cleanup: move checksum code to handler class

make live checksum to be returned in handler::info(),
and slow table-scan checksum to be calculated in handler::checksum().

part of
MDEV-16249 CHECKSUM TABLE for a spider table is not parallel and saves all data in memory in the spider head by default

1 files changed, 93 insertions, 4 deletions

diff --git a/sql/handler.cc b/sql/handler.cc
index f39cb55c7f6..14170c99790 100644
--- a/sql/handler.cc
+++ b/sql/handler.cc
@@ -4876,10 +4876,7 @@ void handler::get_dynamic_partition_info(PARTITION_STATS *stat_info,
   stat_info->create_time=          stats.create_time;
   stat_info->update_time=          stats.update_time;
   stat_info->check_time=           stats.check_time;
-  stat_info->check_sum=            0;
-  if (table_flags() & (HA_HAS_OLD_CHECKSUM | HA_HAS_NEW_CHECKSUM))
-    stat_info->check_sum= checksum();
-  return;
+  stat_info->check_sum=            stats.checksum;
 }
 
 
@@ -5001,6 +4998,98 @@ end:
 }
 
 
+static void flush_checksum(ha_checksum *row_crc, uchar **checksum_start,
+                           size_t *checksum_length)
+{
+  if (*checksum_start)
+  {
+    *row_crc= my_checksum(*row_crc, *checksum_start, *checksum_length);
+    *checksum_start= NULL;
+    *checksum_length= 0;
+  }
+}
+
+
+/* calculating table's checksum */
+int handler::calculate_checksum()
+{
+  int error;
+  THD *thd=ha_thd();
+  DBUG_ASSERT(table->s->last_null_bit_pos < 8);
+  uchar null_mask= table->s->last_null_bit_pos
+                   ? 256 -  (1 << table->s->last_null_bit_pos) : 0;
+
+  table->use_all_columns();
+  stats.checksum= 0;
+
+  if ((error= ha_rnd_init(1)))
+    return error;
+
+  for (;;)
+  {
+    if (thd->killed)
+      return HA_ERR_ABORTED_BY_USER;
+
+    ha_checksum row_crc= 0;
+    error= table->file->ha_rnd_next(table->record[0]);
+    if (error)
+      break;
+
+    if (table->s->null_bytes)
+    {
+      /* fix undefined null bits */
+      table->record[0][table->s->null_bytes-1] |= null_mask;
+      if (!(table->s->db_create_options & HA_OPTION_PACK_RECORD))
+        table->record[0][0] |= 1;
+
+      row_crc= my_checksum(row_crc, table->record[0], table->s->null_bytes);
+    }
+
+    uchar *checksum_start= NULL;
+    size_t checksum_length= 0;
+    for (uint i= 0; i < table->s->fields; i++ )
+    {
+      Field *f= table->field[i];
+
+      if (! thd->variables.old_mode && f->is_real_null(0))
+      {
+        flush_checksum(&row_crc, &checksum_start, &checksum_length);
+        continue;
+      }
+     /*
+       BLOB and VARCHAR have pointers in their field, we must convert
+       to string; GEOMETRY is implemented on top of BLOB.
+       BIT may store its data among NULL bits, convert as well.
+     */
+      switch (f->type()) {
+        case MYSQL_TYPE_BLOB:
+        case MYSQL_TYPE_VARCHAR:
+        case MYSQL_TYPE_GEOMETRY:
+        case MYSQL_TYPE_BIT:
+        {
+          flush_checksum(&row_crc, &checksum_start, &checksum_length);
+          String tmp;
+          f->val_str(&tmp);
+          row_crc= my_checksum(row_crc, (uchar*) tmp.ptr(), tmp.length());
+          break;
+        }
+        default:
+          if (!checksum_start)
+            checksum_start= f->ptr;
+          DBUG_ASSERT(checksum_start + checksum_length == f->ptr);
+          checksum_length+= f->pack_length();
+          break;
+      }
+    }
+    flush_checksum(&row_crc, &checksum_start, &checksum_length);
+
+    stats.checksum+= row_crc;
+  }
+  table->file->ha_rnd_end();
+  return error == HA_ERR_END_OF_FILE ? 0 : error;
+}
+
+
 /****************************************************************************
 ** Some general functions that isn't in the handler class
 ****************************************************************************/