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-rw-r--r--sql/sql_limit.h72
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+/* Copyright (c) 2019, MariaDB Corporation.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; version 2 of the License.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
+
+
+#ifndef INCLUDES_MARIADB_SQL_LIMIT_H
+#define INCLUDES_MARIADB_SQL_LIMIT_H
+/**
+ LIMIT/OFFSET parameters for execution.
+*/
+
+class Select_limit_counters
+{
+ ha_rows select_limit_cnt, offset_limit_cnt;
+
+ public:
+ Select_limit_counters():
+ select_limit_cnt(0), offset_limit_cnt(0)
+ {};
+ Select_limit_counters(Select_limit_counters &orig):
+ select_limit_cnt(orig.select_limit_cnt),
+ offset_limit_cnt(orig.offset_limit_cnt)
+ {};
+
+ void set_limit(ha_rows limit, ha_rows offset)
+ {
+ offset_limit_cnt= offset;
+ select_limit_cnt= limit;
+ if (select_limit_cnt + offset_limit_cnt >=
+ select_limit_cnt)
+ select_limit_cnt+= offset_limit_cnt;
+ else
+ select_limit_cnt= HA_POS_ERROR;
+ }
+
+ void set_single_row()
+ {
+ offset_limit_cnt= 0;
+ select_limit_cnt= 1;
+ }
+
+ bool is_unlimited()
+ { return select_limit_cnt == HA_POS_ERROR; }
+ bool is_unrestricted()
+ { return select_limit_cnt == HA_POS_ERROR && offset_limit_cnt == 0; }
+ void set_unlimited()
+ { select_limit_cnt= HA_POS_ERROR; offset_limit_cnt= 0; }
+
+ bool check_offset(ha_rows sent)
+ {
+ return sent < offset_limit_cnt;
+ }
+ void remove_offset() { offset_limit_cnt= 0; }
+
+ ha_rows get_select_limit()
+ { return select_limit_cnt; }
+ ha_rows get_offset_limit()
+ { return offset_limit_cnt; }
+};
+
+#endif // INCLUDES_MARIADB_SQL_LIMIT_H