// 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 

// 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 () 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 ( *randomWriteScheduler) ( uint32,  OpenStreamOptions) {
	// no-op: idle streams are not tracked
}

func ( *randomWriteScheduler) ( uint32) {
	,  := .sq[]
	if ! {
		return
	}
	delete(.sq, )
	.queuePool.put()
}

func ( *randomWriteScheduler) ( uint32,  PriorityParam) {
	// no-op: priorities are ignored
}

func ( *randomWriteScheduler) ( FrameWriteRequest) {
	if .isControl() {
		.zero.push()
		return
	}
	 := .StreamID()
	,  := .sq[]
	if ! {
		 = .queuePool.get()
		.sq[] = 
	}
	.push()
}

func ( *randomWriteScheduler) () (FrameWriteRequest, bool) {
	// Control and RST_STREAM frames first.
	if !.zero.empty() {
		return .zero.shift(), true
	}
	// Iterate over all non-idle streams until finding one that can be consumed.
	for ,  := range .sq {
		if ,  := .consume(math.MaxInt32);  {
			if .empty() {
				delete(.sq, )
				.queuePool.put()
			}
			return , true
		}
	}
	return FrameWriteRequest{}, false
}