Replay
, (*1)
Re-play functions that error out!, (*2)
Some times things not always works at the first attempt.
Replay comes in allowing you to plan re-tries and fallbacks strategies for your
functions., (*3)
Install
composer require gousto/replay
Features
- Re-try functions within exception scope
- Increase delay for every attempt
- Create advanced re-try fallback strategies
Usage
If you want to replay a function when it throws an Exception here is an example:, (*4)
<?php
use Gousto\Replay\Replay;
try {
$result = Replay::retry(3, function() {
return Http::get('example.com');
}, 50);
Log::info("All good");
} catch(\Gousto\Replay\RetryLogicException $e) {
\Log::error("After 3 times the function still error out!");
}
This code will return you right away the result of Http::get(), if no Exception is occured., (*5)
In case of Exception it will retry again up to 3 times with a 50ms interval., (*6)
Increase delay at every attempt:
Let's say we want to have a re-try strategy that want to increase the interval at every attempt
i.e: 1st attempt 10ms, 2nd attempts 20ms 3rd attempt 40ms, (*7)
<?php
use Gousto\Replay\Replay;
$replay = Replay::times(3, function() {
throw new LogicException();
}, 10);
$replay->onRetry(function(Exception $e, Replay $replay) {
$replay->setDelay($replay->getDelay() * 2);
});
// play the strategy!
$replay->play();
Custom Exceptions
Replay allow you to trigger the retry logic only for particular Exceptions,
pass an array of Exceptions class names as 4th paramter:, (*8)
<?php
use Gousto\Replay\Replay;
// Will throw LogicException and not retry
Replay::retry(3, function() {
throw new LogicException();
}, 0, [RuntimeException::class]);
This will throw a LogicException when the function is invoked.
We are going to retry only when the RuntimeException is thrown., (*9)
API
- retry($attempts = 1, Closure $user_function, $delay = 0, $exception_targets = [Exception::class])
Return the result of the Closure if no exception is occured. Alternatevely it retries invoking the
function until the number of attempts specified. Throw Gousto\Replay\RetryLogicException::class if the number
of attempts remained is 0., (*10)
-
$attempts: int, number of attempts the function might be replayed
-
$user_function: Closure, function which will be replayed if errored
-
$delay: int, delay is measured in milliseconds
-
$exception_targets: array, list of exceptions which will be considered as errors
use Gousto\Replay\Replay;
Replay::retry(1, function() {
throw new Exception();
}, 0, [Exception::class]);
- times($attempts = 1, Closure $user_function, $delay = 0, $exception_targets = [])
Helper function for instantiate Replay, facilitate chaining, (*11)
-
$attempts: int, number of attempts the function might be replayed
-
$user_function: Closure, function which will be replayed if errored
-
$delay: int, delay is measured in milliseconds
-
$exception_targets: array, list of exceptions which will be considered as errors
use Gousto\Replay\Replay;
$replay = Replay::times(1, function() {
throw new Exception();
}, 0, [Exception::class]);
$replay->play();
play($silent = false):
Tell replay to invoke the function and use the retry logic if needed., (*12)
-
$silent: bool, if true will not throw RetryLogicException but will return it.
use Gousto\Replay\Replay;
$replay = Replay::times(2, function() {
throw new Exception();
}, 0, [Exception::class]);
$result = $replay->play(true); // $result instanceof RetryLogicException
$replay->play(); // throw RetryLogicException
onRetry(Closure $handler):
Hook a function that will be trigger for every attempt, this is useful for logging or
any other action., (*13)
use Gousto\Replay\Replay;
$counter = 0;
$replay = Replay::times(3, function() use (&$counter) {
$counter++;
if ($counter === 3) {
return $counter;
}
throw new Exception("Error");
});
// WILL LOG:
// Attempt 1: Failed
// Attempt 2: Failed
$replay->onRetry(function(Exception $exception, Replay $replay) {
Log::error("Attempt {$replay->attempts()}: Failed");
});
try {
$replay->play();
} catch(\Gousto\Replay\RetryLogicException $e) {
}
next():
The next function allow you to manually control the retry cycle, (*14)
use Gousto\Replay\Replay;
$replay = Replay::times(3, function() {
throw new Exception();
}, 0, [Exception::class]);
$replay->next(); // 1 attempt
$replay->next(); // 2 attempts
$replay->next(); // Throw RetryLogicException
attempts():
Return the number of retry attempts, (*15)
use Gousto\Replay\Replay;
$replay = Replay::times(3, function() {
throw new Exception();
}, 0, [Exception::class]);
$replay->next();
$replay->attempts(); // 1
$replay->next();
$replay->attempts(); // 2
isErrored():
Return the state of the function invokation, (*16)
$replay = Replay::times(4, function() {
return 10;
}, 0, [Exception::class]);
$result = $replay->play(); // 10
$replay->isErrored(); // False
Credits
www.gousto.co.uk, (*17)
Wallogit.com
