mirror of
https://github.com/superseriousbusiness/gotosocial.git
synced 2024-12-05 10:02:47 +00:00
120 lines
2.7 KiB
Go
120 lines
2.7 KiB
Go
|
// Copyright 2023 The Go Authors. All rights reserved.
|
||
|
// Use of this source code is governed by a BSD-style
|
||
|
// license that can be found in the LICENSE file.
|
||
|
|
||
|
package http2
|
||
|
|
||
|
import (
|
||
|
"fmt"
|
||
|
"math"
|
||
|
)
|
||
|
|
||
|
type roundRobinWriteScheduler struct {
|
||
|
// control contains control frames (SETTINGS, PING, etc.).
|
||
|
control writeQueue
|
||
|
|
||
|
// streams maps stream ID to a queue.
|
||
|
streams map[uint32]*writeQueue
|
||
|
|
||
|
// stream queues are stored in a circular linked list.
|
||
|
// head is the next stream to write, or nil if there are no streams open.
|
||
|
head *writeQueue
|
||
|
|
||
|
// pool of empty queues for reuse.
|
||
|
queuePool writeQueuePool
|
||
|
}
|
||
|
|
||
|
// newRoundRobinWriteScheduler constructs a new write scheduler.
|
||
|
// The round robin scheduler priorizes control frames
|
||
|
// like SETTINGS and PING over DATA frames.
|
||
|
// When there are no control frames to send, it performs a round-robin
|
||
|
// selection from the ready streams.
|
||
|
func newRoundRobinWriteScheduler() WriteScheduler {
|
||
|
ws := &roundRobinWriteScheduler{
|
||
|
streams: make(map[uint32]*writeQueue),
|
||
|
}
|
||
|
return ws
|
||
|
}
|
||
|
|
||
|
func (ws *roundRobinWriteScheduler) OpenStream(streamID uint32, options OpenStreamOptions) {
|
||
|
if ws.streams[streamID] != nil {
|
||
|
panic(fmt.Errorf("stream %d already opened", streamID))
|
||
|
}
|
||
|
q := ws.queuePool.get()
|
||
|
ws.streams[streamID] = q
|
||
|
if ws.head == nil {
|
||
|
ws.head = q
|
||
|
q.next = q
|
||
|
q.prev = q
|
||
|
} else {
|
||
|
// Queues are stored in a ring.
|
||
|
// Insert the new stream before ws.head, putting it at the end of the list.
|
||
|
q.prev = ws.head.prev
|
||
|
q.next = ws.head
|
||
|
q.prev.next = q
|
||
|
q.next.prev = q
|
||
|
}
|
||
|
}
|
||
|
|
||
|
func (ws *roundRobinWriteScheduler) CloseStream(streamID uint32) {
|
||
|
q := ws.streams[streamID]
|
||
|
if q == nil {
|
||
|
return
|
||
|
}
|
||
|
if q.next == q {
|
||
|
// This was the only open stream.
|
||
|
ws.head = nil
|
||
|
} else {
|
||
|
q.prev.next = q.next
|
||
|
q.next.prev = q.prev
|
||
|
if ws.head == q {
|
||
|
ws.head = q.next
|
||
|
}
|
||
|
}
|
||
|
delete(ws.streams, streamID)
|
||
|
ws.queuePool.put(q)
|
||
|
}
|
||
|
|
||
|
func (ws *roundRobinWriteScheduler) AdjustStream(streamID uint32, priority PriorityParam) {}
|
||
|
|
||
|
func (ws *roundRobinWriteScheduler) Push(wr FrameWriteRequest) {
|
||
|
if wr.isControl() {
|
||
|
ws.control.push(wr)
|
||
|
return
|
||
|
}
|
||
|
q := ws.streams[wr.StreamID()]
|
||
|
if q == nil {
|
||
|
// This is a closed stream.
|
||
|
// wr should not be a HEADERS or DATA frame.
|
||
|
// We push the request onto the control queue.
|
||
|
if wr.DataSize() > 0 {
|
||
|
panic("add DATA on non-open stream")
|
||
|
}
|
||
|
ws.control.push(wr)
|
||
|
return
|
||
|
}
|
||
|
q.push(wr)
|
||
|
}
|
||
|
|
||
|
func (ws *roundRobinWriteScheduler) Pop() (FrameWriteRequest, bool) {
|
||
|
// Control and RST_STREAM frames first.
|
||
|
if !ws.control.empty() {
|
||
|
return ws.control.shift(), true
|
||
|
}
|
||
|
if ws.head == nil {
|
||
|
return FrameWriteRequest{}, false
|
||
|
}
|
||
|
q := ws.head
|
||
|
for {
|
||
|
if wr, ok := q.consume(math.MaxInt32); ok {
|
||
|
ws.head = q.next
|
||
|
return wr, true
|
||
|
}
|
||
|
q = q.next
|
||
|
if q == ws.head {
|
||
|
break
|
||
|
}
|
||
|
}
|
||
|
return FrameWriteRequest{}, false
|
||
|
}
|