func (m *BoltBackend) flushAddBuffer() {
// Insert it in a database transaction
err := m.db.Update(func(tx *bolt.Tx) error {
for seriesName, seriesData := range m.addBuffer {
b, err := tx.CreateBucketIfNotExists([]byte(seriesName))
if err != nil {
return err
}
for _, m := range seriesData {
key := make([]byte, 5)
metrics.TimeToUint40(key, m.Time)
value := putFloat64(m.Value)
// Write data
err = b.Put(key, value)
if err != nil {
return err
}
}
// Remove data from buffer
delete(m.addBuffer, seriesName)
}
return nil
})
m.addBuffer = make(map[string][]metrics.Metric)
m.addBufferSize = 0
if err != nil {
fmt.Errorf("Bolt was unhappy writing data: %v", err)
}
}
func (m *BoltBackend) Start() {
go func() {
t := time.NewTicker(time.Second * 10)
for {
select {
case <-t.C:
// Regularly flush the internal buffer
m.flushAddBuffer()
case metric := <-m.addChan:
// Add it to the internal buffer
m.addBuffer[metric.Name] = append(m.addBuffer[metric.Name], metric)
m.addBufferSize += 1
// Break if our buffer is too small
if m.addBufferSize < 10000 {
break
}
m.flushAddBuffer()
case req := <-m.listRequests:
// List all buckets in a view-transaction
m.db.View(func(tx *bolt.Tx) error {
c := tx.Cursor()
k, _ := c.First()
for k != nil {
// Skip sending this metric if it's in the buffer
if _, ok := m.addBuffer[string(k)]; !ok {
req <- string(k)
}
k, _ = c.Next()
}
return nil
})
// Add whatever we find in the buffer
for name := range m.addBuffer {
req <- name
}
close(req)
case req := <-m.dataRequests:
// List all relevant data in a view-transaction
m.db.View(func(tx *bolt.Tx) error {
b := tx.Bucket([]byte(req.Name))
// Bail if bucket does not exist
if b == nil {
fmt.Printf("Bolt - no series '%v'.\n", req.Name)
return nil
}
// It's kosher - return relevant data
cursor := b.Cursor()
// Generate the first key, seek to it and begin reading data
firstKey := make([]byte, 5)
metrics.TimeToUint40(firstKey, req.From)
rawTime, rawVal := cursor.Seek(firstKey)
metricTime := metrics.Uint40ToTime(rawTime)
// Loop over the rest
for metricTime.Before(req.To) {
// Send the data
req.Result <- metrics.MetricValue{
Time: metricTime,
Value: parseFloat64(rawVal),
}
// Extract a new time/value
rawTime, rawVal = cursor.Next()
// Break from the loop if we reach the end
if rawTime == nil {
break
}
// Parse time and loop-de-loop
metricTime = metrics.Uint40ToTime(rawTime)
}
return nil
})
// Add stuff from the buffer
if data, ok := m.addBuffer[req.Name]; ok {
for _, m := range data {
if m.Time.After(req.From) && m.Time.Before(req.To) {
req.Result <- metrics.MetricValue{
Time: m.Time,
Value: m.Value,
}
}
}
}
close(req.Result)
case <-m.stopChan:
// Stop comm chans and shut down database
t.Stop()
close(m.stopChan)
close(m.addChan)
close(m.listRequests)
close(m.dataRequests)
m.db.Close()
return
}
}
}()
}
