->lk);
+		return (NNG_ENOMEM);
+	}
+	NNI_LIST_NODE_INIT(&newtopic->node);
+	newtopic->len = sz;
+	memcpy(newtopic->buf, buf, sz);
+	if (topic != NULL) {
+		nni_list_insert_before(&s->topics, newtopic, topic);
+	} else {
+		nni_list_append(&s->topics, newtopic);
+	}
+	nni_mtx_unlock(&s->lk);
+	return (0);
+}
+
+static int
+sub0_unsubscribe(void *arg, const void *buf, size_t sz)
+{
+	sub0_sock * s = arg;
+	sub0_topic *topic;
+	int         rv;
+
+	nni_mtx_lock(&s->lk);
+	NNI_LIST_FOREACH (&s->topics, topic) {
+		if (topic->len >= sz) {
+			rv = memcmp(topic->buf, buf, sz);
+		} else {
+			rv = memcmp(topic->buf, buf, topic->len);
+		}
+		if (rv == 0) {
+			if (topic->len == sz) {
+				nni_list_remove(&s->topics, topic);
+				nni_mtx_unlock(&s->lk);
+				nni_free(topic->buf, topic->len);
+				NNI_FREE_STRUCT(topic);
+				return (0);
+			}
+			if (topic->len > sz) {
+				nni_mtx_unlock(&s->lk);
+				return (NNG_ENOENT);
+			}
+		}
+		if (rv > 0) {
+			nni_mtx_unlock(&s->lk);
+			return (NNG_ENOENT);
+		}
+	}
+	nni_mtx_unlock(&s->lk);
+	return (NNG_ENOENT);
+}
+
+static int
+sub0_sock_setopt_raw(void *arg, const void *buf, size_t sz)
+{
+	sub0_sock *s = arg;
+	return (nni_setopt_int(&s->raw, buf, sz, 0, 1));
+}
+
+static int
+sub0_sock_getopt_raw(void *arg, void *buf, size_t *szp)
+{
+	sub0_sock *s = arg;
+	return (nni_getopt_int(s->raw, buf, szp));
+}
+
+static void
+sub0_sock_send(void *arg, nni_aio *aio)
+{
+	nni_aio_finish_error(aio, NNG_ENOTSUP);
+}
+
+static void
+sub0_sock_recv(void *arg, nni_aio *aio)
+{
+	sub0_sock *s = arg;
+
+	nni_msgq_aio_get(s->urq, aio);
+}
+
+static nni_msg *
+sub0_sock_filter(void *arg, nni_msg *msg)
+{
+	sub0_sock * s = arg;
+	sub0_topic *topic;
+	char *      body;
+	size_t      len;
+	int         match;
+
+	nni_mtx_lock(&s->lk);
+	if (s->raw) {
+		nni_mtx_unlock(&s->lk);
+		return (msg);
+	}
+
+	body = nni_msg_body(msg);
+	len  = nni_msg_len(msg);
+
+	match = 0;
+	// Check to see if the message matches one of our subscriptions.
+	NNI_LIST_FOREACH (&s->topics, topic) {
+		if (len >= topic->len) {
+			int rv = memcmp(topic->buf, body, topic->len);
+			if (rv == 0) {
+				// Matched!
+				match = 1;
+				break;
+			}
+			if (rv > 0) {
+				match = 0;
+				break;
+			}
+		} else if (memcmp(topic->buf, body, len) >= 0) {
+			match = 0;
+			break;
+		}
+	}
+	nni_mtx_unlock(&s->lk);
+	if (!match) {
+		nni_msg_free(msg);
+		return (NULL);
+	}
+	return (msg);
+}
+
+// This is the global protocol structure -- our linkage to the core.
+// This should be the only global non-static symbol in this file.
+static nni_proto_pipe_ops sub0_pipe_ops = {
+	.pipe_init  = sub0_pipe_init,
+	.pipe_fini  = sub0_pipe_fini,
+	.pipe_start = sub0_pipe_start,
+	.pipe_stop  = sub0_pipe_stop,
+};
+
+static nni_proto_sock_option sub0_sock_options[] = {
+	{
+	    .pso_name   = NNG_OPT_RAW,
+	    .pso_getopt = sub0_sock_getopt_raw,
+	    .pso_setopt = sub0_sock_setopt_raw,
+	},
+	{
+	    .pso_name   = NNG_OPT_SUB_SUBSCRIBE,
+	    .pso_getopt = NULL,
+	    .pso_setopt = sub0_subscribe,
+	},
+	{
+	    .pso_name   = NNG_OPT_SUB_UNSUBSCRIBE,
+	    .pso_getopt = NULL,
+	    .pso_setopt = sub0_unsubscribe,
+	},
+	// terminate list
+	{ NULL, NULL, NULL },
+};
+
+static nni_proto_sock_ops sub0_sock_ops = {
+	.sock_init    = sub0_sock_init,
+	.sock_fini    = sub0_sock_fini,
+	.sock_open    = sub0_sock_open,
+	.sock_close   = sub0_sock_close,
+	.sock_send    = sub0_sock_send,
+	.sock_recv    = sub0_sock_recv,
+	.sock_filter  = sub0_sock_filter,
+	.sock_options = sub0_sock_options,
+};
+
+static nni_proto sub0_proto = {
+	.proto_version  = NNI_PROTOCOL_VERSION,
+	.proto_self     = { NNI_PROTO_SUB_V0, "sub" },
+	.proto_peer     = { NNI_PROTO_PUB_V0, "pub" },
+	.proto_flags    = NNI_PROTO_FLAG_RCV,
+	.proto_sock_ops = &sub0_sock_ops,
+	.proto_pipe_ops = &sub0_pipe_ops,
+};
+
+int
+nng_sub0_open(nng_socket *sidp)
+{
+	return (nni_proto_open(sidp, &sub0_proto));
+}