[PATCH 08/13] sql: aggregate sql functions support big int

[Stanislav Zudin <szudin@tarantool.org>]

Makes sql functions avg() and sum() accept arguments with
values in the range [2^63, 2^64).
---
 src/box/sql/func.c    | 35 ++++++++++++++++++++++++++++++-----
 src/box/sql/sqlInt.h  |  3 +++
 src/box/sql/vdbeapi.c |  6 ++++++
 3 files changed, 39 insertions(+), 5 deletions(-)

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index 8a8acc216..194dec252 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -1410,6 +1410,7 @@ struct SumCtx {
 	i64 cnt;		/* Number of elements summed */
 	u8 overflow;		/* True if integer overflow seen */
 	u8 approx;		/* True if non-integer value was input to the sum */
+	u8 is_unsigned;		/* True if value exceeded 2^63 */
 };
 
 /*
@@ -1433,16 +1434,38 @@ sumStep(sql_context * context, int argc, sql_value ** argv)
 	type = sql_value_numeric_type(argv[0]);
 	if (p && type != SQL_NULL) {
 		p->cnt++;
+		i64 v = 0;
+		bool is_signed = false;
+
 		if (type == SQL_INTEGER) {
-			i64 v = sql_value_int64(argv[0]);
+			v = sql_value_int64(argv[0]);
 			p->rSum += v;
-			if ((p->approx | p->overflow) == 0
-			    && sqlAddInt64(&p->iSum, true, v, true) != ATHR_SIGNED) {
-				p->overflow = 1;
-			}
+			is_signed = true;
+		} else if (type == SQL_UNSIGNED) {
+			v = sql_value_int64(argv[0]);
+			p->rSum += (u64)v;
+			is_signed = false;
 		} else {
 			p->rSum += sql_value_double(argv[0]);
 			p->approx = 1;
+			return;
+		}
+
+		/* proceed with the integer value */
+		if ((p->approx | p->overflow) == 0) {
+			enum arithmetic_result r = sqlAddInt64(&p->iSum,
+							       p->is_unsigned == 0,
+							       v, is_signed);
+			switch (r) {
+			case ATHR_SIGNED:
+				break;
+			case ATHR_UNSIGNED:
+				p->is_unsigned = 1;
+				break;
+			default:
+				p->overflow = 1;
+				break;
+			}
 		}
 	}
 }
@@ -1455,6 +1478,8 @@ sumFinalize(sql_context * context)
 	if (p && p->cnt > 0) {
 		if (p->overflow) {
 			sql_result_error(context, "integer overflow", -1);
+		} else if (p->is_unsigned) {
+			sql_result_uint64(context, (u64)p->iSum);
 		} else if (p->approx) {
 			sql_result_double(context, p->rSum);
 		} else {
diff --git a/src/box/sql/sqlInt.h b/src/box/sql/sqlInt.h
index 7f8e3f04e..c43d8c193 100644
--- a/src/box/sql/sqlInt.h
+++ b/src/box/sql/sqlInt.h
@@ -495,6 +495,9 @@ sql_result_int(sql_context *, int);
 void
 sql_result_int64(sql_context *, sql_int64);
 
+void
+sql_result_uint64(sql_context *, sql_uint64);
+
 void
 sql_result_null(sql_context *);
 
diff --git a/src/box/sql/vdbeapi.c b/src/box/sql/vdbeapi.c
index c3bdb6f86..6a3413954 100644
--- a/src/box/sql/vdbeapi.c
+++ b/src/box/sql/vdbeapi.c
@@ -451,6 +451,12 @@ sql_result_int64(sql_context * pCtx, i64 iVal)
 	sqlVdbeMemSetInt64(pCtx->pOut, iVal, false);
 }
 
+void
+sql_result_uint64(sql_context * pCtx, u64 iVal)
+{
+	sqlVdbeMemSetInt64(pCtx->pOut, iVal, iVal > INT64_MAX);
+}
+
 void
 sql_result_null(sql_context * pCtx)
 {
-- 
2.17.1