validate.go

Documentation: go.opencensus.io/tag

     1  // Copyright 2017, OpenCensus Authors
     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  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package tag
    16  
    17  import "errors"
    18  
    19  const (
    20  	maxKeyLength = 255
    21  
    22  	// valid are restricted to US-ASCII subset (range 0x20 (' ') to 0x7e ('~')).
    23  	validKeyValueMin = 32
    24  	validKeyValueMax = 126
    25  )
    26  
    27  var (
    28  	errInvalidKeyName = errors.New("invalid key name: only ASCII characters accepted; max length must be 255 characters")
    29  	errInvalidValue   = errors.New("invalid value: only ASCII characters accepted; max length must be 255 characters")
    30  )
    31  
    32  func checkKeyName(name string) bool {
    33  	if len(name) == 0 {
    34  		return false
    35  	}
    36  	if len(name) > maxKeyLength {
    37  		return false
    38  	}
    39  	return isASCII(name)
    40  }
    41  
    42  func isASCII(s string) bool {
    43  	for _, c := range s {
    44  		if (c < validKeyValueMin) || (c > validKeyValueMax) {
    45  			return false
    46  		}
    47  	}
    48  	return true
    49  }
    50  
    51  func checkValue(v string) bool {
    52  	if len(v) > maxKeyLength {
    53  		return false
    54  	}
    55  	return isASCII(v)
    56  }
    57
View as plain text