hydro_lang/
lib.rs

1#![cfg_attr(docsrs, feature(doc_cfg))]
2#![cfg_attr(not(stageleft_trybuild), warn(missing_docs))]
3
4//! Hydro is a high-level distributed programming framework for Rust.
5//! Hydro can help you quickly write scalable distributed services that are correct by construction.
6//! Much like Rust helps with memory safety, Hydro helps with [distributed safety](https://hydro.run/docs/hydro/reference/correctness/).
7//!
8//! The core Hydro API involves [live collections](https://hydro.run/docs/hydro/reference/introduction/live-collections), which represent asynchronously
9//! updated sources of data such as incoming network requests and application state. The most common live collection is
10//! [`live_collections::stream::Stream`]; other live collections can be found in [`live_collections`].
11//!
12//! Hydro uses a unique compilation approach where you define deployment logic as Rust code alongside your distributed system implementation.
13//! For more details on this API, see the [Hydro docs](https://hydro.run/docs/hydro/reference/deploy/) and the [`deploy`] module.
14
15stageleft::stageleft_no_entry_crate!();
16
17#[cfg(feature = "runtime_support")]
18#[cfg_attr(docsrs, doc(cfg(feature = "runtime_support")))]
19#[doc(hidden)]
20pub mod runtime_support {
21    pub use ::{bincode, dfir_rs, slotmap, stageleft};
22    #[cfg(feature = "sim")]
23    pub use colored;
24    #[cfg(feature = "deploy_integration")]
25    pub use hydro_deploy_integration;
26    #[cfg(feature = "tokio")]
27    pub use tokio;
28
29    #[cfg(feature = "deploy_integration")]
30    pub mod launch;
31}
32
33#[doc(hidden)]
34pub mod macro_support {
35    pub use copy_span;
36    #[cfg(feature = "trybuild")]
37    pub use ctor;
38}
39
40pub mod prelude {
41    // taken from `tokio`
42    //! A "prelude" for users of the `hydro_lang` crate.
43    //!
44    //! This prelude is similar to the standard library's prelude in that you'll almost always want to import its entire contents, but unlike the standard library's prelude you'll have to do so manually:
45    //! ```
46    //! # #![allow(warnings)]
47    //! use hydro_lang::prelude::*;
48    //! ```
49    //!
50    //! The prelude may grow over time as additional items see ubiquitous use.
51
52    pub use stageleft::q;
53
54    pub use crate::compile::builder::FlowBuilder;
55    pub use crate::live_collections::boundedness::{Bounded, Unbounded};
56    pub use crate::live_collections::keyed_singleton::{KeyedSingleton, MonotonicKeys};
57    pub use crate::live_collections::keyed_stream::KeyedStream;
58    pub use crate::live_collections::optional::{InitNone, Optional};
59    pub use crate::live_collections::singleton::Singleton;
60    pub use crate::live_collections::sliced::sliced;
61    pub use crate::live_collections::stream::Stream;
62    pub use crate::location::{Cluster, External, Location as _, Process, Tick};
63    pub use crate::networking::{TCP, UDP};
64    pub use crate::nondet::{NonDet, nondet};
65    pub use crate::properties::{
66        ConsistencyProof, ManualProof, VerusCommutativeProof, manual_proof,
67        verus_proof_commutative_effect, verus_proof_commutative_filter,
68        verus_proof_commutative_fold, verus_proof_commutative_map,
69    };
70
71    #[cfg(feature = "trybuild")]
72    /// A macro to set up a Hydro crate.
73    #[macro_export]
74    macro_rules! setup {
75        () => {
76            stageleft::stageleft_no_entry_crate!();
77
78            #[cfg(test)]
79            mod test_init {
80                $crate::macro_support::ctor::declarative::ctor!(
81                    #[ctor(unsafe)]
82                    fn init() {
83                        $crate::compile::init_test();
84                    }
85                );
86            }
87        };
88    }
89
90    #[cfg(not(feature = "trybuild"))]
91    /// A macro to set up a Hydro crate.
92    #[macro_export]
93    macro_rules! setup {
94        () => {
95            stageleft::stageleft_no_entry_crate!();
96        };
97    }
98}
99
100#[cfg(feature = "dfir_context")]
101#[cfg_attr(docsrs, doc(cfg(feature = "dfir_context")))]
102pub mod runtime_context;
103
104pub mod nondet;
105
106pub mod live_collections;
107
108pub mod location;
109
110pub mod networking;
111
112pub mod properties;
113
114pub mod telemetry;
115
116#[cfg(any(
117    feature = "deploy",
118    feature = "sim",
119    feature = "deploy_integration" // hidden internal feature enabled in the trybuild
120))]
121#[cfg_attr(docsrs, doc(cfg(any(feature = "deploy", feature = "sim"))))]
122pub mod deploy;
123
124#[cfg(feature = "sim")]
125#[cfg_attr(docsrs, doc(cfg(feature = "sim")))]
126pub mod sim;
127
128pub mod sim_hooks;
129
130pub mod forward_handle;
131
132pub mod compile;
133
134pub mod handoff_ref;
135
136mod manual_expr;
137
138#[cfg(stageleft_runtime)]
139#[cfg(feature = "viz")]
140#[cfg_attr(docsrs, doc(cfg(feature = "viz")))]
141#[expect(missing_docs, reason = "TODO")]
142pub mod viz;
143
144#[cfg_attr(
145    feature = "stageleft_macro_entrypoint",
146    expect(missing_docs, reason = "staging internals")
147)]
148mod staging_util;
149
150#[cfg(feature = "deploy")]
151#[cfg_attr(docsrs, doc(cfg(feature = "deploy")))]
152pub mod test_util;
153
154#[cfg(feature = "build")]
155ctor::declarative::ctor!(
156    #[ctor(unsafe)]
157    fn init_rewrites() {
158        stageleft::add_private_reexport(
159            vec!["tokio_util", "codec", "lines_codec"],
160            vec!["tokio_util", "codec"],
161        );
162        // TODO: remove once stabilized
163        stageleft::add_private_reexport(
164            vec!["core", "io", "error", "Error"],
165            vec!["std", "io", "Error"],
166        );
167    }
168);
169
170#[cfg(all(test, feature = "trybuild"))]
171mod test_init {
172    ctor::declarative::ctor!(
173        #[ctor(unsafe)]
174        fn init() {
175            crate::compile::init_test();
176            // Install a tracing subscriber so diagnostics (e.g. the `hydro_build` build-timing
177            // events used by scripts/bench_trybuild.sh) can be enabled via RUST_LOG.
178            crate::telemetry::initialize_tracing();
179        }
180    );
181}
182
183/// Creates a newtype wrapper around an integer type.
184///
185/// Usage:
186/// ```rust,ignore
187/// hydro_lang::newtype_counter! {
188///     /// My counter.
189///     pub struct MyCounter(u32);
190///
191///     /// My secret counter.
192///     struct SecretCounter(u64);
193/// }
194/// ```
195#[doc(hidden)]
196#[macro_export]
197macro_rules! newtype_counter {
198    (
199        $(
200            $( #[$attr:meta] )*
201            $vis:vis struct $name:ident($typ:ty);
202        )*
203    ) => {
204        $(
205            $( #[$attr] )*
206            #[repr(transparent)]
207            #[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
208            $vis struct $name($typ);
209
210            #[allow(clippy::allow_attributes, dead_code, reason = "macro-generated methods may be unused")]
211            impl $name {
212                /// Reveals the inner ID.
213                pub fn into_inner(self) -> $typ {
214                    self.0
215                }
216            }
217
218            impl std::fmt::Display for $name {
219                fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
220                    write!(f, "{}", self.0)
221                }
222            }
223
224            impl serde::ser::Serialize for $name {
225                fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
226                where
227                    S: serde::Serializer
228                {
229                    serde::ser::Serialize::serialize(&self.0, serializer)
230                }
231            }
232
233            impl<'de> serde::de::Deserialize<'de> for $name {
234                fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
235                where
236                    D: serde::Deserializer<'de>
237                {
238                    serde::de::Deserialize::deserialize(deserializer).map(Self)
239                }
240            }
241
242            #[sealed::sealed]
243            impl $crate::Countable for $name {
244                fn from_count(val: usize) -> Self {
245                    Self(val as $typ)
246                }
247            }
248        )*
249    };
250}
251
252/// Sealed trait implemented by ID types produced via [`newtype_counter!`].
253///
254/// This allows [`Counter<T>`] to mint new IDs without exposing a public
255/// constructor on the ID types themselves.
256#[doc(hidden)]
257#[sealed::sealed]
258pub trait Countable {
259    #[doc(hidden)]
260    fn from_count(val: usize) -> Self;
261}
262
263/// An opaque counter that produces unique IDs of type `T` via [`Counter::get_and_increment`].
264///
265/// This is separate from the ID types themselves so that holding an ID does not
266/// give the ability to mint new IDs.
267#[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
268pub struct Counter<T: Countable>(usize, std::marker::PhantomData<T>);
269
270impl<T: Countable> Default for Counter<T> {
271    fn default() -> Self {
272        Self(0, std::marker::PhantomData)
273    }
274}
275
276impl<T: Countable> Counter<T> {
277    /// Gets the current counter value and increments for the next call.
278    pub fn get_and_increment(&mut self) -> T {
279        let id = self.0;
280        self.0 += 1;
281        T::from_count(id)
282    }
283
284    /// Returns an iterator from zero up to (but excluding) the current counter value.
285    ///
286    /// This is useful for iterating already-allocated values.
287    pub fn range_up_to(&self) -> impl DoubleEndedIterator<Item = T> + std::iter::FusedIterator {
288        (0..self.0).map(T::from_count)
289    }
290}
hydro_lang/lib.rs

hydro_lang/
lib.rs
