[Tarantool-patches] [PATCH v4 38/53] sql: introduce mem_*_aggregate()

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

This patch introduce mem_prepare_aggregare() and mem_get_aggregate() functions.
These functions are used during execution of aggregate functions.

Part of #5818
---
 src/box/sql/mem.c     | 23 +++++++++++++++++++++++
 src/box/sql/mem.h     |  6 ++++++
 src/box/sql/vdbeapi.c | 33 ++++-----------------------------
 3 files changed, 33 insertions(+), 29 deletions(-)

diff --git a/src/box/sql/mem.c b/src/box/sql/mem.c
index 078de0e62..0211069c6 100644
--- a/src/box/sql/mem.c
+++ b/src/box/sql/mem.c
@@ -613,6 +613,29 @@ mem_set_frame(struct Mem *mem, struct VdbeFrame *frame)
 	mem->field_type = field_type_MAX;
 }
 
+int
+mem_prepare_aggregate(struct Mem *mem, struct func *func, int size)
+{
+	if (size <= 0) {
+		mem_clear(mem);
+		return 0;
+	}
+	if (sqlVdbeMemGrow(mem, size, 0) != 0)
+		return -1;
+	memset(mem->z, 0, size);
+	mem->n = size;
+	mem->flags = MEM_Agg;
+	mem->u.func = func;
+	mem->field_type = field_type_MAX;
+	return 0;
+}
+
+void *
+mem_get_aggregate(struct Mem *mem)
+{
+	return (void *)mem->z;
+}
+
 int
 mem_copy(struct Mem *to, const struct Mem *from)
 {
diff --git a/src/box/sql/mem.h b/src/box/sql/mem.h
index a6c53c615..51802b450 100644
--- a/src/box/sql/mem.h
+++ b/src/box/sql/mem.h
@@ -271,6 +271,12 @@ mem_set_pointer(struct Mem *mem, void *ptr);
 void
 mem_set_frame(struct Mem *mem, struct VdbeFrame *frame);
 
+int
+mem_prepare_aggregate(struct Mem *mem, struct func *func, int size);
+
+void *
+mem_get_aggregate(struct Mem *mem);
+
 int
 mem_copy(struct Mem *to, const struct Mem *from);
 
diff --git a/src/box/sql/vdbeapi.c b/src/box/sql/vdbeapi.c
index 3ad89b87c..8f871ea95 100644
--- a/src/box/sql/vdbeapi.c
+++ b/src/box/sql/vdbeapi.c
@@ -403,29 +403,6 @@ sqlStmtCurrentTime(sql_context * p)
 	return *piTime;
 }
 
-/*
- * Create a new aggregate context for p and return a pointer to
- * its pMem->z element.
- */
-static SQL_NOINLINE void *
-createAggContext(sql_context * p, int nByte)
-{
-	Mem *pMem = p->pMem;
-	assert(!mem_is_aggregate(pMem));
-	if (nByte <= 0) {
-		mem_set_null(pMem);
-		pMem->z = 0;
-	} else {
-		sqlVdbeMemClearAndResize(pMem, nByte);
-		pMem->flags = MEM_Agg;
-		pMem->u.func = p->func;
-		if (pMem->z) {
-			memset(pMem->z, 0, nByte);
-		}
-	}
-	return (void *)pMem->z;
-}
-
 /*
  * Allocate or return the aggregate context for a user function.  A new
  * context is allocated on the first call.  Subsequent calls return the
@@ -437,12 +414,10 @@ sql_aggregate_context(sql_context * p, int nByte)
 	assert(p != NULL && p->func != NULL);
 	assert(p->func->def->language == FUNC_LANGUAGE_SQL_BUILTIN);
 	assert(p->func->def->aggregate == FUNC_AGGREGATE_GROUP);
-	testcase(nByte < 0);
-	if (!mem_is_aggregate(p->pMem)) {
-		return createAggContext(p, nByte);
-	} else {
-		return (void *)p->pMem->z;
-	}
+	if (!mem_is_aggregate(p->pMem) &&
+	    mem_prepare_aggregate(p->pMem, p->func, nByte) != 0)
+		return NULL;
+	return mem_get_aggregate(p->pMem);
 }
 
 /*
-- 
2.25.1