The document describes the key abstractions in Akka Streams - Source, Sink, and Flow. It provides examples of creating Sources from single values, iterators, and ticks. It also gives examples of Sinks like foreach, head, fold, and reduce. Various Flow operations are demonstrated like map, filter, take, drop, and flatMapConcat. The document then gives an example problem of reading log files from HDFS in parallel to find 100 fraudulent transactions using Akka Streams.

1. Практика Akka Streams
Алексей Романчук

2. 2
Обо мне

3. 3

4. 4
Обо мне

5. • Знаете синтаксис Scala
• Знакомы со стандартной библиотекой Scala
• Слышали про Reactive Streams
• Видели Akka Streams*
5
О вас

6. В предыдущих сериях

7. T

8. T
Iterable[T]

9. T
Iterable[T]
Future[T]

10. T
Iterable[T]
Future[T]
Source[T]

11. • Реализуют спецификацию Reactive Streams
• Основаны на Akka
• Умеют Backpressure
• Статически типизированы
8
Akka Streams

12. 9
Ключевые абстракции
Source SinkFlow

13. Базовые комбинаторы

14. 11
Source
Source.single(1)
Source.failed(new Exception())
Source.empty[Int]
Source.repeat(1)
Source.fromIterator(() => Iterator(1, 2, 3))
Source.cycle(() => Iterator(1, 2, 3))
Source.tick(1 second, 100 millis, ())

15. 11
Source
Source.single(1)
Source.failed(new Exception())
Source.empty[Int]
Source.repeat(1)
Source.fromIterator(() => Iterator(1, 2, 3))
Source.cycle(() => Iterator(1, 2, 3))
Source.tick(1 second, 100 millis, ())

16. 11
Source
Source.single(1)
Source.failed(new Exception())
Source.empty[Int]
Source.repeat(1)
Source.fromIterator(() => Iterator(1, 2, 3))
Source.cycle(() => Iterator(1, 2, 3))
Source.tick(1 second, 100 millis, ())

17. 11
Source
Source.single(1)
Source.failed(new Exception())
Source.empty[Int]
Source.repeat(1)
Source.fromIterator(() => Iterator(1, 2, 3))
Source.cycle(() => Iterator(1, 2, 3))
Source.tick(1 second, 100 millis, ())

18. 11
Source
Source.single(1)
Source.failed(new Exception())
Source.empty[Int]
Source.repeat(1)
Source.fromIterator(() => Iterator(1, 2, 3))
Source.cycle(() => Iterator(1, 2, 3))
Source.tick(1 second, 100 millis, ())

19. 11
Source
Source.single(1)
Source.failed(new Exception())
Source.empty[Int]
Source.repeat(1)
Source.fromIterator(() => Iterator(1, 2, 3))
Source.cycle(() => Iterator(1, 2, 3))
Source.tick(1 second, 100 millis, ())

20. 11
Source
Source.single(1)
Source.failed(new Exception())
Source.empty[Int]
Source.repeat(1)
Source.fromIterator(() => Iterator(1, 2, 3))
Source.cycle(() => Iterator(1, 2, 3))
Source.tick(1 second, 100 millis, ())

21. 11
Source
Source.single(1)
Source.failed(new Exception())
Source.empty[Int]
Source.repeat(1)
Source.fromIterator(() => Iterator(1, 2, 3))
Source.cycle(() => Iterator(1, 2, 3))
Source.tick(1 second, 100 millis, ())

22. 11
Source
Source.single(1)
Source.failed(new Exception())
Source.empty[Int]
Source.repeat(1)
Source.fromIterator(() => Iterator(1, 2, 3))
Source.cycle(() => Iterator(1, 2, 3))
Source.tick(1 second, 100 millis, ())

23. 12
Sink
Sink.ignore
Sink.cancelled
Sink.foreach[Int](println)
Sink.head
Sink.headOption
Sink.last
Sink.lastOption
Sink.fold(0)(_ + _)
Sink.reduce[Int](_ + _)

24. 12
Sink
Sink.ignore
Sink.cancelled
Sink.foreach[Int](println)
Sink.head
Sink.headOption
Sink.last
Sink.lastOption
Sink.fold(0)(_ + _)
Sink.reduce[Int](_ + _)

25. 12
Sink
Sink.ignore
Sink.cancelled
Sink.foreach[Int](println)
Sink.head
Sink.headOption
Sink.last
Sink.lastOption
Sink.fold(0)(_ + _)
Sink.reduce[Int](_ + _)

26. 12
Sink
Sink.ignore
Sink.cancelled
Sink.foreach[Int](println)
Sink.head
Sink.headOption
Sink.last
Sink.lastOption
Sink.fold(0)(_ + _)
Sink.reduce[Int](_ + _)

27. 12
Sink
Sink.ignore
Sink.cancelled
Sink.foreach[Int](println)
Sink.head
Sink.headOption
Sink.last
Sink.lastOption
Sink.fold(0)(_ + _)
Sink.reduce[Int](_ + _)

28. 12
Sink
Sink.ignore
Sink.cancelled
Sink.foreach[Int](println)
Sink.head
Sink.headOption
Sink.last
Sink.lastOption
Sink.fold(0)(_ + _)
Sink.reduce[Int](_ + _)

29. 12
Sink
Sink.ignore
Sink.cancelled
Sink.foreach[Int](println)
Sink.head
Sink.headOption
Sink.last
Sink.lastOption
Sink.fold(0)(_ + _)
Sink.reduce[Int](_ + _)

30. 13
Flow
Flow[Int].map(identity)
Flow[Int].mapAsync(10)(Future.successful)
Flow[Int].mapAsyncUnordered(10)(Future.successful)
Flow[Int].filter(_ % 2 == 0)
Flow[Int].collect {
case n if n % 2 == 0 => n
}
Flow[Int].take(10)
Flow[Int].takeWhile(_ > 10)
Flow[Int].drop(10)
Flow[Int].dropWhile(_ > 10)

31. 13
Flow
Flow[Int].map(identity)
Flow[Int].mapAsync(10)(Future.successful)
Flow[Int].mapAsyncUnordered(10)(Future.successful)
Flow[Int].filter(_ % 2 == 0)
Flow[Int].collect {
case n if n % 2 == 0 => n
}
Flow[Int].take(10)
Flow[Int].takeWhile(_ > 10)
Flow[Int].drop(10)
Flow[Int].dropWhile(_ > 10)

32. 13
Flow
Flow[Int].map(identity)
Flow[Int].mapAsync(10)(Future.successful)
Flow[Int].mapAsyncUnordered(10)(Future.successful)
Flow[Int].filter(_ % 2 == 0)
Flow[Int].collect {
case n if n % 2 == 0 => n
}
Flow[Int].take(10)
Flow[Int].takeWhile(_ > 10)
Flow[Int].drop(10)
Flow[Int].dropWhile(_ > 10)

33. 13
Flow
Flow[Int].map(identity)
Flow[Int].mapAsync(10)(Future.successful)
Flow[Int].mapAsyncUnordered(10)(Future.successful)
Flow[Int].filter(_ % 2 == 0)
Flow[Int].collect {
case n if n % 2 == 0 => n
}
Flow[Int].take(10)
Flow[Int].takeWhile(_ > 10)
Flow[Int].drop(10)
Flow[Int].dropWhile(_ > 10)

34. 13
Flow
Flow[Int].map(identity)
Flow[Int].mapAsync(10)(Future.successful)
Flow[Int].mapAsyncUnordered(10)(Future.successful)
Flow[Int].filter(_ % 2 == 0)
Flow[Int].collect {
case n if n % 2 == 0 => n
}
Flow[Int].take(10)
Flow[Int].takeWhile(_ > 10)
Flow[Int].drop(10)
Flow[Int].dropWhile(_ > 10)

35. 13
Flow
Flow[Int].map(identity)
Flow[Int].mapAsync(10)(Future.successful)
Flow[Int].mapAsyncUnordered(10)(Future.successful)
Flow[Int].filter(_ % 2 == 0)
Flow[Int].collect {
case n if n % 2 == 0 => n
}
Flow[Int].take(10)
Flow[Int].takeWhile(_ > 10)
Flow[Int].drop(10)
Flow[Int].dropWhile(_ > 10)

36. 13
Flow
Flow[Int].map(identity)
Flow[Int].mapAsync(10)(Future.successful)
Flow[Int].mapAsyncUnordered(10)(Future.successful)
Flow[Int].filter(_ % 2 == 0)
Flow[Int].collect {
case n if n % 2 == 0 => n
}
Flow[Int].take(10)
Flow[Int].takeWhile(_ > 10)
Flow[Int].drop(10)
Flow[Int].dropWhile(_ > 10)

37. 13
Flow
Flow[Int].map(identity)
Flow[Int].mapAsync(10)(Future.successful)
Flow[Int].mapAsyncUnordered(10)(Future.successful)
Flow[Int].filter(_ % 2 == 0)
Flow[Int].collect {
case n if n % 2 == 0 => n
}
Flow[Int].take(10)
Flow[Int].takeWhile(_ > 10)
Flow[Int].drop(10)
Flow[Int].dropWhile(_ > 10)

38. 14
Flow
Flow[Int].flatMapConcat(n =>
Source.fromIterator(() => Iterator.range(1, n))
)
1 2 3 Х

39. 14
Flow
Flow[Int].flatMapConcat(n =>
Source.fromIterator(() => Iterator.range(1, n))
)
1 2 3 Х
1 Х

40. 14
Flow
Flow[Int].flatMapConcat(n =>
Source.fromIterator(() => Iterator.range(1, n))
)
1 2 3 Х
1 Х 1 2 Х

41. 14
Flow
Flow[Int].flatMapConcat(n =>
Source.fromIterator(() => Iterator.range(1, n))
)
1 2 3 Х
1 Х 1 2 Х 1 2 3 Х

42. 14
Flow
Flow[Int].flatMapConcat(n =>
Source.fromIterator(() => Iterator.range(1, n))
)
1 2 3 Х
1 Х 1 2 Х 1 2 3 Х
1 1 2 1 2 3 Х

43. Пример №1

44. • Прочитать с хадупа логи транзакций и найти там 100
примеров фродных транзакций
16
Задача
List Files APIRead Line Result

45. 17
Наивная реализация
def checkFraud(in: String): Future[Option[TransactionId]]
= ???
val result: List[TransactionId] = (for {
file <- hdfs.listStatusIterator(path)
if file.isFile
line <-fromInputStream(fs.open(file.getPath)).getLines()
resultOpt = Await.result(checkFraud(line), 10 seconds)
result <- resultOpt
} yield result)
.take(100).toList

46. 17
Наивная реализация
def checkFraud(in: String): Future[Option[TransactionId]]
= ???
val result: List[TransactionId] = (for {
file <- hdfs.listStatusIterator(path)
if file.isFile
line <-fromInputStream(fs.open(file.getPath)).getLines()
resultOpt = Await.result(checkFraud(line), 10 seconds)
result <- resultOpt
} yield result)
.take(100).toList

47. 17
Наивная реализация
def checkFraud(in: String): Future[Option[TransactionId]]
= ???
val result: List[TransactionId] = (for {
file <- hdfs.listStatusIterator(path)
if file.isFile
line <-fromInputStream(fs.open(file.getPath)).getLines()
resultOpt = Await.result(checkFraud(line), 10 seconds)
result <- resultOpt
} yield result)
.take(100).toList

48. 17
Наивная реализация
def checkFraud(in: String): Future[Option[TransactionId]]
= ???
val result: List[TransactionId] = (for {
file <- hdfs.listStatusIterator(path)
if file.isFile
line <-fromInputStream(fs.open(file.getPath)).getLines()
resultOpt = Await.result(checkFraud(line), 10 seconds)
result <- resultOpt
} yield result)
.take(100).toList

49. 17
Наивная реализация
def checkFraud(in: String): Future[Option[TransactionId]]
= ???
val result: List[TransactionId] = (for {
file <- hdfs.listStatusIterator(path)
if file.isFile
line <-fromInputStream(fs.open(file.getPath)).getLines()
resultOpt = Await.result(checkFraud(line), 10 seconds)
result <- resultOpt
} yield result)
.take(100).toList

50. 17
Наивная реализация
def checkFraud(in: String): Future[Option[TransactionId]]
= ???
val result: List[TransactionId] = (for {
file <- hdfs.listStatusIterator(path)
if file.isFile
line <-fromInputStream(fs.open(file.getPath)).getLines()
resultOpt = Await.result(checkFraud(line), 10 seconds)
result <- resultOpt
} yield result)
.take(100).toList

51. 17
Наивная реализация
def checkFraud(in: String): Future[Option[TransactionId]]
= ???
val result: List[TransactionId] = (for {
file <- hdfs.listStatusIterator(path)
if file.isFile
line <-fromInputStream(fs.open(file.getPath)).getLines()
resultOpt = Await.result(checkFraud(line), 10 seconds)
result <- resultOpt
} yield result)
.take(100).toList

52. 17
Наивная реализация
def checkFraud(in: String): Future[Option[TransactionId]]
= ???
val result: List[TransactionId] = (for {
file <- hdfs.listStatusIterator(path)
if file.isFile
line <-fromInputStream(fs.open(file.getPath)).getLines()
resultOpt = Await.result(checkFraud(line), 10 seconds)
result <- resultOpt
} yield result)
.take(100).toList

53. 17
Наивная реализация
def checkFraud(in: String): Future[Option[TransactionId]]
= ???
val result: List[TransactionId] = (for {
file <- hdfs.listStatusIterator(path)
if file.isFile
line <-fromInputStream(fs.open(file.getPath)).getLines()
resultOpt = Await.result(checkFraud(line), 10 seconds)
result <- resultOpt
} yield result)
.take(100).toList

54. 17
Наивная реализация
def checkFraud(in: String): Future[Option[TransactionId]]
= ???
val result: List[TransactionId] = (for {
file <- hdfs.listStatusIterator(path)
if file.isFile
line <-fromInputStream(fs.open(file.getPath)).getLines()
resultOpt = Await.result(checkFraud(line), 10 seconds)
result <- resultOpt
} yield result)
.take(100).toList

55. 17
Наивная реализация
def checkFraud(in: String): Future[Option[TransactionId]]
= ???
val result: List[TransactionId] = (for {
file <- hdfs.listStatusIterator(path)
if file.isFile
line <-fromInputStream(fs.open(file.getPath)).getLines()
resultOpt = Await.result(checkFraud(line), 10 seconds)
result <- resultOpt
} yield result)
.take(100).toList

56. Ок?

57. • Не терять лишнего времени на скачивание
• Параллельные запросы к сервису
• Не превышать ограничения в 10 запросов в секунду
19
Требования

58. 20
Красивая картинка со схемой
List Files APIRead Line Result

59. 21
Красивый код на стримах
val stream =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

60. 21
Красивый код на стримах
val stream =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

61. 21
Красивый код на стримах
val stream =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

62. 21
Красивый код на стримах
val stream =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

63. 21
Красивый код на стримах
val stream =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

64. 21
Красивый код на стримах
val stream =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

65. 21
Красивый код на стримах
val stream =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

66. 21
Красивый код на стримах
val stream =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

67. 21
Красивый код на стримах
val stream =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

68. 21
Красивый код на стримах
val stream =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

69. 21
Красивый код на стримах
val stream =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

70. 21
Красивый код на стримах
val stream =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

71. 21
Красивый код на стримах
val stream =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

72. 21
Красивый код на стримах
val stream =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

73. 21
Красивый код на стримах
val stream =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

74. 21
Красивый код на стримах
val stream =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

75. Все на стандартных
комбинаторах

76. 23
Запуск
val result: Future[List[TransactionId]] = stream.run()
val result2: Future[List[TransactionId]] = stream.run()

77. 24
Запуск
List Files APIRead Line Result

78. 24
Запуск
List Files APIRead Line Result
run()
Future Stream

79. 24
Запуск
List Files APIRead Line Result
run()
Future Stream
run()
Future Stream

80. Материализация

81. Чертеж → Деталь

82. 27
RunnableGraph
RunnableGraph[+Mat] {
def run(): Mat
}

83. 28
Mat
final class Source[+Out, +Mat]
final class Flow[-In, +Out, +Mat]
final class Sink[-In, +Mat]

84. 29
Sources
case object NotUsed
def single[T](element: T)
def empty[T]
def failed[T](cause: Throwable)
def repeat[T](element: T)
def fromIterator[T](f: () => Iterator[T])
def cycle[T](f: () => Iterator[T])

85. 30
Sinks
def ignore: Sink[Any, Future[Done]]
def foreach[T](f: T => Unit): Sink[T, Future[Done]]
def head[T]: Sink[T, Future[T]]
def headOption[T]: Sink[T, Future[Option[T]]]
def fold[U, T](z: U)(f: (U, T) => U): Sink[T, Future[U]]
def reduce[T](f: (T, T) => T): Sink[T, Future[T]]

86. 30
Sinks
def ignore: Sink[Any, Future[Done]]
def foreach[T](f: T => Unit): Sink[T, Future[Done]]
def head[T]: Sink[T, Future[T]]
def headOption[T]: Sink[T, Future[Option[T]]]
def fold[U, T](z: U)(f: (U, T) => U): Sink[T, Future[U]]
def reduce[T](f: (T, T) => T): Sink[T, Future[T]]

87. 30
Sinks
def ignore: Sink[Any, Future[Done]]
def foreach[T](f: T => Unit): Sink[T, Future[Done]]
def head[T]: Sink[T, Future[T]]
def headOption[T]: Sink[T, Future[Option[T]]]
def fold[U, T](z: U)(f: (U, T) => U): Sink[T, Future[U]]
def reduce[T](f: (T, T) => T): Sink[T, Future[T]]

88. 30
Sinks
def ignore: Sink[Any, Future[Done]]
def foreach[T](f: T => Unit): Sink[T, Future[Done]]
def head[T]: Sink[T, Future[T]]
def headOption[T]: Sink[T, Future[Option[T]]]
def fold[U, T](z: U)(f: (U, T) => U): Sink[T, Future[U]]
def reduce[T](f: (T, T) => T): Sink[T, Future[T]]

89. 30
Sinks
def ignore: Sink[Any, Future[Done]]
def foreach[T](f: T => Unit): Sink[T, Future[Done]]
def head[T]: Sink[T, Future[T]]
def headOption[T]: Sink[T, Future[Option[T]]]
def fold[U, T](z: U)(f: (U, T) => U): Sink[T, Future[U]]
def reduce[T](f: (T, T) => T): Sink[T, Future[T]]

90. 30
Sinks
def ignore: Sink[Any, Future[Done]]
def foreach[T](f: T => Unit): Sink[T, Future[Done]]
def head[T]: Sink[T, Future[T]]
def headOption[T]: Sink[T, Future[Option[T]]]
def fold[U, T](z: U)(f: (U, T) => U): Sink[T, Future[U]]
def reduce[T](f: (T, T) => T): Sink[T, Future[T]]

91. 30
Sinks
def ignore: Sink[Any, Future[Done]]
def foreach[T](f: T => Unit): Sink[T, Future[Done]]
def head[T]: Sink[T, Future[T]]
def headOption[T]: Sink[T, Future[Option[T]]]
def fold[U, T](z: U)(f: (U, T) => U): Sink[T, Future[U]]
def reduce[T](f: (T, T) => T): Sink[T, Future[T]]

92. 30
Sinks
def ignore: Sink[Any, Future[Done]]
def foreach[T](f: T => Unit): Sink[T, Future[Done]]
def head[T]: Sink[T, Future[T]]
def headOption[T]: Sink[T, Future[Option[T]]]
def fold[U, T](z: U)(f: (U, T) => U): Sink[T, Future[U]]
def reduce[T](f: (T, T) => T): Sink[T, Future[T]]

93. 31
Композиция
val source: Source[Int, NotUsed] = Source.single(1)
val sink: Sink[Any, Future[Done]] = Sink.ignore
val s1: RunnableGraph[NotUsed] = source.to(sink)
val s2: RunnableGraph[Future[Done]] =
source.toMat(sink)(Keep.right)
val s3: RunnableGraph[(NotUsed, Future[Done])] =
source.toMat(sink)(Keep.both)

94. 31
Композиция
val source: Source[Int, NotUsed] = Source.single(1)
val sink: Sink[Any, Future[Done]] = Sink.ignore
val s1: RunnableGraph[NotUsed] = source.to(sink)
val s2: RunnableGraph[Future[Done]] =
source.toMat(sink)(Keep.right)
val s3: RunnableGraph[(NotUsed, Future[Done])] =
source.toMat(sink)(Keep.both)

95. 31
Композиция
val source: Source[Int, NotUsed] = Source.single(1)
val sink: Sink[Any, Future[Done]] = Sink.ignore
val s1: RunnableGraph[NotUsed] = source.to(sink)
val s2: RunnableGraph[Future[Done]] =
source.toMat(sink)(Keep.right)
val s3: RunnableGraph[(NotUsed, Future[Done])] =
source.toMat(sink)(Keep.both)

96. 31
Композиция
val source: Source[Int, NotUsed] = Source.single(1)
val sink: Sink[Any, Future[Done]] = Sink.ignore
val s1: RunnableGraph[NotUsed] = source.to(sink)
val s2: RunnableGraph[Future[Done]] =
source.toMat(sink)(Keep.right)
val s3: RunnableGraph[(NotUsed, Future[Done])] =
source.toMat(sink)(Keep.both)

97. 31
Композиция
val source: Source[Int, NotUsed] = Source.single(1)
val sink: Sink[Any, Future[Done]] = Sink.ignore
val s1: RunnableGraph[NotUsed] = source.to(sink)
val s2: RunnableGraph[Future[Done]] =
source.toMat(sink)(Keep.right)
val s3: RunnableGraph[(NotUsed, Future[Done])] =
source.toMat(sink)(Keep.both)

98. 31
Композиция
val source: Source[Int, NotUsed] = Source.single(1)
val sink: Sink[Any, Future[Done]] = Sink.ignore
val s1: RunnableGraph[NotUsed] = source.to(sink)
val s2: RunnableGraph[Future[Done]] =
source.toMat(sink)(Keep.right)
val s3: RunnableGraph[(NotUsed, Future[Done])] =
source.toMat(sink)(Keep.both)

99. 32
Композиция

100. 33
Красивый код на стримах
val stream: RunnableGraph[Future[List[TransactionId]]] =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

101. 33
Красивый код на стримах
val stream: RunnableGraph[Future[List[TransactionId]]] =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

102. 33
Красивый код на стримах
val stream: RunnableGraph[Future[List[TransactionId]]] =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

103. 33
Красивый код на стримах
val stream: RunnableGraph[Future[List[TransactionId]]] =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

104. 34
Красивая картинка со схемой
List Files APIRead Line Result
run()
Stream
run()
Future StreamFuture

105. 34
Красивая картинка со схемой
List Files APIRead Line Result
run()
Future
Stream
run()
Future StreamFuture

106. Пример №2

107. • Читать данные из очереди и обрабатывать.
36
Задача
Source Process Sink
Future

108. 37
Красивый код на стримах
val source = ZMQSource(context,
mode = ZMQ.PULL,
timeout = 1 second,
addresses = List("tcp: //127.0.0.1:12345")
)
def process(in: ByteString): Future[Int] = ???

109. 37
Красивый код на стримах
val source = ZMQSource(context,
mode = ZMQ.PULL,
timeout = 1 second,
addresses = List("tcp: //127.0.0.1:12345")
)
def process(in: ByteString): Future[Int] = ???

110. 37
Красивый код на стримах
val source = ZMQSource(context,
mode = ZMQ.PULL,
timeout = 1 second,
addresses = List("tcp: //127.0.0.1:12345")
)
def process(in: ByteString): Future[Int] = ???

111. 37
Красивый код на стримах
val source = ZMQSource(context,
mode = ZMQ.PULL,
timeout = 1 second,
addresses = List("tcp: //127.0.0.1:12345")
)
def process(in: ByteString): Future[Int] = ???

112. 38
Красивый код на стримах
val stream = source
.mapAsync(10)(process)
.toMat(Sink.last)(Keep.right)
val result: Future[Int] = stream.run()
result.onComplete(_ => "We are done here")

113. 38
Красивый код на стримах
val stream = source
.mapAsync(10)(process)
.toMat(Sink.last)(Keep.right)
val result: Future[Int] = stream.run()
result.onComplete(_ => "We are done here")

114. 38
Красивый код на стримах
val stream = source
.mapAsync(10)(process)
.toMat(Sink.last)(Keep.right)
val result: Future[Int] = stream.run()
result.onComplete(_ => "We are done here")

115. 38
Красивый код на стримах
val stream = source
.mapAsync(10)(process)
.toMat(Sink.last)(Keep.right)
val result: Future[Int] = stream.run()
result.onComplete(_ => "We are done here")

116. 38
Красивый код на стримах
val stream = source
.mapAsync(10)(process)
.toMat(Sink.last)(Keep.right)
val result: Future[Int] = stream.run()
result.onComplete(_ => "We are done here")

117. 39
Красивая картинка со схемой
Source Process Sink
Future

118. 39
Красивая картинка со схемой
Source Process Sink
Future
StreamFuture

119. Как это остановить?

120. 41
Проблема остановки
val stream = source
.mapAsync(10)(process)
.toMat(Sink.last)(Keep.right)
val result: Future[Int] = stream.run()
result.onComplete(_ => "We are done here")

121. 42
Проблема остановки
Source Process Sink
Future

122. 42
Проблема остановки
Source Process Sink
FutureControl

123. 42
Проблема остановки
Source Process Sink
Future
StreamControl
Control
Future

124. 43
Проблема остановки
trait Control {
/**
* Disconnect the underlying ZMQ socket, deliver the
remaining data and finally close the socket.
*/
def gracefulStop(): Unit
}

125. 44
Проблема остановки
val source: Source[ByteString, Control] = ???
val stream: RunnableGraph[(Control, Future[Int])] =
source
.mapAsync(10)(process)
.toMat(Sink.head)(Keep.both)
val (control: Control, result: Future[Int]) = stream.run()
result.onComplete(_ => "We are done here")
control.gracefulStop()

126. 44
Проблема остановки
val source: Source[ByteString, Control] = ???
val stream: RunnableGraph[(Control, Future[Int])] =
source
.mapAsync(10)(process)
.toMat(Sink.head)(Keep.both)
val (control: Control, result: Future[Int]) = stream.run()
result.onComplete(_ => "We are done here")
control.gracefulStop()

127. 44
Проблема остановки
val source: Source[ByteString, Control] = ???
val stream: RunnableGraph[(Control, Future[Int])] =
source
.mapAsync(10)(process)
.toMat(Sink.head)(Keep.both)
val (control: Control, result: Future[Int]) = stream.run()
result.onComplete(_ => "We are done here")
control.gracefulStop()

128. 44
Проблема остановки
val source: Source[ByteString, Control] = ???
val stream: RunnableGraph[(Control, Future[Int])] =
source
.mapAsync(10)(process)
.toMat(Sink.head)(Keep.both)
val (control: Control, result: Future[Int]) = stream.run()
result.onComplete(_ => "We are done here")
control.gracefulStop()

129. 44
Проблема остановки
val source: Source[ByteString, Control] = ???
val stream: RunnableGraph[(Control, Future[Int])] =
source
.mapAsync(10)(process)
.toMat(Sink.head)(Keep.both)
val (control: Control, result: Future[Int]) = stream.run()
result.onComplete(_ => "We are done here")
control.gracefulStop()

130. 44
Проблема остановки
val source: Source[ByteString, Control] = ???
val stream: RunnableGraph[(Control, Future[Int])] =
source
.mapAsync(10)(process)
.toMat(Sink.head)(Keep.both)
val (control: Control, result: Future[Int]) = stream.run()
result.onComplete(_ => "We are done here")
control.gracefulStop()

131. Пример №3

132. 46
Механика
Flow[T]

133. 46
Механика
Flow[T]
Request
Cancel

134. 46
Механика
Flow[T]
Request Request
Cancel Cancel

135. 46
Механика
Flow[T]
Request Request
T
Error
Complete
Cancel Cancel

136. 46
Механика
Flow[T]
T
Error
Complete
Request Request
T
Error
Complete
Cancel Cancel

137. • Emit элемента
• Завершение
• Ошибка
• Backpressure
• Отмена
47
Что нужно знать про stages

138. 48
Свой Source
val s: Source[Int, ActorRef] =
Source.actorPublisher[Int](Props(new MySourceActor))
class MySourceActor extends ActorPublisher[Int] {
override def receive: Receive = {
case ActorPublisherMessage.Request(n) =>
onNext(100)
onCompleteThenStop()
onErrorThenStop(new Exception)
case ActorPublisherMessage.Cancel =>
context.stop(self)
}
}

139. 48
Свой Source
val s: Source[Int, ActorRef] =
Source.actorPublisher[Int](Props(new MySourceActor))
class MySourceActor extends ActorPublisher[Int] {
override def receive: Receive = {
case ActorPublisherMessage.Request(n) =>
onNext(100)
onCompleteThenStop()
onErrorThenStop(new Exception)
case ActorPublisherMessage.Cancel =>
context.stop(self)
}
}

140. 48
Свой Source
val s: Source[Int, ActorRef] =
Source.actorPublisher[Int](Props(new MySourceActor))
class MySourceActor extends ActorPublisher[Int] {
override def receive: Receive = {
case ActorPublisherMessage.Request(n) =>
onNext(100)
onCompleteThenStop()
onErrorThenStop(new Exception)
case ActorPublisherMessage.Cancel =>
context.stop(self)
}
}

141. 48
Свой Source
val s: Source[Int, ActorRef] =
Source.actorPublisher[Int](Props(new MySourceActor))
class MySourceActor extends ActorPublisher[Int] {
override def receive: Receive = {
case ActorPublisherMessage.Request(n) =>
onNext(100)
onCompleteThenStop()
onErrorThenStop(new Exception)
case ActorPublisherMessage.Cancel =>
context.stop(self)
}
}

142. 48
Свой Source
val s: Source[Int, ActorRef] =
Source.actorPublisher[Int](Props(new MySourceActor))
class MySourceActor extends ActorPublisher[Int] {
override def receive: Receive = {
case ActorPublisherMessage.Request(n) =>
onNext(100)
onCompleteThenStop()
onErrorThenStop(new Exception)
case ActorPublisherMessage.Cancel =>
context.stop(self)
}
}

143. 48
Свой Source
val s: Source[Int, ActorRef] =
Source.actorPublisher[Int](Props(new MySourceActor))
class MySourceActor extends ActorPublisher[Int] {
override def receive: Receive = {
case ActorPublisherMessage.Request(n) =>
onNext(100)
onCompleteThenStop()
onErrorThenStop(new Exception)
case ActorPublisherMessage.Cancel =>
context.stop(self)
}
}

144. 48
Свой Source
val s: Source[Int, ActorRef] =
Source.actorPublisher[Int](Props(new MySourceActor))
class MySourceActor extends ActorPublisher[Int] {
override def receive: Receive = {
case ActorPublisherMessage.Request(n) =>
onNext(100)
onCompleteThenStop()
onErrorThenStop(new Exception)
case ActorPublisherMessage.Cancel =>
context.stop(self)
}
}

145. 48
Свой Source
val s: Source[Int, ActorRef] =
Source.actorPublisher[Int](Props(new MySourceActor))
class MySourceActor extends ActorPublisher[Int] {
override def receive: Receive = {
case ActorPublisherMessage.Request(n) =>
onNext(100)
onCompleteThenStop()
onErrorThenStop(new Exception)
case ActorPublisherMessage.Cancel =>
context.stop(self)
}
}

146. 48
Свой Source
val s: Source[Int, ActorRef] =
Source.actorPublisher[Int](Props(new MySourceActor))
class MySourceActor extends ActorPublisher[Int] {
override def receive: Receive = {
case ActorPublisherMessage.Request(n) =>
onNext(100)
onCompleteThenStop()
onErrorThenStop(new Exception)
case ActorPublisherMessage.Cancel =>
context.stop(self)
}
}

147. 48
Свой Source
val s: Source[Int, ActorRef] =
Source.actorPublisher[Int](Props(new MySourceActor))
class MySourceActor extends ActorPublisher[Int] {
override def receive: Receive = {
case ActorPublisherMessage.Request(n) =>
onNext(100)
onCompleteThenStop()
onErrorThenStop(new Exception)
case ActorPublisherMessage.Cancel =>
context.stop(self)
}
}

148. 49
Reactive Zmq
case object GracefulStop
case object DeliverMore
class MySourceActor(addr: String)
extends ActorPublisher[Array[Byte]] {
var conn: ZMQ.Socket = ???
override def preStart(): Unit = {
conn.connect(addr)
}
override def postStop(): Unit = {
conn.disconnect(addr)
}

149. 49
Reactive Zmq
case object GracefulStop
case object DeliverMore
class MySourceActor(addr: String)
extends ActorPublisher[Array[Byte]] {
var conn: ZMQ.Socket = ???
override def preStart(): Unit = {
conn.connect(addr)
}
override def postStop(): Unit = {
conn.disconnect(addr)
}

150. 49
Reactive Zmq
case object GracefulStop
case object DeliverMore
class MySourceActor(addr: String)
extends ActorPublisher[Array[Byte]] {
var conn: ZMQ.Socket = ???
override def preStart(): Unit = {
conn.connect(addr)
}
override def postStop(): Unit = {
conn.disconnect(addr)
}

151. 49
Reactive Zmq
case object GracefulStop
case object DeliverMore
class MySourceActor(addr: String)
extends ActorPublisher[Array[Byte]] {
var conn: ZMQ.Socket = ???
override def preStart(): Unit = {
conn.connect(addr)
}
override def postStop(): Unit = {
conn.disconnect(addr)
}

152. 49
Reactive Zmq
case object GracefulStop
case object DeliverMore
class MySourceActor(addr: String)
extends ActorPublisher[Array[Byte]] {
var conn: ZMQ.Socket = ???
override def preStart(): Unit = {
conn.connect(addr)
}
override def postStop(): Unit = {
conn.disconnect(addr)
}

153. 49
Reactive Zmq
case object GracefulStop
case object DeliverMore
class MySourceActor(addr: String)
extends ActorPublisher[Array[Byte]] {
var conn: ZMQ.Socket = ???
override def preStart(): Unit = {
conn.connect(addr)
}
override def postStop(): Unit = {
conn.disconnect(addr)
}

154. 49
Reactive Zmq
case object GracefulStop
case object DeliverMore
class MySourceActor(addr: String)
extends ActorPublisher[Array[Byte]] {
var conn: ZMQ.Socket = ???
override def preStart(): Unit = {
conn.connect(addr)
}
override def postStop(): Unit = {
conn.disconnect(addr)
}

155. 50
Reactive Zmq
override def receive: Receive = {
case ActorPublisherMessage.Request(_) | DeliverMore =>
Option(conn.recv()) match {
case Some(msg) =>
onNext(msg)
if(totalDemand > 0) self ! DeliverMore
case None => self ! DeliverMore
}
case ActorPublisherMessage.Cancel | GracefulStop =>
conn.disconnect(addr)
onCompleteThenStop()
}

156. 50
Reactive Zmq
override def receive: Receive = {
case ActorPublisherMessage.Request(_) | DeliverMore =>
Option(conn.recv()) match {
case Some(msg) =>
onNext(msg)
if(totalDemand > 0) self ! DeliverMore
case None => self ! DeliverMore
}
case ActorPublisherMessage.Cancel | GracefulStop =>
conn.disconnect(addr)
onCompleteThenStop()
}

157. 50
Reactive Zmq
override def receive: Receive = {
case ActorPublisherMessage.Request(_) | DeliverMore =>
Option(conn.recv()) match {
case Some(msg) =>
onNext(msg)
if(totalDemand > 0) self ! DeliverMore
case None => self ! DeliverMore
}
case ActorPublisherMessage.Cancel | GracefulStop =>
conn.disconnect(addr)
onCompleteThenStop()
}

158. 50
Reactive Zmq
override def receive: Receive = {
case ActorPublisherMessage.Request(_) | DeliverMore =>
Option(conn.recv()) match {
case Some(msg) =>
onNext(msg)
if(totalDemand > 0) self ! DeliverMore
case None => self ! DeliverMore
}
case ActorPublisherMessage.Cancel | GracefulStop =>
conn.disconnect(addr)
onCompleteThenStop()
}

159. 50
Reactive Zmq
override def receive: Receive = {
case ActorPublisherMessage.Request(_) | DeliverMore =>
Option(conn.recv()) match {
case Some(msg) =>
onNext(msg)
if(totalDemand > 0) self ! DeliverMore
case None => self ! DeliverMore
}
case ActorPublisherMessage.Cancel | GracefulStop =>
conn.disconnect(addr)
onCompleteThenStop()
}

160. 50
Reactive Zmq
override def receive: Receive = {
case ActorPublisherMessage.Request(_) | DeliverMore =>
Option(conn.recv()) match {
case Some(msg) =>
onNext(msg)
if(totalDemand > 0) self ! DeliverMore
case None => self ! DeliverMore
}
case ActorPublisherMessage.Cancel | GracefulStop =>
conn.disconnect(addr)
onCompleteThenStop()
}

161. 50
Reactive Zmq
override def receive: Receive = {
case ActorPublisherMessage.Request(_) | DeliverMore =>
Option(conn.recv()) match {
case Some(msg) =>
onNext(msg)
if(totalDemand > 0) self ! DeliverMore
case None => self ! DeliverMore
}
case ActorPublisherMessage.Cancel | GracefulStop =>
conn.disconnect(addr)
onCompleteThenStop()
}

162. 50
Reactive Zmq
override def receive: Receive = {
case ActorPublisherMessage.Request(_) | DeliverMore =>
Option(conn.recv()) match {
case Some(msg) =>
onNext(msg)
if(totalDemand > 0) self ! DeliverMore
case None => self ! DeliverMore
}
case ActorPublisherMessage.Cancel | GracefulStop =>
conn.disconnect(addr)
onCompleteThenStop()
}

163. 50
Reactive Zmq
override def receive: Receive = {
case ActorPublisherMessage.Request(_) | DeliverMore =>
Option(conn.recv()) match {
case Some(msg) =>
onNext(msg)
if(totalDemand > 0) self ! DeliverMore
case None => self ! DeliverMore
}
case ActorPublisherMessage.Cancel | GracefulStop =>
conn.disconnect(addr)
onCompleteThenStop()
}

164. 50
Reactive Zmq
override def receive: Receive = {
case ActorPublisherMessage.Request(_) | DeliverMore =>
Option(conn.recv()) match {
case Some(msg) =>
onNext(msg)
if(totalDemand > 0) self ! DeliverMore
case None => self ! DeliverMore
}
case ActorPublisherMessage.Cancel | GracefulStop =>
conn.disconnect(addr)
onCompleteThenStop()
}

165. 50
Reactive Zmq
override def receive: Receive = {
case ActorPublisherMessage.Request(_) | DeliverMore =>
Option(conn.recv()) match {
case Some(msg) =>
onNext(msg)
if(totalDemand > 0) self ! DeliverMore
case None => self ! DeliverMore
}
case ActorPublisherMessage.Cancel | GracefulStop =>
conn.disconnect(addr)
onCompleteThenStop()
}

166. 51
Reactive Zmq
val source: Source[Array[Byte], Control] =
Source.actorPublisher[Array[Byte]](
Props(new MySourceActor( ???))
).mapMaterializedValue { ref =>
new Control {
override def gracefulStop() = ref ! GracefulStop
}
}

167. 51
Reactive Zmq
val source: Source[Array[Byte], Control] =
Source.actorPublisher[Array[Byte]](
Props(new MySourceActor( ???))
).mapMaterializedValue { ref =>
new Control {
override def gracefulStop() = ref ! GracefulStop
}
}

168. 51
Reactive Zmq
val source: Source[Array[Byte], Control] =
Source.actorPublisher[Array[Byte]](
Props(new MySourceActor( ???))
).mapMaterializedValue { ref =>
new Control {
override def gracefulStop() = ref ! GracefulStop
}
}

169. 51
Reactive Zmq
val source: Source[Array[Byte], Control] =
Source.actorPublisher[Array[Byte]](
Props(new MySourceActor( ???))
).mapMaterializedValue { ref =>
new Control {
override def gracefulStop() = ref ! GracefulStop
}
}

170. 51
Reactive Zmq
val source: Source[Array[Byte], Control] =
Source.actorPublisher[Array[Byte]](
Props(new MySourceActor( ???))
).mapMaterializedValue { ref =>
new Control {
override def gracefulStop() = ref ! GracefulStop
}
}

171. 51
Reactive Zmq
val source: Source[Array[Byte], Control] =
Source.actorPublisher[Array[Byte]](
Props(new MySourceActor( ???))
).mapMaterializedValue { ref =>
new Control {
override def gracefulStop() = ref ! GracefulStop
}
}

172. 51
Reactive Zmq
val source: Source[Array[Byte], Control] =
Source.actorPublisher[Array[Byte]](
Props(new MySourceActor( ???))
).mapMaterializedValue { ref =>
new Control {
override def gracefulStop() = ref ! GracefulStop
}
}

173. 52
Свой Sink
val s = Sink.actorSubscriber[Int](Props(new MySinkActor))
class MySinkActor extends ActorSubscriber {
override def receive: Receive = {
case ActorSubscriberMessage.OnNext =>
cancel()
request(100)
case ActorSubscriberMessage.OnComplete =>
case ActorSubscriberMessage.OnError =>
}

174. 52
Свой Sink
val s = Sink.actorSubscriber[Int](Props(new MySinkActor))
class MySinkActor extends ActorSubscriber {
override def receive: Receive = {
case ActorSubscriberMessage.OnNext =>
cancel()
request(100)
case ActorSubscriberMessage.OnComplete =>
case ActorSubscriberMessage.OnError =>
}

175. 52
Свой Sink
val s = Sink.actorSubscriber[Int](Props(new MySinkActor))
class MySinkActor extends ActorSubscriber {
override def receive: Receive = {
case ActorSubscriberMessage.OnNext =>
cancel()
request(100)
case ActorSubscriberMessage.OnComplete =>
case ActorSubscriberMessage.OnError =>
}

176. 52
Свой Sink
val s = Sink.actorSubscriber[Int](Props(new MySinkActor))
class MySinkActor extends ActorSubscriber {
override def receive: Receive = {
case ActorSubscriberMessage.OnNext =>
cancel()
request(100)
case ActorSubscriberMessage.OnComplete =>
case ActorSubscriberMessage.OnError =>
}

177. 52
Свой Sink
val s = Sink.actorSubscriber[Int](Props(new MySinkActor))
class MySinkActor extends ActorSubscriber {
override def receive: Receive = {
case ActorSubscriberMessage.OnNext =>
cancel()
request(100)
case ActorSubscriberMessage.OnComplete =>
case ActorSubscriberMessage.OnError =>
}

178. 52
Свой Sink
val s = Sink.actorSubscriber[Int](Props(new MySinkActor))
class MySinkActor extends ActorSubscriber {
override def receive: Receive = {
case ActorSubscriberMessage.OnNext =>
cancel()
request(100)
case ActorSubscriberMessage.OnComplete =>
case ActorSubscriberMessage.OnError =>
}

179. 52
Свой Sink
val s = Sink.actorSubscriber[Int](Props(new MySinkActor))
class MySinkActor extends ActorSubscriber {
override def receive: Receive = {
case ActorSubscriberMessage.OnNext =>
cancel()
request(100)
case ActorSubscriberMessage.OnComplete =>
case ActorSubscriberMessage.OnError =>
}

180. 52
Свой Sink
val s = Sink.actorSubscriber[Int](Props(new MySinkActor))
class MySinkActor extends ActorSubscriber {
override def receive: Receive = {
case ActorSubscriberMessage.OnNext =>
cancel()
request(100)
case ActorSubscriberMessage.OnComplete =>
case ActorSubscriberMessage.OnError =>
}

181. 52
Свой Sink
val s = Sink.actorSubscriber[Int](Props(new MySinkActor))
class MySinkActor extends ActorSubscriber {
override def receive: Receive = {
case ActorSubscriberMessage.OnNext =>
cancel()
request(100)
case ActorSubscriberMessage.OnComplete =>
case ActorSubscriberMessage.OnError =>
}

182. Итоги

183. • Стандартные комбинаторы
• Материализация
• Управление жизненным циклом
• Свои stages
54
Итоги

184. Серебряная пуля

185. • Более простая технология не подходит
• Backpressure
• Упорядоченные потоки
• Локальность
• Фиксированная топология
56
Когда стоит использовать

186. • Документация Akka Streams
• Альпака
• reactive-zmq
• reactive-kafka
• Первое видео про Akka Streams
57
Ссылки

187. Вопросы?
alexey.romanchuk@gmail.com @1esha

188. Backpressure

189. 60
Событий слишком много

190. 60
Событий слишком много
Отправитель

191. 60
Событий слишком много
Отправитель Получатель

192. 60
Событий слишком много
Отправитель Получатель

193. 61
Событий слишком много
Отправитель Получатель

194. 62
Событий слишком много
Отправитель Получатель

195. 63
Событий слишком много
Отправитель Получатель

196. 64
Событий слишком много
Отправитель Получатель

197. 65
Событий слишком много
Отправитель Получатель

198. 66
Событий слишком много
Отправитель Получатель

199. 67
Событий слишком много
Отправитель Получатель

200. 68
Блокирующий вызов
Отправитель Получатель

201. 68
Блокирующий вызов
Отправитель Получатель

202. 68
Блокирующий вызов
Отправитель Получатель

203. 69
Pull
Отправитель Получатель

204. 69
Pull
Отправитель Получатель

205. 69
Pull
Отправитель Получатель

206. 70
Negative Acknowledge
Отправитель Получатель

207. 70
Negative Acknowledge
Отправитель Получатель

208. 70
Negative Acknowledge
Отправитель Получатель

209. 71
Negative Acknowledge
Отправитель Получатель

210. 72
Dynamic pull-push
Отправитель Получатель

211. 72
Dynamic pull-push
Отправитель Получатель
4

212. 73
Dynamic pull-push
4
Отправитель Получатель

213. 74
Dynamic pull-push
3
Отправитель Получатель

214. 75
Dynamic pull-push
3
Отправитель Получатель

215. 76
Dynamic pull-push
0
Отправитель Получатель

216. 77
Dynamic pull-push
0
Отправитель Получатель

217. 78
Dynamic pull-push
0
Отправитель Получатель

218. 78
Dynamic pull-push
0
Отправитель Получатель
2

219. 79
Dynamic pull-push
2
Отправитель Получатель

220. 80
Dynamic pull-push
0
Отправитель Получатель

221. 81
Balance
Balance

222. 81
Balance
Balance

223. 81
Balance
Balance

224. 82
Broadcast
Broadcast

225. 82
Broadcast
Broadcast

226. 82
Broadcast
Broadcast

227. 83
Zip
Zip

228. 83
Zip
Zip

229. 83
Zip
Zip

230. 84
Unzip
Unzip

231. 84
Unzip
Unzip

232. 84
Unzip
Unzip

233. 85
Красивый код на стримах
val stream: RunnableGraph[Future[List[TransactionId]]] =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

234. 85
Красивый код на стримах
val stream: RunnableGraph[Future[List[TransactionId]]] =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

235. 85
Красивый код на стримах
val stream: RunnableGraph[Future[List[TransactionId]]] =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

236. 85
Красивый код на стримах
val stream: RunnableGraph[Future[List[TransactionId]]] =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

237. 85
Красивый код на стримах
val stream: RunnableGraph[Future[List[TransactionId]]] =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

238. 85
Красивый код на стримах
val stream: RunnableGraph[Future[List[TransactionId]]] =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

239. 85
Красивый код на стримах
val stream: RunnableGraph[Future[List[TransactionId]]] =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

240. 85
Красивый код на стримах
val stream: RunnableGraph[Future[List[TransactionId]]] =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

241. 85
Красивый код на стримах
val stream: RunnableGraph[Future[List[TransactionId]]] =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

242. 85
Красивый код на стримах
val stream: RunnableGraph[Future[List[TransactionId]]] =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

243. 85
Красивый код на стримах
val stream: RunnableGraph[Future[List[TransactionId]]] =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

244. 85
Красивый код на стримах
val stream: RunnableGraph[Future[List[TransactionId]]] =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

245. 85
Красивый код на стримах
val stream: RunnableGraph[Future[List[TransactionId]]] =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

246. 85
Красивый код на стримах
val stream: RunnableGraph[Future[List[TransactionId]]] =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

247. 85
Красивый код на стримах
val stream: RunnableGraph[Future[List[TransactionId]]] =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)

248. 85
Красивый код на стримах
val stream: RunnableGraph[Future[List[TransactionId]]] =
Source
.fromIterator { () => hdfs.listStatusIterator(path) }
.filter(_.isFile)
.flatMapConcat { file =>
val s = fromInputStream(hdfs.open(file.getPath))
Source.fromIterator(() => s.getLines())
}
.throttle(10, 1 second, 0, ThrottleMode.Shaping)
.mapAsyncUnordered(50)(checkFraud)
.collect { case Some(value) => value }
.take(100)
.fold(List.empty[TransactionId])(_ :+ _)
.toMat(Sink.head)(Keep.right)