genmap

Specialized hash maps for integer types in Go.

The builtin maps of Go are good but sometimes you need some extra performance.

This library offers specialized hash maps from A to B with A, B from all of
int, int8, int16, int32, int64,
uint, uint8, uint16, uint32 and uint64.

The maps are named in camel case MapAToB.
So a map from e.g. int8 to uint32 is called MapInt8ToUint32.

Installation

You need a Go1 environment.

$ go get github.com/s-l-teichmann/genmap

Find the API documentation here.

Example program using a uint64 to int map:

package main

import (
	"fmt"
	"github.com/s-l-teichmann/genmap"
)

func main() {
	// Create a new hash map.
	h := genmap.NewHashUint64ToInt(16)

	// Creates new key/value pairs 42 -> 10 and 47 -> 11.
	h.Add(42, 10)
	h.Add(47, 11)

	// Increases the value of key 47 to 111.
	h.Add(47, 100)

	// Increments value 42 to 43 of key 42.
	h.Inc(42)

	// Fetch value of key 42 from map.
	fmt.Printf("value: %d\n", h.Get(42))

	// Prints the number of key/value pairs in the map.
	fmt.Printf("size: %d\n", h.Size())

	// Prints all key/value pairs in map in undefined order.
	h.Visit(func(k uint64, v int) {
		fmt.Printf("key: %d value: %d\n", k, v)
	})
}

For a more complete set of methods see the API index.

For contributors

The maps are generated from a template in generators/genmaps.go.
Re-generate the maps with

$ go generate

For pull request ensure that the files are generated in a way that a go fmt call would not change them and the go test -coverprofile=count stays at 100%.

License

This is Free Software covered by the terms of the MIT license.
(c) 2016 by Sascha L. Teichmann