nsscash: improve comments

[nsscash/nsscash.git] / group.go

diff --git a/group.go b/group.go
index 02502f62a147464eee533c8ce3a3ec1683fb0748..0ad86711431d068ff0922ceace8c39cdba01a1a0 100644 (file)
--- a/group.go
+++ b/group.go
@@ -39,11 +39,13 @@ type Group struct {
        Gid     uint64
        Members []string
 }
+
+// Go does not support slices in map keys; therefore, use this separate struct
 type GroupKey struct {
        Name    string
        Passwd  string
        Gid     uint64
-       Members string
+       Members string // "," separated
 }
 
 func toKey(g Group) GroupKey {
@@ -56,7 +58,7 @@ func toKey(g Group) GroupKey {
 }
 
 // ParseGroups parses a file in the format of /etc/group and returns all
-// entries as Group structs.
+// entries as slice of Group structs.
 func ParseGroups(r io.Reader) ([]Group, error) {
        var res []Group
 
@@ -112,10 +114,7 @@ func SerializeGroup(g Group) []byte {
        offPasswd := uint16(data.Len())
        data.Write([]byte(g.Passwd))
        data.WriteByte(0)
-       // Padding to align the following uint16
-       if data.Len()%2 != 0 {
-               data.WriteByte(0)
-       }
+       alignBufferTo(&data, 2) // align the following uint16
        offMemOff := uint16(data.Len())
        // Offsets for group members
        offMem := offMemOff + 2*uint16(len(mems_off))
@@ -152,12 +151,7 @@ func SerializeGroup(g Group) []byte {
        res.Write(data.Bytes())
        // We must pad each entry so that all uint64 at the beginning of the
        // struct are 8 byte aligned
-       l := res.Len()
-       if l%8 != 0 {
-               for i := 0; i < 8-l%8; i++ {
-                       res.WriteByte(0)
-               }
-       }
+       alignBufferTo(&res, 8)
 
        return res.Bytes()
 }
@@ -209,7 +203,8 @@ func SerializeGroups(w io.Writer, grs []Group) error {
        }
 
        // Sanity check
-       if indexOrig.Len() != indexId.Len() ||
+       if len(grs)*8 != indexOrig.Len() ||
+               indexOrig.Len() != indexId.Len() ||
                indexId.Len() != indexName.Len() {
                return fmt.Errorf("indexes have inconsistent length")
        }