Function lookupCreateVariable

src/bin/pgbench/pgbench.c:1604–1645

* Lookup a variable by name, creating it if need be. * Caller is expected to assign a value to the variable. * Returns NULL on failure (bad name). */

 * Returns NULL on failure (bad name).
 */
static Variable *
lookupCreateVariable(CState *st, const char *context, char *name)
{
	Variable   *var;

	var = lookupVariable(st, name);
	if (var == NULL)
	{
		Variable   *newvars;

		/*
		 * Check for the name only when declaring a new variable to avoid
		 * overhead.
		 */
		if (!valid_variable_name(name))
		{
			pg_log_error("%s: invalid variable name: \"%s\"", context, name);
			return NULL;
		}

		/* Create variable at the end of the array */
		if (st->variables)
			newvars = (Variable *) pg_realloc(st->variables,
											  (st->nvariables + 1) * sizeof(Variable));
		else
			newvars = (Variable *) pg_malloc(sizeof(Variable));

		st->variables = newvars;

		var = &newvars[st->nvariables];

		var->name = pg_strdup(name);
		var->svalue = NULL;
		/* caller is expected to initialize remaining fields */

		st->nvariables++;
		/* we don't re-sort the array till we have to */
		st->vars_sorted = false;
	}

	return var;
}

/* Assign a string value to a variable, creating it if need be */
/* Returns false on failure (bad name) */