prometheus/storage/metric/samplekey.go
Matt T. Proud 4a87c002e8 Update low-level i'faces to reflect wireformats.
This commit fixes a critique of the old storage API design, whereby
the input parameters were always as raw bytes and never Protocol
Buffer messages that encapsulated the data, meaning every place a
read or mutation was conducted needed to manually perform said
translations on its own.  This is taxing.

Change-Id: I4786938d0d207cefb7782bd2bd96a517eead186f
2013-09-04 17:13:58 +02:00

124 lines
3.2 KiB
Go

// Copyright 2013 Prometheus Team
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package metric
import (
"fmt"
"time"
"code.google.com/p/goprotobuf/proto"
clientmodel "github.com/prometheus/client_golang/model"
"github.com/prometheus/prometheus/coding/indexable"
dto "github.com/prometheus/prometheus/model/generated"
)
// SampleKey models the business logic around the data-transfer object
// SampleKey.
type SampleKey struct {
Fingerprint *clientmodel.Fingerprint
FirstTimestamp time.Time
LastTimestamp time.Time
SampleCount uint32
}
// Constrain merges the underlying SampleKey to fit within the keyspace of
// the provided first and last keys and returns whether the key was modified.
func (s *SampleKey) Constrain(first, last *SampleKey) bool {
switch {
case s.Before(first.Fingerprint, first.FirstTimestamp):
*s = *first
return true
case last.Before(s.Fingerprint, s.FirstTimestamp):
*s = *last
return true
default:
return false
}
}
func (s *SampleKey) Equal(o *SampleKey) bool {
if s == o {
return true
}
if !s.Fingerprint.Equal(o.Fingerprint) {
return false
}
if !s.FirstTimestamp.Equal(o.FirstTimestamp) {
return false
}
if !s.LastTimestamp.Equal(o.LastTimestamp) {
return false
}
return s.SampleCount == o.SampleCount
}
// MayContain indicates whether the given SampleKey could potentially contain a
// value at the provided time. Even if true is emitted, that does not mean a
// satisfactory value, in fact, exists.
func (s *SampleKey) MayContain(t time.Time) bool {
switch {
case t.Before(s.FirstTimestamp):
return false
case t.After(s.LastTimestamp):
return false
default:
return true
}
}
func (s *SampleKey) Before(fp *clientmodel.Fingerprint, t time.Time) bool {
if s.Fingerprint.Less(fp) {
return true
}
if !s.Fingerprint.Equal(fp) {
return false
}
if s.FirstTimestamp.Before(t) {
return true
}
return s.LastTimestamp.Before(t)
}
// ToDTO converts this SampleKey into a DTO for use in serialization purposes.
func (s *SampleKey) Dump(d *dto.SampleKey) {
d.Reset()
fp := &dto.Fingerprint{}
dumpFingerprint(fp, s.Fingerprint)
d.Fingerprint = fp
d.Timestamp = indexable.EncodeTime(s.FirstTimestamp)
d.LastTimestamp = proto.Int64(s.LastTimestamp.Unix())
d.SampleCount = proto.Uint32(s.SampleCount)
}
func (s *SampleKey) String() string {
return fmt.Sprintf("SampleKey for %s at %s to %s with %d values.", s.Fingerprint, s.FirstTimestamp, s.LastTimestamp, s.SampleCount)
}
func (s *SampleKey) Load(d *dto.SampleKey) {
f := &clientmodel.Fingerprint{}
loadFingerprint(f, d.GetFingerprint())
s.Fingerprint = f
s.FirstTimestamp = indexable.DecodeTime(d.Timestamp)
s.LastTimestamp = time.Unix(d.GetLastTimestamp(), 0).UTC()
s.SampleCount = d.GetSampleCount()
}