A simple demo of TiKV's prefix seek API

benchseek.go

// A simple demo of TiKV's prefix seek API

/*
$./benchseek
INFO[0000] [pd] create pd client with endpoints [localhost:2379]
INFO[0000] [pd] leader switches to: http://127.0.0.1:2379, previous:
INFO[0000] [pd] init cluster id 6508961674812833664
hello_1
hello_2
hello_3
hello_4
*/
package main

import (
	"bytes"
	"flag"
	"fmt"

	"github.com/pingcap/tidb/kv"
	"github.com/pingcap/tidb/store/tikv"
	"github.com/pingcap/tidb/terror"

	goctx "golang.org/x/net/context"
)

var (
	store  kv.Storage
	pdAddr = flag.String("pd", "localhost:2379", "pd address:localhost:2379")
)

// Init initializes information.
func initStore() {
	driver := tikv.Driver{}
	var err error
	store, err = driver.Open(fmt.Sprintf("tikv://%s", *pdAddr))
	terror.MustNil(err)
}

func doSeek() {
	// insert keys
	txn, err := store.Begin()
	terror.MustNil(err)

	txn.Set(kv.Key("hello_1"), []byte("value"))
	txn.Set(kv.Key("hello_2"), []byte("value"))
	txn.Set(kv.Key("hello_3"), []byte("value"))
	txn.Set(kv.Key("hello_4"), []byte("value"))

	err = txn.Commit(goctx.Background())
	terror.MustNil(err)

	// using seek API
	txn, err = store.Begin()
	terror.MustNil(err)

	it, err := txn.Seek(kv.Key("hello_"))
	terror.MustNil(err)

	// iterate keys and then delete them
	for it.Valid() && bytes.HasPrefix(it.Key(), []byte("hello_")) {
		fmt.Println(string(it.Key()))
		txn.Delete(it.Key())
		it.Next()
	}
	it.Close()

	err = txn.Commit(goctx.Background())
	terror.MustNil(err)
}

func main() {
	flag.Parse()
	initStore()

	doSeek()
}

$./benchseek
INFO[0000] [pd] create pd client with endpoints [localhost:2379]
INFO[0000] [pd] leader switches to: http://127.0.0.1:2379, previous:
INFO[0000] [pd] init cluster id 6508961674812833664
hello_1
hello_2
hello_3
hello_4