fields.go

Documentation: sigs.k8s.io/structured-merge-diff/v4/value

     1  /*
     2  Copyright 2019 The Kubernetes Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package value
    18  
    19  import (
    20  	"sort"
    21  	"strings"
    22  )
    23  
    24  // Field is an individual key-value pair.
    25  type Field struct {
    26  	Name  string
    27  	Value Value
    28  }
    29  
    30  // FieldList is a list of key-value pairs. Each field is expected to
    31  // have a different name.
    32  type FieldList []Field
    33  
    34  // Sort sorts the field list by Name.
    35  func (f FieldList) Sort() {
    36  	if len(f) < 2 {
    37  		return
    38  	}
    39  	if len(f) == 2 {
    40  		if f[1].Name < f[0].Name {
    41  			f[0], f[1] = f[1], f[0]
    42  		}
    43  		return
    44  	}
    45  	sort.SliceStable(f, func(i, j int) bool {
    46  		return f[i].Name < f[j].Name
    47  	})
    48  }
    49  
    50  // Less compares two lists lexically.
    51  func (f FieldList) Less(rhs FieldList) bool {
    52  	return f.Compare(rhs) == -1
    53  }
    54  
    55  // Compare compares two lists lexically. The result will be 0 if f==rhs, -1
    56  // if f < rhs, and +1 if f > rhs.
    57  func (f FieldList) Compare(rhs FieldList) int {
    58  	i := 0
    59  	for {
    60  		if i >= len(f) && i >= len(rhs) {
    61  			// Maps are the same length and all items are equal.
    62  			return 0
    63  		}
    64  		if i >= len(f) {
    65  			// F is shorter.
    66  			return -1
    67  		}
    68  		if i >= len(rhs) {
    69  			// RHS is shorter.
    70  			return 1
    71  		}
    72  		if c := strings.Compare(f[i].Name, rhs[i].Name); c != 0 {
    73  			return c
    74  		}
    75  		if c := Compare(f[i].Value, rhs[i].Value); c != 0 {
    76  			return c
    77  		}
    78  		// The items are equal; continue.
    79  		i++
    80  	}
    81  }
    82  
    83  // Equals returns true if the two fieldslist are equals, false otherwise.
    84  func (f FieldList) Equals(rhs FieldList) bool {
    85  	if len(f) != len(rhs) {
    86  		return false
    87  	}
    88  	for i := range f {
    89  		if f[i].Name != rhs[i].Name {
    90  			return false
    91  		}
    92  		if !Equals(f[i].Value, rhs[i].Value) {
    93  			return false
    94  		}
    95  	}
    96  	return true
    97  }
    98
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