client-go/examples/txnkv/unsafedestoryrange/unsafedestoryrange.go

109 lines
3.1 KiB
Go

// Copyright 2021 TiKV 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 main
import (
"bytes"
"context"
"flag"
"fmt"
"math/rand"
"os"
"github.com/tikv/client-go/v2/txnkv"
)
var (
client *txnkv.Client
pdAddr = flag.String("pd", "127.0.0.1:2379", "pd address")
)
// Init initializes information.
func initStore() {
var err error
client, err = txnkv.NewClient([]string{*pdAddr})
panicWhenErrNotNil(err)
}
func panicWhenErrNotNil(err error) {
if err != nil {
panic(err)
}
}
func main() {
pdAddr := os.Getenv("PD_ADDR")
if pdAddr != "" {
os.Args = append(os.Args, "-pd", pdAddr)
}
flag.Parse()
initStore()
data := map[string][]byte{}
ctx := context.Background()
// Generate a sequence of keys and random values
for _, i := range []byte("abcd") {
txn, err := client.Begin()
panicWhenErrNotNil(err)
for j := byte('0'); j <= byte('9'); j++ {
key := []byte{i, j}
value := []byte{byte(rand.Intn(256)), byte(rand.Intn(256))}
data[string(key)] = value
err = txn.Set(key, value)
panicWhenErrNotNil(err)
}
err = txn.Commit(ctx)
panicWhenErrNotNil(err)
}
fmt.Println("commit data success!")
// check data
txn, err := client.Begin()
panicWhenErrNotNil(err)
it, err := txn.Iter([]byte("a"), nil)
panicWhenErrNotNil(err)
for it.Valid() {
key := string(it.Key())
if evalue, ok := data[key]; ok {
if !bytes.Equal(evalue, it.Value()) {
fmt.Printf("Unexpect value, is the value changed by other transaction? key:%+v, expect value:%+v, real value:%+v\n", key, evalue, it.Value())
}
}
err = it.Next()
panicWhenErrNotNil(err)
}
// UnsafeDestroyRange Cleans up all keys in a range[startKey,endKey) and quickly free the disk space.
// The range might span over multiple regions, and the `ctx` doesn't indicate region. The request will be done directly
// on RocksDB, bypassing the Raft layer. User must promise that, after calling `UnsafeDestroyRange`,
// the range will never be accessed any more.
err = client.UnsafeDestroyRange(ctx, []byte("b"), []byte("c0"))
panicWhenErrNotNil(err)
fmt.Println("UnsafeDestroyRange [b,c0) success.")
//`UnsafeDestroyRange` is allowed to be called multiple times on an single range.
err = client.UnsafeDestroyRange(ctx, []byte("b"), []byte("c0"))
panicWhenErrNotNil(err)
fmt.Println("UnsafeDestroyRange [b,c0) again success.")
err = client.UnsafeDestroyRange(ctx, []byte("d0"), []byte("d0"))
panicWhenErrNotNil(err)
fmt.Println("UnsafeDestroyRange [d0,d0) success.")
err = client.UnsafeDestroyRange(ctx, []byte("a"), []byte("e"))
panicWhenErrNotNil(err)
fmt.Println("UnsafeDestroyRange [a,e) success.")
}