lib-var-expand: Reuse previous literal when adding new one

If the previous program was already a literal-only program,
append next literal to it, instead of creating a new program.

diff --git a/src/lib-var-expand/var-expand-parser.y b/src/lib-var-expand/var-expand-parser.y
index f02b688ae24ba99f196b98d72f504d4960cd4889..8a83179e88da9524cbbc66cdf7ae5dfa5edab199 100644 (file)
--- a/src/lib-var-expand/var-expand-parser.y
+++ b/src/lib-var-expand/var-expand-parser.y
@@ -245,6 +245,28 @@ static void push_new_program(VAR_EXPAND_PARSER_STYPE *pstate)
        pstate->p = NULL;
 }
 
+/* Special optimization: If the previous program was also a literal, reuse it
+   instead of creating a new program.
+ */
+static void create_literal(VAR_EXPAND_PARSER_STYPE *pstate,
+                          const char *value)
+{
+       union var_expand_parameter_value ep_value = {
+               .str = value
+       };
+       if (pstate->pp != NULL && pstate->pp->only_literal) {
+               struct var_expand_parameter *param =
+                       (struct var_expand_parameter *)pstate->pp->first->params;
+               /* just put it as extra value */
+               param->value.str = p_strconcat(pstate->plist->pool,
+                                              param->value.str, value, NULL);
+               return;
+       }
+       push_argument(pstate, VAR_EXPAND_PARAMETER_VALUE_TYPE_STRING, &ep_value);
+       push_function(pstate, "literal");
+       pstate->p->only_literal = TRUE;
+}
+
 static union var_expand_parameter_value tmp_value;
 
 %}
@@ -268,9 +290,9 @@ expression_list:
               | expression_list expression { push_new_program(state); }
               ;
 
-expression: VALUE { i_zero(&tmp_value); tmp_value.str = str_c($1); push_argument(state, VAR_EXPAND_PARAMETER_VALUE_TYPE_STRING, &tmp_value); push_function(state, "literal"); state->p->only_literal = TRUE;}
-          | OCBRACE filter_list CCBRACE
-         | PERC { i_zero(&tmp_value); tmp_value.str = "%"; push_argument(state, VAR_EXPAND_PARAMETER_VALUE_TYPE_STRING, &tmp_value); push_function(state, "literal"); state->p->only_literal = TRUE; }
+expression: VALUE { create_literal(state, str_c($1)); }
+         | OCBRACE filter_list CCBRACE
+         | PERC { create_literal(state, "%"); }
          | error { return -1; }
          ;