// Map will write in any mutations needed to maintain this timeseries index
// based on the current item and the lastRead item
func (ts *TimeSeries) Map(writer gossie.Writer, item, lastRead interface{}) error {
uid, t := ts.Marshaler(item)
b, err := json.Marshal(item)
if err != nil {
log.Errorf("Error marshalling item %s", err) // TODO should probably bubble this up
return err
}
rowPrefix := ""
if ts.SecondaryIndexer != nil {
rowPrefix = ts.SecondaryIndexer(item)
}
// C* ttl for ageing out columns
var ttl int32
if ts.Ttler != nil {
ttl = ts.Ttler(item)
}
// always mutate against current marshaled value -- if not zero time
if !t.IsZero() {
tsRow := &gossie.Row{
Key: ts.toRowKey(rowPrefix, t),
Columns: []*gossie.Column{
{
Name: idTimeToColumnName(uid, t),
Value: b,
Ttl: ttl,
},
},
}
writer.Insert(ts.Cf, tsRow)
}
// old one that's different (and old one not zero)? add deletion...
if lastRead != nil && !reflect.ValueOf(lastRead).IsNil() {
lUid, lT := ts.Marshaler(lastRead)
if ts.SecondaryIndexer != nil {
lRowPrefix := ts.SecondaryIndexer(lastRead)
if !lT.IsZero() && (!lT.Equal(t) || lRowPrefix != rowPrefix) {
writer.DeleteColumns(ts.Cf, ts.toRowKey(lRowPrefix, lT), [][]byte{idTimeToColumnName(lUid, lT)})
}
}
}
// update index, if we have one defined
if ts.IndexCf != "" {
i := newIndex(ts, rowPrefix)
i.write(writer, t.Truncate(ts.RowGranularity))
}
return nil
}
// write will add a row into a mutation to update the index view
func (i *index) write(writer gossie.Writer, rowTime time.Time) {
if rowTime.IsZero() {
return
}
// truncate to our minimum granularity (24 hours - in order to constrain max cols per row to a few thousand likely)
rowTime = i.truncate(rowTime)
row := &gossie.Row{
Key: i.rowKey(),
Columns: []*gossie.Column{
{
Name: i.colName(rowTime),
Value: placeholderValue,
},
},
}
writer.Insert(i.ts.IndexCf, row)
//log.Debugf("Writing timeseries INDEX mutation for row key=%v %v", string(i.rowKey()), row)
}