github.com/pingcap/tiflow@v0.0.0-20240520035814-5bf52d54e205/dm/pkg/utils/string.go (about)

     1  // Copyright 2019 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 utils
    15  
    16  import (
    17  	"fmt"
    18  )
    19  
    20  const (
    21  	defaultStringLenLimit = 1024
    22  )
    23  
    24  // TruncateString returns a string with only the leading (at most) n runes of the input string.
    25  // If the string is truncated, a `...` tail will be appended.
    26  func TruncateString(s string, n int) string {
    27  	if n < 0 {
    28  		n = defaultStringLenLimit
    29  	}
    30  	if len(s) <= n {
    31  		return s
    32  	}
    33  	return s[:n] + "..." // mark as some content is truncated
    34  }
    35  
    36  // TruncateInterface converts the interface to a string
    37  // and returns a string with only the leading (at most) n runes of the input string.
    38  // If the converted string is truncated, a `...` tail will be appended.
    39  // It is not effective for large structure now.
    40  func TruncateInterface(v interface{}, n int) string {
    41  	return TruncateString(fmt.Sprintf("%+v", v), n)
    42  }
    43  
    44  // TruncateStringQuiet returns a string with only the leading (at most) n runes of the input string.
    45  func TruncateStringQuiet(s string, n int) string {
    46  	if n < 0 {
    47  		n = defaultStringLenLimit
    48  	}
    49  	if len(s) <= n {
    50  		return s
    51  	}
    52  
    53  	return s[:n]
    54  }