[Tarantool-patches] [PATCH v4 08/16] sql: refactor SUM() function

[Mergen Imeev via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

Part of #4145
---
 src/box/sql/func.c | 38 +++++++++++++++++++++++++-------------
 src/box/sql/vdbe.c |  1 -
 2 files changed, 25 insertions(+), 14 deletions(-)

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index 2e84f61b5..f18f1b4d1 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -53,6 +53,29 @@
 static struct mh_strnptr_t *built_in_functions = NULL;
 static struct func_sql_builtin **functions;
 
+/** Implementation of the SUM() function. */
+static void
+step_sum(struct sql_context *ctx, int argc, struct Mem **argv)
+{
+	assert(argc == 1);
+	(void)argc;
+	assert(mem_is_null(ctx->pMem) || mem_is_num(ctx->pMem));
+	if (mem_is_null(argv[0]))
+		return;
+	if (mem_is_null(ctx->pMem))
+		return mem_copy_as_ephemeral(ctx->pMem, argv[0]);
+	if (mem_add(ctx->pMem, argv[0], ctx->pMem) != 0)
+		ctx->is_aborted = true;
+}
+
+/** Finalizer for the SUM() function. */
+static void
+fin_sum(struct sql_context *ctx)
+{
+	assert(mem_is_null(ctx->pMem) || mem_is_num(ctx->pMem));
+	mem_copy_as_ephemeral(ctx->pOut, ctx->pMem);
+}
+
 static const unsigned char *
 mem_as_ustr(struct Mem *mem)
 {
@@ -1661,17 +1684,6 @@ sum_step(struct sql_context *context, int argc, sql_value **argv)
 		context->is_aborted = true;
 }
 
-static void
-sumFinalize(sql_context * context)
-{
-	SumCtx *p;
-	p = sql_aggregate_context(context, 0);
-	if (p == NULL || p->count == 0)
-		mem_set_null(context->pOut);
-	else
-		mem_copy_as_ephemeral(context->pOut, &p->mem);
-}
-
 static void
 avgFinalize(sql_context * context)
 {
@@ -2120,8 +2132,8 @@ static struct sql_func_definition definitions[] = {
 	{"SUBSTR", 3,
 	 {FIELD_TYPE_VARBINARY, FIELD_TYPE_INTEGER, FIELD_TYPE_INTEGER},
 	 FIELD_TYPE_VARBINARY, substrFunc, NULL},
-	{"SUM", 1, {FIELD_TYPE_INTEGER}, FIELD_TYPE_INTEGER, sum_step, sumFinalize},
-	{"SUM", 1, {FIELD_TYPE_DOUBLE}, FIELD_TYPE_DOUBLE, sum_step, sumFinalize},
+	{"SUM", 1, {FIELD_TYPE_INTEGER}, FIELD_TYPE_INTEGER, step_sum, fin_sum},
+	{"SUM", 1, {FIELD_TYPE_DOUBLE}, FIELD_TYPE_DOUBLE, step_sum, fin_sum},
 	{"TOTAL", 1, {FIELD_TYPE_INTEGER}, FIELD_TYPE_DOUBLE, sum_step,
 	 totalFinalize},
 	{"TOTAL", 1, {FIELD_TYPE_DOUBLE}, FIELD_TYPE_DOUBLE, sum_step,
diff --git a/src/box/sql/vdbe.c b/src/box/sql/vdbe.c
index 067065a97..a3d403176 100644
--- a/src/box/sql/vdbe.c
+++ b/src/box/sql/vdbe.c
@@ -4199,7 +4199,6 @@ case OP_AggFinal: {
 	assert(pOp->p1>0 && pOp->p1<=(p->nMem+1 - p->nCursor));
 	struct func_sql_builtin *func = (struct func_sql_builtin *)pOp->p4.func;
 	struct Mem *pIn1 = &aMem[pOp->p1];
-	assert(mem_is_null(pIn1) || mem_is_agg(pIn1));
 
 	struct sql_context ctx;
 	memset(&ctx, 0, sizeof(ctx));
-- 
2.25.1