implement a map for incoming streams

streams_map_incoming_generic.go

@@ -0,0 +1,99 @@
+package quic
+
+import (
+	"fmt"
+	"sync"
+
+	"github.com/lucas-clemente/quic-go/internal/protocol"
+)
+
+//go:generate genny -in $GOFILE -out streams_map_incoming_bidi.go gen "item=streamI Item=BidiStream"
+//go:generate genny -in $GOFILE -out streams_map_incoming_uni.go gen "item=receiveStreamI Item=UniStream"
+type incomingItemsMap struct {
+	mutex sync.RWMutex
+	cond  sync.Cond
+
+	streams map[protocol.StreamID]item
+
+	nextStream    protocol.StreamID
+	highestStream protocol.StreamID
+	newStream     func(protocol.StreamID) item
+
+	closeErr error
+}
+
+func newIncomingItemsMap(nextStream protocol.StreamID, newStream func(protocol.StreamID) item) *incomingItemsMap {
+	m := &incomingItemsMap{
+		streams:    make(map[protocol.StreamID]item),
+		nextStream: nextStream,
+		newStream:  newStream,
+	}
+	m.cond.L = &m.mutex
+	return m
+}
+
+func (m *incomingItemsMap) AcceptStream() (item, error) {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+
+	var str item
+	for {
+		var ok bool
+		if m.closeErr != nil {
+			return nil, m.closeErr
+		}
+		str, ok = m.streams[m.nextStream]
+		if ok {
+			break
+		}
+		m.cond.Wait()
+	}
+	m.nextStream += 4
+	return str, nil
+}
+
+func (m *incomingItemsMap) GetOrOpenStream(id protocol.StreamID) (item, error) {
+	// if the id is smaller than the highest we accepted
+	// * this stream exists in the map, and we can return it, or
+	// * this stream was already closed, then we can return the nil
+	if id <= m.highestStream {
+		m.mutex.RLock()
+		s := m.streams[id]
+		m.mutex.RUnlock()
+		return s, nil
+	}
+
+	m.mutex.Lock()
+	var start protocol.StreamID
+	if m.highestStream == 0 {
+		start = m.nextStream
+	} else {
+		start = m.highestStream + 4
+	}
+	for newID := start; newID <= id; newID += 4 {
+		m.streams[newID] = m.newStream(newID)
+		m.cond.Signal()
+	}
+	m.highestStream = id
+	s := m.streams[id]
+	m.mutex.Unlock()
+	return s, nil
+}
+
+func (m *incomingItemsMap) DeleteStream(id protocol.StreamID) error {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+
+	if _, ok := m.streams[id]; !ok {
+		return fmt.Errorf("Tried to delete unknown stream %d", id)
+	}
+	delete(m.streams, id)
+	return nil
+}
+
+func (m *incomingItemsMap) CloseWithError(err error) {
+	m.mutex.Lock()
+	m.closeErr = err
+	m.mutex.Unlock()
+	m.cond.Broadcast()
+}