108 lines
2.0 KiB
Go
108 lines
2.0 KiB
Go
// SPDX-FileCopyrightText: 2021 The NGI Pointer Secure-Scuttlebutt Team of 2020/2021
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//
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// SPDX-License-Identifier: MIT
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package broadcasts
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import (
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"io"
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"sync"
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"github.com/ssbc/go-ssb-room/v2/internal/maybemod/multierror"
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)
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type EndpointsEmitter interface {
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Update(members []string) error
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io.Closer
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}
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// NewEndpointsEmitter returns the Sink, to write to the broadcaster, and the new
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// broadcast instance.
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func NewEndpointsEmitter() (EndpointsEmitter, *EndpointsBroadcast) {
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bcst := EndpointsBroadcast{
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mu: &sync.Mutex{},
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sinks: make(map[*EndpointsEmitter]struct{}),
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}
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return (*endpointsSink)(&bcst), &bcst
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}
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// EndpointsBroadcast is an interface for registering one or more Sinks to recieve
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// updates.
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type EndpointsBroadcast struct {
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mu *sync.Mutex
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sinks map[*EndpointsEmitter]struct{}
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}
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// Register a Sink for updates to be sent. also returns
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func (bcst *EndpointsBroadcast) Register(sink EndpointsEmitter) func() {
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bcst.mu.Lock()
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defer bcst.mu.Unlock()
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bcst.sinks[&sink] = struct{}{}
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return func() {
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bcst.mu.Lock()
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defer bcst.mu.Unlock()
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delete(bcst.sinks, &sink)
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sink.Close()
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}
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}
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type endpointsSink EndpointsBroadcast
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// Pour implements the Sink interface.
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func (bcst *endpointsSink) Update(members []string) error {
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bcst.mu.Lock()
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for s := range bcst.sinks {
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err := (*s).Update(members)
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if err != nil {
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delete(bcst.sinks, s)
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}
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}
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bcst.mu.Unlock()
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return nil
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}
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// Close implements the Sink interface.
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func (bcst *endpointsSink) Close() error {
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var sinks []EndpointsEmitter
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bcst.mu.Lock()
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defer bcst.mu.Unlock()
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sinks = make([]EndpointsEmitter, 0, len(bcst.sinks))
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for sink := range bcst.sinks {
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sinks = append(sinks, *sink)
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}
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var (
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wg sync.WaitGroup
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me multierror.List
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)
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// might be fine without the waitgroup and concurrency
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wg.Add(len(sinks))
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for _, sink_ := range sinks {
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go func(sink EndpointsEmitter) {
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defer wg.Done()
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err := sink.Close()
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if err != nil {
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me.Errs = append(me.Errs, err)
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return
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}
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}(sink_)
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}
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wg.Wait()
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if len(me.Errs) == 0 {
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return nil
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}
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return me
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}
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