VictoriaMetrics/lib/storage/tsid.go

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2019-05-22 23:16:55 +02:00
package storage
import (
"fmt"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/encoding"
)
// TSID is unique id for a time series.
//
// Time series blocks are sorted by TSID.
//
// All the fields except MetricID are optional. They exist solely for better
// grouping of related metrics.
// It is OK if their meaning differ from their naming.
type TSID struct {
// MetricGroupID is the id of metric group inside the given project.
//
// MetricGroupID must be unique.
//
// Metric group contains metrics with the identical name like
// 'memory_usage', 'http_requests', but with different
// labels. For instance, the following metrics belong
// to a metric group 'memory_usage':
//
// memory_usage{datacenter="foo1", job="bar1", instance="baz1:1234"}
// memory_usage{datacenter="foo1", job="bar1", instance="baz2:1234"}
// memory_usage{datacenter="foo1", job="bar2", instance="baz1:1234"}
// memory_usage{datacenter="foo2", job="bar1", instance="baz2:1234"}
MetricGroupID uint64
// JobID is the id of an individual job (aka service)
// for the given project.
//
// JobID must be unique.
//
// Service may consist of multiple instances.
// See https://prometheus.io/docs/concepts/jobs_instances/ for details.
JobID uint32
// InstanceID is the id of an instance (aka process)
// for the given project.
//
// InstanceID must be unique.
//
// See https://prometheus.io/docs/concepts/jobs_instances/ for details.
InstanceID uint32
// MetricID is the unique id of the metric (time series).
//
// All the other TSID fields may be obtained by MetricID.
MetricID uint64
}
// marshaledTSIDSize is the size of marshaled TSID.
var marshaledTSIDSize = func() int {
var t TSID
dst := t.Marshal(nil)
return len(dst)
}()
// Marshal appends marshaled t to dst and returns the result.
func (t *TSID) Marshal(dst []byte) []byte {
dst = encoding.MarshalUint64(dst, t.MetricGroupID)
dst = encoding.MarshalUint32(dst, t.JobID)
dst = encoding.MarshalUint32(dst, t.InstanceID)
dst = encoding.MarshalUint64(dst, t.MetricID)
return dst
}
// Unmarshal unmarshals t from src and returns the rest of src.
func (t *TSID) Unmarshal(src []byte) ([]byte, error) {
if len(src) < marshaledTSIDSize {
return nil, fmt.Errorf("too short src; got %d bytes; want %d bytes", len(src), marshaledTSIDSize)
}
t.MetricGroupID = encoding.UnmarshalUint64(src)
src = src[8:]
t.JobID = encoding.UnmarshalUint32(src)
src = src[4:]
t.InstanceID = encoding.UnmarshalUint32(src)
src = src[4:]
t.MetricID = encoding.UnmarshalUint64(src)
src = src[8:]
return src, nil
}
// Less return true if t < b.
func (t *TSID) Less(b *TSID) bool {
if t.MetricID == b.MetricID {
// Fast path - two TSID values are identical.
return false
}
if t.MetricGroupID < b.MetricGroupID {
return true
}
if t.MetricGroupID > b.MetricGroupID {
return false
}
if t.JobID < b.JobID {
return true
}
if t.JobID > b.JobID {
return false
}
if t.InstanceID < b.InstanceID {
return true
}
if t.InstanceID > b.InstanceID {
return false
}
if t.MetricID < b.MetricID {
return true
}
if t.MetricID > b.MetricID {
return false
}
return false
}