hashstructure is a Go library for creating a unique hash value for arbitrary values in Go.
This can be used to key values in a hash (for use in a map, set, etc.) that are complex. The most common use case is comparing two values without sending data across the network, caching values locally (de-dup), and so on.
Features
-
Hash any arbitrary Go value, including complex types.
-
Tag a struct field to ignore it and not affect the hash value.
-
Tag a slice type struct field to treat it as a set where ordering doesn't affect the hash code but the field itself is still taken into account to create the hash value.
-
Optionally specify a custom hash function to optimize for speed, collision avoidance for your data set, etc.
-
Optionally hash the output of
.String()
on structs that implement fmt.Stringer, allowing effective hashing of time.Time
Installation
Standard go get
:
$ go get github.com/mitchellh/hashstructure
Usage & Example
For usage and examples see the Godoc.
A quick code example is shown below:
type ComplexStruct struct {
Name string
Age uint
Metadata map[string]interface{}
}
v := ComplexStruct{
Name: "mitchellh",
Age: 64,
Metadata: map[string]interface{}{
"car": true,
"location": "California",
"siblings": []string{"Bob", "John"},
},
}
hash, err := hashstructure.Hash(v, nil)
if err != nil {
panic(err)
}
fmt.Printf("%d", hash)
// Output:
// 2307517237273902113