mox/vendor/golang.org/x/net/http2/writesched_random.go
s0ph0s 3c77e076e2
Add support for negotiating IMAP and SMTP on the HTTPS port 443 using TLS ALPN "imap" and "smtp"
Intended for future use with chatmail servers. Standard email ports may be
blocked on some networks, while the HTTPS port may be accessible.

This is a squashed commit of PR #255 by s0ph0s-dog.
2025-01-23 11:16:20 +01:00

78 lines
2.0 KiB
Go

// Copyright 2014 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 "math"
// NewRandomWriteScheduler constructs a WriteScheduler that ignores HTTP/2
// priorities. Control frames like SETTINGS and PING are written before DATA
// frames, but if no control frames are queued and multiple streams have queued
// HEADERS or DATA frames, Pop selects a ready stream arbitrarily.
func NewRandomWriteScheduler() WriteScheduler {
return &randomWriteScheduler{sq: make(map[uint32]*writeQueue)}
}
type randomWriteScheduler struct {
// zero are frames not associated with a specific stream.
zero writeQueue
// sq contains the stream-specific queues, keyed by stream ID.
// When a stream is idle, closed, or emptied, it's deleted
// from the map.
sq map[uint32]*writeQueue
// pool of empty queues for reuse.
queuePool writeQueuePool
}
func (ws *randomWriteScheduler) OpenStream(streamID uint32, options OpenStreamOptions) {
// no-op: idle streams are not tracked
}
func (ws *randomWriteScheduler) CloseStream(streamID uint32) {
q, ok := ws.sq[streamID]
if !ok {
return
}
delete(ws.sq, streamID)
ws.queuePool.put(q)
}
func (ws *randomWriteScheduler) AdjustStream(streamID uint32, priority PriorityParam) {
// no-op: priorities are ignored
}
func (ws *randomWriteScheduler) Push(wr FrameWriteRequest) {
if wr.isControl() {
ws.zero.push(wr)
return
}
id := wr.StreamID()
q, ok := ws.sq[id]
if !ok {
q = ws.queuePool.get()
ws.sq[id] = q
}
q.push(wr)
}
func (ws *randomWriteScheduler) Pop() (FrameWriteRequest, bool) {
// Control and RST_STREAM frames first.
if !ws.zero.empty() {
return ws.zero.shift(), true
}
// Iterate over all non-idle streams until finding one that can be consumed.
for streamID, q := range ws.sq {
if wr, ok := q.consume(math.MaxInt32); ok {
if q.empty() {
delete(ws.sq, streamID)
ws.queuePool.put(q)
}
return wr, true
}
}
return FrameWriteRequest{}, false
}