Add API for listener removal, report listener id under /listeners and mount header

README.md

@@ -11,14 +11,15 @@ Radio streamer ([kawa](https://github.com/Luminarys/kawa) drop-in compatible).
 * Implements ICY metadata (artist, title, url).
 * Uses sample/timed packet buffers, instead of kawa byte buffers, which caused wild differences between endpoints. Mounts usually align within 0.2s of each other, depending on client.
   * Use `queue.buffer_size` to specify number of seconds to buffer (by default 0, automatic per client).
-* Implements `queue.nr` and `/random` (to be deprecated/changed)
+* Implements `queue.nr` and `/random` (to be deprecated/changed).
 * Supports max queue length via `queue.length` config.
 * Supports extra encoder bitrate control settings (CBR, VBR, auto, etc.)
 * Can set custom sample rate / channel count / bitdepth / compression level per stream mount.
 * Can read and apply ReplayGain tags, or normalize audio loudness.
 * Can have audio sources over HTTP(s) URLs on `path` property, and supports seeking.
 * [Precise metadata and timing information packet stream](PACKET_STREAM.md), trigger via `x-audio-packet-stream: 1` HTTP header.
-* Workaround to allow FLAC streaming under Safari
+* Workaround to allow FLAC streaming under Safari.
+* API additions to allow working with direct queue items or listeners.
 
 ## Dependencies
 ### Go >= 1.18
@@ -96,6 +97,57 @@ Same as kawa's, but `queue_id` is added to response directly.
 }
 ```
 
+### `NEW` DELETE /listeners/<listener_id>
+Drops the listener connection with `listener_id` specified as a parameter.
+
+#### Response
+```json
+{
+    "success": true,
+    "reason": null
+}
+```
+
+### `CHANGED` GET /listeners
+Same as kawa's, but `identifier` is added to each listener entry.
+
+The listener `identifier` is generated based on user connection address, port, user-agent and mount.
+
+Additionally, a `x-listener-identifier` header is exposed to mount response.
+
+#### Response
+```json
+[
+  {
+    "identifier": "641df131cb52f8f6381d9946cccb822e",
+    "mount": "stream.flac",
+    "path": "/stream.flac",
+    "headers": [
+      {
+        "name": "User-Agent",
+        "value": "libmpv"
+      },
+      {
+        "name": "Accept",
+        "value": "*/*"
+      },
+      {
+        "name": "Range",
+        "value": "bytes=0-"
+      },
+      {
+        "name": "Connection",
+        "value": "close"
+      },
+      {
+        "name": "Icy-Metadata",
+        "value": "1"
+      }
+    ]
+  }
+]
+```
+
 ## Mount API
 ### `NEW` GET /mounts
 A simple listing of the working mounts + settings are made available.

api.go

@@ -5,7 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"git.gammaspectra.live/S.O.N.G/Kirika/audio/queue"
-	"io/ioutil"
+	"io"
 	"log"
 	"net/http"
 	"strconv"
@@ -83,7 +83,7 @@ func (a *API) getRandomTrack() *QueueTrackEntry {
 	}
 
 	defer response.Body.Close()
-	body, err := ioutil.ReadAll(response.Body)
+	body, err := io.ReadAll(response.Body)
 	if err != nil {
 		return nil
 	}
@@ -151,8 +151,8 @@ func (a *API) handleQueue() {
 func (a *API) listen() {
 
 	type resultResponse struct {
-		Success bool  `json:"success"`
+		Success bool    `json:"success"`
-		Reason  error `json:"reason"`
+		Reason  *string `json:"reason"`
 	}
 
 	type queueResultResponse struct {
@@ -174,8 +174,26 @@ func (a *API) listen() {
 				if len(pathSegments) > 1 {
 					switch pathSegments[1] {
 					case "listeners":
-						jsonData, _ := json.Marshal(a.queue.GetListeners())
+						if len(pathSegments) > 2 {
-						writer.Write(jsonData)
+							if request.Method != "DELETE" {
+								return
+							}
+
+							result := resultResponse{
+								Success: a.queue.RemoveListener(pathSegments[2]),
+							}
+							if !result.Success {
+								resultErr := fmt.Sprintf("listener %s not found", pathSegments[2])
+								result.Reason = &resultErr
+							}
+							jsonData, _ := json.Marshal(result)
+							writer.Write(jsonData)
+
+							return
+						} else {
+							jsonData, _ := json.Marshal(a.queue.GetListeners())
+							writer.Write(jsonData)
+						}
 
 						return
 					case "np":
@@ -214,12 +232,14 @@ func (a *API) listen() {
 							case "head":
 								if request.Method == "POST" {
 									result := queueResultResponse{}
-									if body, err := ioutil.ReadAll(request.Body); err == nil {
+									if body, err := io.ReadAll(request.Body); err == nil {
 										if e := a.getQueueEntryFromBody(body); e != nil {
 											if err = a.queue.AddTrack(e, false); err == nil {
 												result.Success = true
 												result.QueueId = e.QueueIdentifier
 											} else {
+												resultErr := err.Error()
+												result.Reason = &resultErr
 												log.Printf("track addition error: \"%s\"", err)
 											}
 										}
@@ -244,12 +264,14 @@ func (a *API) listen() {
 							case "tail":
 								if request.Method == "POST" {
 									result := queueResultResponse{}
-									if body, err := ioutil.ReadAll(request.Body); err == nil {
+									if body, err := io.ReadAll(request.Body); err == nil {
 										if e := a.getQueueEntryFromBody(body); e != nil {
 											if err = a.queue.AddTrack(e, true); err == nil {
 												result.Success = true
 												result.QueueId = e.QueueIdentifier
 											} else {
+												resultErr := err.Error()
+												result.Reason = &resultErr
 												log.Printf("track addition error: \"%s\"", err)
 											}
 										}

mount.go

@@ -237,9 +237,34 @@ func (m *StreamMount) AddListener(listener *StreamListener) {
 	m.listeners = append(m.listeners, listener)
 }
 
+func (m *StreamMount) RemoveListener(identifier string, direct ...bool) bool {
+	if (len(direct) > 0 && direct[0]) || func() bool {
+		m.listenersLock.RLock()
+		defer m.listenersLock.RUnlock()
+		for _, l := range m.listeners {
+			if l.Information.Identifier == identifier {
+				return true
+			}
+		}
+		return false
+	}() {
+		m.listenersLock.Lock()
+		defer m.listenersLock.Unlock()
+		for i := range m.listeners {
+			l := m.listeners[i]
+			if l.Information.Identifier == identifier {
+				m.listeners = append(m.listeners[:i], m.listeners[i+1:]...)
+				l.Close()
+				return true
+			}
+		}
+	}
+	return false
+}
+
 func (m *StreamMount) GetListeners() (entries []*ListenerInformation) {
-	m.listenersLock.Lock()
+	m.listenersLock.RLock()
-	defer m.listenersLock.Unlock()
+	defer m.listenersLock.RUnlock()
 	for _, l := range m.listeners {
 		entries = append(entries, &l.Information)
 	}
@@ -248,39 +273,28 @@ func (m *StreamMount) GetListeners() (entries []*ListenerInformation) {
 }
 
 func (m *StreamMount) handlePacket(packet packetizer.Packet) {
-	var toRemove []int
+	var toRemove []string
 
 	//TODO: do this via goroutine messaging?
 	func() {
 		m.listenersLock.RLock()
 		defer m.listenersLock.RUnlock()
 		var err error
-		for i, l := range m.listeners {
+		for _, l := range m.listeners {
 			if l.Start != nil {
 				l.Start(m.keepBuffer)
 				l.Start = nil
 			}
 			if err = l.Write(packet); err != nil {
 				log.Printf("failed to write data to %s client: %s\n", l.Information.Identifier, err)
-				toRemove = append(toRemove, i)
+				toRemove = append(toRemove, l.Information.Identifier)
 			}
 		}
 
 	}()
 
-	if len(toRemove) > 0 {
+	for _, id := range toRemove {
-		func() {
+		m.RemoveListener(id, true)
-			m.listenersLock.Lock()
-			defer m.listenersLock.Unlock()
-			//TODO: remove more than one per iteration
-			for _, i := range toRemove {
-				l := m.listeners[i]
-				m.listeners = append(m.listeners[:i], m.listeners[i+1:]...)
-				l.Close()
-				break
-			}
-			toRemove = toRemove[:0]
-		}()
 	}
 
 	sampleLimit := packet.GetEndSampleNumber() - int64(maxBufferSize*m.SampleRate)
@@ -306,6 +320,7 @@ func (m *StreamMount) handlePacket(packet packetizer.Packet) {
 func (m *StreamMount) Process(group *sync.WaitGroup) {
 	defer group.Done()
 	defer func() {
+		//Teardown all listeners
 		m.listenersLock.Lock()
 		for _, l := range m.listeners {
 			l.Close()

queue.go

@@ -402,6 +402,17 @@ func (q *Queue) Remove(identifier queue.QueueIdentifier) bool {
 	return false
 }
 
+func (q *Queue) RemoveListener(identifier string) bool {
+	q.mutex.RLock()
+	defer q.mutex.RUnlock()
+	for _, mount := range q.mounts {
+		if mount.RemoveListener(identifier) {
+			return true
+		}
+	}
+	return false
+}
+
 func (q *Queue) GetListeners() (listeners []*ListenerInformation) {
 	q.mutex.RLock()
 	defer q.mutex.RUnlock()
@@ -595,7 +606,7 @@ func (q *Queue) HandleRadioRequest(writer http.ResponseWriter, request *http.Req
 			writeChannel := make(chan []byte, byteSliceChannelBuffer)
 
 			requestDone := struct {
-				Done  atomic.Bool
+				Done  uint32
 				Lock  sync.Mutex
 				Error error
 			}{}
@@ -609,7 +620,7 @@ func (q *Queue) HandleRadioRequest(writer http.ResponseWriter, request *http.Req
 				writer.Header().Set("Content-Type", "application/x-audio-packet-stream")
 
 				packetWriteCallback = func(packet packetizer.Packet) error {
-					if requestDone.Done.Load() {
+					if atomic.LoadUint32(&requestDone.Done) == 1 {
 						return requestDone.Error
 					}
 					if metadataPacket, ok := packet.(*QueueMetadataPacket); ok {
@@ -621,7 +632,7 @@ func (q *Queue) HandleRadioRequest(writer http.ResponseWriter, request *http.Req
 							requestDone.Lock.Lock()
 							defer requestDone.Lock.Unlock()
 							requestDone.Error = errors.New("client ran out of buffer")
-							requestDone.Done.Store(true)
+							atomic.StoreUint32(&requestDone.Done, 1)
 							return requestDone.Error
 						}
 
@@ -638,7 +649,7 @@ func (q *Queue) HandleRadioRequest(writer http.ResponseWriter, request *http.Req
 								requestDone.Lock.Lock()
 								defer requestDone.Lock.Unlock()
 								requestDone.Error = errors.New("client ran out of buffer")
-								requestDone.Done.Store(true)
+								atomic.StoreUint32(&requestDone.Done, 1)
 								return requestDone.Error
 							}
 
@@ -657,7 +668,7 @@ func (q *Queue) HandleRadioRequest(writer http.ResponseWriter, request *http.Req
 						requestDone.Lock.Lock()
 						defer requestDone.Lock.Unlock()
 						requestDone.Error = errors.New("client ran out of buffer")
-						requestDone.Done.Store(true)
+						atomic.StoreUint32(&requestDone.Done, 1)
 						return requestDone.Error
 					}
 
@@ -738,7 +749,7 @@ func (q *Queue) HandleRadioRequest(writer http.ResponseWriter, request *http.Req
 				var streamStartOffset int64 = -1
 
 				packetWriteCallback = func(packet packetizer.Packet) error {
-					if requestDone.Done.Load() {
+					if atomic.LoadUint32(&requestDone.Done) == 1 {
 						return requestDone.Error
 					}
 					if metadataPacket, ok := packet.(*QueueMetadataPacket); ok {
@@ -788,7 +799,7 @@ func (q *Queue) HandleRadioRequest(writer http.ResponseWriter, request *http.Req
 						requestDone.Lock.Lock()
 						defer requestDone.Lock.Unlock()
 						requestDone.Error = errors.New("client ran out of buffer")
-						requestDone.Done.Store(true)
+						atomic.StoreUint32(&requestDone.Done, 1)
 						return requestDone.Error
 					}
 					writeChannel <- data
@@ -797,7 +808,7 @@ func (q *Queue) HandleRadioRequest(writer http.ResponseWriter, request *http.Req
 			} else {
 				var streamStartOffset int64 = -1
 				packetWriteCallback = func(packet packetizer.Packet) error {
-					if requestDone.Done.Load() {
+					if atomic.LoadUint32(&requestDone.Done) == 1 {
 						return requestDone.Error
 					}
 					if _, ok := packet.(*QueueMetadataPacket); ok {
@@ -808,7 +819,7 @@ func (q *Queue) HandleRadioRequest(writer http.ResponseWriter, request *http.Req
 						requestDone.Lock.Lock()
 						defer requestDone.Lock.Unlock()
 						requestDone.Error = errors.New("client ran out of buffer")
-						requestDone.Done.Store(true)
+						atomic.StoreUint32(&requestDone.Done, 1)
 						return requestDone.Error
 					}
 
@@ -844,7 +855,7 @@ func (q *Queue) HandleRadioRequest(writer http.ResponseWriter, request *http.Req
 						requestDone.Lock.Lock()
 						defer requestDone.Lock.Unlock()
 						requestDone.Error = errors.New("client ran out of buffer")
-						requestDone.Done.Store(true)
+						atomic.StoreUint32(&requestDone.Done, 1)
 						return
 					}
 					//try flush
@@ -905,6 +916,9 @@ func (q *Queue) HandleRadioRequest(writer http.ResponseWriter, request *http.Req
 
 			hashSum := sha256.Sum256([]byte(fmt.Sprintf("%s-%s-%s-%s", request.RequestURI, request.RemoteAddr, request.Proto, request.Header.Get("user-agent"))))
 			listenerIdentifier := hex.EncodeToString(hashSum[16:])
+
+			writer.Header().Set("x-listener-identifier", listenerIdentifier)
+
 			mount.AddListener(&StreamListener{
 				Information: ListenerInformation{
 					Identifier: listenerIdentifier,