package packp
import (
"fmt"
"strings"
"gopkg.in/src-d/go-git.v4/plumbing"
"gopkg.in/src-d/go-git.v4/plumbing/storer"
"gopkg.in/src-d/go-git.v4/storage/memory"
)
const (
symref = "symref"
)
// AdvRefs values represent the information transmitted on an
// advertised-refs message. Values from this type are not zero-value
// safe, use the New function instead.
//
// When using this messages over (smart) HTTP, you have to add a pktline
// before the whole thing with the following payload:
//
// '# service=$servicename" LF
//
// Moreover, some (all) git HTTP smart servers will send a flush-pkt
// just after the first pkt-line.
//
// To accomodate both situations, the Prefix field allow you to store
// any data you want to send before the actual pktlines. It will also
// be filled up with whatever is found on the line.
type AdvRefs struct {
Prefix [][]byte // payloads of the prefix
Head *plumbing.Hash
Capabilities *Capabilities
References map[string]plumbing.Hash
Peeled map[string]plumbing.Hash
Shallows []plumbing.Hash
}
// NewAdvRefs returns a pointer to a new AdvRefs value, ready to be used.
func NewAdvRefs() *AdvRefs {
return &AdvRefs{
Prefix: [][]byte{},
Capabilities: NewCapabilities(),
References: make(map[string]plumbing.Hash),
Peeled: make(map[string]plumbing.Hash),
Shallows: []plumbing.Hash{},
}
}
func (a *AdvRefs) AddReference(r *plumbing.Reference) error {
switch r.Type() {
case plumbing.SymbolicReference:
v := fmt.Sprintf("%s:%s", r.Name().String(), r.Target().String())
a.Capabilities.Add(symref, v)
case plumbing.HashReference:
a.References[r.Name().String()] = r.Hash()
default:
return plumbing.ErrInvalidType
}
return nil
}
func (a *AdvRefs) AllReferences() (memory.ReferenceStorage, error) {
s := memory.ReferenceStorage{}
if err := addRefs(s, a); err != nil {
return s, plumbing.NewUnexpectedError(err)
}
return s, nil
}
func addRefs(s storer.ReferenceStorer, ar *AdvRefs) error {
for name, hash := range ar.References {
ref := plumbing.NewReferenceFromStrings(name, hash.String())
if err := s.SetReference(ref); err != nil {
return err
}
}
return addSymbolicRefs(s, ar)
}
func addSymbolicRefs(s storer.ReferenceStorer, ar *AdvRefs) error {
if !hasSymrefs(ar) {
return nil
}
for _, symref := range ar.Capabilities.Get(symref).Values {
chunks := strings.Split(symref, ":")
if len(chunks) != 2 {
err := fmt.Errorf("bad number of `:` in symref value (%q)", symref)
return plumbing.NewUnexpectedError(err)
}
name := plumbing.ReferenceName(chunks[0])
target := plumbing.ReferenceName(chunks[1])
ref := plumbing.NewSymbolicReference(name, target)
if err := s.SetReference(ref); err != nil {
return nil
}
}
return nil
}
func hasSymrefs(ar *AdvRefs) bool {
return ar.Capabilities.Supports(symref)
}
