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miden_core/events/
sys_events.rs

1use core::fmt;
2
3use super::{EventId, EventName};
4
5// SYSTEM EVENTS
6// ================================================================================================
7
8/// Defines a set of actions which can be initiated from the VM to inject new data into the advice
9/// provider.
10///
11/// These actions can affect all 3 components of the advice provider: Merkle store, advice stack,
12/// and advice map.
13///
14/// All actions, except for `MerkleNodeMerge`, `Ext2Inv` and `UpdateMerkleNode` can be invoked
15/// directly from Miden assembly via dedicated instructions.
16///
17/// System event IDs are derived from blake3-hashing their names (prefixed with "sys::").
18///
19/// The enum variant order matches the indices in SYSTEM_EVENT_LOOKUP, allowing efficient const
20/// lookup via `to_event_id()`. The discriminants are implicitly 0, 1, 2, ... 15.
21#[derive(Copy, Clone, Debug, Eq, PartialEq)]
22#[repr(u8)]
23pub enum SystemEvent {
24    // MERKLE STORE EVENTS
25    // --------------------------------------------------------------------------------------------
26    /// Creates a new Merkle tree in the advice provider by combining Merkle trees with the
27    /// specified roots. The root of the new tree is defined as `Hash(LEFT_ROOT, RIGHT_ROOT)`.
28    ///
29    /// Inputs:
30    ///   Operand stack: [LEFT_ROOT, RIGHT_ROOT, ...]
31    ///   Merkle store: {LEFT_ROOT, RIGHT_ROOT}
32    ///
33    /// Outputs:
34    ///   Operand stack: [LEFT_ROOT, RIGHT_ROOT, ...]
35    ///   Merkle store: {LEFT_ROOT, RIGHT_ROOT, hash(LEFT_ROOT, RIGHT_ROOT)}
36    ///
37    /// After the operation, both the original trees and the new tree remains in the advice
38    /// provider (i.e., the input trees are not removed).
39    MerkleNodeMerge,
40
41    // ADVICE STACK SYSTEM EVENTS
42    // --------------------------------------------------------------------------------------------
43    /// Pushes a node of the Merkle tree specified by the values on the top of the operand stack
44    /// onto the advice stack in structural order for consumption by `AdvPopW`.
45    ///
46    /// Inputs:
47    ///   Operand stack: [depth, index, TREE_ROOT, ...]
48    ///   Advice stack: [...]
49    ///   Merkle store: {TREE_ROOT<-NODE}
50    ///
51    /// Outputs:
52    ///   Operand stack: [depth, index, TREE_ROOT, ...]
53    ///   Advice stack: [NODE, ...]
54    ///   Merkle store: {TREE_ROOT<-NODE}
55    MerkleNodeToStack,
56
57    /// Pushes a list of field elements onto the advice stack. The list is looked up in the advice
58    /// map using the specified word from the operand stack as the key.
59    ///
60    /// Inputs:
61    ///   Operand stack: [KEY, ...]
62    ///   Advice stack: [...]
63    ///   Advice map: {KEY: values}
64    ///
65    /// Outputs:
66    ///   Operand stack: [KEY, ...]
67    ///   Advice stack: [values, ...]
68    ///   Advice map: {KEY: values}
69    MapValueToStack,
70
71    /// Pushes the number of elements in a list of field elements onto the advice stack. The list is
72    /// looked up in the advice map using the specified word from the operand stack as the key.
73    ///
74    /// Inputs:
75    ///   Operand stack: [KEY, ...]
76    ///   Advice stack: [...]
77    ///   Advice map: {KEY: values}
78    ///
79    /// Outputs:
80    ///   Operand stack: [KEY, ...]
81    ///   Advice stack: [values.len(), ...]
82    ///   Advice map: {KEY: values}
83    MapValueCountToStack,
84
85    /// Pushes a list of field elements onto the advice stack, along with the number of elements in
86    /// that list. The list is looked up in the advice map using the word at the top of the operand
87    /// stack as the key.
88    ///
89    /// Notice that the resulting elements list is not padded.
90    ///
91    /// Inputs:
92    ///   Operand stack: [KEY, ...]
93    ///   Advice stack: [...]
94    ///   Advice map: {KEY: values}
95    ///
96    /// Outputs:
97    ///   Operand stack: [KEY, ...]
98    ///   Advice stack: [num_values, values, ...]
99    ///   Advice map: {KEY: values}
100    MapValueToStackN0,
101
102    /// Pushes a padded list of field elements onto the advice stack, along with the number of
103    /// elements in that list. The list is looked up in the advice map using the word at the top of
104    /// the operand stack as the key.
105    ///
106    /// Notice that the elements list obtained from the advice map will be padded with zeros,
107    /// increasing its length to the next multiple of 4.
108    ///
109    /// Inputs:
110    ///   Operand stack: [KEY, ...]
111    ///   Advice stack: [...]
112    ///   Advice map: {KEY: values}
113    ///
114    /// Outputs:
115    ///   Operand stack: [KEY, ...]
116    ///   Advice stack: [num_values, values, padding, ...]
117    ///   Advice map: {KEY: values}
118    MapValueToStackN4,
119
120    /// Pushes a padded list of field elements onto the advice stack, along with the number of
121    /// elements in that list. The list is looked up in the advice map using the word at the top of
122    /// the operand stack as the key.
123    ///
124    /// Notice that the elements list obtained from the advice map will be padded with zeros,
125    /// increasing its length to the next multiple of 8.
126    ///
127    /// Inputs:
128    ///   Operand stack: [KEY, ...]
129    ///   Advice stack: [...]
130    ///   Advice map: {KEY: values}
131    ///
132    /// Outputs:
133    ///   Operand stack: [KEY, ...]
134    ///   Advice stack: [num_values, values, padding, ...]
135    ///   Advice map: {KEY: values}
136    MapValueToStackN8,
137
138    /// Pushes a flag onto the advice stack whether advice map has an entry with specified key.
139    ///
140    /// If the advice map has the entry with the key equal to the key placed at the top of the
141    /// operand stack, `1` will be pushed to the advice stack and `0` otherwise.
142    ///
143    /// Inputs:
144    ///   Operand stack: [KEY, ...]
145    ///   Advice stack:  [...]
146    ///
147    /// Outputs:
148    ///   Operand stack: [KEY, ...]
149    ///   Advice stack:  [has_mapkey, ...]
150    HasMapKey,
151
152    /// Given an element in a quadratic extension field on the top of the stack (i.e., a0, b1),
153    /// computes its multiplicative inverse and push the result onto the advice stack.
154    ///
155    /// Inputs:
156    ///   Operand stack: [a1, a0, ...]
157    ///   Advice stack: [...]
158    ///
159    /// Outputs:
160    ///   Operand stack: [a1, a0, ...]
161    ///   Advice stack: [b0, b1...]
162    ///
163    /// Where (b0, b1) is the multiplicative inverse of the extension field element (a0, a1) at the
164    /// top of the stack.
165    Ext2Inv,
166
167    /// Pushes the number of the leading zeros of the top stack element onto the advice stack.
168    ///
169    /// Inputs:
170    ///   Operand stack: [n, ...]
171    ///   Advice stack: [...]
172    ///
173    /// Outputs:
174    ///   Operand stack: [n, ...]
175    ///   Advice stack: [leading_zeros, ...]
176    U32Clz,
177
178    /// Pushes the number of the trailing zeros of the top stack element onto the advice stack.
179    ///
180    /// Inputs:
181    ///   Operand stack: [n, ...]
182    ///   Advice stack: [...]
183    ///
184    /// Outputs:
185    ///   Operand stack: [n, ...]
186    ///   Advice stack: [trailing_zeros, ...]
187    U32Ctz,
188
189    /// Pushes the number of the leading ones of the top stack element onto the advice stack.
190    ///
191    /// Inputs:
192    ///   Operand stack: [n, ...]
193    ///   Advice stack: [...]
194    ///
195    /// Outputs:
196    ///   Operand stack: [n, ...]
197    ///   Advice stack: [leading_ones, ...]
198    U32Clo,
199
200    /// Pushes the number of the trailing ones of the top stack element onto the advice stack.
201    ///
202    /// Inputs:
203    ///   Operand stack: [n, ...]
204    ///   Advice stack: [...]
205    ///
206    /// Outputs:
207    ///   Operand stack: [n, ...]
208    ///   Advice stack: [trailing_ones, ...]
209    U32Cto,
210
211    /// Pushes the base 2 logarithm of the top stack element, rounded down.
212    /// Inputs:
213    ///   Operand stack: [n, ...]
214    ///   Advice stack: [...]
215    ///
216    /// Outputs:
217    ///   Operand stack: [n, ...]
218    ///   Advice stack: [ilog2(n), ...]
219    ILog2,
220
221    // ADVICE MAP SYSTEM EVENTS
222    // --------------------------------------------------------------------------------------------
223    /// Reads words from memory at the specified range and inserts them into the advice map under
224    /// the key `KEY` located at the top of the stack.
225    ///
226    /// Inputs:
227    ///   Operand stack: [KEY, start_addr, end_addr, ...]
228    ///   Advice map: {...}
229    ///
230    /// Outputs:
231    ///   Operand stack: [KEY, start_addr, end_addr, ...]
232    ///   Advice map: {KEY: values}
233    ///
234    /// Where `values` are the elements located in memory[start_addr..end_addr].
235    MemToMap,
236
237    /// Reads two word from the operand stack and inserts them into the advice map under the key
238    /// defined by the hash of these words.
239    ///
240    /// Inputs:
241    ///   Operand stack: [A, B, ...]
242    ///   Advice map: {...}
243    ///
244    /// Outputs:
245    ///   Operand stack: [A, B, ...]
246    ///   Advice map: {KEY: [a0, a1, a2, a3, b0, b1, b2, b3]}
247    ///
248    /// Where KEY is computed as hash(A || B, domain=0).
249    HdwordToMap,
250
251    /// Reads two words from the operand stack and inserts them into the advice map under the key
252    /// defined by the hash of these words (using `d` as the domain).
253    ///
254    /// Inputs:
255    ///   Operand stack: [A, B, d, ...]
256    ///   Advice map: {...}
257    ///
258    /// Outputs:
259    ///   Operand stack: [A, B, d, ...]
260    ///   Advice map: {KEY: [a0, a1, a2, a3, b0, b1, b2, b3]}
261    ///
262    /// Where KEY is computed as hash(A || B, d).
263    HdwordToMapWithDomain,
264
265    /// Reads four words from the operand stack and inserts them into the advice map under the key
266    /// defined by the hash of these words.
267    ///
268    /// Inputs:
269    ///   Operand stack: [A, B, C, D, ...]
270    ///   Advice map: {...}
271    ///
272    /// Outputs:
273    ///   Operand stack: [A, B, C, D, ...]
274    ///   Advice map: {KEY: [A, B, C, D]} (16 elements)
275    ///
276    /// Where:
277    /// - KEY is computed as hash_elements([A, B, C, D]) using the sponge construction (sequential
278    ///   absorption; two rounds for four words).
279    HqwordToMap,
280
281    /// Reads three words from the operand stack and inserts the top two words into the advice map
282    /// under the key defined by applying a Poseidon2 permutation to all three words.
283    ///
284    /// Inputs:
285    ///   Operand stack: [A, B, C, ...]
286    ///   Advice map: {...}
287    ///
288    /// Outputs:
289    ///   Operand stack: [A, B, C, ...]
290    ///   Advice map: {KEY: [a0, a1, a2, a3, b0, b1, b2, b3]}
291    ///
292    /// Where KEY is computed by extracting the digest elements from hperm([C, A, B]). For example,
293    /// if C is [0, d, 0, 0], KEY will be set as hash(A || B, d).
294    HpermToMap,
295}
296
297impl SystemEvent {
298    /// Attempts to convert an EventId into a SystemEvent by looking it up in the const table.
299    ///
300    /// Returns `Some(SystemEvent)` if the ID matches a known system event, `None` otherwise.
301    /// This uses a const lookup table with hardcoded EventIds, avoiding runtime hash computation.
302    pub const fn from_event_id(event_id: EventId) -> Option<Self> {
303        let lookup = Self::LOOKUP;
304        let mut i = 0;
305        while i < lookup.len() {
306            if lookup[i].id.as_u64() == event_id.as_u64() {
307                return Some(lookup[i].event);
308            }
309            i += 1;
310        }
311        None
312    }
313
314    /// Attempts to convert a name into a SystemEvent by looking it up in the const table.
315    ///
316    /// Returns `Some(SystemEvent)` if the name matches a known system event, `None` otherwise.
317    /// This uses const string comparison against the lookup table.
318    pub const fn from_name(name: &str) -> Option<Self> {
319        let lookup = Self::LOOKUP;
320        let mut i = 0;
321        while i < lookup.len() {
322            if str_eq(name, lookup[i].name) {
323                return Some(lookup[i].event);
324            }
325            i += 1;
326        }
327        None
328    }
329
330    /// Returns the human-readable name of this system event as an [`EventName`].
331    ///
332    /// System event names are prefixed with `sys::` to distinguish them from user-defined events.
333    pub const fn event_name(&self) -> EventName {
334        EventName::new(Self::LOOKUP[*self as usize].name)
335    }
336
337    /// Returns the [`EventId`] for this system event.
338    ///
339    /// The ID is looked up from the const LOOKUP table using the enum's discriminant
340    /// as the index. The discriminants are explicitly set to match the array indices.
341    pub const fn event_id(&self) -> EventId {
342        Self::LOOKUP[*self as usize].id
343    }
344
345    /// Returns an array of all system event variants.
346    pub const fn all() -> [Self; Self::COUNT] {
347        [
348            Self::MerkleNodeMerge,
349            Self::MerkleNodeToStack,
350            Self::MapValueToStack,
351            Self::MapValueCountToStack,
352            Self::MapValueToStackN0,
353            Self::MapValueToStackN4,
354            Self::MapValueToStackN8,
355            Self::HasMapKey,
356            Self::Ext2Inv,
357            Self::U32Clz,
358            Self::U32Ctz,
359            Self::U32Clo,
360            Self::U32Cto,
361            Self::ILog2,
362            Self::MemToMap,
363            Self::HdwordToMap,
364            Self::HdwordToMapWithDomain,
365            Self::HqwordToMap,
366            Self::HpermToMap,
367        ]
368    }
369}
370
371impl From<SystemEvent> for EventName {
372    fn from(system_event: SystemEvent) -> Self {
373        system_event.event_name()
374    }
375}
376
377impl crate::prettier::PrettyPrint for SystemEvent {
378    fn render(&self) -> crate::prettier::Document {
379        crate::prettier::display(self)
380    }
381}
382
383impl fmt::Display for SystemEvent {
384    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
385        const PREFIX_LEN: usize = "sys::".len();
386
387        let (_prefix, rest) = Self::LOOKUP[*self as usize].name.split_at(PREFIX_LEN);
388        write!(f, "{rest}")
389    }
390}
391
392// LOOKUP TABLE
393// ================================================================================================
394
395/// An entry in the system event lookup table, containing all metadata for a system event.
396#[derive(Copy, Clone, Debug)]
397pub(crate) struct SystemEventEntry {
398    /// The unique event ID (hash of the name)
399    pub id: EventId,
400    /// The system event variant
401    pub event: SystemEvent,
402    /// The full event name string (e.g., "sys::merkle_node_merge")
403    pub name: &'static str,
404}
405
406impl SystemEvent {
407    /// The total number of system events.
408    pub const COUNT: usize = 19;
409
410    /// Lookup table mapping system events to their metadata.
411    ///
412    /// The enum variant order matches the indices in this table, allowing efficient const
413    /// lookup via array indexing using discriminants.
414    const LOOKUP: [SystemEventEntry; Self::COUNT] = [
415        SystemEventEntry {
416            id: EventId::from_u64(7243907139105902342),
417            event: SystemEvent::MerkleNodeMerge,
418            name: "sys::merkle_node_merge",
419        },
420        SystemEventEntry {
421            id: EventId::from_u64(6873007751276594108),
422            event: SystemEvent::MerkleNodeToStack,
423            name: "sys::merkle_node_to_stack",
424        },
425        SystemEventEntry {
426            id: EventId::from_u64(17843484659000820118),
427            event: SystemEvent::MapValueToStack,
428            name: "sys::map_value_to_stack",
429        },
430        SystemEventEntry {
431            id: EventId::from_u64(3470274154276391308),
432            event: SystemEvent::MapValueCountToStack,
433            name: "sys::map_value_count_to_stack",
434        },
435        SystemEventEntry {
436            id: EventId::from_u64(11775886982554463322),
437            event: SystemEvent::MapValueToStackN0,
438            name: "sys::map_value_to_stack_n_0",
439        },
440        SystemEventEntry {
441            id: EventId::from_u64(3443305460233942990),
442            event: SystemEvent::MapValueToStackN4,
443            name: "sys::map_value_to_stack_n_4",
444        },
445        SystemEventEntry {
446            id: EventId::from_u64(1741586542981559489),
447            event: SystemEvent::MapValueToStackN8,
448            name: "sys::map_value_to_stack_n_8",
449        },
450        SystemEventEntry {
451            id: EventId::from_u64(5642583036089175977),
452            event: SystemEvent::HasMapKey,
453            name: "sys::has_map_key",
454        },
455        SystemEventEntry {
456            id: EventId::from_u64(9660728691489438960),
457            event: SystemEvent::Ext2Inv,
458            name: "sys::ext2_inv",
459        },
460        SystemEventEntry {
461            id: EventId::from_u64(1503707361178382932),
462            event: SystemEvent::U32Clz,
463            name: "sys::u32_clz",
464        },
465        SystemEventEntry {
466            id: EventId::from_u64(10656887096526143429),
467            event: SystemEvent::U32Ctz,
468            name: "sys::u32_ctz",
469        },
470        SystemEventEntry {
471            id: EventId::from_u64(12846584985739176048),
472            event: SystemEvent::U32Clo,
473            name: "sys::u32_clo",
474        },
475        SystemEventEntry {
476            id: EventId::from_u64(6773574803673468616),
477            event: SystemEvent::U32Cto,
478            name: "sys::u32_cto",
479        },
480        SystemEventEntry {
481            id: EventId::from_u64(7444351342957461231),
482            event: SystemEvent::ILog2,
483            name: "sys::ilog2",
484        },
485        SystemEventEntry {
486            id: EventId::from_u64(5768534446586058686),
487            event: SystemEvent::MemToMap,
488            name: "sys::mem_to_map",
489        },
490        SystemEventEntry {
491            id: EventId::from_u64(5988159172915333521),
492            event: SystemEvent::HdwordToMap,
493            name: "sys::hdword_to_map",
494        },
495        SystemEventEntry {
496            id: EventId::from_u64(6143777601072385586),
497            event: SystemEvent::HdwordToMapWithDomain,
498            name: "sys::hdword_to_map_with_domain",
499        },
500        SystemEventEntry {
501            id: EventId::from_u64(11723176702659679401),
502            event: SystemEvent::HqwordToMap,
503            name: "sys::hqword_to_map",
504        },
505        SystemEventEntry {
506            id: EventId::from_u64(6190830263511605775),
507            event: SystemEvent::HpermToMap,
508            name: "sys::hperm_to_map",
509        },
510    ];
511}
512
513// HELPERS
514// ================================================================================================
515
516/// Const-compatible string equality check.
517const fn str_eq(a: &str, b: &str) -> bool {
518    let a_bytes = a.as_bytes();
519    let b_bytes = b.as_bytes();
520
521    if a_bytes.len() != b_bytes.len() {
522        return false;
523    }
524
525    let mut i = 0;
526    while i < a_bytes.len() {
527        if a_bytes[i] != b_bytes[i] {
528            return false;
529        }
530        i += 1;
531    }
532    true
533}
534
535#[cfg(test)]
536mod test {
537    use super::*;
538
539    #[test]
540    fn test_system_events() {
541        // Comprehensive test verifying consistency between SystemEvent::all() and
542        // SystemEvent::LOOKUP. This ensures all() and LOOKUP are in sync, lookup table has
543        // correct IDs/names, and all variants are covered.
544
545        // Verify lengths match COUNT
546        assert_eq!(SystemEvent::all().len(), SystemEvent::COUNT);
547        assert_eq!(SystemEvent::LOOKUP.len(), SystemEvent::COUNT);
548
549        // Iterate through both all() and LOOKUP together, checking all invariants
550        for (i, (event, entry)) in
551            SystemEvent::all().iter().zip(SystemEvent::LOOKUP.iter()).enumerate()
552        {
553            // Verify LOOKUP entry matches the event at the same index
554            assert_eq!(
555                entry.event, *event,
556                "LOOKUP[{}].event ({:?}) doesn't match all()[{}] ({:?})",
557                i, entry.event, i, event
558            );
559
560            // Verify LOOKUP entry ID matches the computed ID
561            let computed_id = event.event_id();
562            assert_eq!(
563                entry.id,
564                computed_id,
565                "LOOKUP[{}].id is EventId::from_u64({}), but {:?}.to_event_id() returns EventId::from_u64({})",
566                i,
567                entry.id.as_u64(),
568                event,
569                computed_id.as_u64()
570            );
571
572            // Verify name has correct "sys::" prefix
573            assert!(
574                entry.name.starts_with("sys::"),
575                "SystemEvent name should start with 'sys::': {}",
576                entry.name
577            );
578
579            // Verify from_event_id lookup works
580            let looked_up =
581                SystemEvent::from_event_id(entry.id).expect("SystemEvent should be found by ID");
582            assert_eq!(looked_up, *event);
583
584            // Verify from_name lookup works
585            let looked_up_by_name =
586                SystemEvent::from_name(entry.name).expect("SystemEvent should be found by name");
587            assert_eq!(looked_up_by_name, *event);
588
589            // Verify EventName conversion works
590            let event_name = event.event_name();
591            assert_eq!(event_name.as_str(), entry.name);
592            assert!(SystemEvent::from_name(event_name.as_str()).is_some());
593            let event_name_from_into: EventName = (*event).into();
594            assert_eq!(event_name_from_into.as_str(), entry.name);
595            assert!(SystemEvent::from_name(event_name_from_into.as_str()).is_some());
596
597            // Exhaustive match to ensure compile-time error when adding new variants
598            match event {
599                SystemEvent::MerkleNodeMerge
600                | SystemEvent::MerkleNodeToStack
601                | SystemEvent::MapValueToStack
602                | SystemEvent::MapValueCountToStack
603                | SystemEvent::MapValueToStackN0
604                | SystemEvent::MapValueToStackN4
605                | SystemEvent::MapValueToStackN8
606                | SystemEvent::HasMapKey
607                | SystemEvent::Ext2Inv
608                | SystemEvent::U32Clz
609                | SystemEvent::U32Ctz
610                | SystemEvent::U32Clo
611                | SystemEvent::U32Cto
612                | SystemEvent::ILog2
613                | SystemEvent::MemToMap
614                | SystemEvent::HdwordToMap
615                | SystemEvent::HdwordToMapWithDomain
616                | SystemEvent::HqwordToMap
617                | SystemEvent::HpermToMap => {},
618            }
619        }
620    }
621}