com.linkedin.parseq

Interface Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8>

All Superinterfaces:

Cancellable, Promise<Tuple8<T1,T2,T3,T4,T5,T6,T7,T8>>, Task<Tuple8<T1,T2,T3,T4,T5,T6,T7,T8>>

All Known Implementing Classes:

Par8Task, Tuple8TaskDelegate

public interface Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8>
extends Task<Tuple8<T1,T2,T3,T4,T5,T6,T7,T8>>

Field Summary

Fields inherited from interface com.linkedin.parseq.Task

_taskDescriptor, LOGGER

Method Summary

Modifier and Type	Method and Description
default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8>	andThen(Consumer8<T1,T2,T3,T4,T5,T6,T7,T8> consumer) Equivalent to andThen("andThen", consumer).
default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8>	andThen(String desc, Consumer8<T1,T2,T3,T4,T5,T6,T7,T8> consumer) Creates a new task which applies a consumer to the result of this task and completes with a result of this task.
static <T1,T2,T3,T4,T5,T6,T7,T8> Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8>	cast(Task<Tuple8<T1,T2,T3,T4,T5,T6,T7,T8>> task)
default <R> Task<R>	flatMap(Function8<T1,T2,T3,T4,T5,T6,T7,T8,Task<R>> f) Equivalent to flatMap("flatMap", f).
default <R> Task<R>	flatMap(String desc, Function8<T1,T2,T3,T4,T5,T6,T7,T8,Task<R>> f) Creates a new task by applying a function to the successful result of this task and returns the result of a function as the new task.
default <R> Task<R>	map(Function8<T1,T2,T3,T4,T5,T6,T7,T8,R> f) Equivalent to map("map", f).
default <R> Task<R>	map(String desc, Function8<T1,T2,T3,T4,T5,T6,T7,T8,R> f) Creates a new task by applying a function to the successful result of this task.
default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8>	onFailure(Consumer1<Throwable> consumer) Equivalent to onFailure("onFailure", consumer).
default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8>	onFailure(String desc, Consumer1<Throwable> consumer) Creates a new task which applies a consumer to the exception this task may fail with.
default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8>	recover(Function1<Throwable,Tuple8<T1,T2,T3,T4,T5,T6,T7,T8>> f) Equivalent to recover("recover", func).
default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8>	recover(String desc, Function1<Throwable,Tuple8<T1,T2,T3,T4,T5,T6,T7,T8>> f) Creates a new task that will handle failure of this task.
default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8>	recoverWith(Function1<Throwable,Task<Tuple8<T1,T2,T3,T4,T5,T6,T7,T8>>> f) Equivalent to recoverWith("recoverWith", func).
default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8>	recoverWith(String desc, Function1<Throwable,Task<Tuple8<T1,T2,T3,T4,T5,T6,T7,T8>>> f) Creates a new task that will handle failure of this task.
default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8>	shareable() Creates a new task that can be safely shared within a plan or between multiple plans.
default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8>	withSideEffect(Function8<T1,T2,T3,T4,T5,T6,T7,T8,Task<?>> func) Equivalent to withSideEffect("sideEffect", func).
default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8>	withSideEffect(String desc, Function8<T1,T2,T3,T4,T5,T6,T7,T8,Task<?>> func) Creates a new task that will run another task as a side effect once the primary task completes successfully.
default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8>	withTimeout(long time, TimeUnit unit) Equivalent to withTimeout(null, time, unit).

Methods inherited from interface com.linkedin.parseq.Task

action, action, andThen, andThen, andThen, andThen, apply, async, async, async, async, blocking, blocking, callable, callable, contextRun, failure, failure, flatMap, flatMap, flatten, flatten, fromCompletionStage, fromCompletionStage, getId, getName, getPriority, getShallowTrace, getShallowTraceBuilder, getTrace, getTraceBuilder, map, map, par, par, par, par, par, par, par, par, par, par, par, par, par, par, par, setPriority, setTraceValueSerializer, toTry, toTry, transform, transform, value, value, withDelay, withDelay, withRetryPolicy, withRetryPolicy, withRetryPolicy, withRetryPolicy, withSafeSideEffect, withSafeSideEffect, withSafeSideEffect, withSafeSideEffect, withSideEffect, withSideEffect, withSideEffect, withSideEffect, withTimeout

Methods inherited from interface com.linkedin.parseq.promise.Promise

addListener, await, await, get, getError, getOrDefault, isDone, isFailed, toCompletionStage

Methods inherited from interface com.linkedin.parseq.Cancellable

cancel

Method Detail

map

default <R> Task<R> map(Function8<T1,T2,T3,T4,T5,T6,T7,T8,R> f)

Equivalent to map("map", f).

See Also:

map(String, Function8)

map

default <R> Task<R> map(String desc,
                        Function8<T1,T2,T3,T4,T5,T6,T7,T8,R> f)

Creates a new task by applying a function to the successful result of this task. Returned task will complete with value calculated by a function.

 Task <String> hello = Task.value("Hello World");

 // this task will complete with value 11
 Task <Integer> length = hello.map("length", s  -> s.length());
 

If this task is completed with an exception then the new task will also complete with that exception.

  Task <String> failing = Task.callable("hello", ()  -> {
    return "Hello World".substring(100);
  });

  // this task will fail with java.lang.StringIndexOutOfBoundsException
  Task <Integer> length = failing.map("length", s  -> s.length());
 

Type Parameters:

R - return type of function func

Parameters:

desc - description of a mapping function, it will show up in a trace

f - function to be applied to successful result of this task.

Returns:

a new task which will apply given function on result of successful completion of this task

flatMap

default <R> Task<R> flatMap(Function8<T1,T2,T3,T4,T5,T6,T7,T8,Task<R>> f)

Equivalent to flatMap("flatMap", f).

See Also:

flatMap(String, Function8)

flatMap

default <R> Task<R> flatMap(String desc,
                            Function8<T1,T2,T3,T4,T5,T6,T7,T8,Task<R>> f)

Creates a new task by applying a function to the successful result of this task and returns the result of a function as the new task. Returned task will complete with value calculated by a task returned by the function.

  Task <URI> url = Task.value("uri", URI.create("http://linkedin.com"));

  // this task will complete with contents of a LinkedIn homepage
  // assuming fetch(u) fetches contents given by a URI
  Task <String> homepage = url.flatMap("fetch", u  -> fetch(u));
 

If this task is completed with an exception then the new task will also contain that exception.

  Task <URI> url = Task.callable("uri", ()  -> URI.create("not a URI"));

  // this task will fail with java.lang.IllegalArgumentException
  Task <String> homepage = url.flatMap("fetch", u  -> fetch(u));
 

Type Parameters:

R - return type of function func

Parameters:

desc - description of a mapping function, it will show up in a trace

f - function to be applied to successful result of this task which returns new task to be executed

Returns:

a new task which will apply given function on result of successful completion of this task to get instance of a task which will be executed next

andThen

default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8> andThen(Consumer8<T1,T2,T3,T4,T5,T6,T7,T8> consumer)

Equivalent to andThen("andThen", consumer).

See Also:

andThen(String, Consumer8)

andThen

default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8> andThen(String desc,
                                                    Consumer8<T1,T2,T3,T4,T5,T6,T7,T8> consumer)

Creates a new task which applies a consumer to the result of this task and completes with a result of this task. It is used in situations where consumer needs to be called after successful completion of this task.

  Task <String> hello = Task.value("greeting", "Hello World");

  // this task will print "Hello World"
  Task <String> sayHello = hello.andThen("say", System.out::println);
 

If this task fails then consumer will not be called and failure will be propagated to task returned by this method.

  Task <String> failing = Task.callable("greeting", ()  -> {
    return "Hello World".substring(100);
  });

  // this task will fail with java.lang.StringIndexOutOfBoundsException
  Task <String> sayHello = failing.andThen("say", System.out::println);
 

Parameters:

desc - description of a consumer, it will show up in a trace

consumer - consumer of a value returned by this task

Returns:

a new task which will complete with result of this task

recover

default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8> recover(Function1<Throwable,Tuple8<T1,T2,T3,T4,T5,T6,T7,T8>> f)

Equivalent to recover("recover", func).

Specified by:

recover in interface Task<Tuple8<T1,T2,T3,T4,T5,T6,T7,T8>>

See Also:

Task.recover(String, Function1)

recover

default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8> recover(String desc,
                                                    Function1<Throwable,Tuple8<T1,T2,T3,T4,T5,T6,T7,T8>> f)

Creates a new task that will handle failure of this task. Early completion due to cancellation is not considered to be a failure. If this task completes successfully, then recovery function is not called.

 // this method return task which asynchronously retrieves Person by id
 Task <Person> fetchPerson(Long id) {
 (...)
 }

 // this task will fetch Person object and transform it into  "<first name> <last name>"
 // if fetching Person failed then form  "Member <id>" will be return
 Task <String> userName = fetchPerson(id)
      .map("toSignature", p  -> p.getFirstName() + " " + p.getLastName())
      .recover(e  -> "Member " + id);
 

Note that task cancellation is not considered to be a failure. If this task has been cancelled then task returned by this method will also be cancelled and recovery function will not be applied.

Specified by:

recover in interface Task<Tuple8<T1,T2,T3,T4,T5,T6,T7,T8>>

Parameters:

desc - description of a recovery function, it will show up in a trace

f - recovery function which can complete task with a value depending on failure of this task

Returns:

a new task which can recover from failure of this task

recoverWith

default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8> recoverWith(Function1<Throwable,Task<Tuple8<T1,T2,T3,T4,T5,T6,T7,T8>>> f)

Equivalent to recoverWith("recoverWith", func).

Specified by:

recoverWith in interface Task<Tuple8<T1,T2,T3,T4,T5,T6,T7,T8>>

See Also:

Task.recoverWith(String, Function1)

recoverWith

default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8> recoverWith(String desc,
                                                        Function1<Throwable,Task<Tuple8<T1,T2,T3,T4,T5,T6,T7,T8>>> f)

Creates a new task that will handle failure of this task. Early completion due to cancellation is not considered to be a failure. If this task completes successfully, then recovery function is not called.

 // this method return task which asynchronously retrieves Person by id from cache
 Task <Person> fetchFromCache(Long id) {
 (...)
 }

 // this method return task which asynchronously retrieves Person by id from DB
 Task <Person> fetchFromDB(Long id) {
 (...)
 }

 // this task will try to fetch Person from cache and
 // if it fails for any reason it will attempt to fetch from DB
 Task <Person> user = fetchFromCache(id).recoverWith(e  -> fetchFromDB(id));
 

If recovery task fails then returned task is completed with that failure.

Note that task cancellation is not considered to be a failure. If this task has been cancelled then task returned by this method will also be cancelled and recovery function will not be applied.

Specified by:

recoverWith in interface Task<Tuple8<T1,T2,T3,T4,T5,T6,T7,T8>>

Parameters:

desc - description of a recovery function, it will show up in a trace

f - recovery function provides task which will be used to recover from failure of this task

Returns:

a new task which can recover from failure of this task

onFailure

default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8> onFailure(Consumer1<Throwable> consumer)

Equivalent to onFailure("onFailure", consumer).

Specified by:

onFailure in interface Task<Tuple8<T1,T2,T3,T4,T5,T6,T7,T8>>

See Also:

Task.onFailure(String, Consumer1)

onFailure

default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8> onFailure(String desc,
                                                      Consumer1<Throwable> consumer)

Creates a new task which applies a consumer to the exception this task may fail with. It is used in situations where consumer needs to be called after failure of this task. Result of task returned by this method will be exactly the same as result of this task.

  Task <String> failing = Task.callable("greeting", ()  -> {
    return "Hello World".substring(100);
  });

  // this task will print out java.lang.StringIndexOutOfBoundsException
  // and complete with that exception as a reason for failure
  Task <String> sayHello = failing.onFailure("printFailure", System.out::println);
 

If this task completes successfully then consumer will not be called.

  Task <String> hello = Task.value("greeting", "Hello World");

  // this task will return "Hello World"
  Task <String> sayHello = hello.onFailure(System.out::println);
 

Exceptions thrown by a consumer will be ignored.

Note that task cancellation is not considered to be a failure. If this task has been cancelled then task returned by this method will also be cancelled and consumer will not be called.

Specified by:

onFailure in interface Task<Tuple8<T1,T2,T3,T4,T5,T6,T7,T8>>

Parameters:

desc - description of a consumer, it will show up in a trace

consumer - consumer of an exception this task failed with

Returns:

a new task which will complete with result of this task

shareable

default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8> shareable()

Creates a new task that can be safely shared within a plan or between multiple plans. Cancellation of returned task will not cause cancellation of the original task.

Sharing tasks within a plan or among different plans is generally not safe because task can be cancelled if it's parent has been resolved. Imagine situation where fetch task that fetches data from a remote server is shared among few plans. If one of those plans times out then all started tasks that belong to it will be automatically cancelled. This means that fetch may also be cancelled and this can affect other plans that are still running. Similar situation can happen even within one plan if task is used multiple times.

In example below google task has timeout 10ms what causes entire plan to fail and as a consequence all tasks that belong to it that have been started - in this case bing task. This may be problematic if bing task is used somewhere else.

 final Task <Response> google = HttpClient.get("http://google.com").task();
 final Task <Response> bing = HttpClient.get("http://bing.com").task();

 // this task will fail because google task will timeout after 10ms
 // as a consequence bing task will be cancelled
 final Task both = Task.par(google.withTimeout(10, TimeUnit.MILLISECONDS), bing);
 

shareable method solves above problem. Task returned by shareable() can be can be cancelled without affecting original task.

 final Task <Response> google = HttpClient.get("http://google.com").task();
 final Task <Response> bing = HttpClient.get("http://bing.com").task();

 // this task will fail because wrapped google task will timeout after 10ms
 // notice however that original googel and bing tasks were not cancelled
   final Task both =
       Task.par(google.shareable().withTimeout(10, TimeUnit.MILLISECONDS), bing.shareable());
 

Specified by:

shareable in interface Task<Tuple8<T1,T2,T3,T4,T5,T6,T7,T8>>

Returns:

new task that can be safely shared within a plan or between multiple plans. Cancellation of returned task will not cause cancellation of the original task.

withTimeout

default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8> withTimeout(long time,
                                                        TimeUnit unit)

Equivalent to withTimeout(null, time, unit).

Specified by:

withTimeout in interface Task<Tuple8<T1,T2,T3,T4,T5,T6,T7,T8>>

See Also:

Task.withTimeout(String, long, TimeUnit)

withSideEffect

default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8> withSideEffect(Function8<T1,T2,T3,T4,T5,T6,T7,T8,Task<?>> func)

Equivalent to withSideEffect("sideEffect", func).

See Also:

withSideEffect(String, Function8)

withSideEffect

default Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8> withSideEffect(String desc,
                                                           Function8<T1,T2,T3,T4,T5,T6,T7,T8,Task<?>> func)

Creates a new task that will run another task as a side effect once the primary task completes successfully. The properties of side effect task are:

• The side effect task will not be run if the primary task has not run e.g. due to failure or cancellation.
• The side effect does not affect returned task. It means that failure of side effect task is not propagated to returned task.
• The returned task is marked done once this task completes, even if the side effect has not been run yet.

The side effect task is useful in situations where operation (side effect) should continue to run in the background but it's execution is not required for the main computation. An example might be updating cache once data has been retrieved from the main source.

  Task <Long> id = Task.value("id", 1223L);

  // this task will be completed as soon as user name is fetched
  // by fetch() method and will not fail even if updateMemcache() fails
  Task <String> userName = id.flatMap("fetch", u  -> fetch(u))
      .withSideEffect("update memcache", u  -> updateMemcache(u));
 

Parameters:

desc - description of a side effect, it will show up in a trace

func - function to be applied on result of successful completion of this task to get side effect task

Returns:

a new task that will run side effect task specified by given function upon succesful completion of this task

cast

static <T1,T2,T3,T4,T5,T6,T7,T8> Tuple8Task<T1,T2,T3,T4,T5,T6,T7,T8> cast(Task<Tuple8<T1,T2,T3,T4,T5,T6,T7,T8>> task)