Various adjustments

[pstop.git] / performance_schema / table_io_waits_summary_by_table / table_io_waits_summary_by_table_row.go

diff --git a/performance_schema/table_io_waits_summary_by_table/table_io_waits_summary_by_table_row.go b/performance_schema/table_io_waits_summary_by_table/table_io_waits_summary_by_table_row.go
index cde898f..2551e0d 100644 (file)
--- a/performance_schema/table_io_waits_summary_by_table/table_io_waits_summary_by_table_row.go
+++ b/performance_schema/table_io_waits_summary_by_table/table_io_waits_summary_by_table_row.go
@@ -126,22 +126,31 @@ func (this *table_io_waits_summary_by_table_row) add(other table_io_waits_summar
        this.COUNT_WRITE += other.COUNT_WRITE
 }
 
+// subtract the countable values in one row from another
 func (this *table_io_waits_summary_by_table_row) subtract(other table_io_waits_summary_by_table_row) {
-       this.SUM_TIMER_WAIT -= other.SUM_TIMER_WAIT
-       this.SUM_TIMER_FETCH -= other.SUM_TIMER_FETCH
-       this.SUM_TIMER_INSERT -= other.SUM_TIMER_INSERT
-       this.SUM_TIMER_UPDATE -= other.SUM_TIMER_UPDATE
-       this.SUM_TIMER_DELETE -= other.SUM_TIMER_DELETE
-       this.SUM_TIMER_READ -= other.SUM_TIMER_READ
-       this.SUM_TIMER_WRITE -= other.SUM_TIMER_WRITE
-
-       this.COUNT_STAR -= other.COUNT_STAR
-       this.COUNT_FETCH -= other.COUNT_FETCH
-       this.COUNT_INSERT -= other.COUNT_INSERT
-       this.COUNT_UPDATE -= other.COUNT_UPDATE
-       this.COUNT_DELETE -= other.COUNT_DELETE
-       this.COUNT_READ -= other.COUNT_READ
-       this.COUNT_WRITE -= other.COUNT_WRITE
+       // check for issues here (we have a bug) and log it
+       // - this situation should not happen so there's a logic bug somewhere else
+       if this.SUM_TIMER_WAIT >= other.SUM_TIMER_WAIT {
+               this.SUM_TIMER_WAIT -= other.SUM_TIMER_WAIT
+               this.SUM_TIMER_FETCH -= other.SUM_TIMER_FETCH
+               this.SUM_TIMER_INSERT -= other.SUM_TIMER_INSERT
+               this.SUM_TIMER_UPDATE -= other.SUM_TIMER_UPDATE
+               this.SUM_TIMER_DELETE -= other.SUM_TIMER_DELETE
+               this.SUM_TIMER_READ -= other.SUM_TIMER_READ
+               this.SUM_TIMER_WRITE -= other.SUM_TIMER_WRITE
+
+               this.COUNT_STAR -= other.COUNT_STAR
+               this.COUNT_FETCH -= other.COUNT_FETCH
+               this.COUNT_INSERT -= other.COUNT_INSERT
+               this.COUNT_UPDATE -= other.COUNT_UPDATE
+               this.COUNT_DELETE -= other.COUNT_DELETE
+               this.COUNT_READ -= other.COUNT_READ
+               this.COUNT_WRITE -= other.COUNT_WRITE
+       } else {
+               lib.Logger.Println("WARNING: table_io_waits_summary_by_table_row.subtract() - subtraction problem! (not subtracting)")
+               lib.Logger.Println("this=", this)
+               lib.Logger.Println("other=", other)
+       }
 }
 
 func (t table_io_waits_summary_by_table_rows) totals() table_io_waits_summary_by_table_row {
@@ -233,17 +242,18 @@ func (t table_io_waits_summary_by_table_rows) Sort(want_latency bool) {
 // remove the initial values from those rows where there's a match
 // - if we find a row we can't match ignore it
 func (this *table_io_waits_summary_by_table_rows) subtract(initial table_io_waits_summary_by_table_rows) {
-       i_by_name := make(map[string]int)
+       initial_by_name := make(map[string]int)
 
        // iterate over rows by name
        for i := range initial {
-               i_by_name[initial[i].name()] = i
+               initial_by_name[initial[i].name()] = i
        }
 
        for i := range *this {
-               if _, ok := i_by_name[(*this)[i].name()]; ok {
-                       initial_i := i_by_name[(*this)[i].name()]
-                       (*this)[i].subtract(initial[initial_i])
+               this_name := (*this)[i].name()
+               if _, ok := initial_by_name[this_name]; ok {
+                       initial_index := initial_by_name[this_name]
+                       (*this)[i].subtract(initial[initial_index])
                }
        }
 }