From e20c5b9d3b2938d2fa0a035e3b925db87318bfba Mon Sep 17 00:00:00 2001
From: Juan Batiz-Benet <juan@benet.ai>
Date: Fri, 4 Jul 2014 00:12:05 -0700
Subject: [PATCH] protocols

---
 README.md         | 16 ++++------------
 index.go          | 31 +++++++++++++++++++++++++++++++
 multiaddr_test.go | 23 +++++++++++++++++++++++
 protocols.csv     |  9 +++++++++
 protocols.go      | 18 +++++++++---------
 5 files changed, 76 insertions(+), 21 deletions(-)
 create mode 100644 protocols.csv

diff --git a/README.md b/README.md
index 06f3e04..8a40027 100644
--- a/README.md
+++ b/README.md
@@ -24,19 +24,11 @@ m = multiaddr.Multiaddr{ Bytes: m.Bytes }
 ### Protocols
 
 ```go
-// get the multiaddr protocol codes
-m.ProtoCodes()
-// []int{4, 6}
-
-// get the multiaddr protocol string codes
-m.ProtoNames()
-// []string{"ip4", "tcp"}
-
 // get the multiaddr protocol description objects
-addr.Protos()
-// []Protocol{
-//   Protocol{ Code: 4, Name: 'ip4', Size: 32},
-//   Protocol{ Code: 17, Name: 'udp', Size: 16},
+addr.Protocols()
+// []*Protocol{
+//   &Protocol{ Code: 4, Name: 'ip4', Size: 32},
+//   &Protocol{ Code: 17, Name: 'udp', Size: 16},
 // }
 ```
 
diff --git a/index.go b/index.go
index b0165e1..ec0e054 100644
--- a/index.go
+++ b/index.go
@@ -1,5 +1,9 @@
 package multiaddr
 
+import (
+  "fmt"
+)
+
 type Multiaddr struct {
   Bytes []byte
 }
@@ -11,3 +15,30 @@ func NewString(s string) (*Multiaddr, error) {
   }
   return &Multiaddr{Bytes: b}, nil
 }
+
+func (m *Multiaddr) String() (string, error) {
+  return BytesToString(m.Bytes)
+}
+
+func (m *Multiaddr) Protocols() (ret []*Protocol, err error) {
+
+  // panic handler, in case we try accessing bytes incorrectly.
+  defer func() {
+    if e := recover(); e != nil {
+      ret = nil
+      err = e.(error)
+    }
+  }()
+
+  ps := []*Protocol{}
+  b := m.Bytes[:]
+  for ; len(b) > 0 ; {
+    p := ProtocolWithCode(int(b[0]))
+    if p == nil {
+      return nil, fmt.Errorf("no protocol with code %d", b[0])
+    }
+    ps = append(ps, p)
+    b = b[1 + (p.Size / 8):]
+  }
+  return ps, nil
+}
diff --git a/multiaddr_test.go b/multiaddr_test.go
index e14f79c..60deda4 100644
--- a/multiaddr_test.go
+++ b/multiaddr_test.go
@@ -49,3 +49,26 @@ func TestBytesToString(t *testing.T) {
   testString("/ip4/127.0.0.1/udp/1234", "047f0000011104d2")
 }
 
+
+func TestProtocols(t *testing.T) {
+  m, err := NewString("/ip4/127.0.0.1/udp/1234")
+  if err != nil {
+    t.Error("failed to construct", "/ip4/127.0.0.1/udp/1234")
+  }
+
+  ps, err := m.Protocols()
+  if err != nil {
+    t.Error("failed to get protocols", "/ip4/127.0.0.1/udp/1234")
+  }
+
+  if ps[0] != ProtocolWithName("ip4") {
+    t.Error(ps[0], ProtocolWithName("ip4"))
+    t.Error("failed to get ip4 protocol")
+  }
+
+  if ps[1] != ProtocolWithName("udp") {
+    t.Error(ps[1], ProtocolWithName("udp"))
+    t.Error("failed to get udp protocol")
+  }
+
+}
diff --git a/protocols.csv b/protocols.csv
new file mode 100644
index 0000000..62bc5c2
--- /dev/null
+++ b/protocols.csv
@@ -0,0 +1,9 @@
+code	size	name
+4	32	ip4
+6	16	tcp
+17	16	udp
+33	16	dccp
+41	128	ip6
+132	16	sctp
+480	0	http
+443	0	https
diff --git a/protocols.go b/protocols.go
index fac7344..d408578 100644
--- a/protocols.go
+++ b/protocols.go
@@ -11,14 +11,14 @@ type Protocol struct {
 // 2. ensuring errors in the csv don't screw up code.
 // 3. changing a number has to happen in two places.
 
-var Protocols = []Protocol{
-  Protocol{4,  32,  "ip4"},
-  Protocol{6,  16,  "tcp"},
-  Protocol{17, 16,  "udp"},
-  Protocol{33, 16,  "dccp"},
-  Protocol{41, 128, "ip6"},
+var Protocols = []*Protocol{
+  &Protocol{4,  32,  "ip4"},
+  &Protocol{6,  16,  "tcp"},
+  &Protocol{17, 16,  "udp"},
+  &Protocol{33, 16,  "dccp"},
+  &Protocol{41, 128, "ip6"},
   // these require varint:
-  Protocol{132, 16, "sctp"},
+  &Protocol{132, 16, "sctp"},
   // {480, 0, "http"},
   // {443, 0, "https"},
 }
@@ -26,7 +26,7 @@ var Protocols = []Protocol{
 func ProtocolWithName(s string) *Protocol {
   for _, p := range(Protocols) {
     if p.Name == s {
-      return &p
+      return p
     }
   }
   return nil
@@ -35,7 +35,7 @@ func ProtocolWithName(s string) *Protocol {
 func ProtocolWithCode(c int) *Protocol {
   for _, p := range(Protocols) {
     if p.Code == c {
-      return &p
+      return p
     }
   }
   return nil