mirror of
				https://github.com/prometheus/prometheus.git
				synced 2025-11-04 10:21:02 +01:00 
			
		
		
		
	* refactor: move from io/ioutil to io and os packages * use fs.DirEntry instead of os.FileInfo after os.ReadDir Signed-off-by: MOREL Matthieu <matthieu.morel@cnp.fr>
		
			
				
	
	
		
			104 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			104 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
// Copyright 2021 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 tsdb
 | 
						|
 | 
						|
import (
 | 
						|
	"context"
 | 
						|
	"fmt"
 | 
						|
	"math"
 | 
						|
	"os"
 | 
						|
	"time"
 | 
						|
 | 
						|
	"github.com/prometheus/prometheus/model/labels"
 | 
						|
)
 | 
						|
 | 
						|
func Example() {
 | 
						|
	// Create a random dir to work in.  Open() doesn't require a pre-existing dir, but
 | 
						|
	// we want to make sure not to make a mess where we shouldn't.
 | 
						|
	dir, err := os.MkdirTemp("", "tsdb-test")
 | 
						|
	noErr(err)
 | 
						|
 | 
						|
	// Open a TSDB for reading and/or writing.
 | 
						|
	db, err := Open(dir, nil, nil, DefaultOptions(), nil)
 | 
						|
	noErr(err)
 | 
						|
 | 
						|
	// Open an appender for writing.
 | 
						|
	app := db.Appender(context.Background())
 | 
						|
 | 
						|
	series := labels.FromStrings("foo", "bar")
 | 
						|
 | 
						|
	// Ref is 0 for the first append since we don't know the reference for the series.
 | 
						|
	ref, err := app.Append(0, series, time.Now().Unix(), 123)
 | 
						|
	noErr(err)
 | 
						|
 | 
						|
	// Another append for a second later.
 | 
						|
	// Re-using the ref from above since it's the same series, makes append faster.
 | 
						|
	time.Sleep(time.Second)
 | 
						|
	_, err = app.Append(ref, series, time.Now().Unix(), 124)
 | 
						|
	noErr(err)
 | 
						|
 | 
						|
	// Commit to storage.
 | 
						|
	err = app.Commit()
 | 
						|
	noErr(err)
 | 
						|
 | 
						|
	// In case you want to do more appends after app.Commit(),
 | 
						|
	// you need a new appender.
 | 
						|
	app = db.Appender(context.Background())
 | 
						|
	// ... adding more samples.
 | 
						|
 | 
						|
	// Open a querier for reading.
 | 
						|
	querier, err := db.Querier(context.Background(), math.MinInt64, math.MaxInt64)
 | 
						|
	noErr(err)
 | 
						|
	ss := querier.Select(false, nil, labels.MustNewMatcher(labels.MatchEqual, "foo", "bar"))
 | 
						|
 | 
						|
	for ss.Next() {
 | 
						|
		series := ss.At()
 | 
						|
		fmt.Println("series:", series.Labels().String())
 | 
						|
 | 
						|
		it := series.Iterator()
 | 
						|
		for it.Next() {
 | 
						|
			_, v := it.At() // We ignore the timestamp here, only to have a predictable output we can test against (below)
 | 
						|
			fmt.Println("sample", v)
 | 
						|
		}
 | 
						|
 | 
						|
		fmt.Println("it.Err():", it.Err())
 | 
						|
	}
 | 
						|
	fmt.Println("ss.Err():", ss.Err())
 | 
						|
	ws := ss.Warnings()
 | 
						|
	if len(ws) > 0 {
 | 
						|
		fmt.Println("warnings:", ws)
 | 
						|
	}
 | 
						|
	err = querier.Close()
 | 
						|
	noErr(err)
 | 
						|
 | 
						|
	// Clean up any last resources when done.
 | 
						|
	err = db.Close()
 | 
						|
	noErr(err)
 | 
						|
	err = os.RemoveAll(dir)
 | 
						|
	noErr(err)
 | 
						|
 | 
						|
	// Output:
 | 
						|
	// series: {foo="bar"}
 | 
						|
	// sample 123
 | 
						|
	// sample 124
 | 
						|
	// it.Err(): <nil>
 | 
						|
	// ss.Err(): <nil>
 | 
						|
}
 | 
						|
 | 
						|
func noErr(err error) {
 | 
						|
	if err != nil {
 | 
						|
		panic(err)
 | 
						|
	}
 | 
						|
}
 |