fixes #1740 Public ID hash API

This includes a manual page documenting the entire set of
functions in one step.  The hash is 64-bit based for now, to
be maximally flexible.  An internal 32-bit convenience for the
common internal use is also provided (not public).

The public API includes a test suite.

1 files changed, 60 insertions, 0 deletions

diff --git a/src/supplemental/idhash/idhash.c b/src/supplemental/idhash/idhash.c
new file mode 100644
index 00000000..051b686a
--- /dev/null
+++ b/src/supplemental/idhash/idhash.c
@@ -0,0 +1,60 @@
+//
+// Copyright 2023 Staysail Systems, Inc. <info@staysail.tech>
+//
+// 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 "supplemental/idhash/idhash.h"
+#include "core/nng_impl.h"
+
+struct nng_id_map_s {
+	nni_id_map m;
+};
+
+int
+nng_id_map_alloc(nng_id_map **map, uint64_t lo, uint64_t hi, int flags)
+{
+	nng_id_map *m;
+
+	if ((m = NNI_ALLOC_STRUCT(m)) == NULL) {
+		return (NNG_ENOMEM);
+	}
+	nni_id_map_init(
+	    &m->m, lo, hi, (flags & NNG_MAP_RANDOM) ? true : false);
+	*map = m;
+	return (0);
+}
+
+void
+nng_id_map_free(nng_id_map *map)
+{
+	nni_id_map_fini(&map->m);
+	NNI_FREE_STRUCT(map);
+}
+
+void *
+nng_id_get(nng_id_map *map, uint64_t id)
+{
+	return (nni_id_get(&map->m, id));
+}
+
+int
+nng_id_set(nng_id_map *map, uint64_t id, void *val)
+{
+	return (nni_id_set(&map->m, id, val));
+}
+
+int
+nng_id_remove(nng_id_map *map, uint64_t id)
+{
+	return (nni_id_remove(&map->m, id));
+}
+
+int
+nng_id_alloc(nng_id_map *map, uint64_t *id, void *val)
+{
+	return (nni_id_alloc(&map->m, id, val));
+}