loci: add a function to parse messages without allocating memory
This will be used by the Indigo connection manager to parse messages directly
from the read buffer, saving three allocations and a memcpy.
diff --git a/c_gen/templates/of_object.c b/c_gen/templates/of_object.c
index 005965e..8fd0aab 100644
--- a/c_gen/templates/of_object.c
+++ b/c_gen/templates/of_object.c
@@ -180,6 +180,54 @@
}
/**
+ * Parse a message without allocating memory
+ *
+ * @param storage Pointer to an uninitialized of_object_storage_t
+ * @param buf Pointer to the buffer
+ * @param length Length of buf
+ * @returns Pointer to an initialized of_object_t
+ *
+ * The lifetime of the returned object is the minimum of the lifetimes of
+ * 'buf' and 'storage'.
+ */
+
+of_object_t *
+of_object_new_from_message_preallocated(of_object_storage_t *storage,
+ uint8_t *buf, int len)
+{
+ of_object_t *obj = &storage->obj;
+ of_wire_buffer_t *wbuf = &storage->wbuf;
+ of_message_t msg = buf;
+ of_version_t version;
+ of_object_id_t object_id;
+
+ memset(storage, 0, sizeof(*storage));
+
+ version = of_message_version_get(msg);
+ if (!OF_VERSION_OKAY(version)) {
+ return NULL;
+ }
+
+ if (of_validate_message(msg, len) != 0) {
+ LOCI_LOG_ERROR("message validation failed\n");
+ return NULL;
+ }
+
+ object_id = of_message_to_object_id(msg, len);
+ /* Already validated */
+ LOCI_ASSERT(object_id != OF_OBJECT_INVALID);
+
+ of_object_init_map[object_id](obj, version, len, 0);
+
+ obj->wire_object.wbuf = wbuf;
+ wbuf->buf = msg;
+ wbuf->alloc_bytes = len;
+ wbuf->current_bytes = len;
+
+ return obj;
+}
+
+/**
* Bind an existing buffer to an LOCI object
*
* @param obj Pointer to the object to be updated