kex: added mi cmd clear_statistics

- return the values and rested the counters for statistics
- patch by Paul Pankhurst

modules_k/kex/core_stats.c

@@ -95,10 +95,12 @@ stat_export_t shm_stats[] = {
 
 static struct mi_root *mi_get_stats(struct mi_root *cmd, void *param);
 static struct mi_root *mi_reset_stats(struct mi_root *cmd, void *param);
+static struct mi_root *mi_clear_stats(struct mi_root *cmd, void *param);
 
 static mi_export_t mi_stat_cmds[] = {
 	{ "get_statistics",    mi_get_stats,    0  ,  0,  0 },
 	{ "reset_statistics",  mi_reset_stats,  0  ,  0,  0 },
+	{ "clear_statistics",  mi_clear_stats,  0  ,  0,  0 },
 	{ 0, 0, 0, 0, 0}
 };
 
@@ -329,6 +331,126 @@ static struct mi_root *mi_reset_stats(struct mi_root *cmd, void *param)
 	return rpl_tree;
 }
 
+
+inline static int mi_reset_and_add_stat(struct mi_node *rpl, stat_var *stat)
+{
+	struct mi_node *node;
+	long old_val, new_val;
+
+	if (stats_support()==0) return -1;
+
+	old_val=get_stat_val_long(stat);
+	reset_stat(stat);
+	new_val=get_stat_val_long(stat);
+
+	if (old_val==new_val)
+	{
+		node = addf_mi_node_child(rpl, 0, 0, 0, "%s:%s = %lu",
+				ZSW(get_stat_module(stat)),
+				ZSW(get_stat_name(stat)),
+				new_val);
+	} else {
+		node = addf_mi_node_child(rpl, 0, 0, 0, "%s:%s = %lu (%lu)",
+				ZSW(get_stat_module(stat)),
+				ZSW(get_stat_name(stat)),
+				new_val, old_val );
+	}
+
+	if (node==0)
+		return -1;
+	return 0;
+}
+
+
+/* callback for counter_iterate_grp_vars to reset counters */
+static void mi_add_grp_vars_cbk2(void* r, str* g, str* n, counter_handle_t h)
+{
+	struct mi_node *rpl;
+	struct mi_node *node;
+	counter_val_t old_val, new_val;
+
+	rpl = r;
+	old_val = counter_get_val(h);
+	counter_reset(h);
+	new_val = counter_get_val(h);
+
+	if (old_val==new_val)
+	{
+		node = addf_mi_node_child(rpl, 0, 0, 0, "%.*s:%.*s = %lu",
+					g->len, g->s, n->len, n->s, new_val);
+	} else {
+		node = addf_mi_node_child(rpl, 0, 0, 0, "%.*s:%.*s = %lu (%lu)",
+					g->len, g->s, n->len, n->s, new_val, old_val);
+	}
+}
+
+
+/* callback for counter_iterate_grp_names to reset counters */
+static void mi_add_all_grps_cbk2(void* p, str* g)
+{
+	counter_iterate_grp_vars(g->s, mi_add_grp_vars_cbk2, p);
+}
+
+
+static struct mi_root *mi_clear_stats(struct mi_root *cmd, void *param)
+{
+	struct mi_root *rpl_tree;
+	struct mi_node *rpl;
+	struct mi_node *arg;
+	stat_var       *stat;
+	str val;
+
+	if(stats_support()==0)
+		return init_mi_tree( 404, "Statistics Not Found", 20);
+
+	if (cmd->node.kids==NULL)
+	return init_mi_tree( 400, MI_MISSING_PARM_S, MI_MISSING_PARM_LEN);
+
+	rpl_tree = init_mi_tree( 200, MI_OK_S, MI_OK_LEN);
+	if (rpl_tree==0)
+		return 0;
+	rpl = &rpl_tree->node;
+
+	for( arg=cmd->node.kids ; arg ; arg=arg->next)
+	{
+		if (arg->value.len==0)
+			continue;
+
+		val = arg->value;
+
+		if ( val.len==3 && memcmp(val.s,"all",3)==0) {
+			/* add all statistic variables */
+			/* use direct counters access for that */
+			counter_iterate_grp_names(mi_add_all_grps_cbk2, rpl);
+		} else if ( val.len>1 && val.s[val.len-1]==':') {
+			/* add module statistics */
+			val.len--;
+			val.s[val.len]=0; /* zero term. */
+			/* use direct counters access for that */
+			counter_iterate_grp_vars(val.s, mi_add_grp_vars_cbk2, rpl);
+			val.s[val.len]=':' /* restore */;
+		} else {
+			/* reset & return only one statistic */
+			stat = get_stat( &val );
+
+			if (stat==0)
+				continue;
+			if (mi_reset_and_add_stat(rpl,stat)!=0)
+				goto error;
+		}
+	}
+
+	if (rpl->kids==0) {
+		free_mi_tree(rpl_tree);
+		return init_mi_tree( 404, "Statistics Not Found", 20);
+	}
+
+	return rpl_tree;
+error:
+	free_mi_tree(rpl_tree);
+	return 0;
+}
+
 /*** shm stats ***/
 
 static struct mem_info _stats_shm_mi;