icydb_core/db/response/
mod.rs

1//! Module: response
2//! Responsibility: materialized query/write response payload contracts.
3//! Does not own: execution routing, planning policy, or cursor token protocol.
4//! Boundary: Tier-2 db API DTO surface returned by session execution.
5//! Architecture: `Response<R>` is transport-only and row-shape-agnostic.
6//! Query semantics (for example cardinality checks) must live in query/session
7//! extension traits rather than inherent response DTO methods.
8
9mod grouped;
10mod paged;
11
12#[cfg(test)]
13use crate::value::Value;
14use crate::{prelude::*, traits::EntityValue, types::Id, value::OutputValue};
15use thiserror::Error as ThisError;
16
17mod private {
18    ///
19    /// Sealed
20    ///
21    /// Internal marker used to seal response row-shape marker implementations.
22    ///
23
24    pub trait Sealed {}
25}
26
27pub use grouped::{GroupedRow, PagedGroupedExecution, PagedGroupedExecutionWithTrace};
28pub use paged::{PagedLoadExecution, PagedLoadExecutionWithTrace};
29
30///
31/// ResponseRow
32///
33/// Marker trait for row-shape DTOs that are valid payloads for `Response<R>`.
34/// This trait is sealed to keep row-shape admission local to the response layer.
35///
36
37pub trait ResponseRow: private::Sealed {}
38
39impl ResponseRow for GroupedRow {}
40
41impl private::Sealed for GroupedRow {}
42
43///
44/// Row
45///
46/// Materialized entity row with explicit identity and payload accessors.
47///
48
49#[derive(Clone, Debug, Eq, PartialEq)]
50pub struct Row<E: EntityKind> {
51    id: Id<E>,
52    entity: E,
53}
54
55impl<E: EntityKind> Row<E> {
56    /// Construct one row from identity and entity payload.
57    #[must_use]
58    pub const fn new(id: Id<E>, entity: E) -> Self {
59        Self { id, entity }
60    }
61
62    /// Borrow this row's identity.
63    #[must_use]
64    pub const fn id(&self) -> Id<E> {
65        self.id
66    }
67
68    /// Consume and return this row's entity payload.
69    #[must_use]
70    pub fn entity(self) -> E {
71        self.entity
72    }
73
74    /// Borrow this row's entity payload.
75    #[must_use]
76    pub const fn entity_ref(&self) -> &E {
77        &self.entity
78    }
79
80    /// Consume and return `(id, entity)` parts.
81    #[must_use]
82    pub fn into_parts(self) -> (Id<E>, E) {
83        (self.id, self.entity)
84    }
85}
86
87impl<E: EntityKind> From<(Id<E>, E)> for Row<E> {
88    fn from(value: (Id<E>, E)) -> Self {
89        Self::new(value.0, value.1)
90    }
91}
92
93impl<E: EntityKind> private::Sealed for Row<E> {}
94
95impl<E: EntityKind> ResponseRow for Row<E> {}
96
97///
98/// ProjectedRow
99///
100/// One scalar projection output row emitted in planner declaration order.
101/// `values` carries evaluated expression outputs for this row.
102///
103
104#[derive(Clone, Debug, Eq, PartialEq)]
105pub struct ProjectedRow<E: EntityKind> {
106    id: Id<E>,
107    values: Vec<OutputValue>,
108}
109
110impl<E: EntityKind> ProjectedRow<E> {
111    /// Construct one projected scalar row.
112    #[must_use]
113    pub const fn new(id: Id<E>, values: Vec<OutputValue>) -> Self {
114        Self { id, values }
115    }
116
117    /// Build one projected row from runtime values at the public output boundary.
118    #[cfg(test)]
119    #[must_use]
120    pub(in crate::db) fn from_runtime_values(id: Id<E>, values: Vec<Value>) -> Self {
121        Self::new(id, values.into_iter().map(OutputValue::from).collect())
122    }
123
124    /// Borrow the source row identifier.
125    #[must_use]
126    pub const fn id(&self) -> Id<E> {
127        self.id
128    }
129
130    /// Borrow projected scalar values in declaration order.
131    #[must_use]
132    pub const fn values(&self) -> &[OutputValue] {
133        self.values.as_slice()
134    }
135
136    /// Consume and return `(id, projected_values)`.
137    #[must_use]
138    pub fn into_parts(self) -> (Id<E>, Vec<OutputValue>) {
139        (self.id, self.values)
140    }
141}
142
143impl<E: EntityKind> private::Sealed for ProjectedRow<E> {}
144
145impl<E: EntityKind> ResponseRow for ProjectedRow<E> {}
146
147///
148/// ResponseError
149///
150
151#[derive(Debug, ThisError)]
152pub enum ResponseError {
153    #[error("expected exactly one row, found 0 (entity {entity})")]
154    NotFound { entity: &'static str },
155
156    #[error("expected exactly one row, found {count} (entity {entity})")]
157    NotUnique { entity: &'static str, count: u32 },
158}
159
160impl ResponseError {
161    /// Construct one response not-found cardinality error.
162    #[must_use]
163    pub const fn not_found(entity: &'static str) -> Self {
164        Self::NotFound { entity }
165    }
166
167    /// Construct one response not-unique cardinality error.
168    #[must_use]
169    pub const fn not_unique(entity: &'static str, count: u32) -> Self {
170        Self::NotUnique { entity, count }
171    }
172}
173
174///
175/// Response
176///
177/// Generic response transport container for one row shape `R`.
178///
179
180#[derive(Debug)]
181pub struct Response<R: ResponseRow>(Vec<R>);
182
183///
184/// EntityResponse
185///
186/// Entity-row response transport alias.
187///
188
189pub type EntityResponse<E> = Response<Row<E>>;
190
191///
192/// ProjectionResponse
193///
194/// Scalar projection response transport alias.
195///
196
197pub type ProjectionResponse<E> = Response<ProjectedRow<E>>;
198
199impl<R: ResponseRow> Response<R> {
200    /// Construct one response from ordered rows.
201    #[must_use]
202    pub const fn new(rows: Vec<R>) -> Self {
203        Self(rows)
204    }
205
206    /// Construct one response from rows convertible into `R`.
207    #[must_use]
208    pub fn from_rows<T>(rows: Vec<T>) -> Self
209    where
210        T: Into<R>,
211    {
212        Self(rows.into_iter().map(Into::into).collect())
213    }
214
215    /// Return the number of rows.
216    #[must_use]
217    pub const fn len(&self) -> usize {
218        self.0.len()
219    }
220
221    /// Return the number of rows as a u32 API contract count.
222    #[must_use]
223    #[expect(clippy::cast_possible_truncation)]
224    pub const fn count(&self) -> u32 {
225        self.0.len() as u32
226    }
227
228    /// Return whether this response has no rows.
229    #[must_use]
230    pub const fn is_empty(&self) -> bool {
231        self.0.is_empty()
232    }
233
234    /// Consume and return all rows in response order.
235    #[must_use]
236    pub fn rows(self) -> Vec<R> {
237        self.0
238    }
239
240    /// Borrow an iterator over rows in response order.
241    pub fn iter(&self) -> std::slice::Iter<'_, R> {
242        self.0.iter()
243    }
244}
245
246impl<R: ResponseRow> AsRef<[R]> for Response<R> {
247    fn as_ref(&self) -> &[R] {
248        self.0.as_slice()
249    }
250}
251
252impl<R: ResponseRow> std::ops::Deref for Response<R> {
253    type Target = [R];
254
255    fn deref(&self) -> &Self::Target {
256        self.0.as_slice()
257    }
258}
259
260impl<E: EntityKind> Response<Row<E>> {
261    /// Return the first row identifier, if present.
262    #[must_use]
263    pub fn id(&self) -> Option<Id<E>> {
264        self.0.first().map(Row::id)
265    }
266
267    /// Consume and return all entities in response order.
268    #[must_use]
269    pub fn entities(self) -> Vec<E> {
270        self.0.into_iter().map(Row::entity).collect()
271    }
272
273    /// Borrow an iterator over row identifiers in response order.
274    pub fn ids(&self) -> impl Iterator<Item = Id<E>> + '_ {
275        self.0.iter().map(Row::id)
276    }
277
278    /// Check whether the response contains the provided identifier.
279    pub fn contains_id(&self, id: &Id<E>) -> bool {
280        self.0.iter().any(|row| row.id() == *id)
281    }
282}
283
284impl<R: ResponseRow> IntoIterator for Response<R> {
285    type Item = R;
286    type IntoIter = std::vec::IntoIter<Self::Item>;
287
288    fn into_iter(self) -> Self::IntoIter {
289        self.0.into_iter()
290    }
291}
292
293impl<'a, R: ResponseRow> IntoIterator for &'a Response<R> {
294    type Item = &'a R;
295    type IntoIter = std::slice::Iter<'a, R>;
296
297    fn into_iter(self) -> Self::IntoIter {
298        self.iter()
299    }
300}
301
302///
303/// WriteBatchResponse
304///
305/// Result of a batch write operation.
306/// Provides explicit access to stored entities and their identifiers.
307///
308
309#[derive(Debug)]
310pub struct WriteBatchResponse<E> {
311    entities: Vec<E>,
312}
313
314impl<E> WriteBatchResponse<E> {
315    /// Construct a batch response from stored entities.
316    #[must_use]
317    pub const fn new(entities: Vec<E>) -> Self {
318        Self { entities }
319    }
320
321    /// Return the number of entries.
322    #[must_use]
323    pub const fn len(&self) -> usize {
324        self.entities.len()
325    }
326
327    /// Returns `true` if the batch is empty.
328    #[must_use]
329    pub const fn is_empty(&self) -> bool {
330        self.entities.is_empty()
331    }
332
333    /// Return all stored entities.
334    #[must_use]
335    pub fn entities(self) -> Vec<E> {
336        self.entities
337    }
338
339    /// Borrow an iterator over primary keys in stable batch order.
340    pub fn ids(&self) -> impl Iterator<Item = Id<E>> + '_
341    where
342        E: EntityValue,
343    {
344        self.entities.iter().map(EntityValue::id)
345    }
346
347    /// Borrow an iterator over write entries in stable batch order.
348    pub fn iter(&self) -> std::slice::Iter<'_, E> {
349        self.entities.iter()
350    }
351}
352
353impl<E> IntoIterator for WriteBatchResponse<E> {
354    type Item = E;
355    type IntoIter = std::vec::IntoIter<E>;
356
357    fn into_iter(self) -> Self::IntoIter {
358        self.entities.into_iter()
359    }
360}
361
362impl<'a, E> IntoIterator for &'a WriteBatchResponse<E> {
363    type Item = &'a E;
364    type IntoIter = std::slice::Iter<'a, E>;
365
366    fn into_iter(self) -> Self::IntoIter {
367        self.iter()
368    }
369}
icydb_core/db/response/mod.rs

icydb_core/db/response/
mod.rs
