[Minor] Add ability to log mempool usage for a task

src/libserver/cfg_file.h

@@ -262,6 +262,8 @@ enum rspamd_log_format_type {
 	RSPAMD_LOG_SETTINGS_ID,
 	RSPAMD_LOG_GROUPS,
 	RSPAMD_LOG_PUBLIC_GROUPS,
+	RSPAMD_LOG_MEMPOOL_SIZE,
+	RSPAMD_LOG_MEMPOOL_WASTE,
 };
 
 enum rspamd_log_format_flags {

src/libserver/cfg_utils.c

@@ -518,6 +518,12 @@ rspamd_config_process_var (struct rspamd_config *cfg, const rspamd_ftok_t *var,
 	else if (rspamd_ftok_cstr_equal (&tok, "settings_id", TRUE)) {
 		type = RSPAMD_LOG_SETTINGS_ID;
 	}
+	else if (rspamd_ftok_cstr_equal (&tok, "mempool_size", TRUE)) {
+		type = RSPAMD_LOG_MEMPOOL_SIZE;
+	}
+	else if (rspamd_ftok_cstr_equal (&tok, "mempool_waste", TRUE)) {
+		type = RSPAMD_LOG_MEMPOOL_WASTE;
+	}
 	else {
 		msg_err_config ("unknown log variable: %T", &tok);
 		return FALSE;

src/libserver/task.c

@@ -1544,6 +1544,18 @@ rspamd_task_log_variable (struct rspamd_task *task,
 			var.len = sizeof (undef) - 1;
 		}
 		break;
+	case RSPAMD_LOG_MEMPOOL_SIZE:
+		var.len = rspamd_snprintf (numbuf, sizeof (numbuf),
+				"%Hz",
+				task->task_pool->used_memory);
+		var.begin = numbuf;
+		break;
+	case RSPAMD_LOG_MEMPOOL_WASTE:
+		var.len = rspamd_snprintf (numbuf, sizeof (numbuf),
+				"%Hz",
+				task->task_pool->wasted_memory);
+		var.begin = numbuf;
+		break;
 	default:
 		var = rspamd_task_log_metric_res (task, lf);
 		break;