78 lines
2.0 KiB
Go
78 lines
2.0 KiB
Go
// Copyright 2014 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package http2
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import "math"
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// NewRandomWriteScheduler constructs a WriteScheduler that ignores HTTP/2
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// priorities. Control frames like SETTINGS and PING are written before DATA
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// frames, but if no control frames are queued and multiple streams have queued
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// HEADERS or DATA frames, Pop selects a ready stream arbitrarily.
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func NewRandomWriteScheduler() WriteScheduler {
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return &randomWriteScheduler{sq: make(map[uint32]*writeQueue)}
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}
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type randomWriteScheduler struct {
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// zero are frames not associated with a specific stream.
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zero writeQueue
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// sq contains the stream-specific queues, keyed by stream ID.
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// When a stream is idle, closed, or emptied, it's deleted
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// from the map.
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sq map[uint32]*writeQueue
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// pool of empty queues for reuse.
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queuePool writeQueuePool
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}
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func (ws *randomWriteScheduler) OpenStream(streamID uint32, options OpenStreamOptions) {
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// no-op: idle streams are not tracked
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}
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func (ws *randomWriteScheduler) CloseStream(streamID uint32) {
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q, ok := ws.sq[streamID]
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if !ok {
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return
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}
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delete(ws.sq, streamID)
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ws.queuePool.put(q)
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}
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func (ws *randomWriteScheduler) AdjustStream(streamID uint32, priority PriorityParam) {
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// no-op: priorities are ignored
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}
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func (ws *randomWriteScheduler) Push(wr FrameWriteRequest) {
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id := wr.StreamID()
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if id == 0 {
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ws.zero.push(wr)
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return
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}
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q, ok := ws.sq[id]
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if !ok {
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q = ws.queuePool.get()
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ws.sq[id] = q
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}
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q.push(wr)
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}
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func (ws *randomWriteScheduler) Pop() (FrameWriteRequest, bool) {
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// Control frames first.
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if !ws.zero.empty() {
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return ws.zero.shift(), true
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}
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// Iterate over all non-idle streams until finding one that can be consumed.
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for streamID, q := range ws.sq {
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if wr, ok := q.consume(math.MaxInt32); ok {
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if q.empty() {
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delete(ws.sq, streamID)
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ws.queuePool.put(q)
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}
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return wr, true
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}
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}
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return FrameWriteRequest{}, false
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}
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