archlinux/util.go

package archlinux

import (
	"bytes"
	"fmt"
	"hash"
	"sort"
	"strings"
)

// name is an interface for instances that have a name, such as *os.File
type namer interface {
	// Name returns the instance name
	Name() string
}

type multiHasher struct {
	hash.Hash
	Expect []byte
}

type multiHash map[string]multiHasher

func newMultiHash() multiHash {
	return make(multiHash)
}

func (mh multiHash) Add(name string, fn func() hash.Hash, expect []byte) {
	if len(expect) == 0 || bytes.Equal(expect, []byte(skip)) {
		return
	}
	mh[name] = multiHasher{fn(), expect}
}

func (mh multiHash) Check() error {
	var errors []string
	for name, h := range mh {
		sum := h.Sum(nil)
		if !bytes.Equal(sum, h.Expect) {
			errors = append(errors, fmt.Sprintf("%s check failed", name))
		}
	}
	if len(errors) > 0 {
		sort.Strings(errors)
		return fmt.Errorf("archlinux: %s", strings.Join(errors, ", "))
	}
	return nil
}

func (mh multiHash) Write(p []byte) (int, error) {
	for _, h := range mh {
		if n, err := h.Write(p); err != nil {
			return n, err
		}
	}
	return len(p), nil
}