github.com/pingcap/ticdc@v0.0.0-20220526033649-485a10ef2652/cdc/model/string.go (about)

     1  // Copyright 2020 PingCAP, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package model
    15  
    16  import (
    17  	"strings"
    18  
    19  	cerror "github.com/pingcap/ticdc/pkg/errors"
    20  )
    21  
    22  // HolderString returns a string of place holders separated by comma
    23  // n must be greater or equal than 1, or the function will panic
    24  func HolderString(n int) string {
    25  	var builder strings.Builder
    26  	builder.Grow((n-1)*2 + 1)
    27  	for i := 0; i < n; i++ {
    28  		if i > 0 {
    29  			builder.WriteString(",")
    30  		}
    31  		builder.WriteString("?")
    32  	}
    33  	return builder.String()
    34  }
    35  
    36  // ExtractKeySuffix extracts the suffix of an etcd key, such as extracting
    37  // "6a6c6dd290bc8732" from /tidb/cdc/changefeed/config/6a6c6dd290bc8732
    38  func ExtractKeySuffix(key string) (string, error) {
    39  	subs := strings.Split(key, "/")
    40  	if len(subs) < 2 {
    41  		return "", cerror.ErrInvalidEtcdKey.GenWithStackByArgs(key)
    42  	}
    43  	return subs[len(subs)-1], nil
    44  }