dragonsinth

package concurrency

import (
	"context"
	"fmt"
	"golang.org/x/sync/errgroup"
)

const (
	doThingWorkers    = 4

dragonsinth

///usr/bin/env true; exec /usr/bin/env go run "$0" "$@"

package main

import (
	"fmt"
	"log"
	"os"
	"os/exec"
	"path/filepath"

dragonsinth

go install github.com/fullstorydev/go/examples/chatterbox/...@latest
chatterbox server
chatterbox monitor # in another terminal
chatterbox client  # in another terminal

dragonsinth

type LogReplicatedModel struct {
	mu       sync.RWMutex
	snapshot Model
	stream   eventstream.EventStream
}

func (m *LogReplicatedModel) ReadAndSubscribe() (Model, eventstream.Promise) {
	m.mu.RLock()
	defer m.mu.RUnlock()
	return m.snapshot, m.stream.Subscribe()

dragonsinth

for it := eventStream.Subscribe().Iterator(); true; {
	v, err := it.Next(ctx)
	if err == eventstream.ErrDone {
		return nil
	} else if err != nil {
		return err
	}
	msg := v.(bwamp.Event)
	// [Send msg to client]
}

dragonsinth

promise := eventStream.Subscribe()
for {
	select {
	case <-ctx.Done():
		return ctx.Err()
	case <-promise.Ready():
		v, nextPromise := promise.Next()
		if v == nil {
			return nil
		}

dragonsinth

type node struct {
	value interface{}   // the value of the event (nil until ready)
	next  *node         // the next node in the stream (nil until ready)
	ready chan struct{} // a channel whose closure marks readiness
}

dragonsinth

package main

import (
	"context"
	"encoding/base64"
	"flag"
	"fmt"
	"log"

	container "google.golang.org/api/container/v1beta1"

dragonsinth

func GetFriends(ctx context.Context, user int64) (map[string]*User, error) {
  // Produce
  var friendIds []int64
  for it := GetFriendIds(user); ; {
     if id, err := it.Next(ctx); err != nil {
        if err == io.EOF {
           break
        }
        return nil, fmt.Errorf("GetFriendIds %d: %w", user, err)
     } else {

dragonsinth

func GetFriends(ctx context.Context, user int64) (map[string]*User, error) {
  friendIds := make(chan int64)

  // Produce
  go func() {
     defer close(friendIds)
     for it := GetFriendIds(user); ; {
        if id, err := it.Next(ctx); err != nil {
           if err == io.EOF {
              break