move bitmap to internal package (#65)

conn.go

@@ -12,6 +12,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/Azure/go-amqp/internal/bitmap"
 	"github.com/Azure/go-amqp/internal/buffer"
 	"github.com/Azure/go-amqp/internal/encoding"
 	"github.com/Azure/go-amqp/internal/frames"
@@ -333,10 +334,10 @@ func (c *conn) getErr() error {
 func (c *conn) mux() {
 	var (
 		// allocated channels
-		channels = &bitmap{max: uint32(c.channelMax)}
+		channels = bitmap.New(uint32(c.channelMax))
 
 		// create the next session to allocate
-		nextChannel, _ = channels.next()
+		nextChannel, _ = channels.Next()
 		nextSession    = newSessionResp{session: newSession(c, uint16(nextChannel))}
 
 		// map channels to sessions
@@ -421,7 +422,7 @@ func (c *conn) mux() {
 			sessionsByChannel[ch] = nextSession.session
 
 			// get next available channel
-			next, ok := channels.next()
+			next, ok := channels.Next()
 			if !ok {
 				nextSession = newSessionResp{err: fmt.Errorf("reached connection channel max (%d)", c.channelMax)}
 				continue
@@ -434,7 +435,7 @@ func (c *conn) mux() {
 		case s := <-c.delSession:
 			delete(sessionsByChannel, s.channel)
 			delete(sessionsByRemoteChannel, s.remoteChannel)
-			channels.remove(uint32(s.channel))
+			channels.Remove(uint32(s.channel))
 
 		// connection is complete
 		case <-c.closeMux:

internal/bitmap/bitmap.go

@@ -1,21 +1,25 @@
-package amqp
+package bitmap
 
 import (
 	"math/bits"
 )
 
 // bitmap is a lazily initialized bitmap
-type bitmap struct {
+type Bitmap struct {
 	max  uint32
 	bits []uint64
 }
 
+func New(max uint32) *Bitmap {
+	return &Bitmap{max: max}
+}
+
 // add sets n in the bitmap.
 //
 // bits will be expanded as needed.
 //
 // If n is greater than max, the call has no effect.
-func (b *bitmap) add(n uint32) {
+func (b *Bitmap) Add(n uint32) {
 	if n > b.max {
 		return
 	}
@@ -35,7 +39,7 @@ func (b *bitmap) add(n uint32) {
 // remove clears n from the bitmap.
 //
 // If n is not set or greater than max the call has not effect.
-func (b *bitmap) remove(n uint32) {
+func (b *Bitmap) Remove(n uint32) {
 	var (
 		idx    = n / 64
 		offset = n % 64
@@ -54,7 +58,7 @@ func (b *bitmap) remove(n uint32) {
 //
 // If there are no unset bits below max, the second return
 // value will be false.
-func (b *bitmap) next() (uint32, bool) {
+func (b *Bitmap) Next() (uint32, bool) {
 	// find the first unset bit
 	for i, v := range b.bits {
 		// skip if all bits are set

internal/bitmap/bitmap_test.go

@@ -1,4 +1,4 @@
-package amqp
+package bitmap
 
 import (
 	"math"
@@ -118,24 +118,24 @@ func TestBitmap(t *testing.T) {
 
 	for i, tt := range tests {
 		t.Run(strconv.Itoa(i), func(t *testing.T) {
-			bm := &bitmap{max: tt.max}
+			bm := New(tt.max)
 
 			for _, op := range tt.ops {
 				switch op := op.(type) {
 				case add:
-					bm.add(uint32(op))
+					bm.Add(uint32(op))
 				case rem:
-					bm.remove(uint32(op))
+					bm.Remove(uint32(op))
 				case next:
 					for i := int64(0); i < int64(op); i++ {
-						bm.next()
+						bm.Next()
 					}
 				default:
 					panic("unhandled op " + reflect.TypeOf(op).String())
 				}
 			}
 
-			next, ok := bm.next()
+			next, ok := bm.Next()
 			if ok == tt.nextFail {
 				t.Errorf("next() failed with %d", next)
 			}
@@ -154,10 +154,10 @@ func TestBitmap(t *testing.T) {
 
 func TestBitmap_Sequence(t *testing.T) {
 	const max = 1024
-	bm := &bitmap{max: max}
+	bm := New(max)
 
 	for i := uint32(0); i <= max; i++ {
-		next, ok := bm.next()
+		next, ok := bm.Next()
 		if !ok {
 			t.Errorf("next() failed with %d", next)
 		}
@@ -173,7 +173,7 @@ func TestBitmap_Sequence(t *testing.T) {
 	}
 }
 
-func countBitmap(bm *bitmap) uint32 {
+func countBitmap(bm *Bitmap) uint32 {
 	var count uint32
 	for _, v := range bm.bits {
 		count += uint32(bits.OnesCount64(v))

session.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"sync"
 
+	"github.com/Azure/go-amqp/internal/bitmap"
 	"github.com/Azure/go-amqp/internal/encoding"
 	"github.com/Azure/go-amqp/internal/frames"
 )
@@ -139,9 +140,9 @@ func (s *Session) mux(remoteBegin *frames.PerformBegin) {
 	}()
 
 	var (
-		links      = make(map[uint32]*link)    // mapping of remote handles to links
-		linksByKey = make(map[linkKey]*link)   // mapping of name+role link
-		handles    = &bitmap{max: s.handleMax} // allocated handles
+		links      = make(map[uint32]*link)  // mapping of remote handles to links
+		linksByKey = make(map[linkKey]*link) // mapping of name+role link
+		handles    = bitmap.New(s.handleMax) // allocated handles
 
 		handlesByDeliveryID       = make(map[uint32]uint32) // mapping of deliveryIDs to handles
 		deliveryIDByHandle        = make(map[uint32]uint32) // mapping of handles to latest deliveryID
@@ -201,7 +202,7 @@ func (s *Session) mux(remoteBegin *frames.PerformBegin) {
 				continue
 			}
 
-			next, ok := handles.next()
+			next, ok := handles.Next()
 			if !ok {
 				l.err = fmt.Errorf("reached session handle max (%d)", s.handleMax)
 				l.rx <- nil
@@ -217,7 +218,7 @@ func (s *Session) mux(remoteBegin *frames.PerformBegin) {
 			delete(links, l.remoteHandle)
 			delete(deliveryIDByHandle, l.handle)
 			delete(linksByKey, l.key)
-			handles.remove(l.handle)
+			handles.Remove(l.handle)
 			close(l.rx) // close channel to indicate deallocation
 
 		// incoming frame for link