packer-cn/vendor/github.com/ulikunitz/xz/lzma/matchalgorithm.go

53 lines
1.2 KiB
Go

// Copyright 2014-2017 Ulrich Kunitz. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package lzma
import "errors"
// MatchAlgorithm identifies an algorithm to find matches in the
// dictionary.
type MatchAlgorithm byte
// Supported matcher algorithms.
const (
HashTable4 MatchAlgorithm = iota
BinaryTree
)
// maStrings are used by the String method.
var maStrings = map[MatchAlgorithm]string{
HashTable4: "HashTable4",
BinaryTree: "BinaryTree",
}
// String returns a string representation of the Matcher.
func (a MatchAlgorithm) String() string {
if s, ok := maStrings[a]; ok {
return s
}
return "unknown"
}
var errUnsupportedMatchAlgorithm = errors.New(
"lzma: unsupported match algorithm value")
// verify checks whether the matcher value is supported.
func (a MatchAlgorithm) verify() error {
if _, ok := maStrings[a]; !ok {
return errUnsupportedMatchAlgorithm
}
return nil
}
func (a MatchAlgorithm) new(dictCap int) (m matcher, err error) {
switch a {
case HashTable4:
return newHashTable(dictCap, 4)
case BinaryTree:
return newBinTree(dictCap)
}
return nil, errUnsupportedMatchAlgorithm
}