Php sdk-v3-async
- 1. AWS PHP SDK v3 Asynchronous Requests Michael Dowling @mtdowling
- 2. AWS PHP SDK v3 Asynchronous Requests Michael Dowling @mtdowling
- 3. What we’ll cover • Promises • Handlers and Middleware • ReactPHP in the SDK
- 4. • A promise represents the eventual result of an asynchronous operation. • Promises are values and are composable https://promisesaplus.com/ Promises/A+
- 5. Promises • A promise has a then() method, which allows access to its current or eventual value or reason. • Promises are resolved with a value or rejected with a reason. • State transitions: Pending -> (Fulfilled | Rejected) • Fulfilled and rejected promises are immutable. https://promisesaplus.com/
- 6. Promises
- 7. then() • Calling then() on a promise will return a new promise that is fulfilled or rejected based on the result of invoking the provided then($onFullfilled, $onRejected) callbacks. • If a callback throws, the promise is rejected and downstream promises are rejected. • If a rejected callback does not throw, downstream promises are fulfilled. • If a promise is fulfilled or rejected with a promise, any callbacks registered on the promise will not be invoked until the promise is resolved.
- 8. then()
- 9. Promises in the SDK 1. 2.
- 10. • Multiple promises can be composed together into a single promise using combinators • Guzzle ships with several combinators Promise Combinators
- 17. SDK Pool
- 18. Handlers and Middleware • A handler is a function that performs the actual transformation of a command and request into a result (e.g., Guzzle is a handler). • A middleware is a higher-order function that modifies a command, request, or result as it passes through the middleware. • A HandlerList is used by clients and commands to compose middleware on a handler.
- 19. Handlers
- 20. HandlerList • A client has a HandlerList that contains a handler and a list of middleware. • Each command created by a client get a clone of the client’s HandlerList that allows per/ command customizations.
- 21. HandlerList • Request lifecycle in the HandlerList init -> validate -> build -> sign sign -> build -> validate -> init execute returns Promise<Result, Exception> Command
- 23. Middleware
- 24. Anatomy of a middleware Example: Validation middleware. 2) Shared state 3) Return a composable function 4) Return a new composed handler 5) Call the next handler and return a promise 1) Wrapping function
- 26. • Some handlers support async, some emulate. • cURL handlers support async but must use wait or you must tick the curl event loop explicitly. • Some handlers support async interop with event loops… Custom Handlers
- 27. Using a custom handler • http_handler: works at the PSR-7 layer. handler($request, $options): Promise<Response, Error> • handler: works at the SDK layer. handler($command, $request): Promise<Result, Error>
- 28. Using a custom handler
- 29. React Guzzle Handler • The SDK supports Guzzle. • Cees-Jan Kiewiet created a React Guzzle handler. • Therefore you can use React with the SDK! composer require wyrihaximus/react-‐guzzle-‐psr7 https://github.com/WyriHaximus/react-guzzle-psr7
- 30. Questions?