[tarantool-patches] [PATCH v2 3/8] sql: wrap all trim functions in dispatcher

[Kirill Shcherbatov <kshcherbatov@tarantool.org>]

A new dispatcher function trim_func calls corresponding trim_
function implementation in relation with number of argc - a count
of arguments.

This is an important stem to get rid of function's name
overloading required for replace FuncDef cache with Tarantool's
function cache.

Needed for #2200, #4113, #2233
---
 src/box/sql/func.c | 32 +++++++++++++++++++++++++++++---
 1 file changed, 29 insertions(+), 3 deletions(-)

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index e00764c3f..f9c0a819e 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -1496,6 +1496,32 @@ trim_func_three_args(struct sql_context *context, int argc, sql_value **argv)
 		       char_cnt, input_str, input_str_sz);
 	sql_free(char_len);
 }
+
+/**
+ * Normalize args from @a argv input array when it has one,
+ * two or three args.
+ *
+ * This is a dispatcher function that call corresponding
+ * implementation depending on the number of arguments.
+*/
+static void
+trim_func(struct sql_context *context, int argc, sql_value **argv)
+{
+	switch (argc) {
+	case 1:
+		trim_func_one_arg(context, argc, argv);
+		break;
+	case 2:
+		trim_func_two_args(context, argc, argv);
+		break;
+	case 3:
+		trim_func_three_args(context, argc, argv);
+		break;
+	default:
+		unreachable();
+	}
+}
+
 /*
  * Compute the soundex encoding of a word.
  *
@@ -1840,9 +1866,9 @@ sqlRegisterBuiltinFunctions(void)
 			  FIELD_TYPE_BOOLEAN),
 		FUNCTION2(likely, 1, 0, 0, noopFunc, SQL_FUNC_UNLIKELY,
 			  FIELD_TYPE_BOOLEAN),
-		FUNCTION_COLL(trim, 1, 3, 0, trim_func_one_arg),
-		FUNCTION_COLL(trim, 2, 3, 0, trim_func_two_args),
-		FUNCTION_COLL(trim, 3, 3, 0, trim_func_three_args),
+		FUNCTION_COLL(trim, 1, 3, 0, trim_func),
+		FUNCTION_COLL(trim, 2, 3, 0, trim_func),
+		FUNCTION_COLL(trim, 3, 3, 0, trim_func),
 		FUNCTION(least, -1, 0, 1, minmaxFunc, FIELD_TYPE_SCALAR),
 		AGGREGATE2(min, 1, 0, 1, minmaxStep, minMaxFinalize,
 			   SQL_FUNC_MINMAX, FIELD_TYPE_SCALAR),
-- 
2.22.0