hydro_lang/compile/
builder.rs

1use std::any::type_name;
2use std::cell::RefCell;
3use std::marker::PhantomData;
4use std::rc::Rc;
5
6use slotmap::{SecondaryMap, SlotMap};
7
8#[cfg(feature = "build")]
9use super::compiled::CompiledFlow;
10#[cfg(feature = "build")]
11use super::deploy::{DeployFlow, DeployResult};
12#[cfg(feature = "build")]
13use super::deploy_provider::{ClusterSpec, Deploy, ExternalSpec, IntoProcessSpec};
14use super::ir::HydroRoot;
15use crate::location::{Cluster, External, LocationKey, LocationType, Process};
16
17/// A compile-time directive to spawn a future on a location's `LocalSet`
18/// alongside the DFIR scheduler.
19pub enum Sidecar {
20    /// A ready-to-go future expression (e.g. telemetry metrics collection).
21    Simple {
22        location_key: LocationKey,
23        future_expr: Box<syn::Expr>,
24    },
25    /// A user-owned sidecar that returns a `(Stream, Sink)` pair to the framework.
26    /// The closure is called at startup; the returned stream feeds items into the
27    /// dataflow and the returned sink receives items from the dataflow.
28    Bidi {
29        location_key: LocationKey,
30        sidecar_id: SidecarId,
31        sidecar_closure: Box<syn::Expr>,
32    },
33}
34#[cfg(feature = "sim")]
35#[cfg(stageleft_runtime)]
36use crate::sim::flow::SimFlow;
37use crate::staging_util::Invariant;
38
39#[stageleft::export(ExternalPortId, CycleId, ClockId, SidecarId, StmtId, HandoffId)]
40crate::newtype_counter! {
41    /// ID for an external output.
42    pub struct ExternalPortId(usize);
43
44    /// ID for a [`crate::location::Location::forward_ref`] cycle.
45    pub struct CycleId(usize);
46
47    /// ID for clocks (ticks).
48    pub struct ClockId(usize);
49
50    /// ID for user-owned sidecars.
51    pub struct SidecarId(usize);
52
53    /// ID for a statement in the emitted DFIR graph.
54    pub struct StmtId(usize);
55
56    /// ID for a handoff channel in the simulator.
57    pub struct HandoffId(usize);
58}
59
60impl CycleId {
61    #[cfg(feature = "build")]
62    pub(crate) fn as_ident(&self) -> syn::Ident {
63        syn::Ident::new(&format!("cycle_{}", self), proc_macro2::Span::call_site())
64    }
65}
66
67impl SidecarId {
68    /// Derives the two idents for a bidi sidecar: `(stream, sink)`.
69    pub fn idents(&self) -> (syn::Ident, syn::Ident) {
70        let span = proc_macro2::Span::call_site();
71        (
72            syn::Ident::new(&format!("__hydro_sidecar_{}_stream", self), span),
73            syn::Ident::new(&format!("__hydro_sidecar_{}_sink", self), span),
74        )
75    }
76}
77
78pub(crate) type FlowState = Rc<RefCell<FlowStateInner>>;
79
80pub(crate) struct FlowStateInner {
81    /// Tracks the roots of the dataflow IR. This is referenced by
82    /// `Stream` and `HfCycle` to build the IR. The inner option will
83    /// be set to `None` when this builder is finalized.
84    roots: Option<Vec<HydroRoot>>,
85
86    /// Counter for generating unique external output identifiers.
87    next_external_port: ExternalPortId,
88
89    /// Counters for generating identifiers for cycles.
90    next_cycle_id: CycleId,
91
92    /// Counters for clock IDs.
93    next_clock_id: ClockId,
94
95    /// Counter for generating unique sidecar identifiers, not used for anything else.
96    next_sidecar_id: SidecarId,
97
98    /// Compile-time sidecar directives. Processed during compilation,
99    /// not part of the dataflow IR.
100    pub sidecars: Vec<Sidecar>,
101}
102
103impl FlowStateInner {
104    pub fn next_external_port(&mut self) -> ExternalPortId {
105        self.next_external_port.get_and_increment()
106    }
107
108    pub fn next_cycle_id(&mut self) -> CycleId {
109        self.next_cycle_id.get_and_increment()
110    }
111
112    pub fn next_clock_id(&mut self) -> ClockId {
113        self.next_clock_id.get_and_increment()
114    }
115
116    pub fn next_sidecar_id(&mut self) -> SidecarId {
117        self.next_sidecar_id.get_and_increment()
118    }
119
120    pub fn push_root(&mut self, root: HydroRoot) {
121        self.roots
122            .as_mut()
123            .expect("Attempted to add a root to a flow that has already been finalized. No roots can be added after the flow has been compiled.")
124            .push(root);
125    }
126
127    pub fn try_push_root(&mut self, root: HydroRoot) {
128        if let Some(roots) = self.roots.as_mut() {
129            roots.push(root);
130        }
131    }
132}
133
134pub struct FlowBuilder<'a> {
135    /// Hydro IR and associated counters
136    flow_state: FlowState,
137
138    /// Locations and their type.
139    locations: SlotMap<LocationKey, LocationType>,
140    /// Map from raw location ID to name (including externals).
141    location_names: SecondaryMap<LocationKey, String>,
142
143    /// Application name used in telemetry.
144    #[cfg_attr(
145        not(feature = "build"),
146        expect(dead_code, reason = "unused without build")
147    )]
148    flow_name: String,
149
150    /// Tracks whether this flow has been finalized; it is an error to
151    /// drop without finalizing.
152    finalized: bool,
153
154    /// 'a on a FlowBuilder is used to ensure that staged code does not
155    /// capture more data that it is allowed to; 'a is generated at the
156    /// entrypoint of the staged code and we keep it invariant here
157    /// to enforce the appropriate constraints
158    _phantom: Invariant<'a>,
159}
160
161impl Drop for FlowBuilder<'_> {
162    fn drop(&mut self) {
163        if !self.finalized && !std::thread::panicking() {
164            panic!(
165                "Dropped FlowBuilder without finalizing, you may have forgotten to call `with_default_optimize`, `optimize_with`, or `finalize`."
166            );
167        }
168    }
169}
170
171#[expect(missing_docs, reason = "TODO")]
172impl<'a> FlowBuilder<'a> {
173    /// Creates a new `FlowBuilder` to construct a Hydro program, using the Cargo package name as the program name.
174    #[expect(
175        clippy::new_without_default,
176        reason = "call `new` explicitly, not `default`"
177    )]
178    pub fn new() -> Self {
179        let mut name = std::env::var("CARGO_PKG_NAME").unwrap_or_else(|_| "unknown".to_owned());
180        if let Ok(bin_path) = std::env::current_exe()
181            && let Some(bin_name) = bin_path.file_stem()
182        {
183            name = format!("{}/{}", name, bin_name.display());
184        }
185        Self::with_name(name)
186    }
187
188    /// Creates a new `FlowBuilder` to construct a Hydro program, with the given program name.
189    pub fn with_name(name: impl Into<String>) -> Self {
190        Self {
191            flow_state: Rc::new(RefCell::new(FlowStateInner {
192                roots: Some(vec![]),
193                next_external_port: ExternalPortId::default(),
194                next_cycle_id: CycleId::default(),
195                next_clock_id: ClockId::default(),
196                next_sidecar_id: SidecarId::default(),
197                sidecars: Vec::new(),
198            })),
199            locations: SlotMap::with_key(),
200            location_names: SecondaryMap::new(),
201            flow_name: name.into(),
202            finalized: false,
203            _phantom: PhantomData,
204        }
205    }
206
207    pub(crate) fn flow_state(&self) -> &FlowState {
208        &self.flow_state
209    }
210
211    pub fn process<P>(&mut self) -> Process<'a, P> {
212        let key = self.locations.insert(LocationType::Process);
213        self.location_names.insert(key, type_name::<P>().to_owned());
214        Process {
215            key,
216            flow_state: self.flow_state().clone(),
217            _phantom: PhantomData,
218        }
219    }
220
221    pub fn cluster<C>(&mut self) -> Cluster<'a, C> {
222        let key = self.locations.insert(LocationType::Cluster);
223        self.location_names.insert(key, type_name::<C>().to_owned());
224        Cluster {
225            key,
226            flow_state: self.flow_state().clone(),
227            _phantom: PhantomData,
228        }
229    }
230
231    pub fn external<E>(&mut self) -> External<'a, E> {
232        let key = self.locations.insert(LocationType::External);
233        self.location_names.insert(key, type_name::<E>().to_owned());
234        External {
235            key,
236            flow_state: self.flow_state().clone(),
237            _phantom: PhantomData,
238        }
239    }
240}
241
242#[cfg(feature = "build")]
243#[cfg_attr(docsrs, doc(cfg(feature = "build")))]
244#[expect(missing_docs, reason = "TODO")]
245impl<'a> FlowBuilder<'a> {
246    pub fn finalize(mut self) -> super::built::BuiltFlow<'a> {
247        self.finalized = true;
248
249        let mut flow_state = self.flow_state.borrow_mut();
250        let mut ir = flow_state.roots.take().unwrap();
251        let sidecars = std::mem::take(&mut flow_state.sidecars);
252        drop(flow_state);
253
254        super::ir::unify_atomic_ticks(&mut ir);
255
256        super::built::BuiltFlow {
257            ir,
258            locations: std::mem::take(&mut self.locations),
259            location_names: std::mem::take(&mut self.location_names),
260            sidecars,
261            flow_name: std::mem::take(&mut self.flow_name),
262            _phantom: PhantomData,
263        }
264    }
265
266    pub fn with_default_optimize<D: Deploy<'a>>(self) -> DeployFlow<'a, D> {
267        self.finalize().with_default_optimize()
268    }
269
270    pub fn optimize_with(self, f: impl FnOnce(&mut [HydroRoot])) -> super::built::BuiltFlow<'a> {
271        self.finalize().optimize_with(f)
272    }
273
274    pub fn with_process<P, D: Deploy<'a>>(
275        self,
276        process: &Process<P>,
277        spec: impl IntoProcessSpec<'a, D>,
278    ) -> DeployFlow<'a, D> {
279        self.with_default_optimize().with_process(process, spec)
280    }
281
282    pub fn with_remaining_processes<D: Deploy<'a>, S: IntoProcessSpec<'a, D> + 'a>(
283        self,
284        spec: impl Fn() -> S,
285    ) -> DeployFlow<'a, D> {
286        self.with_default_optimize().with_remaining_processes(spec)
287    }
288
289    pub fn with_external<P, D: Deploy<'a>>(
290        self,
291        process: &External<P>,
292        spec: impl ExternalSpec<'a, D>,
293    ) -> DeployFlow<'a, D> {
294        self.with_default_optimize().with_external(process, spec)
295    }
296
297    pub fn with_remaining_externals<D: Deploy<'a>, S: ExternalSpec<'a, D> + 'a>(
298        self,
299        spec: impl Fn() -> S,
300    ) -> DeployFlow<'a, D> {
301        self.with_default_optimize().with_remaining_externals(spec)
302    }
303
304    pub fn with_cluster<C, D: Deploy<'a>>(
305        self,
306        cluster: &Cluster<C>,
307        spec: impl ClusterSpec<'a, D>,
308    ) -> DeployFlow<'a, D> {
309        self.with_default_optimize().with_cluster(cluster, spec)
310    }
311
312    pub fn with_remaining_clusters<D: Deploy<'a>, S: ClusterSpec<'a, D> + 'a>(
313        self,
314        spec: impl Fn() -> S,
315    ) -> DeployFlow<'a, D> {
316        self.with_default_optimize().with_remaining_clusters(spec)
317    }
318
319    pub fn compile<D: Deploy<'a, InstantiateEnv = ()>>(self) -> CompiledFlow<'a> {
320        self.with_default_optimize::<D>().compile()
321    }
322
323    pub fn deploy<D: Deploy<'a>>(self, env: &mut D::InstantiateEnv) -> DeployResult<'a, D> {
324        self.with_default_optimize().deploy(env)
325    }
326
327    #[cfg(feature = "sim")]
328    /// Creates a simulation for this builder, which can be used to run deterministic simulations
329    /// of the Hydro program.
330    pub fn sim(self) -> SimFlow<'a> {
331        self.finalize().sim()
332    }
333
334    pub fn from_built<'b>(built: &super::built::BuiltFlow) -> FlowBuilder<'b> {
335        FlowBuilder {
336            flow_state: Rc::new(RefCell::new(FlowStateInner {
337                roots: None,
338                next_external_port: ExternalPortId::default(),
339                next_cycle_id: CycleId::default(),
340                next_clock_id: ClockId::default(),
341                next_sidecar_id: SidecarId::default(),
342                sidecars: Vec::new(),
343            })),
344            locations: built.locations.clone(),
345            location_names: built.location_names.clone(),
346            flow_name: built.flow_name.clone(),
347            finalized: false,
348            _phantom: PhantomData,
349        }
350    }
351
352    #[doc(hidden)] // TODO(mingwei): This is an unstable API for now
353    pub fn replace_ir(&mut self, roots: Vec<HydroRoot>) {
354        self.flow_state.borrow_mut().roots = Some(roots);
355    }
356
357    #[doc(hidden)] // TODO(mingwei): This is an unstable API for now
358    pub fn next_clock_id(&mut self) -> ClockId {
359        self.flow_state.borrow_mut().next_clock_id()
360    }
361
362    #[doc(hidden)] // TODO(mingwei): This is an unstable API for now
363    pub fn next_cycle_id(&mut self) -> CycleId {
364        self.flow_state.borrow_mut().next_cycle_id()
365    }
366}
hydro_lang/compile/builder.rs

hydro_lang/compile/
builder.rs
