go-mtree/entry.go
Vincent Batts 8074df1973 *: refactoring to support streams
when creating a manifest from, or validating, a stream like a tar
archive, it requires thinking about some of the functions differently
than walking a directory tree.

This is the beginning of allowing for such features.

Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>
2016-07-20 17:41:17 -04:00

80 lines
2.6 KiB
Go

package mtree
import (
"fmt"
"path/filepath"
"strings"
)
type byPos []Entry
func (bp byPos) Len() int { return len(bp) }
func (bp byPos) Less(i, j int) bool { return bp[i].Pos < bp[j].Pos }
func (bp byPos) Swap(i, j int) { bp[i], bp[j] = bp[j], bp[i] }
// Entry is each component of content in the mtree spec file
type Entry struct {
Parent *Entry // up
Children []*Entry // down
Prev, Next *Entry // left, right
Set *Entry // current `/set` for additional keywords
Pos int // order in the spec
Raw string // file or directory name
Name string // file or directory name
Keywords []string // TODO(vbatts) maybe a keyword typed set of values?
Type EntryType
}
// Path provides the full path of the file, despite RelativeType or FullType
func (e Entry) Path() string {
if e.Parent == nil || e.Type == FullType {
return filepath.Clean(e.Name)
}
return filepath.Clean(filepath.Join(e.Parent.Path(), e.Name))
}
func (e Entry) String() string {
if e.Raw != "" {
return e.Raw
}
if e.Type == BlankType {
return ""
}
if e.Type == DotDotType {
return e.Name
}
// TODO(vbatts) if type is RelativeType and a keyword of not type=dir
if e.Type == SpecialType || e.Type == FullType || inSlice("type=dir", e.Keywords) {
return fmt.Sprintf("%s %s", e.Name, strings.Join(e.Keywords, " "))
}
return fmt.Sprintf(" %s %s", e.Name, strings.Join(e.Keywords, " "))
}
// EntryType are the formats of lines in an mtree spec file
type EntryType int
// The types of lines to be found in an mtree spec file
const (
SignatureType EntryType = iota // first line of the file, like `#mtree v2.0`
BlankType // blank lines are ignored
CommentType // Lines beginning with `#` are ignored
SpecialType // line that has `/` prefix issue a "special" command (currently only /set and /unset)
RelativeType // if the first white-space delimited word does not have a '/' in it. Options/keywords are applied.
DotDotType // .. - A relative path step. keywords/options are ignored
FullType // if the first word on the line has a `/` after the first character, it interpretted as a file pathname with options
)
// String returns the name of the EntryType
func (et EntryType) String() string {
return typeNames[et]
}
var typeNames = map[EntryType]string{
SignatureType: "SignatureType",
BlankType: "BlankType",
CommentType: "CommentType",
SpecialType: "SpecialType",
RelativeType: "RelativeType",
DotDotType: "DotDotType",
FullType: "FullType",
}