kern: Add initial object namespace sources

Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 200 insertions, 0 deletions

diff --git a/src/sys/os/os_ns.c b/src/sys/os/os_ns.c
new file mode 100644
index 0000000..2e0426f
--- /dev/null
+++ b/src/sys/os/os_ns.c
@@ -0,0 +1,200 @@
+/*
+ * Copyright (c) 2025 Ian Marco Moffett and L5 engineers
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * Description: System object namespace
+ * Author: Ian Marco Moffett
+ */
+
+#include <sys/errno.h>
+#include <sys/param.h>
+#include <os/nsvar.h>
+#include <os/ns.h>
+#include <string.h>
+
+#define NS_HM_ENTRIES 16
+
+/* Name space object hashmap entry */
+struct hashmap_entry {
+    void *data;
+    char *name;
+    uint32_t key;
+};
+
+/* Namespace object hashmap */
+struct ns_hashmap {
+    struct hashmap_entry entries[NS_HM_ENTRIES];
+    size_t entry_count;
+    struct ns_hashmap *next;
+};
+
+/* Global namespace */
+static struct ns_hashmap namespace;
+
+/*
+ * Fowler–Noll–Vo hash function
+ *
+ * @s: String to hash
+ */
+static uint32_t
+fnv1_hash(const char *s)
+{
+    uint32_t hash = 2166136261UL;
+    const uint8_t *p = (uint8_t *)s;
+
+    while (*p != '\0') {
+        hash ^= *p;
+        hash = hash * 0x01000193;
+        ++p;
+    }
+
+    return hash;
+}
+
+/*
+ * Initialize an object
+ */
+int
+ns_obj_init(struct ns_obj *nsop)
+{
+    if (nsop == NULL) {
+        return -EINVAL;
+    }
+
+    memset(nsop, 0, sizeof(*nsop));
+    nsop->refcount = 1;
+    return 0;
+}
+
+/*
+ * Read data from an object
+ */
+ssize_t
+ns_obj_read(struct ns_obj *nsop, void *buf, off_t off, size_t len)
+{
+    if (nsop == NULL || buf == NULL) {
+        return -EINVAL;
+    }
+
+    if (len == 0) {
+        return -EINVAL;
+    }
+
+    /*
+     * Prefer read() but fallback to data if we
+     * need to
+     */
+    if (nsop->read == NULL && nsop->data != NULL) {
+        memcpy(buf, nsop->data, len);
+    }
+
+    return len;
+}
+
+/*
+ * Place an object into the namespace
+ */
+int
+ns_obj_enter(ns_t ns, void *obj, const char *name)
+{
+    uint32_t hash, key;
+    struct ns_hashmap *hm;
+    struct hashmap_entry *entry;
+
+    if (obj == NULL || name == NULL) {
+        return -EINVAL;
+    }
+
+    /* Get the index */
+    hash = fnv1_hash(name);
+    key = hash % NS_HM_ENTRIES;
+
+    /* Find a free slot */
+    hm = &namespace;
+    while (hm != NULL) {
+        entry = &hm->entries[key];
+
+        if (entry->data == NULL) {
+            entry->data = obj;
+            entry->name = strdup(name);
+            return 0;
+        }
+
+        hm = hm->next;
+    }
+
+    return 0;
+}
+
+/*
+ * Look up and object within the namespace
+ */
+int
+ns_obj_lookup(ns_t ns, const char *name, void *res_p)
+{
+    uint32_t hash, key;
+    struct ns_hashmap *hm;
+    struct hashmap_entry *entry;
+
+    if (name == NULL || res_p == NULL) {
+        return -EINVAL;
+    }
+
+    /* Get the index */
+    hash = fnv1_hash(name);
+    key = hash % NS_HM_ENTRIES;
+
+    hm = &namespace;
+    while (hm != NULL) {
+        entry = &hm->entries[key];
+        if (entry->name == NULL) {
+            hm = hm->next;
+            continue;
+        }
+
+        if (strcmp(entry->name, name) == 0) {
+            *((void **)res_p) = entry->data;
+            return 0;
+        }
+
+        hm = hm->next;
+    }
+
+    return -ENOENT;
+}
+
+/*
+ * Initialize the namespace
+ */
+int
+ns_init(void)
+{
+    memset(&namespace, 0, sizeof(namespace));
+    return 0;
+}