Add cursor->key_datum()/val_datum()

Author: vmxdev

README.md

@@ -91,6 +91,18 @@ while (rc == TKVDB_OK) {
 cursor->free(cursor);
 ```
 
+`while` loop can be written in alternative way
+
+```
+while (rc == TKVDB_OK) {
+	tkvdb_datum key = cursor->key_datum(cursor);
+	tkvdb_datum value = cursor->val_datum(cursor);
+
+	rc = cursor->next(cursor);
+}
+```
+
+
 To iterate in reverse order use `cursor->last()` and `cursor->prev()`.
 
 If you want to search a key-value pair in database by prefix use `cursor->seek(cursor, &key, TKVDB_SEEK)`

tkvdb.c

@@ -554,6 +554,30 @@ tkvdb_cursor_valsize(tkvdb_cursor *c)
 	return cdata->val_size;
 }
 
+static tkvdb_datum
+tkvdb_cursor_key_datum(tkvdb_cursor *c)
+{
+	tkvdb_datum dat;
+	tkvdb_cursor_data *cdata = c->data;
+
+	dat.data = cdata->prefix;
+	dat.size = cdata->prefix_size;
+
+	return dat;
+}
+
+static tkvdb_datum
+tkvdb_cursor_val_datum(tkvdb_cursor *c)
+{
+	tkvdb_datum dat;
+	tkvdb_cursor_data *cdata = c->data;
+
+	dat.data = cdata->val;
+	dat.size = cdata->val_size;
+
+	return dat;
+}
+
 static int
 tkvdb_cursor_resize_prefix(tkvdb_cursor *c, size_t n, int grow)
 {
@@ -895,6 +919,9 @@ tkvdb_cursor_create(tkvdb_tr *tr)
 	c->val = &tkvdb_cursor_val;
 	c->valsize = &tkvdb_cursor_valsize;
 
+	c->key_datum = &tkvdb_cursor_key_datum;
+	c->val_datum = &tkvdb_cursor_val_datum;
+
 	c->free = &tkvdb_cursor_free;
 
 	if (trdata->params.alignval > 1) {

tkvdb.h

@@ -110,6 +110,10 @@ struct tkvdb_cursor
 	void *(*val)(tkvdb_cursor *c);
 	size_t (*valsize)(tkvdb_cursor *c);
 
+	/* alternate way to get key/value */
+	tkvdb_datum (*key_datum)(tkvdb_cursor *c);
+	tkvdb_datum (*val_datum)(tkvdb_cursor *c);
+
 	TKVDB_RES (*seek)(tkvdb_cursor *c,
 		const tkvdb_datum *key, TKVDB_SEEK seek);
 	TKVDB_RES (*first)(tkvdb_cursor *c);
@@ -120,6 +124,7 @@ struct tkvdb_cursor
 
 	void (*free)(tkvdb_cursor *c);
 
+
 	void *data;
 };