go-mtree/parse.go

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package mtree
import (
"bufio"
"io"
"strings"
)
// ParseSpec reads a stream of an mtree specification, and returns the DirectoryHierarchy
func ParseSpec(r io.Reader) (*DirectoryHierarchy, error) {
s := bufio.NewScanner(r)
i := int(0)
dh := DirectoryHierarchy{}
for s.Scan() {
str := s.Text()
e := Entry{Pos: i}
switch {
case strings.HasPrefix(str, "#"):
e.Raw = str
if strings.HasPrefix(str, "#mtree") {
e.Type = SignatureType
} else {
e.Type = CommentType
// from here, the comment could be "# key: value" metadata
// or a relative path hint
}
case str == "":
e.Type = BlankType
// nothing else to do here
case strings.HasPrefix(str, "/"):
e.Type = SpecialType
// collapse any escaped newlines
for {
if strings.HasSuffix(str, `\`) {
str = str[:len(str)-1]
s.Scan()
str += s.Text()
} else {
break
}
}
// parse the options
f := strings.Fields(str)
e.Name = f[0]
e.Keywords = f[1:]
case len(strings.Fields(str)) > 0 && strings.Fields(str)[0] == "..":
e.Type = DotDotType
e.Raw = str
// nothing else to do here
case len(strings.Fields(str)) > 0:
// collapse any escaped newlines
for {
if strings.HasSuffix(str, `\`) {
str = str[:len(str)-1]
s.Scan()
str += s.Text()
} else {
break
}
}
// parse the options
f := strings.Fields(str)
if strings.Contains(str, "/") {
e.Type = FullType
} else {
e.Type = RelativeType
}
e.Name = f[0]
e.Keywords = f[1:]
default:
// TODO(vbatts) log a warning?
continue
}
dh.Entries = append(dh.Entries, e)
i++
}
return &dh, s.Err()
}