package packp
import (
"bytes"
"io"
"sort"
"gopkg.in/src-d/go-git.v4/plumbing"
"gopkg.in/src-d/go-git.v4/plumbing/format/pktline"
"gopkg.in/src-d/go-git.v4/plumbing/protocol/packp/capability"
)
// Encode writes the AdvRefs encoding to a writer.
//
// All the payloads will end with a newline character. Capabilities,
// references and shallows are writen in alphabetical order, except for
// peeled references that always follow their corresponding references.
func (a *AdvRefs) Encode(w io.Writer) error {
e := newAdvRefsEncoder(w)
return e.Encode(a)
}
type advRefsEncoder struct {
data *AdvRefs // data to encode
pe *pktline.Encoder // where to write the encoded data
err error // sticky error
}
func newAdvRefsEncoder(w io.Writer) *advRefsEncoder {
return &advRefsEncoder{
pe: pktline.NewEncoder(w),
}
}
func (e *advRefsEncoder) Encode(v *AdvRefs) error {
e.data = v
for state := encodePrefix; state != nil; {
state = state(e)
}
return e.err
}
type encoderStateFn func(*advRefsEncoder) encoderStateFn
func encodePrefix(e *advRefsEncoder) encoderStateFn {
for _, p := range e.data.Prefix {
if bytes.Equal(p, pktline.Flush) {
if e.err = e.pe.Flush(); e.err != nil {
return nil
}
continue
}
if e.err = e.pe.Encodef("%s\n", string(p)); e.err != nil {
return nil
}
}
return encodeFirstLine
}
// Adds the first pkt-line payload: head hash, head ref and capabilities.
// Also handle the special case when no HEAD ref is found.
func encodeFirstLine(e *advRefsEncoder) encoderStateFn {
head := formatHead(e.data.Head)
separator := formatSeparator(e.data.Head)
capabilities := formatCaps(e.data.Capabilities)
if e.err = e.pe.Encodef("%s %s\x00%s\n", head, separator, capabilities); e.err != nil {
return nil
}
return encodeRefs
}
func formatHead(h *plumbing.Hash) string {
if h == nil {
return plumbing.ZeroHash.String()
}
return h.String()
}
func formatSeparator(h *plumbing.Hash) string {
if h == nil {
return noHead
}
return head
}
func formatCaps(c *capability.List) string {
if c == nil {
return ""
}
return c.String()
}
// Adds the (sorted) refs: hash SP refname EOL
// and their peeled refs if any.
func encodeRefs(e *advRefsEncoder) encoderStateFn {
refs := sortRefs(e.data.References)
for _, r := range refs {
hash, _ := e.data.References[r]
if e.err = e.pe.Encodef("%s %s\n", hash.String(), r); e.err != nil {
return nil
}
if hash, ok := e.data.Peeled[r]; ok {
if e.err = e.pe.Encodef("%s %s^{}\n", hash.String(), r); e.err != nil {
return nil
}
}
}
return encodeShallow
}
func sortRefs(m map[string]plumbing.Hash) []string {
ret := make([]string, 0, len(m))
for k := range m {
ret = append(ret, k)
}
sort.Strings(ret)
return ret
}
// Adds the (sorted) shallows: "shallow" SP hash EOL
func encodeShallow(e *advRefsEncoder) encoderStateFn {
sorted := sortShallows(e.data.Shallows)
for _, hash := range sorted {
if e.err = e.pe.Encodef("shallow %s\n", hash); e.err != nil {
return nil
}
}
return encodeFlush
}
func sortShallows(c []plumbing.Hash) []string {
ret := []string{}
for _, h := range c {
ret = append(ret, h.String())
}
sort.Strings(ret)
return ret
}
func encodeFlush(e *advRefsEncoder) encoderStateFn {
e.err = e.pe.Flush()
return nil
}
