prometheus/storage/metric/sample.go
Bjoern Rabenstein 6bc083f38b Major code cleanup in storage.
- Mostly docstring fixed/additions.
  (Please review these carefully, since most of them were missing, I
  had to guess them from an outsider's perspective. (Which on the
  other hand proves how desperately required many of these docstrings
  are.))

- Removed all uses of new(...) to meet our own style guide (draft).

- Fixed all other 'go vet' and 'golint' issues (except those that are
  not fixable (i.e. caused by bugs in or by design of 'go vet' and
  'golint')).

- Some trivial refactorings, like reorder functions, minor renames, ...

- Some slightly less trivial refactoring, mostly to reduce code
  duplication by embedding types instead of writing many explicit
  forwarders.

- Cleaned up the interface structure a bit. (Most significant probably
  the removal of the View-like methods from MetricPersistenc. Now they
  are only in View and not duplicated anymore.)

- Removed dead code. (Probably not all of it, but it's a first
  step...)

- Fixed a leftover in storage/metric/end_to_end_test.go (that made
  some parts of the code never execute (incidentally, those parts
  were broken (and I fixed them, too))).

Change-Id: Ibcac069940d118a88f783314f5b4595dce6641d5
2014-02-27 15:22:37 +01:00

198 lines
4.9 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 (
"bytes"
"fmt"
"sort"
"code.google.com/p/goprotobuf/proto"
clientmodel "github.com/prometheus/client_golang/model"
dto "github.com/prometheus/prometheus/model/generated"
)
// MarshalJSON implements json.Marshaler.
func (s SamplePair) MarshalJSON() ([]byte, error) {
return []byte(fmt.Sprintf("{\"Value\": \"%f\", \"Timestamp\": %d}", s.Value, s.Timestamp)), nil
}
// SamplePair pairs a SampleValue with a Timestamp.
type SamplePair struct {
Value clientmodel.SampleValue
Timestamp clientmodel.Timestamp
}
// Equal returns true if this SamplePair and o have equal Values and equal
// Timestamps.
func (s *SamplePair) Equal(o *SamplePair) bool {
if s == o {
return true
}
return s.Value.Equal(o.Value) && s.Timestamp.Equal(o.Timestamp)
}
func (s *SamplePair) dump(d *dto.SampleValueSeries_Value) {
d.Reset()
d.Timestamp = proto.Int64(s.Timestamp.Unix())
d.Value = proto.Float64(float64(s.Value))
}
func (s *SamplePair) String() string {
return fmt.Sprintf("SamplePair at %s of %s", s.Timestamp, s.Value)
}
// Values is a sortable slice of SamplePair pointers (as in: it implements
// sort.Interface). Sorting happens by Timestamp.
type Values []*SamplePair
// Len implements sort.Interface.
func (v Values) Len() int {
return len(v)
}
// Less implements sort.Interface.
func (v Values) Less(i, j int) bool {
return v[i].Timestamp.Before(v[j].Timestamp)
}
// Swap implements sort.Interface.
func (v Values) Swap(i, j int) {
v[i], v[j] = v[j], v[i]
}
// Equal returns true if these Values are of the same length as o, and each
// value is equal to the corresponding value in o (i.e. at the same index).
func (v Values) Equal(o Values) bool {
if len(v) != len(o) {
return false
}
for i, expected := range v {
if !expected.Equal(o[i]) {
return false
}
}
return true
}
// FirstTimeAfter indicates whether the first sample of a set is after a given
// timestamp.
func (v Values) FirstTimeAfter(t clientmodel.Timestamp) bool {
return v[0].Timestamp.After(t)
}
// LastTimeBefore indicates whether the last sample of a set is before a given
// timestamp.
func (v Values) LastTimeBefore(t clientmodel.Timestamp) bool {
return v[len(v)-1].Timestamp.Before(t)
}
// InsideInterval indicates whether a given range of sorted values could contain
// a value for a given time.
func (v Values) InsideInterval(t clientmodel.Timestamp) bool {
switch {
case v.Len() == 0:
return false
case t.Before(v[0].Timestamp):
return false
case !v[v.Len()-1].Timestamp.Before(t):
return false
default:
return true
}
}
// TruncateBefore returns a subslice of the original such that extraneous
// samples in the collection that occur before the provided time are
// dropped. The original slice is not mutated
func (v Values) TruncateBefore(t clientmodel.Timestamp) Values {
index := sort.Search(len(v), func(i int) bool {
timestamp := v[i].Timestamp
return !timestamp.Before(t)
})
return v[index:]
}
func (v Values) dump(d *dto.SampleValueSeries) {
d.Reset()
for _, value := range v {
element := &dto.SampleValueSeries_Value{}
value.dump(element)
d.Value = append(d.Value, element)
}
}
// ToSampleKey returns the SampleKey for these Values.
func (v Values) ToSampleKey(f *clientmodel.Fingerprint) *SampleKey {
return &SampleKey{
Fingerprint: f,
FirstTimestamp: v[0].Timestamp,
LastTimestamp: v[len(v)-1].Timestamp,
SampleCount: uint32(len(v)),
}
}
func (v Values) String() string {
buffer := bytes.Buffer{}
fmt.Fprintf(&buffer, "[")
for i, value := range v {
fmt.Fprintf(&buffer, "%d. %s", i, value)
if i != len(v)-1 {
fmt.Fprintf(&buffer, "\n")
}
}
fmt.Fprintf(&buffer, "]")
return buffer.String()
}
// NewValuesFromDTO deserializes Values from a DTO.
func NewValuesFromDTO(d *dto.SampleValueSeries) Values {
// BUG(matt): Incogruent from the other load/dump API types, but much
// more performant.
v := make(Values, 0, len(d.Value))
for _, value := range d.Value {
v = append(v, &SamplePair{
Timestamp: clientmodel.TimestampFromUnix(value.GetTimestamp()),
Value: clientmodel.SampleValue(value.GetValue()),
})
}
return v
}
// SampleSet is Values with a Metric attached.
type SampleSet struct {
Metric clientmodel.Metric
Values Values
}
// Interval describes the inclusive interval between two Timestamps.
type Interval struct {
OldestInclusive clientmodel.Timestamp
NewestInclusive clientmodel.Timestamp
}