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::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;
64    pub use crate::nondet::{NonDet, nondet};
65    pub use crate::properties::{ConsistencyProof, ManualProof, manual_proof};
66
67    #[cfg(feature = "trybuild")]
68    /// A macro to set up a Hydro crate.
69    #[macro_export]
70    macro_rules! setup {
71        () => {
72            stageleft::stageleft_no_entry_crate!();
73
74            #[cfg(test)]
75            mod test_init {
76                $crate::macro_support::ctor::declarative::ctor!(
77                    #[ctor(unsafe)]
78                    fn init() {
79                        $crate::compile::init_test();
80                    }
81                );
82            }
83        };
84    }
85
86    #[cfg(not(feature = "trybuild"))]
87    /// A macro to set up a Hydro crate.
88    #[macro_export]
89    macro_rules! setup {
90        () => {
91            stageleft::stageleft_no_entry_crate!();
92        };
93    }
94}
95
96#[cfg(feature = "dfir_context")]
97#[cfg_attr(docsrs, doc(cfg(feature = "dfir_context")))]
98pub mod runtime_context;
99
100pub mod nondet;
101
102pub mod live_collections;
103
104pub mod location;
105
106pub mod networking;
107
108pub mod properties;
109
110pub mod telemetry;
111
112#[cfg(any(
113    feature = "deploy",
114    feature = "sim",
115    feature = "deploy_integration" // hidden internal feature enabled in the trybuild
116))]
117#[cfg_attr(docsrs, doc(cfg(any(feature = "deploy", feature = "sim"))))]
118pub mod deploy;
119
120#[cfg(feature = "sim")]
121#[cfg_attr(docsrs, doc(cfg(feature = "sim")))]
122pub mod sim;
123
124pub mod forward_handle;
125
126pub mod compile;
127
128pub mod handoff_ref;
129
130mod manual_expr;
131
132#[cfg(stageleft_runtime)]
133#[cfg(feature = "viz")]
134#[cfg_attr(docsrs, doc(cfg(feature = "viz")))]
135#[expect(missing_docs, reason = "TODO")]
136pub mod viz;
137
138#[cfg_attr(
139    feature = "stageleft_macro_entrypoint",
140    expect(missing_docs, reason = "staging internals")
141)]
142mod staging_util;
143
144#[cfg(feature = "deploy")]
145#[cfg_attr(docsrs, doc(cfg(feature = "deploy")))]
146pub mod test_util;
147
148#[cfg(feature = "build")]
149ctor::declarative::ctor!(
150    #[ctor(unsafe)]
151    fn init_rewrites() {
152        stageleft::add_private_reexport(
153            vec!["tokio_util", "codec", "lines_codec"],
154            vec!["tokio_util", "codec"],
155        );
156        // TODO: remove once stabilized
157        stageleft::add_private_reexport(
158            vec!["core", "io", "error", "Error"],
159            vec!["std", "io", "Error"],
160        );
161    }
162);
163
164#[cfg(all(test, feature = "trybuild"))]
165mod test_init {
166    ctor::declarative::ctor!(
167        #[ctor(unsafe)]
168        fn init() {
169            crate::compile::init_test();
170        }
171    );
172}
173
174/// Creates a newtype wrapper around an integer type.
175///
176/// Usage:
177/// ```rust,ignore
178/// hydro_lang::newtype_counter! {
179///     /// My counter.
180///     pub struct MyCounter(u32);
181///
182///     /// My secret counter.
183///     struct SecretCounter(u64);
184/// }
185/// ```
186#[doc(hidden)]
187#[macro_export]
188macro_rules! newtype_counter {
189    (
190        $(
191            $( #[$attr:meta] )*
192            $vis:vis struct $name:ident($typ:ty);
193        )*
194    ) => {
195        $(
196            $( #[$attr] )*
197            #[repr(transparent)]
198            #[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
199            $vis struct $name($typ);
200
201            #[allow(clippy::allow_attributes, dead_code, reason = "macro-generated methods may be unused")]
202            impl $name {
203                /// Reveals the inner ID.
204                pub fn into_inner(self) -> $typ {
205                    self.0
206                }
207            }
208
209            impl std::fmt::Display for $name {
210                fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
211                    write!(f, "{}", self.0)
212                }
213            }
214
215            impl serde::ser::Serialize for $name {
216                fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
217                where
218                    S: serde::Serializer
219                {
220                    serde::ser::Serialize::serialize(&self.0, serializer)
221                }
222            }
223
224            impl<'de> serde::de::Deserialize<'de> for $name {
225                fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
226                where
227                    D: serde::Deserializer<'de>
228                {
229                    serde::de::Deserialize::deserialize(deserializer).map(Self)
230                }
231            }
232
233            #[sealed::sealed]
234            impl $crate::Countable for $name {
235                fn from_count(val: usize) -> Self {
236                    Self(val as $typ)
237                }
238            }
239        )*
240    };
241}
242
243/// Sealed trait implemented by ID types produced via [`newtype_counter!`].
244///
245/// This allows [`Counter<T>`] to mint new IDs without exposing a public
246/// constructor on the ID types themselves.
247#[doc(hidden)]
248#[sealed::sealed]
249pub trait Countable {
250    #[doc(hidden)]
251    fn from_count(val: usize) -> Self;
252}
253
254/// An opaque counter that produces unique IDs of type `T` via [`Counter::get_and_increment`].
255///
256/// This is separate from the ID types themselves so that holding an ID does not
257/// give the ability to mint new IDs.
258#[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
259pub struct Counter<T: Countable>(usize, std::marker::PhantomData<T>);
260
261impl<T: Countable> Default for Counter<T> {
262    fn default() -> Self {
263        Self(0, std::marker::PhantomData)
264    }
265}
266
267impl<T: Countable> Counter<T> {
268    /// Gets the current counter value and increments for the next call.
269    pub fn get_and_increment(&mut self) -> T {
270        let id = self.0;
271        self.0 += 1;
272        T::from_count(id)
273    }
274
275    /// Returns an iterator from zero up to (but excluding) the current counter value.
276    ///
277    /// This is useful for iterating already-allocated values.
278    pub fn range_up_to(&self) -> impl DoubleEndedIterator<Item = T> + std::iter::FusedIterator {
279        (0..self.0).map(T::from_count)
280    }
281}
hydro_lang/lib.rs

hydro_lang/
lib.rs
