hashstructure

hashstructure

a go library for creating a unique hash value for arbitrary values

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), etc.

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

• Optionally, override the hashing process with a hash field or by implementing hashstructure.Hashable.

Installation

go get -u github.com/gofunky/hashstructure

Example

package hashstructure

import (
	"fmt"
)

func ExampleHash() {
	type ComplexStruct struct {
		Name     string
		Age      uint
		Metadata map[string]interface{}
	}

	v := ComplexStruct{
		Name: "gofunky",
		Age:  64,
		Metadata: map[string]interface{}{
			"car":      true,
			"location": "California",
			"siblings": []string{"Bob", "John"},
		},
	}

	hash, err := Hash(v, nil)
	if err != nil {
		panic(err)
	}

	fmt.Printf("%d", hash)
	// Output:
	// 12836943650294093551
}