func (self *LevelDbDatastore) executeQueryForSeries(database, series string, columns []string, query *parser.Query, yield func(*protocol.Series) error) error {
startTimeBytes, endTimeBytes := self.byteArraysForStartAndEndTimes(common.TimeToMicroseconds(query.GetStartTime()), common.TimeToMicroseconds(query.GetEndTime()))
fields, err := self.getFieldsForSeries(database, series, columns)
if err != nil {
return err
}
fieldCount := len(fields)
prefixes := make([][]byte, fieldCount, fieldCount)
iterators := make([]*levigo.Iterator, fieldCount, fieldCount)
fieldNames := make([]string, len(fields))
// start the iterators to go through the series data
for i, field := range fields {
fieldNames[i] = field.Name
prefixes[i] = field.Id
iterators[i] = self.db.NewIterator(self.readOptions)
if query.Ascending {
iterators[i].Seek(append(field.Id, startTimeBytes...))
} else {
iterators[i].Seek(append(append(field.Id, endTimeBytes...), MAX_SEQUENCE...))
if iterators[i].Valid() {
iterators[i].Prev()
}
}
}
result := &protocol.Series{Name: &series, Fields: fieldNames, Points: make([]*protocol.Point, 0)}
rawColumnValues := make([]*rawColumnValue, fieldCount, fieldCount)
isValid := true
limit := query.Limit
if limit == 0 {
limit = MAX_POINTS_TO_SCAN
}
resultByteCount := 0
// TODO: clean up, this is super gnarly
// optimize for the case where we're pulling back only a single column or aggregate
for isValid {
isValid = false
latestTimeRaw := make([]byte, 8, 8)
latestSequenceRaw := make([]byte, 8, 8)
point := &protocol.Point{Values: make([]*protocol.FieldValue, fieldCount, fieldCount)}
for i, it := range iterators {
if rawColumnValues[i] == nil && it.Valid() {
k := it.Key()
if len(k) >= 16 {
t := k[8:16]
if bytes.Equal(k[:8], fields[i].Id) && bytes.Compare(t, startTimeBytes) > -1 && bytes.Compare(t, endTimeBytes) < 1 {
v := it.Value()
s := k[16:]
rawColumnValues[i] = &rawColumnValue{time: t, sequence: s, value: v}
timeCompare := bytes.Compare(t, latestTimeRaw)
if timeCompare == 1 {
latestTimeRaw = t
latestSequenceRaw = s
} else if timeCompare == 0 {
if bytes.Compare(s, latestSequenceRaw) == 1 {
latestSequenceRaw = s
}
}
}
}
}
}
for i, iterator := range iterators {
if rawColumnValues[i] != nil && bytes.Equal(rawColumnValues[i].time, latestTimeRaw) && bytes.Equal(rawColumnValues[i].sequence, latestSequenceRaw) {
isValid = true
if query.Ascending {
iterator.Next()
} else {
iterator.Prev()
}
fv := &protocol.FieldValue{}
err := proto.Unmarshal(rawColumnValues[i].value, fv)
if err != nil {
return err
}
resultByteCount += len(rawColumnValues[i].value)
point.Values[i] = fv
var t uint64
binary.Read(bytes.NewBuffer(rawColumnValues[i].time), binary.BigEndian, &t)
time := self.convertUintTimestampToInt64(&t)
var sequence uint64
binary.Read(bytes.NewBuffer(rawColumnValues[i].sequence), binary.BigEndian, &sequence)
seq32 := uint32(sequence)
point.SetTimestampInMicroseconds(time)
point.SequenceNumber = &seq32
rawColumnValues[i] = nil
}
}
if isValid {
limit -= 1
result.Points = append(result.Points, point)
// add byte count for the timestamp and the sequence
resultByteCount += 16
// check if we should send the batch along
if resultByteCount > MAX_SERIES_SIZE {
filteredResult, _ := Filter(query, result)
if err := yield(filteredResult); err != nil {
return err
}
resultByteCount = 0
result = &protocol.Series{Name: &series, Fields: fieldNames, Points: make([]*protocol.Point, 0)}
}
}
if limit < 1 {
break
}
}
filteredResult, _ := Filter(query, result)
if err := yield(filteredResult); err != nil {
return err
}
emptyResult := &protocol.Series{Name: &series, Fields: fieldNames, Points: nil}
return yield(emptyResult)
}
func (self *LevelDbDatastore) executeQueryForSeries(database, series string, columns []string, query *parser.Query, yield func(*protocol.Series) error) error {
startTimeBytes, endTimeBytes := self.byteArraysForStartAndEndTimes(common.TimeToMicroseconds(query.GetStartTime()), common.TimeToMicroseconds(query.GetEndTime()))
fields, err := self.getFieldsForSeries(database, series, columns)
if err != nil {
return err
}
fieldCount := len(fields)
fieldNames, iterators := self.getIterators(fields, startTimeBytes, endTimeBytes, query.Ascending)
// iterators :=
result := &protocol.Series{Name: &series, Fields: fieldNames, Points: make([]*protocol.Point, 0)}
rawColumnValues := make([]*rawColumnValue, fieldCount, fieldCount)
limit := query.Limit
if limit == 0 {
limit = MAX_POINTS_TO_SCAN
}
resultByteCount := 0
// TODO: clean up, this is super gnarly
// optimize for the case where we're pulling back only a single column or aggregate
for {
isValid := false
point := &protocol.Point{Values: make([]*protocol.FieldValue, fieldCount, fieldCount)}
for i, it := range iterators {
if rawColumnValues[i] != nil || !it.Valid() {
continue
}
key := it.Key()
if len(key) < 16 {
continue
}
if !isPointInRange(fields[i].Id, startTimeBytes, endTimeBytes, key) {
continue
}
time := key[8:16]
value := it.Value()
sequenceNumber := key[16:]
rawValue := &rawColumnValue{time: time, sequence: sequenceNumber, value: value}
rawColumnValues[i] = rawValue
}
var pointTimeRaw []byte
var pointSequenceRaw []byte
// choose the highest (or lowest in case of ascending queries) timestamp
// and sequence number. that will become the timestamp and sequence of
// the next point.
for _, value := range rawColumnValues {
if value == nil {
continue
}
pointTimeRaw, pointSequenceRaw = value.updatePointTimeAndSequence(pointTimeRaw,
pointSequenceRaw, query.Ascending)
}
for i, iterator := range iterators {
// if the value is nil, or doesn't match the point's timestamp and sequence number
// then skip it
if rawColumnValues[i] == nil ||
!bytes.Equal(rawColumnValues[i].time, pointTimeRaw) ||
!bytes.Equal(rawColumnValues[i].sequence, pointSequenceRaw) {
continue
}
// if we emitted at lease one column, then we should keep
// trying to get more points
isValid = true
// advance the iterator to read a new value in the next iteration
if query.Ascending {
iterator.Next()
} else {
iterator.Prev()
}
fv := &protocol.FieldValue{}
err := proto.Unmarshal(rawColumnValues[i].value, fv)
if err != nil {
return err
}
resultByteCount += len(rawColumnValues[i].value)
point.Values[i] = fv
var t uint64
binary.Read(bytes.NewBuffer(rawColumnValues[i].time), binary.BigEndian, &t)
time := self.convertUintTimestampToInt64(&t)
var sequence uint64
binary.Read(bytes.NewBuffer(rawColumnValues[i].sequence), binary.BigEndian, &sequence)
seq32 := uint32(sequence)
point.SetTimestampInMicroseconds(time)
point.SequenceNumber = &seq32
rawColumnValues[i] = nil
}
// stop the loop if we ran out of points
if !isValid {
break
}
limit -= 1
result.Points = append(result.Points, point)
// add byte count for the timestamp and the sequence
resultByteCount += 16
// check if we should send the batch along
if resultByteCount > MAX_SERIES_SIZE || limit < 1 {
dropped, err := self.sendBatch(query, result, yield)
if err != nil {
return err
}
limit += dropped
resultByteCount = 0
result = &protocol.Series{Name: &series, Fields: fieldNames, Points: make([]*protocol.Point, 0)}
}
if limit < 1 {
break
}
}
if _, err := self.sendBatch(query, result, yield); err != nil {
return err
}
emptyResult := &protocol.Series{Name: &series, Fields: fieldNames, Points: nil}
_, err = self.sendBatch(query, emptyResult, yield)
return err
}