vendor/github.com/mitchellh/hashstructure/README.md

   1 # hashstructure
   2
   3 hashstructure is a Go library for creating a unique hash value
   4 for arbitrary values in Go.
   5
   6 This can be used to key values in a hash (for use in a map, set, etc.)
   7 that are complex. The most common use case is comparing two values without
   8 sending data across the network, caching values locally (de-dup), and so on.
   9
  10 ## Features
  11
  12   * Hash any arbitrary Go value, including complex types.
  13
  14   * Tag a struct field to ignore it and not affect the hash value.
  15
  16   * Tag a slice type struct field to treat it as a set where ordering
  17     doesn't affect the hash code but the field itself is still taken into
  18     account to create the hash value.
  19
  20   * Optionally specify a custom hash function to optimize for speed, collision
  21     avoidance for your data set, etc.
  22
  23 ## Installation
  24
  25 Standard `go get`:
  26
  27 ```
  28 $ go get github.com/mitchellh/hashstructure
  29 ```
  30
  31 ## Usage & Example
  32
  33 For usage and examples see the [Godoc](http://godoc.org/github.com/mitchellh/hashstructure).
  34
  35 A quick code example is shown below:
  36
  37
  38         type ComplexStruct struct {
  39                 Name     string
  40                 Age      uint
  41                 Metadata map[string]interface{}
  42         }
  43
  44         v := ComplexStruct{
  45                 Name: "mitchellh",
  46                 Age:  64,
  47                 Metadata: map[string]interface{}{
  48                         "car":      true,
  49                         "location": "California",
  50                         "siblings": []string{"Bob", "John"},
  51                 },
  52         }
  53
  54         hash, err := hashstructure.Hash(v, nil)
  55         if err != nil {
  56                 panic(err)
  57         }
  58
  59         fmt.Printf("%d", hash)
  60         // Output:
  61         // 2307517237273902113