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zrx_stream/stream/function/signature/
get.rs

1// Copyright (c) 2025-2026 Zensical and contributors
2
3// SPDX-License-Identifier: MIT
4// All contributions are certified under the DCO
5
6// Permission is hereby granted, free of charge, to any person obtaining a copy
7// of this software and associated documentation files (the "Software"), to
8// deal in the Software without restriction, including without limitation the
9// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
10// sell copies of the Software, and to permit persons to whom the Software is
11// furnished to do so, subject to the following conditions:
12
13// The above copyright notice and this permission notice shall be included in
14// all copies or substantial portions of the Software.
15
16// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18// FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
19// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
22// IN THE SOFTWARE.
23
24// ----------------------------------------------------------------------------
25
26//! Get function.
27
28use std::fmt::Display;
29
30use zrx_scheduler::step::error::IntoResult;
31use zrx_scheduler::step::{Result, Scope};
32use zrx_scheduler::Key;
33
34use crate::stream::function::arguments::{
35    ForId, ForIdSplat, ForIdValue, ForKey, ForKeySplat, ForKeyValue, ForScope,
36    ForScopeSplat, ForScopeValue, ForSplat, ForValue,
37};
38use crate::stream::function::catch;
39
40// ----------------------------------------------------------------------------
41// Traits
42// ----------------------------------------------------------------------------
43
44/// Get function.
45pub trait GetFn<A, I, T, U>: Send + 'static {
46    /// Executes the get function.
47    ///
48    /// # Errors
49    ///
50    /// This method returns an error if the function fails to execute.
51    fn execute(&self, scope: &mut Scope<I>, value: &T) -> Result<U>;
52}
53
54// ----------------------------------------------------------------------------
55// Blanket implementations
56// ----------------------------------------------------------------------------
57
58impl<F, R, I, T, U> GetFn<ForScope, I, T, U> for F
59where
60    F: Fn(&mut Scope<I>) -> R + Send + 'static,
61    R: IntoResult<U>,
62    I: Display,
63{
64    #[cfg_attr(
65        feature = "tracing",
66        tracing::instrument(
67            level = "debug", skip_all, fields(key = %scope.key())
68        )
69    )]
70    #[inline]
71    fn execute(&self, scope: &mut Scope<I>, _: &T) -> Result<U> {
72        catch(|| self(scope).into_result())
73    }
74}
75
76impl<F, R, I, T, U> GetFn<ForScopeValue, I, T, U> for F
77where
78    F: Fn(&mut Scope<I>, &T) -> R + Send + 'static,
79    R: IntoResult<U>,
80    I: Display,
81{
82    #[cfg_attr(
83        feature = "tracing",
84        tracing::instrument(
85            level = "debug", skip_all, fields(key = %scope.key())
86        )
87    )]
88    #[inline]
89    fn execute(&self, scope: &mut Scope<I>, value: &T) -> Result<U> {
90        catch(|| self(scope, value).into_result())
91    }
92}
93
94// ----------------------------------------------------------------------------
95
96impl<F, R, I, T, U> GetFn<ForKey, I, T, U> for F
97where
98    F: Fn(&Key<I>) -> R + Send + 'static,
99    R: IntoResult<U>,
100    I: Display,
101{
102    #[cfg_attr(
103        feature = "tracing",
104        tracing::instrument(
105            level = "debug", skip_all, fields(key = %scope.key())
106        )
107    )]
108    #[inline]
109    fn execute(&self, scope: &mut Scope<I>, _: &T) -> Result<U> {
110        catch(|| self(scope.key()).into_result())
111    }
112}
113
114impl<F, R, I, T, U> GetFn<ForKeyValue, I, T, U> for F
115where
116    F: Fn(&Key<I>, &T) -> R + Send + 'static,
117    R: IntoResult<U>,
118    I: Display,
119{
120    #[cfg_attr(
121        feature = "tracing",
122        tracing::instrument(
123            level = "debug", skip_all, fields(key = %scope.key())
124        )
125    )]
126    #[inline]
127    fn execute(&self, scope: &mut Scope<I>, value: &T) -> Result<U> {
128        catch(|| self(scope.key(), value).into_result())
129    }
130}
131
132// ----------------------------------------------------------------------------
133
134impl<F, R, I, T, U> GetFn<ForId, I, T, U> for F
135where
136    F: Fn(&I) -> R + Send + 'static,
137    R: IntoResult<U>,
138    I: Display,
139{
140    #[cfg_attr(
141        feature = "tracing",
142        tracing::instrument(
143            level = "debug", skip_all, fields(key = %scope.key())
144        )
145    )]
146    #[inline]
147    fn execute(&self, scope: &mut Scope<I>, _: &T) -> Result<U> {
148        catch(|| self(scope.key().try_as_id()?).into_result())
149    }
150}
151
152impl<F, R, I, T, U> GetFn<ForIdValue, I, T, U> for F
153where
154    F: Fn(&I, &T) -> R + Send + 'static,
155    R: IntoResult<U>,
156    I: Display,
157{
158    #[cfg_attr(
159        feature = "tracing",
160        tracing::instrument(
161            level = "debug", skip_all, fields(key = %scope.key())
162        )
163    )]
164    #[inline]
165    fn execute(&self, scope: &mut Scope<I>, value: &T) -> Result<U> {
166        catch(|| self(scope.key().try_as_id()?, value).into_result())
167    }
168}
169
170// ----------------------------------------------------------------------------
171
172impl<F, R, I, T, U> GetFn<ForValue, I, T, U> for F
173where
174    F: Fn(&T) -> R + Send + 'static,
175    R: IntoResult<U>,
176    I: Display,
177{
178    #[cfg_attr(
179        feature = "tracing",
180        tracing::instrument(
181            level = "debug", skip_all, fields(key = %scope.key())
182        )
183    )]
184    #[inline]
185    fn execute(&self, scope: &mut Scope<I>, value: &T) -> Result<U> {
186        catch(|| self(value).into_result())
187    }
188}
189
190// ----------------------------------------------------------------------------
191// Macros
192// ----------------------------------------------------------------------------
193
194/// Implements get function trait for scope and splat arguments.
195macro_rules! impl_get_fn_for_scope_splat {
196    ($($T:ident),+) => {
197        impl<F, R, I, $($T,)+ U> GetFn<ForScopeSplat, I, ($($T,)+), U> for F
198        where
199            F: Fn(&mut Scope<I>, $(&$T),+) -> R + Send + 'static,
200            R: IntoResult<U>,
201            I: Display,
202        {
203            #[cfg_attr(
204                feature = "tracing",
205                tracing::instrument(
206                    level = "debug", skip_all, fields(key = %scope.key())
207                )
208            )]
209            #[inline]
210            fn execute(
211                &self, scope: &mut Scope<I>, value: &($($T,)+)
212            ) -> Result<U> {
213                #[allow(non_snake_case)]
214                let ($($T,)+) = value;
215                catch(|| self(scope, $($T),+).into_result())
216            }
217        }
218    };
219}
220
221/// Implements get function trait for key and splat arguments.
222macro_rules! impl_get_fn_for_key_splat {
223    ($($T:ident),+) => {
224        impl<F, R, I, $($T,)+ U> GetFn<ForKeySplat, I, ($($T,)+), U> for F
225        where
226            F: Fn(&Key<I>, $(&$T),+) -> R + Send + 'static,
227            R: IntoResult<U>,
228            I: Display,
229        {
230            #[cfg_attr(
231                feature = "tracing",
232                tracing::instrument(
233                    level = "debug", skip_all, fields(key = %scope.key())
234                )
235            )]
236            #[inline]
237            fn execute(
238                &self, scope: &mut Scope<I>, value: &($($T,)+)
239            ) -> Result<U> {
240                #[allow(non_snake_case)]
241                let ($($T,)+) = value;
242                catch(|| self(scope.key(), $($T),+).into_result())
243            }
244        }
245    };
246}
247
248/// Implements get function trait for identifier and splat arguments.
249macro_rules! impl_get_fn_for_id_splat {
250    ($($T:ident),+) => {
251        impl<F, R, I, $($T,)+ U> GetFn<ForIdSplat, I, ($($T,)+), U> for F
252        where
253            F: Fn(&I, $(&$T),+) -> R + Send + 'static,
254            R: IntoResult<U>,
255            I: Display,
256        {
257            #[cfg_attr(
258                feature = "tracing",
259                tracing::instrument(
260                    level = "debug", skip_all, fields(key = %scope.key())
261                )
262            )]
263            #[inline]
264            fn execute(
265                &self, scope: &mut Scope<I>, value: &($($T,)+)
266            ) -> Result<U> {
267                #[allow(non_snake_case)]
268                let ($($T,)+) = value;
269                catch(|| self(scope.key().try_as_id()?, $($T),+).into_result())
270            }
271        }
272    };
273}
274
275/// Implements get function trait for splat arguments.
276macro_rules! impl_get_fn_for_splat {
277    ($($T:ident),+) => {
278        impl<F, R, I, $($T,)+ U> GetFn<ForSplat, I, ($($T,)+), U> for F
279        where
280            F: Fn($(&$T),+) -> R + Send + 'static,
281            R: IntoResult<U>,
282            I: Display,
283        {
284            #[cfg_attr(
285                feature = "tracing",
286                tracing::instrument(
287                    level = "debug", skip_all, fields(key = %scope.key())
288                )
289            )]
290            #[inline]
291            fn execute(
292                &self, scope: &mut Scope<I>, value: &($($T,)+)
293            ) -> Result<U> {
294                #[allow(non_snake_case)]
295                let ($($T,)+) = value;
296                catch(|| self($($T),+).into_result())
297            }
298        }
299    };
300}
301
302// ----------------------------------------------------------------------------
303
304/// Implements get function traits.
305macro_rules! impl_get_fn {
306    ($($T:ident),+) => {
307        impl_get_fn_for_scope_splat!($($T),+);
308        impl_get_fn_for_key_splat!($($T),+);
309        impl_get_fn_for_id_splat!($($T),+);
310        impl_get_fn_for_splat!($($T),+);
311    };
312}
313
314// ----------------------------------------------------------------------------
315
316impl_get_fn!(T1);
317impl_get_fn!(T1, T2);
318impl_get_fn!(T1, T2, T3);
319impl_get_fn!(T1, T2, T3, T4);
320impl_get_fn!(T1, T2, T3, T4, T5);
321impl_get_fn!(T1, T2, T3, T4, T5, T6);
322impl_get_fn!(T1, T2, T3, T4, T5, T6, T7);
323impl_get_fn!(T1, T2, T3, T4, T5, T6, T7, T8);