Support setting source selector filter (#5)

* Added `LinkSelectorFilter()` link option.
* Added `describedType`.
* Refactored `readComposite` to try decoding as described type when not a known composite.
* Added `describedType` to marshal tests.
* Added `String()` methods for debugging.

Note: Event Hubs was sending back `0x137000000a` as descriptor code when `LinkSelectorFilter()` was using a string as the descriptor. I haven't been able to figure out what that code refers to.

.gitattributes

@@ -0,0 +1,3 @@
+# Binary files (no line-ending conversions), diff using hexdump
+*.bin binary diff=hex
+

client.go

@@ -3,6 +3,7 @@ package amqp
 import (
 	"bytes"
 	"context"
+	"encoding/binary"
 	"fmt"
 	"math"
 	"math/rand"
@@ -619,6 +620,7 @@ type link struct {
 	senderSettleMode   *SenderSettleMode
 	receiverSettleMode *ReceiverSettleMode
 	maxMessageSize     uint64
+	filters            map[symbol]interface{} // source filters sent during attach
 	peerMaxMessageSize uint64
 	detachSent         bool // detach frame has been sent
 	detachReceived     bool
@@ -684,6 +686,7 @@ func newLink(s *Session, r *Receiver, opts []LinkOption) (*link, error) {
 		attach.Source = &source{
 			Address: l.address,
 			Dynamic: l.dynamicAddr,
+			Filter:  l.filters,
 		}
 	} else {
 		attach.Role = roleSender
@@ -1085,6 +1088,23 @@ func LinkReceiverSettle(mode ReceiverSettleMode) LinkOption {
 	}
 }
 
+// LinkSelectorFilter sets a selector filter (apache.org:selector-filter:string) on the link source.
+func LinkSelectorFilter(filter string) LinkOption {
+	// <descriptor name="apache.org:selector-filter:string" code="0x0000468C:0x00000004"/>
+	const name = symbol("apache.org:selector-filter:string")
+	code := binary.BigEndian.Uint64([]byte{0x00, 0x00, 0x46, 0x8C, 0x00, 0x00, 0x00, 0x04})
+	return func(l *link) error {
+		if l.filters == nil {
+			l.filters = make(map[symbol]interface{})
+		}
+		l.filters[name] = describedType{
+			descriptor: code,
+			value:      filter,
+		}
+		return nil
+	}
+}
+
 // Receiver receives messages on a single AMQP link.
 type Receiver struct {
 	link         *link                   // underlying link

decode.go

@@ -703,12 +703,16 @@ func readComposite(r reader) (interface{}, error) {
 		return nil, err
 	}
 
+	var iface interface{}
+
+	// check if known composite type
 	construct := compositeTypes[amqpType(v)]
-	if construct == nil {
-		return nil, errorErrorf("unmarshaling composite %0x not implemented", v)
+	if construct != nil {
+		iface = construct()
+	} else {
+		iface = new(describedType) // try as described type
 	}
 
-	iface := construct()
 	_, err = unmarshal(r, iface)
 	return iface, err
 }
@@ -726,6 +730,42 @@ var compositeTypes = [256]func() interface{}{
 	typeCodeStateReceived: func() interface{} { return new(stateReceived) },
 	typeCodeStateRejected: func() interface{} { return new(stateRejected) },
 	typeCodeStateReleased: func() interface{} { return new(stateReleased) },
+
+	typeCodeOpen:                  notImplementedConstructor("typeCodeOpen"),
+	typeCodeBegin:                 notImplementedConstructor("typeCodeBegin"),
+	typeCodeAttach:                notImplementedConstructor("typeCodeAttach"),
+	typeCodeFlow:                  notImplementedConstructor("typeCodeFlow"),
+	typeCodeTransfer:              notImplementedConstructor("typeCodeTransfer"),
+	typeCodeDisposition:           notImplementedConstructor("typeCodeDisposition"),
+	typeCodeDetach:                notImplementedConstructor("typeCodeDetach"),
+	typeCodeEnd:                   notImplementedConstructor("typeCodeEnd"),
+	typeCodeClose:                 notImplementedConstructor("typeCodeClose"),
+	typeCodeSource:                notImplementedConstructor("typeCodeSource"),
+	typeCodeTarget:                notImplementedConstructor("typeCodeTarget"),
+	typeCodeMessageHeader:         notImplementedConstructor("typeCodeMessageHeader"),
+	typeCodeDeliveryAnnotations:   notImplementedConstructor("typeCodeDeliveryAnnotations"),
+	typeCodeMessageAnnotations:    notImplementedConstructor("typeCodeMessageAnnotations"),
+	typeCodeMessageProperties:     notImplementedConstructor("typeCodeMessageProperties"),
+	typeCodeApplicationProperties: notImplementedConstructor("typeCodeApplicationProperties"),
+	typeCodeApplicationData:       notImplementedConstructor("typeCodeApplicationData"),
+	typeCodeAMQPSequence:          notImplementedConstructor("typeCodeAMQPSequence"),
+	typeCodeAMQPValue:             notImplementedConstructor("typeCodeAMQPValue"),
+	typeCodeFooter:                notImplementedConstructor("typeCodeFooter"),
+	typeCodeSASLMechanism:         notImplementedConstructor("typeCodeSASLMechanism"),
+	typeCodeSASLInit:              notImplementedConstructor("typeCodeSASLInit"),
+	typeCodeSASLChallenge:         notImplementedConstructor("typeCodeSASLChallenge"),
+	typeCodeSASLResponse:          notImplementedConstructor("typeCodeSASLResponse"),
+	typeCodeSASLOutcome:           notImplementedConstructor("typeCodeSASLOutcome"),
+}
+
+type notImplemented string
+
+func (ni notImplemented) unmarshal(r reader) error {
+	return errorNew("readComposite unmarshal not implemented for " + string(ni))
+}
+
+func notImplementedConstructor(s string) func() interface{} {
+	return func() interface{} { return notImplemented(s) }
 }
 
 func readTimestamp(r reader) (time.Time, error) {

encode.go

@@ -298,7 +298,7 @@ func writeSymbolArray(wr writer, symbols []symbol) error {
 	defer bufPool.Put(buf)
 
 	for _, symbol := range symbols {
-		err := writeSymbol(buf, symbol, ofType)
+		err := writeSymbolType(buf, symbol, ofType)
 		if err != nil {
 			return err
 		}
@@ -313,7 +313,16 @@ func writeSymbolArray(wr writer, symbols []symbol) error {
 	return err
 }
 
-func writeSymbol(wr writer, sym symbol, typ amqpType) error {
+func writeSymbol(wr writer, sym symbol) error {
+	ofType := typeCodeSym8
+	if len(sym) > math.MaxUint8 {
+		ofType = typeCodeSym32
+	}
+
+	return writeSymbolType(wr, sym, ofType)
+}
+
+func writeSymbolType(wr writer, sym symbol, typ amqpType) error {
 	if !utf8.ValidString(string(sym)) {
 		return errorNew("not a valid UTF-8 string")
 	}

marshal_test.go

@@ -2,6 +2,7 @@ package amqp
 
 import (
 	"bytes"
+	"encoding/binary"
 	"fmt"
 	"io/ioutil"
 	"math"
@@ -328,6 +329,10 @@ func TestMarshalUnmarshal(t *testing.T) {
 		uint16(math.MaxUint16),
 		uint32(math.MaxUint32),
 		uint64(math.MaxUint64),
+		describedType{
+			descriptor: binary.BigEndian.Uint64([]byte{0x00, 0x00, 0x46, 0x8C, 0x00, 0x00, 0x00, 0x04}),
+			value:      "amqp.annotation.x-opt-offset > '312'",
+		},
 	}
 
 	for _, typ := range types {
@@ -352,7 +357,7 @@ func TestMarshalUnmarshal(t *testing.T) {
 			newTyp := reflect.New(reflect.TypeOf(typ))
 			_, err = unmarshal(&buf, newTyp.Interface())
 			if err != nil {
-				t.Error(fmt.Sprintf("%v", err))
+				t.Error(fmt.Sprintf("%+v", err))
 				return
 			}
 

types.go

@@ -106,7 +106,6 @@ const (
 	typeCodeSASLResponse  amqpType = 0x43
 	typeCodeSASLOutcome   amqpType = 0x44
 
-	// Lifetime Policies
 	typeCodeDeleteOnClose             amqpType = 0x2b
 	typeCodeDeleteOnNoLinks           amqpType = 0x2c
 	typeCodeDeleteOnNoMessages        amqpType = 0x2d
@@ -761,6 +760,24 @@ func (s *source) unmarshal(r reader) error {
 	}...)
 }
 
+func (s source) String() string {
+	return fmt.Sprintf("source{Address: %s, Durable: %d, ExpiryPolicy: %s, Timeout: %d, "+
+		"Dynamic: %t, DynamicNodeProperties: %v, DistributionMode: %s, Filter: %v, DefaultOutcome: %v"+
+		"Outcomes: %v, Capabilities: %v}",
+		s.Address,
+		s.Durable,
+		s.ExpiryPolicy,
+		s.Timeout,
+		s.Dynamic,
+		s.DynamicNodeProperties,
+		s.DistributionMode,
+		s.Filter,
+		s.DefaultOutcome,
+		s.Outcomes,
+		s.Capabilities,
+	)
+}
+
 /*
 <type name="target" class="composite" source="list" provides="target">
     <descriptor name="amqp:target:list" code="0x00000000:0x00000029"/>
@@ -882,6 +899,19 @@ func (t *target) unmarshal(r reader) error {
 	}...)
 }
 
+func (t target) String() string {
+	return fmt.Sprintf("source{Address: %s, Durable: %d, ExpiryPolicy: %s, Timeout: %d, "+
+		"Dynamic: %t, DynamicNodeProperties: %v, Capabilities: %v}",
+		t.Address,
+		t.Durable,
+		t.ExpiryPolicy,
+		t.Timeout,
+		t.Dynamic,
+		t.DynamicNodeProperties,
+		t.Capabilities,
+	)
+}
+
 /*
 <type name="flow" class="composite" source="list" provides="frame">
     <descriptor name="amqp:flow:list" code="0x00000000:0x00000013"/>
@@ -2263,12 +2293,16 @@ func (s symbol) marshal(wr writer) error {
 
 	var err error
 	switch {
-	// List8
+	// Sym8
 	case l < 256:
 		_, err = wr.Write(append([]byte{byte(typeCodeSym8), byte(l)}, []byte(s)...))
 
-	// List32
+	// Sym32
 	case l < math.MaxUint32:
+		err = wr.WriteByte(uint8(typeCodeSym32))
+		if err != nil {
+			return err
+		}
 		err = binary.Write(wr, binary.BigEndian, uint32(l))
 		if err != nil {
 			return err
@@ -2545,3 +2579,40 @@ func (m *ReceiverSettleMode) unmarshal(r reader) error {
 	_, err := unmarshal(r, (*uint8)(m))
 	return err
 }
+
+type describedType struct {
+	descriptor interface{}
+	value      interface{}
+}
+
+func (t describedType) marshal(wr writer) error {
+	err := wr.WriteByte(0x0) // descriptor constructor
+	if err != nil {
+		return err
+	}
+	err = marshal(wr, t.descriptor)
+	if err != nil {
+		return err
+	}
+	return marshal(wr, t.value)
+}
+
+func (t *describedType) unmarshal(r reader) error {
+	b, err := r.ReadByte()
+	if b != 0x0 {
+		return errorErrorf("invalid described type header %0x", b)
+	}
+	_, err = unmarshal(r, &t.descriptor)
+	if err != nil {
+		return err
+	}
+	_, err = unmarshal(r, &t.value)
+	return err
+}
+
+func (t describedType) String() string {
+	return fmt.Sprintf("describedType{descriptor: %v, value: %v}",
+		t.descriptor,
+		t.value,
+	)
+}