influxdb/tsdb/cursor.go

72 lines
1.4 KiB
Go

package tsdb
import (
"context"
"github.com/influxdata/influxdb/models"
"github.com/influxdata/influxdb/query"
)
// EOF represents a "not found" key returned by a Cursor.
const EOF = query.ZeroTime
// Cursor represents an iterator over a series.
type Cursor interface {
Close()
Err() error
}
type IntegerBatchCursor interface {
Cursor
Next() (keys []int64, values []int64)
}
type FloatBatchCursor interface {
Cursor
Next() (keys []int64, values []float64)
}
type UnsignedBatchCursor interface {
Cursor
Next() (keys []int64, values []uint64)
}
type StringBatchCursor interface {
Cursor
Next() (keys []int64, values []string)
}
type BooleanBatchCursor interface {
Cursor
Next() (keys []int64, values []bool)
}
type CursorRequest struct {
Name []byte
Tags models.Tags
Field string
Ascending bool
StartTime int64
EndTime int64
}
type CursorIterator interface {
Next(ctx context.Context, r *CursorRequest) (Cursor, error)
}
type CursorIterators []CursorIterator
func CreateCursorIterators(ctx context.Context, shards []*Shard) (CursorIterators, error) {
q := make(CursorIterators, 0, len(shards))
for _, s := range shards {
// possible errors are ErrEngineClosed or ErrShardDisabled, so we can safely skip those shards
if cq, err := s.CreateCursorIterator(ctx); cq != nil && err == nil {
q = append(q, cq)
}
}
if len(q) == 0 {
return nil, nil
}
return q, nil
}