move: format/packp -> protocol/packp (#141)

* move: format/packp -> protocol/packp

* format/packp -> protocol/packp
* format/packp/pktline -> format/pktline.

* move: protocol/packp/ulreq/* -> protocol/packp/*

* protocol/packp: rename UlReq types to make them unique.

* * protocol/packp: namespace UlReq encoder.

* protocol/packp: namespace UlReq decoder.

* protocol/packp: fix example names

* move: protocol/packp/advrefs/* -> protocol/packp/*

* further ulreq namespacing

* protocol/packp: namespace AdvRefs types.

1 files changed, 45 insertions, 0 deletions

diff --git a/plumbing/protocol/packp/common.go b/plumbing/protocol/packp/common.go
new file mode 100644
index 0000000..c4b44f7
--- /dev/null
+++ b/plumbing/protocol/packp/common.go
@@ -0,0 +1,45 @@
+package packp
+
+import "bytes"
+
+type stateFn func() stateFn
+
+const (
+	// common
+	hashSize = 40
+
+	// advrefs
+	head   = "HEAD"
+	noHead = "capabilities^{}"
+)
+
+var (
+	// common
+	sp  = []byte(" ")
+	eol = []byte("\n")
+
+	// advrefs
+	null       = []byte("\x00")
+	peeled     = []byte("^{}")
+	noHeadMark = []byte(" capabilities^{}\x00")
+
+	// ulreq
+	want            = []byte("want ")
+	shallow         = []byte("shallow ")
+	deepen          = []byte("deepen")
+	deepenCommits   = []byte("deepen ")
+	deepenSince     = []byte("deepen-since ")
+	deepenReference = []byte("deepen-not ")
+)
+
+// Capabilities are a single string or a name=value.
+// Even though we are only going to read at moust 1 value, we return
+// a slice of values, as Capability.Add receives that.
+func readCapability(data []byte) (name string, values []string) {
+	pair := bytes.SplitN(data, []byte{'='}, 2)
+	if len(pair) == 2 {
+		values = append(values, string(pair[1]))
+	}
+
+	return string(pair[0]), values
+}