Refactor option handling APIs.

This makes the APIs use string keys, and largely eliminates the use of
integer option IDs altogether.  The underlying registration for options
is also now a bit richer, letting protcols and transports declare the
actual options they use, rather than calling down into each entry point
carte blanche and relying on ENOTSUP.

This code may not be as fast as the integers was, but it is more intuitive,
easier to extend, and is not on any hot code paths.  (If you're diddling
options on a hot code path you're doing something wrong.)

2 files changed, 83 insertions, 88 deletions

diff --git a/src/protocol/pair/pair_v0.c b/src/protocol/pair/pair_v0.c
index 277d5cb1..9cabe3c7 100644
--- a/src/protocol/pair/pair_v0.c
+++ b/src/protocol/pair/pair_v0.c
@@ -230,31 +230,17 @@ pair0_sock_close(void *arg)
 }
 
 static int
-pair0_sock_setopt(void *arg, int opt, const void *buf, size_t sz)
+pair0_sock_setopt_raw(void *arg, const void *buf, size_t sz)
 {
 	pair0_sock *s = arg;
-	int         rv;
-
-	if (opt == nng_optid_raw) {
-		rv = nni_setopt_int(&s->raw, buf, sz, 0, 1);
-	} else {
-		rv = NNG_ENOTSUP;
-	}
-	return (rv);
+	return (nni_setopt_int(&s->raw, buf, sz, 0, 1));
 }
 
 static int
-pair0_sock_getopt(void *arg, int opt, void *buf, size_t *szp)
+pair0_sock_getopt_raw(void *arg, void *buf, size_t *szp)
 {
 	pair0_sock *s = arg;
-	int         rv;
-
-	if (opt == nng_optid_raw) {
-		rv = nni_getopt_int(s->raw, buf, szp);
-	} else {
-		rv = NNG_ENOTSUP;
-	}
-	return (rv);
+	return (nni_getopt_int(s->raw, buf, szp));
 }
 
 static nni_proto_pipe_ops pair0_pipe_ops = {
@@ -264,13 +250,22 @@ static nni_proto_pipe_ops pair0_pipe_ops = {
 	.pipe_stop  = pair0_pipe_stop,
 };
 
+static nni_proto_sock_option pair0_sock_options[] = {
+	{
+	    .pso_name   = NNG_OPT_RAW,
+	    .pso_getopt = pair0_sock_getopt_raw,
+	    .pso_setopt = pair0_sock_setopt_raw,
+	},
+	// terminate list
+	{ NULL, NULL, NULL },
+};
+
 static nni_proto_sock_ops pair0_sock_ops = {
-	.sock_init   = pair0_sock_init,
-	.sock_fini   = pair0_sock_fini,
-	.sock_open   = pair0_sock_open,
-	.sock_close  = pair0_sock_close,
-	.sock_setopt = pair0_sock_setopt,
-	.sock_getopt = pair0_sock_getopt,
+	.sock_init    = pair0_sock_init,
+	.sock_fini    = pair0_sock_fini,
+	.sock_open    = pair0_sock_open,
+	.sock_close   = pair0_sock_close,
+	.sock_options = pair0_sock_options,
 };
 
 // Legacy protocol (v0)
diff --git a/src/protocol/pair/pair_v1.c b/src/protocol/pair/pair_v1.c
index 68dbc6f7..2cd5782b 100644
--- a/src/protocol/pair/pair_v1.c
+++ b/src/protocol/pair/pair_v1.c
@@ -25,9 +25,9 @@ static void pair1_pipe_getq_cb(void *);
 static void pair1_pipe_putq_cb(void *);
 static void pair1_pipe_fini(void *);
 
-// These are exposed as external names for external consumers.
-int         nng_optid_pair1_poly;
-const char *nng_opt_pair1_poly = "pair1-polyamorous";
+// This is exposed as an external name for external consumers.
+#define NNG_OPT_PAIR1_POLY "pair1-polyamorous"
+const char *nng_opt_pair1_poly = NNG_OPT_PAIR1_POLY;
 
 // pair1_sock is our per-socket protocol private structure.
 struct pair1_sock {
@@ -394,74 +394,57 @@ pair1_sock_close(void *arg)
 }
 
 static int
-pair1_sock_setopt(void *arg, int opt, const void *buf, size_t sz)
+pair1_sock_setopt_raw(void *arg, const void *buf, size_t sz)
 {
-	pair1_sock *s  = arg;
-	int         rv = NNG_ENOTSUP;
-
-	if (opt == nng_optid_raw) {
-		nni_mtx_lock(&s->mtx);
-		if (s->started) {
-			rv = NNG_ESTATE;
-		} else {
-			rv = nni_setopt_int(&s->raw, buf, sz, 0, 1);
-		}
-		nni_mtx_unlock(&s->mtx);
-	} else if (opt == nng_optid_maxttl) {
-		nni_mtx_lock(&s->mtx);
-		rv = nni_setopt_int(&s->ttl, buf, sz, 1, 255);
-		nni_mtx_unlock(&s->mtx);
-	} else if (opt == nng_optid_pair1_poly) {
-		nni_mtx_lock(&s->mtx);
-		if (s->started) {
-			rv = NNG_ESTATE;
-		} else {
-			rv = nni_setopt_int(&s->poly, buf, sz, 0, 1);
-		}
-		nni_mtx_unlock(&s->mtx);
-	}
-
+	pair1_sock *s = arg;
+	int         rv;
+	nni_mtx_lock(&s->mtx);
+	rv = s->started ? NNG_ESTATE : nni_setopt_int(&s->raw, buf, sz, 0, 1);
+	nni_mtx_unlock(&s->mtx);
 	return (rv);
 }
 
 static int
-pair1_sock_getopt(void *arg, int opt, void *buf, size_t *szp)
+pair1_sock_getopt_raw(void *arg, void *buf, size_t *szp)
 {
-	pair1_sock *s  = arg;
-	int         rv = NNG_ENOTSUP;
+	pair1_sock *s = arg;
+	return (nni_getopt_int(s->raw, buf, szp));
+}
 
-	if (opt == nng_optid_raw) {
-		nni_mtx_lock(&s->mtx);
-		rv = nni_getopt_int(s->raw, buf, szp);
-		nni_mtx_unlock(&s->mtx);
-	} else if (opt == nng_optid_maxttl) {
-		nni_mtx_lock(&s->mtx);
-		rv = nni_getopt_int(s->ttl, buf, szp);
-		nni_mtx_unlock(&s->mtx);
-	} else if (opt == nng_optid_pair1_poly) {
-		nni_mtx_lock(&s->mtx);
-		rv = nni_getopt_int(s->poly, buf, szp);
-		nni_mtx_unlock(&s->mtx);
-	}
+static int
+pair1_sock_setopt_maxttl(void *arg, const void *buf, size_t sz)
+{
+	pair1_sock *s = arg;
+	int         rv;
+	nni_mtx_lock(&s->mtx); // Have to be locked against recv cb.
+	rv = nni_setopt_int(&s->ttl, buf, sz, 1, 255);
+	nni_mtx_unlock(&s->mtx);
 	return (rv);
 }
 
-static void
-pair1_fini(void)
+static int
+pair1_sock_getopt_maxttl(void *arg, void *buf, size_t *szp)
 {
-	nng_optid_pair1_poly = -1;
+	pair1_sock *s = arg;
+	return (nni_getopt_int(s->ttl, buf, szp));
 }
 
 static int
-pair1_init(void)
+pair1_sock_setopt_poly(void *arg, const void *buf, size_t sz)
 {
-	int rv;
-	if ((rv = nni_option_register(
-	         nng_opt_pair1_poly, &nng_optid_pair1_poly)) != 0) {
-		pair1_fini();
-		return (rv);
-	}
-	return (0);
+	pair1_sock *s = arg;
+	int         rv;
+	nni_mtx_lock(&s->mtx);
+	rv = s->started ? NNG_ESTATE : nni_setopt_int(&s->poly, buf, sz, 0, 1);
+	nni_mtx_unlock(&s->mtx);
+	return (rv);
+}
+
+static int
+pair1_sock_getopt_poly(void *arg, void *buf, size_t *szp)
+{
+	pair1_sock *s = arg;
+	return (nni_getopt_int(s->poly, buf, szp));
 }
 
 static nni_proto_pipe_ops pair1_pipe_ops = {
@@ -471,13 +454,32 @@ static nni_proto_pipe_ops pair1_pipe_ops = {
 	.pipe_stop  = pair1_pipe_stop,
 };
 
+static nni_proto_sock_option pair1_sock_options[] = {
+	{
+	    .pso_name   = NNG_OPT_RAW,
+	    .pso_getopt = pair1_sock_getopt_raw,
+	    .pso_setopt = pair1_sock_setopt_raw,
+	},
+	{
+	    .pso_name   = NNG_OPT_MAXTTL,
+	    .pso_getopt = pair1_sock_getopt_maxttl,
+	    .pso_setopt = pair1_sock_setopt_maxttl,
+	},
+	{
+	    .pso_name   = NNG_OPT_PAIR1_POLY,
+	    .pso_getopt = pair1_sock_getopt_poly,
+	    .pso_setopt = pair1_sock_setopt_poly,
+	},
+	// terminate list
+	{ NULL, NULL, NULL },
+};
+
 static nni_proto_sock_ops pair1_sock_ops = {
-	.sock_init   = pair1_sock_init,
-	.sock_fini   = pair1_sock_fini,
-	.sock_open   = pair1_sock_open,
-	.sock_close  = pair1_sock_close,
-	.sock_setopt = pair1_sock_setopt,
-	.sock_getopt = pair1_sock_getopt,
+	.sock_init    = pair1_sock_init,
+	.sock_fini    = pair1_sock_fini,
+	.sock_open    = pair1_sock_open,
+	.sock_close   = pair1_sock_close,
+	.sock_options = pair1_sock_options,
 };
 
 static nni_proto pair1_proto = {
@@ -487,8 +489,6 @@ static nni_proto pair1_proto = {
 	.proto_flags    = NNI_PROTO_FLAG_SNDRCV,
 	.proto_sock_ops = &pair1_sock_ops,
 	.proto_pipe_ops = &pair1_pipe_ops,
-	.proto_init     = &pair1_init,
-	.proto_fini     = &pair1_fini,
 };
 
 int