net: rewrite nsswitch.conf parsing to work like other parsers

Seems simpler than having two different parsing mechanisms.

Change-Id: I4f8468bc025f8e03f59ec9c79b17721581b64eed
Reviewed-on: https://go-review.googlesource.com/c/go/+/448855
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Joedian Reid <joedian@golang.org>
Reviewed-by: Damien Neil <dneil@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>

1 files changed, 13 insertions, 37 deletions

diff --git a/src/net/parse.go b/src/net/parse.go
index ee2890fe2c..fbc50144c2 100644
--- a/src/net/parse.go
+++ b/src/net/parse.go
@@ -64,6 +64,14 @@ func (f *file) readLine() (s string, ok bool) {
 	return
 }
 
+func (f *file) stat() (mtime time.Time, size int64, err error) {
+	st, err := f.file.Stat()
+	if err != nil {
+		return time.Time{}, 0, err
+	}
+	return st.ModTime(), st.Size(), nil
+}
+
 func open(name string) (*file, error) {
 	fd, err := os.Open(name)
 	if err != nil {
@@ -236,7 +244,7 @@ func lowerASCII(b byte) byte {
 }
 
 // trimSpace returns x without any leading or trailing ASCII whitespace.
-func trimSpace(x []byte) []byte {
+func trimSpace(x string) string {
 	for len(x) > 0 && isSpace(x[0]) {
 		x = x[1:]
 	}
@@ -253,37 +261,19 @@ func isSpace(b byte) bool {
 
 // removeComment returns line, removing any '#' byte and any following
 // bytes.
-func removeComment(line []byte) []byte {
-	if i := bytealg.IndexByte(line, '#'); i != -1 {
+func removeComment(line string) string {
+	if i := bytealg.IndexByteString(line, '#'); i != -1 {
 		return line[:i]
 	}
 	return line
 }
 
-// foreachLine runs fn on each line of x.
-// Each line (except for possibly the last) ends in '\n'.
-// It returns the first non-nil error returned by fn.
-func foreachLine(x []byte, fn func(line []byte) error) error {
-	for len(x) > 0 {
-		nl := bytealg.IndexByte(x, '\n')
-		if nl == -1 {
-			return fn(x)
-		}
-		line := x[:nl+1]
-		x = x[nl+1:]
-		if err := fn(line); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
 // foreachField runs fn on each non-empty run of non-space bytes in x.
 // It returns the first non-nil error returned by fn.
-func foreachField(x []byte, fn func(field []byte) error) error {
+func foreachField(x string, fn func(field string) error) error {
 	x = trimSpace(x)
 	for len(x) > 0 {
-		sp := bytealg.IndexByte(x, ' ')
+		sp := bytealg.IndexByteString(x, ' ')
 		if sp == -1 {
 			return fn(x)
 		}
@@ -327,17 +317,3 @@ func stringsEqualFold(s, t string) bool {
 	}
 	return true
 }
-
-func readFull(r io.Reader) (all []byte, err error) {
-	buf := make([]byte, 1024)
-	for {
-		n, err := r.Read(buf)
-		all = append(all, buf[:n]...)
-		if err == io.EOF {
-			return all, nil
-		}
-		if err != nil {
-			return nil, err
-		}
-	}
-}