capabilities: full integration (#151)

* format/pktline: fix readPayloadLen err handling

* protocol/pakp: UploadReq validation and creation of capabilities

* protocol/pakp: AdvRef tests

* protocol/pakp: capability.List.Delete

* protocol: filter unsupported capabilities

* remote capability negociation

* transport: UploadRequest validation

* requested changes

1 files changed, 84 insertions, 0 deletions

diff --git a/plumbing/protocol/packp/uppackreq.go b/plumbing/protocol/packp/uppackreq.go
new file mode 100644
index 0000000..2b1cb84
--- /dev/null
+++ b/plumbing/protocol/packp/uppackreq.go
@@ -0,0 +1,84 @@
+package packp
+
+import (
+	"fmt"
+	"io"
+
+	"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"
+)
+
+// UploadPackRequest represents a upload-pack request.
+// Zero-value is not safe, use NewUploadPackRequest instead.
+type UploadPackRequest struct {
+	*UploadRequest
+	*UploadHaves
+}
+
+// NewUploadPackRequest creates a new UploadPackRequest and returns a pointer.
+func NewUploadPackRequest() *UploadPackRequest {
+	return &UploadPackRequest{
+		UploadHaves:   &UploadHaves{},
+		UploadRequest: NewUploadRequest(),
+	}
+}
+
+// NewUploadPackRequestFromCapabilities creates a new UploadPackRequest and
+// returns a pointer. The request capabilities are filled with the most optiomal
+// ones, based on the adv value (advertaised capabilities), the UploadPackRequest
+// it has no wants, haves or shallows and an infinite depth
+func NewUploadPackRequestFromCapabilities(adv *capability.List) *UploadPackRequest {
+	return &UploadPackRequest{
+		UploadHaves:   &UploadHaves{},
+		UploadRequest: NewUploadRequestFromCapabilities(adv),
+	}
+}
+
+// IsEmpty a request if empty if Haves are contained in the Wants, or if Wants
+// length is zero
+func (r *UploadPackRequest) IsEmpty() bool {
+	return isSubset(r.Wants, r.Haves)
+}
+
+func isSubset(needle []plumbing.Hash, haystack []plumbing.Hash) bool {
+	for _, h := range needle {
+		found := false
+		for _, oh := range haystack {
+			if h == oh {
+				found = true
+				break
+			}
+		}
+
+		if !found {
+			return false
+		}
+	}
+
+	return true
+}
+
+// UploadHaves is a message to signal the references that a client has in a
+// upload-pack. Do not use this directly. Use UploadPackRequest request instead.
+type UploadHaves struct {
+	Haves []plumbing.Hash
+}
+
+// Encode encodes the UploadHaves into the Writer.
+func (u *UploadHaves) Encode(w io.Writer) error {
+	e := pktline.NewEncoder(w)
+	for _, have := range u.Haves {
+		if err := e.Encodef("have %s\n", have); err != nil {
+			return fmt.Errorf("sending haves for %q: %s", have, err)
+		}
+	}
+
+	if len(u.Haves) != 0 {
+		if err := e.Flush(); err != nil {
+			return fmt.Errorf("sending flush-pkt after haves: %s", err)
+		}
+	}
+
+	return nil
+}