prometheus/storage/interface.go
李国忠 f7a322fa6d
[comments] change the word "liike" to "like" (#6859)
Signed-off-by: fuling <fuling.lgz@alibaba-inc.com>
2020-02-22 20:48:54 +00:00

168 lines
5.6 KiB
Go

// Copyright 2014 The Prometheus Authors
// 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 storage
import (
"context"
"errors"
"github.com/prometheus/prometheus/pkg/labels"
"github.com/prometheus/prometheus/tsdb/chunkenc"
"github.com/prometheus/prometheus/tsdb/chunks"
"github.com/prometheus/prometheus/tsdb/tombstones"
)
// The errors exposed.
var (
ErrNotFound = errors.New("not found")
ErrOutOfOrderSample = errors.New("out of order sample")
ErrDuplicateSampleForTimestamp = errors.New("duplicate sample for timestamp")
ErrOutOfBounds = errors.New("out of bounds")
)
// Appendable allows creating appenders.
type Appendable interface {
// Appender returns a new appender for the storage.
Appender() Appender
}
// Storage ingests and manages samples, along with various indexes. All methods
// are goroutine-safe. Storage implements storage.SampleAppender.
type Storage interface {
Queryable
Appendable
// StartTime returns the oldest timestamp stored in the storage.
StartTime() (int64, error)
// Close closes the storage and all its underlying resources.
Close() error
}
// A Queryable handles queries against a storage.
type Queryable interface {
// Querier returns a new Querier on the storage.
Querier(ctx context.Context, mint, maxt int64) (Querier, error)
}
// Querier provides querying access over time series data of a fixed
// time range.
type Querier interface {
// Select returns a set of series that matches the given label matchers.
Select(*SelectParams, ...*labels.Matcher) (SeriesSet, Warnings, error)
// SelectSorted returns a sorted set of series that matches the given label matchers.
SelectSorted(*SelectParams, ...*labels.Matcher) (SeriesSet, Warnings, error)
// LabelValues returns all potential values for a label name.
// It is not safe to use the strings beyond the lifefime of the querier.
LabelValues(name string) ([]string, Warnings, error)
// LabelNames returns all the unique label names present in the block in sorted order.
LabelNames() ([]string, Warnings, error)
// Close releases the resources of the Querier.
Close() error
}
// SelectParams specifies parameters passed to data selections.
type SelectParams struct {
Start int64 // Start time in milliseconds for this select.
End int64 // End time in milliseconds for this select.
Step int64 // Query step size in milliseconds.
Func string // String representation of surrounding function or aggregation.
Grouping []string // List of label names used in aggregation.
By bool // Indicate whether it is without or by.
Range int64 // Range vector selector range in milliseconds.
}
// QueryableFunc is an adapter to allow the use of ordinary functions as
// Queryables. It follows the idea of http.HandlerFunc.
type QueryableFunc func(ctx context.Context, mint, maxt int64) (Querier, error)
// Querier calls f() with the given parameters.
func (f QueryableFunc) Querier(ctx context.Context, mint, maxt int64) (Querier, error) {
return f(ctx, mint, maxt)
}
// Appender provides batched appends against a storage.
// It must be completed with a call to Commit or Rollback and must not be reused afterwards.
//
// Operations on the Appender interface are not goroutine-safe.
type Appender interface {
// Add adds a sample pair for the given series. A reference number is
// returned which can be used to add further samples in the same or later
// transactions.
// Returned reference numbers are ephemeral and may be rejected in calls
// to AddFast() at any point. Adding the sample via Add() returns a new
// reference number.
// If the reference is 0 it must not be used for caching.
Add(l labels.Labels, t int64, v float64) (uint64, error)
// AddFast adds a sample pair for the referenced series. It is generally
// faster than adding a sample by providing its full label set.
AddFast(ref uint64, t int64, v float64) error
// Commit submits the collected samples and purges the batch.
Commit() error
// Rollback rolls back all modifications made in the appender so far.
// Appender has to be discarded after rollback.
Rollback() error
}
// SeriesSet contains a set of series.
type SeriesSet interface {
Next() bool
At() Series
Err() error
}
var emptySeriesSet = errSeriesSet{}
// EmptySeriesSet returns a series set that's always empty.
func EmptySeriesSet() SeriesSet {
return emptySeriesSet
}
type errSeriesSet struct {
err error
}
func (s errSeriesSet) Next() bool { return false }
func (s errSeriesSet) At() Series { return nil }
func (s errSeriesSet) Err() error { return s.err }
// Series represents a single time series.
type Series interface {
// Labels returns the complete set of labels identifying the series.
Labels() labels.Labels
// Iterator returns a new iterator of the data of the series.
Iterator() chunkenc.Iterator
}
// ChunkSeriesSet exposes the chunks and intervals of a series instead of the
// actual series itself.
// TODO(bwplotka): Move it to Series like Iterator that iterates over chunks and avoiding loading all of them at once.
type ChunkSeriesSet interface {
Next() bool
At() (labels.Labels, []chunks.Meta, tombstones.Intervals)
Err() error
}
type Warnings []error