mirror of https://github.com/rwf2/Rocket.git
Add placeholder v0.5 to v0.6 upgrade guide.
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# Upgrading
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Rocket v0.5 bring many new features and improvements over Rocket v0.4. Rocket
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v0.5 also includes many changes that improve the overall usability, stability,
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and security of the framework and applications written in it. While the Rust
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compiler can guide you through many of these changes, others require special
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attention. The intent of this guide is to guide you through these changes and
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more, migrating your Rocket application to 0.5 and reaping the benefits of new
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features and improvements.
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This guide is _not_ intended to replace, but instead complement, a reading of
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the [CHANGELOG]. The [CHANGELOG] should be considered required reading for all
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developers wishing to migrate their applications to Rocket v0.5.
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[CHANGELOG]: @github/CHANGELOG.md
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! note Don't panic!
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Simply upgrading Rocket's version string to the `0.5` series will result in
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_many_ `rustc` compiler errors. But don't let this faze you! The vast majority
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of changes are simple renames and `#[async_trait]` attributions which manifest
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in a cascading of errors. As such, resolving _one_ top-level issue, typically
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requiring minimal, trivial changes, often resolves _many_ errors in one go.
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## Crate Organization
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Rocket v0.5 incorporates an improved module structure and crate ecosystem.
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Modules and items that have been moved or removed will trigger a compiler error.
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We encourage users to search through the [CHANGELOG] or [API docs](@api/rocket)
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for the v0.5 analog. All previously existing functionality, except for that
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incompatible with async I/O, is available in v0.5.
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### Off-by-Default Secrets
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The `private-cookies` crate feature, which was previously enabled by default,
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has been renamed to `secrets` and is disabled by default. If you are using
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private cookies, you _must_ enable the `secrets` feature in `Cargo.toml`:
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```toml
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[dependencies]
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rocket = { version = "0.5.0", features = ["secrets"] }
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```
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### Contrib Deprecation
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The `rocket_contrib` crate is deprecated and is wholly incompatible with Rocket
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0.5. _All_ users of `rocket_contrib` _must_:
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* Remove all dependencies and references to `rocket_contrib`.
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* For templating support, depend on the new [`rocket_dyn_templates`] crate.
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* For database pools, depend on the new [`rocket_sync_db_pools`] and/or
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[`rocket_db_pools`] crates.
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* Enable [features in `rocket`] as necessary.
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For example, to make use of JSON and Tera templates, make the following changes
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to `Cargo.toml`:
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```diff
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[dependencies]
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- rocket = "0.4"
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- rocket_contrib = { version = "0.4", features = ["json"], default-features = false }
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+ rocket = { version = "0.5.0", features = ["json"] }
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+ rocket_dyn_templates = { version = "0.1.0", features = ["tera"] }
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```
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! note: `rocket_dyn_templates` (and co.) _does not_ follow in version lock-step
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with the `rocket` crate.
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This is intentional. The crate depends on many external dependencies which may
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evolve at a different pace than Rocket itself. Allowing their versions to
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diverge enables keeping dependencies up-to-date without breaking `rocket`
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itself.
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All features previously in `rocket_contrib` are available. Consult the [contrib
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graduation] section of the CHANGELOG for full details.
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[`rocket_dyn_templates`]: @api/rocket_dyn_templates
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[`rocket_sync_db_pools`]: @api/rocket_sync_db_pools
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[`rocket_db_pools`]: @api/rocket_db_pools
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[features in `rocket`]: @api/rocket/#features
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[contrib graduation]: @github/CHANGELOG.md#contrib-graduation
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## Stable and Async Support
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Rocket v0.5 compiles and builds on Rust stable with an entirely asynchronous
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core. You are encouraged to:
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* Switch to the Rust stable release channel for production builds.
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* Remove the previously required `#![feature(..)]` crate attribute.
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All application authors _must_:
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* Use `rocket::build()` instead of `rocket::ignite()`.
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* Use either the `#[launch]` or `#[rocket::main]` async entry attribute.
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* Use `async` versions of any blocking I/O or execute it in another thread.
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Application authors _may_:
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* Prefer to explicitly import macros via `use` instead of `#[macro_use]`.
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The rest of the section describes making these changes in detail.
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### Stable Release Channel
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If you prefer to use Rust's stable release channel, you can switch to it using
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`rustup`:
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```sh
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## switch globally
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rustup default stable
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## switch locally
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rustup override set stable
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```
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Using the stable release channel ensures that _no_ breakages will occur when
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upgrading your Rust compiler or Rocket. That being said, Rocket continues to
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take advantage of features only present in the nightly channel. As a result, the
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development experience will be superior on nightly for the foreseeable future.
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For example, compiler diagnostics on `nightly` are more detailed and accurate:
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<details>
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<summary>Example Diagnostic on Nightly</summary>
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```rust,ignore
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error: invalid parameters for `has_two` route uri
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--> $DIR/typed-uris-bad-params.rs:55:18
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|
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55 | uri!(has_two(id = 100, cookies = "hi"));
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| ^^^^^^^^^^^^^^^^^^^^^^^^
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|
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= note: uri parameters are: id: i32, name: String
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= help: missing parameter: `name`
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help: unknown parameter: `cookies`
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--> $DIR/typed-uris-bad-params.rs:55:28
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|
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55 | uri!(has_two(id = 100, cookies = "hi"));
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| ^^^^^^^
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```
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</details>
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<details>
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<summary>Example Diagnostic on Stable</summary>
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```rust,ignore
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error: invalid parameters for `has_two` route uri
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--- note: uri parameters are: id: i32, name: String
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--- help: missing parameter: `name`
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--> $DIR/typed-uris-bad-params.rs:55:18
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|
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55 | uri!(has_two(id = 100, cookies = "hi"));
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| ^^
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error: [help] unknown parameter: `cookies`
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--> $DIR/typed-uris-bad-params.rs:55:28
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|
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55 | uri!(has_two(id = 100, cookies = "hi"));
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| ^^^^^^^
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```
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</details>
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Our **recommendation** is to develop locally on the nightly channel but build
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and deploy for production on the stable channel.
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### Feature Attribute
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As a result of support for the stable release channel, Rocket applications no
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longer need to enable any features to be used. You should **remove all
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`#[feature(..)]` crate attributes:**
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```diff
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- #![feature(proc_macro_hygiene, decl_macro)]
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-
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#[macro_use] extern crate rocket;
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fn main() { .. }
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```
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### Updates to Launch
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The new asynchronous core requires an async runtime to run. The new
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[`launch`] and [`main`] attributes simplify starting a runtime suitable for
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running Rocket applications. You should use [`launch`] whenever possible.
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Additionally, the `rocket::ignite()` function has been renamed to
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[`rocket::build()`]; calls to the function or method should be replaced
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accordingly. Together, these two changes result in the following diff to what
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was previously the `main` function:
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```diff
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- fn main() {
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- rocket::ignite().mount("/hello", routes![hello]).launch();
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- }
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+ #[launch]
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+ fn rocket() -> _ {
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+ rocket::build().mount("/hello", routes![hello])
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+ }
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```
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[`launch`]: @api/rocket/attr.launch.html
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[`main`]: @api/rocket/attr.main.html
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[`rocket::build()`]: @api/rocket/struct.Rocket.html#method.build
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### Blocking I/O
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Rocket v0.5 takes advantage of the latest developments in async I/O in Rust by
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migrating to a fully asynchronous core powered by [`tokio`]. Specifically,
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_every_ request is handled by an asynchronous task which internally calls one or
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more request handlers. Asynchronous tasks are multiplexed on a [configurable
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number of worker threads]. Though there is no limit to the number of tasks that
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can run concurrently, at most `worker` tasks can run in parallel.
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The runtime can switch between tasks in a single worker thread _iff_ <small>(_if
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and only if_)</small> an `await` point in reached. In other words, context
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switching is _cooperative_, _not_ preemptive. This _iff_ is critical: if an
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`await` point is _not_ reached, no task switching can occur. As such, it is
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important that `await` points occur periodically in a task so that tasks waiting
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to be scheduled are not starved.
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In general, when working with `async` APIs, await points occur naturally.
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However, an application written for synchronous I/O, including all Rocket
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applications prior to v0.5, must take great care to convert all synchronous,
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blocking I/O, to `async` I/O. This is because, as the name implies, blocking I/O
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blocks a thread from making progress until the I/O result is available, meaning
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that no tasks can be scheduled on the waiting thread, wasting valuable resources
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and degrading performance.
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Common sources of blocking I/O and their `async` replacements include:
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* Anything in `std::fs`: replace with `rocket::tokio::fs`.
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* Anything in `std::sync`: replace with `rocket::tokio::sync`.
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* Anything in `std::net`: replace with `rocket::tokio::net`.
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* Anything in `std::io`: replace with `rocket::tokio::io`.
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* Sleep or timers: replace with `rocket::tokio::time`.
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* Any networking: replace with `rocket::tokio::net`.
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* Any file system access: replace with `rocket::tokio::fs`.
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Unfortunately, the Rust compiler provides no support for identifying blocking
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I/O via lints or compile-time checks: it is up to you to scan your application
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for sources of blocking I/O and replace them with their `async` counterpart. If
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no such counterpart exists, you should execute the relevant I/O in its own
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thread by using [`rocket::tokio::task::spawn_blocking`].
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All of Rocket's I/O APIs have been updated to be `async`-safe.
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This results in requiring `.await` calls for common APIs like [`NamedFile`]. To
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use `.await` in a route, the handler must be marked with `async`:
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```rust
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# use rocket::get;
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use rocket::fs::NamedFile;
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#[get("/")]
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async fn index() -> Option<NamedFile> {
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NamedFile::open("index.html").await.ok()
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}
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```
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! warning: Non-`async` routes are _also_ executed on the `async` runtime.
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A route that _isn't_ declared as `async` is _still_ executed on the `async`
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runtime. As a result, it should not execute blocking I/O.
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<details>
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<summary>See a diff of the changes from v0.4.</summary>
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```diff
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- use rocket::response::NamedFile;
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+ use rocket::fs::NamedFile;
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#[get("/")]
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- fn index() -> Option<NamedFile> {
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- NamedFile::open("index.html").ok()
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+ async fn index() -> Option<NamedFile> {
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+ NamedFile::open("index.html").await.ok()
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}
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```
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</details>
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[`tokio`]: https://tokio.rs
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[configurable number of worker threads]: ../configuration/#workers
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[`NamedFile`]: @api/rocket/fs/struct.NamedFile.html
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[`rocket::tokio::task::spawn_blocking`]: @tokio/task/fn.spawn_blocking.html
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### Blocking Compute
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By the same reasoning, performing large amounts of compute (really, just another
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form of I/O) can prevent other tasks from executing in a timely manner. If you
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are performing long computations in a handler, you should execute the
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computation in its own thread, again using [`rocket::tokio::task::spawn_blocking`]:
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```rust
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# use rocket::get;
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use rocket::tokio::task;
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use rocket::response::Debug;
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#[get("/")]
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async fn expensive() -> Result<(), Debug<task::JoinError>> {
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let result = task::spawn_blocking(move || {
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// perform the computation
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}).await?;
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Ok(result)
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}
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```
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### Async Traits
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To support `async` methods in traits, Rocket provides the [`async_trait`]
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attribute. The attribute _must_ be applied to all implementations of _async
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traits_ like [`FromRequest`] and [`Fairing`]:
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```diff
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use rocket::request::{self, Request, FromRequest};
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+ #[rocket::async_trait]
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impl<'r> FromRequest<'r> for MyType {
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type Error = MyError;
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- fn from_request(req: &'r Request<'_>) -> request::Outcome<Self, Self::Error> {
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+ async fn from_request(req: &'r Request<'_>) -> request::Outcome<Self, Self::Error> {
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/* .. */
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}
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}
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```
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All trait documentation has been updated to call out such traits with an example
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implementation that includes the invocation. The example implementation also
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serves as better documentation for trait and trait method signatures than the
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rustdocs. Because `async_trait` modifies these signatures, the rustdocs diverge
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from what is written in the source. For example, rustdoc renders:
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```rust,ignore
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fn from_request<'life0, 'async_trait>(
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request: &'r Request<'life0>
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) -> Pin<Box<dyn Future<Output = Outcome<Self, Self::Error>> + Send + 'async_trait>>;
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```
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...whereas the source looks like:
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```rust,ignore
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async fn from_request(req: &'r Request<'_>) -> Outcome<Self, Self::Error>;
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```
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Unfortunately, rustdoc does not provide a mechanism to render the source as it
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is written. As such, we encourage all authors to use the examples as the source
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of truth for trait and method signatures.
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[`async_trait`]: @api/rocket/attr.async_trait.html
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[`FromRequest`]: @api/rocket/request/trait.FromRequest.html
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[`Fairing`]: @api/rocket/fairing/trait.Fairing.html
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## Configuration
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Rocket's configuration system has been entirely revamped for v0.5. The
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[configuration](../configuration) section of the guide contains a full
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walkthrough of the new system while the [general changes] section of the
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[CHANGELOG] contains further details on configuration changes. We call out the
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most important of these changes here. All users _must_:
|
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|
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* Replace the `ROCKET_ENV` environment variable with `ROCKET_PROFILE`.
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* Replace the `ROCKET_LOG` environment variable with `ROCKET_LOG_LEVEL`.
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* Use only IP addresses for the `address` configuration parameter.
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* Replace the `dev` or `development` profile with `debug`.
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* Note that the `stage`, `staging`, `prod`, and `production` profiles carry no
|
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special meaning in v0.5.
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* Use `0` to disable `keep_alive` instead of `false` or `off`.
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* Replace uses of "extras" with [typed extraction].
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Rocket will emit warnings at launch time if use of the previous functionality is
|
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detected.
|
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### Profiles
|
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The new system deals with "profiles" where there were previously "environments".
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As opposed to environments, profiles:
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* Can be arbitrarily named and any number can exist.
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* Match Rust profiles in naming: `debug` and `release` are the default
|
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profiles for the respective Rust compilation profile.
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* Are programmatically selectable and configurable.
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* Have a `default` profile with fallback values for all profiles.
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* Have a `global` profile with overrides for all profiles.
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|
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Authors should read the new [configuration](../configuration) section of the
|
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guide to determine the scope of changes required. This likely includes:
|
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|
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* Defining most configuration in the `default` profile instead.
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* Using the `debug` profile where `dev` or `development` was used.
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* Using the `release` profile where `prod` or `production` was used.
|
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|
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[general changes]: @github/CHANGELOG.md#general
|
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[typed extraction]: ../configuration/#extracting-values
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### Typed Extraction
|
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|
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The "extras" configuration in v0.4 is entirely replaced by [typed extraction],
|
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which allows any `Deserialize` structure to be derived from configuration
|
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sources. All users _should_ make use of typed extraction where "extras" were
|
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being used previously. The diff below illustrates one such example:
|
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|
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```diff
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use rocket::fairing::AdHoc;
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+ #[derive(Deserialize)]
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struct AppConfig {
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id: Option<usize>,
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port: u16,
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}
|
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|
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- fn main() {
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- rocket::ignite()
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- .attach(AdHoc::on_attach("Token Config", |rocket| {
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- println!("Adding token managed state from config...");
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- let id = match rocket.config().get_int("id") {
|
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- Ok(v) if v >= 0 => Some(v as usize),
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- _ => None,
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- };
|
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-
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- let port = match rocket.config().get_int("port") {
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- Ok(v) if v => 0 && v < 1 << 16 => v as u16,
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- _ => return Err(rocket)
|
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- };
|
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-
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- Ok(rocket.manage(AppConfig { id, port }))
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- }))
|
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- }
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||||
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+ #[launch]
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+ fn rocket() -> _ {
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+ rocket::build().attach(AdHoc::config::<AppConfig>())
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||||
+ }
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```
|
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|
||||
## Routing
|
||||
|
||||
Rocket v0.5 brings several major changes that affect routing:
|
||||
|
||||
1. [Default ranking] is more precise, so fewer routes need manual ranking.
|
||||
2. Multi-segment route parameters (`<foo..>`) now match _zero_ or more
|
||||
segments.
|
||||
3. Parameters are _always_ percent-decoded, so `&RawStr` no longer implements
|
||||
`FromParam`.
|
||||
4. Query parameters parse with [`FromForm`] instead of `FromQuery` and support
|
||||
arbitrarily collections, nesting, structures, etc.
|
||||
5. All UTF-8 characters are allowed in static path components: `#[get("/🚀")]`.
|
||||
6. The [`register()`] method require a path to [scope catchers] under. Using
|
||||
`"/"` emulates the previous behavior.
|
||||
|
||||
[Default ranking]: ../requests#default-ranking
|
||||
[`FromForm`]: @api/rocket/form/trait.FromForm.html
|
||||
[`FromParam`]: @api/rocket/request/trait.FromParam.html
|
||||
[`register()`]: @api/rocket/struct.Rocket.html#method.register
|
||||
[scope catchers]: ../requests/#scoping
|
||||
|
||||
### Default Ranks
|
||||
|
||||
Default route ranking now takes into account partially dynamic paths, increasing
|
||||
the range of default ranks from `[-6, -1]` to `[-12, -1]`. The net effect is
|
||||
that fewer routes collide by default, requiring less manual ranking. For
|
||||
example, the following two routes collide in v0.4 but not in v0.5:
|
||||
|
||||
```rust
|
||||
# use rocket::get;
|
||||
|
||||
#[get("/foo/<_>/bar")]
|
||||
fn foo_bar() { }
|
||||
|
||||
#[get("/<_..>")]
|
||||
fn everything() { }
|
||||
```
|
||||
|
||||
<details>
|
||||
<summary>See a diff of the changes from v0.4.</summary>
|
||||
|
||||
```diff
|
||||
- #[get("/foo/<_>/bar", rank = 1)]
|
||||
+ #[get("/foo/<_>/bar")]
|
||||
fn foo_bar() { }
|
||||
|
||||
- #[get("/<_..>", rank = 2)]
|
||||
+ #[get("/<_..>")]
|
||||
fn everything() { }
|
||||
```
|
||||
</details>
|
||||
|
||||
**The recommendation** is to remove all unnecessary manual ranking parameters.
|
||||
For smaller applications, you may find that _all_ manual ranks can be removed.
|
||||
Larger applications may still require ranks to resolve ambiguities.
|
||||
|
||||
### Kleene Multi-Segments
|
||||
|
||||
The multi-segment route parameter `<foo..>` now matches _zero or more_ segments,
|
||||
a change from the previous _one_ or more segments. The implication is two-fold:
|
||||
|
||||
1. Where previously two routes were required to match a prefix and its
|
||||
suffixes, now one suffices:
|
||||
|
||||
```diff
|
||||
- #[get("/")]
|
||||
- fn index();
|
||||
|
||||
- #[get("/<path..>")]
|
||||
- fn rest(path: PathBuf);
|
||||
|
||||
+ #[get("/<path..>")]
|
||||
+ fn all(path: PathBuf);
|
||||
```
|
||||
|
||||
2. A prefix collides with a route that matches all of its suffixes. For
|
||||
example, `index` and `rest` above collide.
|
||||
|
||||
Most applications will likely benefit from this change by allowing the extra
|
||||
prefix-only route to be removed entirely. If the previous functionality of
|
||||
requiring at least one segment is desired, a route that explicitly matches the
|
||||
first segment can be used:
|
||||
|
||||
```rust
|
||||
# use std::path::PathBuf;
|
||||
# use rocket::get;
|
||||
|
||||
#[get("/<first>/<rest..>")]
|
||||
fn rest(first: PathBuf, rest: PathBuf) { /* .. */ }
|
||||
```
|
||||
|
||||
### Fewer Raw Strings
|
||||
|
||||
Rocket v0.5 makes a concerted effort to limit the exposure to strings from the
|
||||
raw HTTP payload. In line with this philosophy, Rocket now percent-decodes all
|
||||
incoming parameters automatically as opposed to doing so on-demand. The
|
||||
corollary is three-fold:
|
||||
|
||||
1. The `&RawStr` type no longer implements [`FromParam`].
|
||||
2. The `&str` type now implements [`FromParam`] and is fully decoded.
|
||||
3. The `String` parameter type is identical to the `&str` type and should be
|
||||
avoided.
|
||||
|
||||
Most applications can simply swap uses of `&RawStr` and `String` for `&str` in
|
||||
routes, forms, and so on to benefit from the increased safety and performance.
|
||||
For instance, the front-page example becomes:
|
||||
|
||||
```diff
|
||||
#[get("/<name>/<age>")]
|
||||
- fn hello(name: String, age: u8) -> String {
|
||||
+ fn hello(name: &str, age: u8) -> String {
|
||||
format!("Hello, {} year old named {}!", age, name)
|
||||
}
|
||||
```
|
||||
|
||||
A form that previously used `String` becomes:
|
||||
|
||||
```diff
|
||||
#[derive(FromForm)]
|
||||
- struct MyForm {
|
||||
+ struct MyForm<'r> {
|
||||
- value: String,
|
||||
+ value: &'r str,
|
||||
}
|
||||
```
|
||||
|
||||
### Queries as Forms
|
||||
|
||||
Query strings in Rocket v0.5 are in parity with forms and support their [full
|
||||
breadth](../requests#forms). Single segment query parameters (`<foo>`) should
|
||||
require little to no changes, except that they now support collections,
|
||||
structures, and any other `FromForm` type. This implies that the majority, if
|
||||
not _all_ custom `FromQuery` implementations, should be derivable via `FromForm`
|
||||
or have a built-in equivalent like `Vec<T>`:
|
||||
|
||||
```rust
|
||||
# use rocket::post;
|
||||
|
||||
#[post("/?<numbers>")]
|
||||
fn form(numbers: Vec<usize>) { /* .. */ }
|
||||
```
|
||||
|
||||
Multi-segment query parameters (`<foo..>`) no longer require the use of a
|
||||
`Form<T>` guard. Instead, `T` can be used directly:
|
||||
|
||||
```diff
|
||||
#[derive(FromForm)]
|
||||
struct Person { /* .. */ }
|
||||
|
||||
#[get("/hello?<person..>")]
|
||||
- fn hello(person: Option<Form<Person>>)
|
||||
+ fn hello(person: Option<Person>)
|
||||
```
|
||||
|
||||
## Forms
|
||||
|
||||
Rocket v0.5 introduces entirely revamped [forms] with support for:
|
||||
|
||||
* [Multipart uploads.](../requests#multipart)
|
||||
* [Collections: maps, vectors, and more.](../requests#collections)
|
||||
* [Nesting.](../requests#nesting)
|
||||
* [Ad-Hoc validation.](../requests#ad-hoc-validation)
|
||||
|
||||
Additionally, the [`FromForm` derive] has been substantially improved so that
|
||||
nearly all custom implementations of `FromForm` or [`FromFormField`], which
|
||||
replaces `FromFormValue` from v0.4, can be derived. Altogether, this means that
|
||||
any external crate dependency for form handling and most custom `FromForm` or
|
||||
`FromFormValue` implementations are unnecessary and should be removed.
|
||||
|
||||
[`FromFormField`]: @api/rocket/form/trait.FromFormField.html
|
||||
|
||||
### Multipart
|
||||
|
||||
If your application used an external crate to accept multipart form submissions,
|
||||
the dependency should be removed: Rocket v0.5 natively handles multipart. A file
|
||||
upload can be accepted via the [`TempFile`] form guard:
|
||||
|
||||
```rust
|
||||
# #[macro_use] extern crate rocket;
|
||||
|
||||
use rocket::form::Form;
|
||||
use rocket::fs::TempFile;
|
||||
|
||||
#[derive(FromForm)]
|
||||
struct Upload<'r> {
|
||||
save: bool,
|
||||
file: TempFile<'r>,
|
||||
}
|
||||
|
||||
#[post("/upload", data = "<upload>")]
|
||||
fn upload(upload: Form<Upload<'_>>) { /* .. */ }
|
||||
```
|
||||
|
||||
[`TempFile`]: @api/rocket/fs/enum.TempFile.html
|
||||
|
||||
### Field Validation
|
||||
|
||||
In Rocket v0.4, it was encouraged and often required to implement
|
||||
`FromFormValue` to introduce typed field validation. In v0.5, this can be
|
||||
accomplished by [deriving `FromForm`]:
|
||||
|
||||
```diff
|
||||
- use rocket::request::FromFormValue;
|
||||
- use rocket::http::RawStr;
|
||||
-
|
||||
- struct AdultAge(usize);
|
||||
-
|
||||
- impl<'v> FromFormValue<'v> for AdultAge {
|
||||
- type Error = &'v RawStr;
|
||||
-
|
||||
- fn from_form_value(form_value: &'v RawStr) -> Result<AdultAge, &'v RawStr> {
|
||||
- match form_value.parse::<usize>() {
|
||||
- Ok(age) if age >= 21 => Ok(AdultAge(age)),
|
||||
- _ => Err(form_value),
|
||||
- }
|
||||
- }
|
||||
- }
|
||||
|
||||
+ #[derive(FromForm)]
|
||||
+ #[field(validate = range(21..))]
|
||||
+ struct AdultAge(usize);
|
||||
```
|
||||
|
||||
If a given validation is used once, a new type may offer no additional safety.
|
||||
The validation can be performed directly on a field:
|
||||
|
||||
```rust
|
||||
use rocket::form::FromForm;
|
||||
|
||||
#[derive(FromForm)]
|
||||
struct MyForm {
|
||||
#[field(validate = range(21..))]
|
||||
age: usize,
|
||||
}
|
||||
```
|
||||
|
||||
[forms]: ../requests#forms
|
||||
[`FromForm` derive]: @api/rocket/derive.FromForm.html
|
||||
[deriving `FromForm`]: @api/rocket/derive.FromForm.html
|
||||
|
||||
## Notable New Features
|
||||
|
||||
Rocket v0.5 brings an abundance of new features that enable new functionality,
|
||||
increase productivity, and make existing applications more robust. We encourage
|
||||
all users to take advantage of these new features.
|
||||
|
||||
### Sentinels
|
||||
|
||||
Rocket v0.5 introduces [sentinels]. Entirely unique to Rocket, sentinels offer
|
||||
an automatic last line of defense against runtime errors by enabling any type
|
||||
that appears in a route to abort application launch if invalid conditions are
|
||||
detected. For example, the [`&State<T>`] guard in v0.5 is a [`Sentinel`] that
|
||||
aborts launch if the type `T` is not in managed state, thus preventing
|
||||
associated runtime errors.
|
||||
|
||||
You should consider implementing `Sentinel` for your types if you have guards
|
||||
(request, data, form, etc.) or responders that depend on `Rocket` state to
|
||||
function properly. For example, consider a `MyResponder` that expects:
|
||||
|
||||
* An error catcher to be registered for the `400` status code.
|
||||
* A specific type `T` to be in managed state.
|
||||
|
||||
Making `MyResponder` a sentinel that guards against these conditions is as
|
||||
simple as:
|
||||
|
||||
```rust
|
||||
use rocket::{Rocket, Ignite, Sentinel};
|
||||
# struct MyResponder;
|
||||
# struct T;
|
||||
|
||||
impl Sentinel for MyResponder {
|
||||
fn abort(r: &Rocket<Ignite>) -> bool {
|
||||
!r.catchers().any(|c| c.code == Some(400)) || r.state::<T>().is_none()
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
[sentinels]: @api/rocket/trait.Sentinel.html
|
||||
[`Sentinel`]: @api/rocket/trait.Sentinel.html
|
||||
[`&State<T>`]: @api/rocket/struct.State.html
|
||||
|
||||
### More Typed URIs
|
||||
|
||||
Rocket v0.5 brings a completely overhauled [`uri!()`] macro and support for
|
||||
typed URIs in more APIs. Notably, the `uri!()` macro now:
|
||||
|
||||
* Allows URIs to be constructed from and as static values:
|
||||
|
||||
```rust
|
||||
# use rocket::uri;
|
||||
use rocket::http::uri::Absolute;
|
||||
|
||||
const HOST: Absolute<'static> = uri!("http://localhost:8000");
|
||||
```
|
||||
|
||||
* Allows static and dynamic [prefixes and suffixes] to route URIs to be
|
||||
specified:
|
||||
|
||||
```rust
|
||||
# use rocket::{uri, get};
|
||||
|
||||
#[get("/person/<name>?<age>")]
|
||||
fn person(name: &str, age: Option<u8>) { }
|
||||
|
||||
let uri = uri!("https://rocket.rs/", person("Bob", Some(28)), "#woo");
|
||||
assert_eq!(uri.to_string(), "https://rocket.rs/person/Bob?age=28#woo");
|
||||
|
||||
let host = uri!("http://bob.me");
|
||||
let uri = uri!(host, person("Bob", Some(28)));
|
||||
assert_eq!(uri.to_string(), "http://bob.me/person/Bob?age=28");
|
||||
```
|
||||
|
||||
APIs like [`Redirect`] and [`Client`] now accept typed URIs:
|
||||
|
||||
```rust
|
||||
# #[macro_use] extern crate rocket;
|
||||
|
||||
use rocket::response::Redirect;
|
||||
|
||||
#[get("/bye/<name>/<age>")]
|
||||
fn bye(name: &str, age: u8) -> Redirect {
|
||||
Redirect::to(uri!("https://rocket.rs", bye(name, age), "?bye#now"))
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test() {
|
||||
use rocket::local::blocking::Client;
|
||||
|
||||
let client = Client::new(rocket::build());
|
||||
let r = client.get(uri!(super::bye("Bob", 30))).dispatch();
|
||||
}
|
||||
```
|
||||
|
||||
[URI types] have been overhauled accordingly. A new [`Reference`] type encodes
|
||||
URI-references. Additionally, all URI types are now `Serialize` and
|
||||
`Deserialize`, allowing URIs to be used in configuration and passed over the
|
||||
wire.
|
||||
|
||||
[`Redirect`]: @api/rocket/response/struct.Redirect.html
|
||||
[`Client`]: @api/rocket/local/index.html
|
||||
[prefixes and suffixes]: @api/rocket/macro.uri.html#prefixes-and-suffixes
|
||||
[`uri!()`]: @api/rocket/macro.uri.html
|
||||
[URI types]: @api/rocket/http/uri/index.html
|
||||
[`Reference`]: @api/rocket/http/uri/struct.Reference.html
|
||||
|
||||
### Real-Time Streams
|
||||
|
||||
Rocket v0.5 introduces real-time, typed, `async` [streams]. The new [async
|
||||
streams] section of the guide contains further details, and we encourage all
|
||||
interested parties to see the new real-time, multi-room [chat example].
|
||||
|
||||
As a taste of what's possible, the following `stream` route emits a `"ping"`
|
||||
Server-Sent Event every `n` seconds, defaulting to `1`:
|
||||
|
||||
```rust
|
||||
# use rocket::*;
|
||||
use rocket::response::stream::{Event, EventStream};;
|
||||
use rocket::tokio::time::{interval, Duration};
|
||||
|
||||
#[get("/ping?<n>")]
|
||||
fn stream(n: Option<u64>) -> EventStream![] {
|
||||
EventStream! {
|
||||
let mut timer = interval(Duration::from_secs(n.unwrap_or(1)));
|
||||
loop {
|
||||
yield Event::data("ping");
|
||||
timer.tick().await;
|
||||
}
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
[streams]: @api/rocket/response/stream/index.html
|
||||
[async streams]: ../responses/#async-streams
|
||||
[chat example]: @example/chat
|
||||
|
||||
### WebSockets
|
||||
|
||||
Rocket v0.5 introduces support for HTTP connection upgrades via a new [upgrade
|
||||
API]. The API allows responders to take over an HTTP connection and perform raw
|
||||
I/O with the client. In other words, an HTTP connection can be _upgraded_ to any
|
||||
protocol, including HTTP WebSockets!
|
||||
|
||||
The newly introduced [`rocket_ws`] library takes advantage of the new API to
|
||||
implement first-class support for WebSockets entirely outside of Rocket's core.
|
||||
The simplest use of the library, implementing an echo server and showcasing that
|
||||
the incoming message stream is `async`, looks like this:
|
||||
|
||||
```rust
|
||||
# use rocket::get;
|
||||
# use rocket_ws as ws;
|
||||
|
||||
#[get("/echo")]
|
||||
fn echo_compose(ws: ws::WebSocket) -> ws::Stream!['static] {
|
||||
ws.stream(|io| io)
|
||||
}
|
||||
```
|
||||
|
||||
The simplified [async streams] generator syntax can also be used:
|
||||
|
||||
```rust
|
||||
# use rocket::get;
|
||||
# use rocket_ws as ws;
|
||||
|
||||
#[get("/echo")]
|
||||
fn echo_stream(ws: ws::WebSocket) -> ws::Stream!['static] {
|
||||
ws::Stream! { ws =>
|
||||
for await message in ws {
|
||||
yield message?;
|
||||
}
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
For complete usage details, see the [`rocket_ws`] documentation.
|
||||
|
||||
[upgrade API]: @api/rocket/response/struct.Response.html#upgrading
|
||||
[`rocket_ws`]: @api/rocket_ws
|
||||
This a placeholder for an eventual migration guide from v0.5 to v0.6.
|
||||
|
||||
## Getting Help
|
||||
|
||||
|
|
|
@ -14,7 +14,7 @@ aspect of Rocket. The sections are:
|
|||
- **[Introduction](introduction/):** introduces Rocket and its philosophy.
|
||||
- **[Quickstart](quickstart/):** presents the minimal steps necessary to
|
||||
run your first Rocket application.
|
||||
- **[Upgrading from v0.4](upgrading/):** a migration guide from v0.4 to v0.5.
|
||||
- **[Upgrading from v0.5](upgrading/):** a migration guide from v0.5 to v0.6.
|
||||
- **[Getting Started](getting-started/):** a gentle introduction to getting
|
||||
your first Rocket application running.
|
||||
- **[Overview](overview/):** describes the core concepts of Rocket.
|
||||
|
|
Loading…
Reference in New Issue