influxdb/cmd/influx_tools/internal/storage/series_cursor.go

177 lines
3.1 KiB
Go

package storage
import (
"context"
"errors"
"sort"
"github.com/influxdata/influxdb/models"
"github.com/influxdata/influxdb/query"
"github.com/influxdata/influxdb/tsdb"
"github.com/influxdata/influxql"
)
type seriesCursor interface {
Close()
Next() *seriesRow
Err() error
}
type seriesRow struct {
name []byte // measurement name
tags models.Tags // unmodified series tags
field field
query tsdb.CursorIterators
}
type indexSeriesCursor struct {
sqry tsdb.SeriesCursor
fields measurementFields
nf []field
err error
row seriesRow
eof bool
}
func newIndexSeriesCursor(ctx context.Context, shards []*tsdb.Shard) (*indexSeriesCursor, error) {
queries, err := tsdb.CreateCursorIterators(ctx, shards)
if err != nil {
return nil, err
}
if queries == nil {
return nil, nil
}
p := &indexSeriesCursor{row: seriesRow{query: queries}}
sg := tsdb.Shards(shards)
p.sqry, err = sg.CreateSeriesCursor(ctx, tsdb.SeriesCursorRequest{}, nil)
if p.sqry != nil && err == nil {
var itr query.Iterator
var fi query.FloatIterator
var opt = query.IteratorOptions{
Aux: []influxql.VarRef{{Val: "key"}},
Authorizer: query.OpenAuthorizer,
Ascending: true,
Ordered: true,
}
if itr, err = sg.CreateIterator(ctx, &influxql.Measurement{SystemIterator: "_fieldKeys"}, opt); itr != nil && err == nil {
if fi, err = toFloatIterator(itr); err != nil {
goto CLEANUP
}
p.fields = extractFields(fi)
fi.Close()
return p, nil
}
}
CLEANUP:
p.Close()
return nil, err
}
func (c *indexSeriesCursor) Close() {
if !c.eof {
c.eof = true
if c.sqry != nil {
c.sqry.Close()
c.sqry = nil
}
}
}
func (c *indexSeriesCursor) Next() *seriesRow {
if c.eof {
return nil
}
if len(c.nf) == 0 {
// next series key
sr, err := c.sqry.Next()
if err != nil {
c.err = err
c.Close()
return nil
} else if sr == nil {
c.Close()
return nil
}
c.row.name = sr.Name
c.row.tags = sr.Tags
c.nf = c.fields[string(sr.Name)]
}
c.row.field, c.nf = c.nf[0], c.nf[1:]
return &c.row
}
func (c *indexSeriesCursor) Err() error {
return c.err
}
func toFloatIterator(iter query.Iterator) (query.FloatIterator, error) {
sitr, ok := iter.(query.FloatIterator)
if !ok {
return nil, errors.New("expected FloatIterator")
}
return sitr, nil
}
type measurementFields map[string][]field
type field struct {
n string
d influxql.DataType
}
func extractFields(itr query.FloatIterator) measurementFields {
mf := make(measurementFields)
for {
p, err := itr.Next()
if err != nil {
return nil
} else if p == nil {
break
}
// Aux is populated by `fieldKeysIterator#Next`
fields := append(mf[p.Name], field{
n: p.Aux[0].(string),
d: influxql.DataTypeFromString(p.Aux[1].(string)),
})
mf[p.Name] = fields
}
if len(mf) == 0 {
return nil
}
for k, fields := range mf {
sort.Slice(fields, func(i, j int) bool {
return fields[i].n < fields[j].n
})
// deduplicate
i := 1
for j := 1; j < len(fields); j++ {
if fields[j].n != fields[j-1].n {
fields[i] = fields[j]
i++
}
}
mf[k] = fields[:i]
}
return mf
}