ixa/
global_properties.rs

1//! A generic mechanism for storing context-wide data.
2//!
3//! Global properties are not mutable and represent variables that are
4//! required in a global scope during the simulation, such as
5//! simulation parameters.
6//! A global property can be of any type and is just a value
7//! stored in the context. Global properties are defined by the
8//! [`crate::define_global_property!()`] macro and can then be
9//! set in one of two ways:
10//!
11//! * Directly by using [`Context::set_global_property_value()`]
12//! * Loaded from a configuration file using [`Context::load_global_properties()`]
13//!
14//! Attempting to change a global property which has been set already
15//! will result in an error.
16//!
17//! Global properties can be read with [`Context::get_global_property_value()`]
18use std::any::Any;
19use std::cell::RefCell;
20use std::error::Error;
21use std::fmt::Debug;
22use std::fs;
23use std::io::BufReader;
24use std::path::Path;
25use std::sync::atomic::{AtomicUsize, Ordering};
26use std::sync::{Arc, LazyLock, Mutex};
27
28use serde::de::DeserializeOwned;
29
30use crate::context::Context;
31use crate::error::IxaError;
32use crate::{trace, ContextBase, HashMap, HashMapExt};
33
34type PropertySetterFn =
35    dyn Fn(&mut Context, &str, serde_json::Value) -> Result<(), IxaError> + Send + Sync;
36
37// This is a global list of all the global properties that
38// are compiled in. Fundamentally it's a HashMap of property
39// names to the setter function, but it's wrapped in the
40// RefCell/Mutex/LazyLock combo to allow it to be globally
41// shared and initialized at startup time while still being
42// safe.
43#[doc(hidden)]
44#[allow(clippy::type_complexity)]
45pub static GLOBAL_PROPERTIES: LazyLock<Mutex<RefCell<HashMap<String, Arc<PropertySetterFn>>>>> =
46    LazyLock::new(|| Mutex::new(RefCell::new(HashMap::new())));
47
48/// Global property ID counter, keeps track of the ID that will be assigned to
49/// the next global property that requests an ID.
50static NEXT_GLOBAL_PROPERTY_ID: Mutex<usize> = Mutex::new(0);
51
52/// A convenience getter for `NEXT_GLOBAL_PROPERTY_ID`.
53#[must_use]
54pub fn get_global_property_count() -> usize {
55    *NEXT_GLOBAL_PROPERTY_ID.lock().unwrap()
56}
57
58/// Encapsulates the synchronization logic for initializing a global property's ID.
59///
60/// Acquires a global lock on the next available global property ID, but only
61/// increments it if we successfully initialize the provided ID. The ID of a
62/// global property is assigned at runtime but only once per type.
63#[must_use]
64pub fn initialize_global_property_id(global_property_id: &AtomicUsize) -> usize {
65    let mut guard = NEXT_GLOBAL_PROPERTY_ID.lock().unwrap();
66    let candidate = *guard;
67
68    match global_property_id.compare_exchange(
69        usize::MAX,
70        candidate,
71        Ordering::AcqRel,
72        Ordering::Acquire,
73    ) {
74        Ok(_) => {
75            *guard += 1;
76            candidate
77        }
78        Err(existing) => existing,
79    }
80}
81
82pub fn add_global_property<T: GlobalProperty>(name: &str)
83where
84    for<'de> <T as GlobalProperty>::Value: serde::Deserialize<'de>,
85{
86    trace!("Adding global property {name}");
87    let properties = GLOBAL_PROPERTIES.lock().unwrap();
88    properties
89        .borrow_mut()
90        .insert(
91            name.to_string(),
92            Arc::new(
93                |context: &mut Context, name, value| -> Result<(), IxaError> {
94                    let val: T::Value = serde_json::from_value(value)?;
95                    if context.get_global_property_value(T::new()).is_some() {
96                        return Err(IxaError::DuplicateProperty {
97                            name: name.to_string(),
98                        });
99                    }
100                    context.set_global_property_value(T::new(), val)?;
101                    Ok(())
102                },
103            ),
104        )
105        .inspect(|_| panic!("Duplicate global property {}", name));
106}
107
108fn get_global_property_setter(name: &str) -> Option<Arc<PropertySetterFn>> {
109    let properties = GLOBAL_PROPERTIES.lock().unwrap();
110    let tmp = properties.borrow();
111    tmp.get(name).map(Arc::clone)
112}
113
114fn get_global_property_setter_for_config_key(name: &str) -> Option<Arc<PropertySetterFn>> {
115    get_global_property_setter(name).or_else(|| {
116        if name.contains('-') {
117            get_global_property_setter(&name.replace('-', "_"))
118        } else {
119            None
120        }
121    })
122}
123
124pub(crate) fn load_global_properties_from_map(
125    context: &mut Context,
126    val: serde_json::Map<String, serde_json::Value>,
127) -> Result<(), IxaError> {
128    for (k, v) in val {
129        if let Some(setter) = get_global_property_setter_for_config_key(&k) {
130            setter(context, &k, v)?;
131        } else {
132            return Err(IxaError::NoGlobalProperty { name: k });
133        }
134    }
135
136    Ok(())
137}
138
139/// The trait representing a global property. Do not use this
140/// directly, but instead define global properties with
141/// [`define_global_property!`](crate::define_global_property!).
142///
143/// Validation errors are produced by client code and should be returned as
144/// `Box<dyn std::error::Error + Send + Sync + 'static>`. Ixa wraps those
145/// values in [`IxaError::IllegalGlobalPropertyValue`]
146/// when a global property is set or loaded.
147pub trait GlobalProperty: Any {
148    /// The actual type of the data stored in the global property
149    type Value: Any;
150
151    #[must_use]
152    fn id() -> usize;
153
154    fn new() -> Self;
155
156    #[must_use]
157    fn name() -> &'static str {
158        let full = std::any::type_name::<Self>();
159        full.rsplit("::").next().unwrap()
160    }
161
162    /// A function which validates the global property.
163    ///
164    /// Client code should box any produced error itself.
165    fn validate(value: &Self::Value) -> Result<(), Box<dyn Error + Send + Sync + 'static>>;
166}
167
168pub trait ContextGlobalPropertiesExt: ContextBase {
169    /// Set the value of a global property of type T
170    ///
171    /// # Errors
172    /// Will return an error if an attempt is made to change a value.
173    fn set_global_property_value<T: GlobalProperty + 'static>(
174        &mut self,
175        property: T,
176        value: T::Value,
177    ) -> Result<(), IxaError>;
178
179    /// Return value of global property T
180    #[must_use]
181    fn get_global_property_value<T: GlobalProperty + 'static>(
182        &self,
183        _property: T,
184    ) -> Option<&T::Value>;
185
186    /// Given a file path for a valid json file, deserialize parameter values
187    /// for a given struct T
188    ///
189    /// # Errors
190    ///
191    /// Will return an [`IxaError`] if the `file_path` does not exist or
192    /// cannot be deserialized
193    fn load_parameters_from_json<T: 'static + Debug + DeserializeOwned>(
194        &mut self,
195        file_name: &Path,
196    ) -> Result<T, IxaError> {
197        trace!("Loading parameters from JSON: {file_name:?}");
198        let config_file = fs::File::open(file_name)?;
199        let reader = BufReader::new(config_file);
200        let config = serde_json::from_reader(reader)?;
201        Ok(config)
202    }
203
204    /// Load global properties from a JSON file.
205    ///
206    /// The expected structure is a dictionary with each name being
207    /// the name of the struct prefixed with the crate name, as in:
208    /// `ixa.NumFluVariants` and the value being an object which can
209    /// serde deserialize into the relevant struct. If a package name contains
210    /// hyphens, either the package spelling or Rust's underscore-normalized
211    /// crate spelling can be used.
212    ///
213    /// # Errors
214    /// Will return an [`IxaError`] if:
215    /// * The `file_path` doesn't exist
216    /// * The file isn't valid JSON
217    /// * A specified object doesn't correspond to an existing global property.
218    /// * There are two values for the same object.
219    ///
220    /// Ixa automatically knows about any property defined with
221    /// [`define_global_property!`](crate::define_global_property) so you don't need to register them
222    /// explicitly.
223    ///
224    /// It is possible to call [`Context::load_global_properties()`] multiple
225    /// times with different files as long as the files have disjoint
226    /// sets of properties.
227    ///
228    /// Note: when a config file is passed to a runner entry point via
229    /// `--config`, its top-level `args` key is reserved for runner arguments
230    /// and is excluded from global properties. This method does not treat
231    /// `args` specially; every key must name a global property.
232    fn load_global_properties(&mut self, file_name: &Path) -> Result<(), IxaError>;
233}
234impl ContextGlobalPropertiesExt for Context {
235    fn set_global_property_value<T: GlobalProperty + 'static>(
236        &mut self,
237        _property: T,
238        value: T::Value,
239    ) -> Result<(), IxaError> {
240        T::validate(&value).map_err(|source| IxaError::IllegalGlobalPropertyValue {
241            name: T::name().to_string(),
242            source,
243        })?;
244        let index = T::id();
245        let cell = self.global_properties.get_mut(index).unwrap_or_else(|| {
246            panic!(
247                "No global property found with index = {index:?}. You must use the \
248                 `define_global_property!` macro to create a global property."
249            )
250        });
251        if cell.get().is_some() {
252            // Note: If we change global properties to be mutable, we'll need to
253            // update define_derived_person_property to either handle updates or only
254            // allow immutable properties.
255            return Err(IxaError::EntryAlreadyExists);
256        }
257        let _ = cell.set(Box::new(value));
258        Ok(())
259    }
260
261    fn get_global_property_value<T: GlobalProperty + 'static>(
262        &self,
263        _property: T,
264    ) -> Option<&T::Value> {
265        let index = T::id();
266        self.global_properties
267            .get(index)
268            .unwrap_or_else(|| {
269                panic!(
270                    "No global property found with index = {index:?}. You must use the \
271                     `define_global_property!` macro to create a global property."
272                )
273            })
274            .get()
275            .map(|property| {
276                property.downcast_ref::<T::Value>().expect(
277                    "TypeID does not match global property type. You must use the \
278                     `define_global_property!` macro to create a global property.",
279                )
280            })
281    }
282
283    fn load_global_properties(&mut self, file_name: &Path) -> Result<(), IxaError> {
284        trace!("Loading global properties from {file_name:?}");
285        let config_file = fs::File::open(file_name)?;
286        let reader = BufReader::new(config_file);
287        let val: serde_json::Map<String, serde_json::Value> = serde_json::from_reader(reader)?;
288
289        load_global_properties_from_map(self, val)
290    }
291}
292
293#[cfg(test)]
294mod test {
295    use std::error::Error;
296    use std::fmt;
297    use std::path::PathBuf;
298
299    use serde::{Deserialize, Serialize};
300    use tempfile::tempdir;
301
302    use super::*;
303    use crate::context::Context;
304    use crate::define_global_property;
305    use crate::error::IxaError;
306
307    fn fixture_path(name: &str) -> PathBuf {
308        PathBuf::from(env!("CARGO_MANIFEST_DIR"))
309            .join("integration-tests/fixtures/global-properties")
310            .join(name)
311    }
312
313    #[derive(Debug)]
314    struct InvalidProperty3Value {
315        field_int: u32,
316    }
317
318    impl fmt::Display for InvalidProperty3Value {
319        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
320            write!(f, "field_int must be zero, got {}", self.field_int)
321        }
322    }
323
324    impl Error for InvalidProperty3Value {}
325
326    #[derive(Serialize, Deserialize, Debug, Clone)]
327    pub struct ParamType {
328        pub days: usize,
329        pub diseases: usize,
330    }
331
332    define_global_property!(DiseaseParams, ParamType);
333
334    #[test]
335    fn set_get_global_property() {
336        let params: ParamType = ParamType {
337            days: 10,
338            diseases: 2,
339        };
340        let params2: ParamType = ParamType {
341            days: 11,
342            diseases: 3,
343        };
344
345        let mut context = Context::new();
346
347        // Set and check the stored value.
348        context
349            .set_global_property_value(DiseaseParams, params.clone())
350            .unwrap();
351        let global_params = context
352            .get_global_property_value(DiseaseParams)
353            .unwrap()
354            .clone();
355        assert_eq!(global_params.days, params.days);
356        assert_eq!(global_params.diseases, params.diseases);
357
358        // Setting again should fail because global properties are immutable.
359        assert!(context
360            .set_global_property_value(DiseaseParams, params2.clone())
361            .is_err());
362
363        // Check that the value is unchanged.
364        let global_params = context
365            .get_global_property_value(DiseaseParams)
366            .unwrap()
367            .clone();
368        assert_eq!(global_params.days, params.days);
369        assert_eq!(global_params.diseases, params.diseases);
370    }
371
372    #[test]
373    fn get_global_propert_missing() {
374        let context = Context::new();
375        let global_params = context.get_global_property_value(DiseaseParams);
376        assert!(global_params.is_none());
377    }
378
379    #[test]
380    fn set_parameters() {
381        let mut context = Context::new();
382        let temp_dir = tempdir().unwrap();
383        let config_path = PathBuf::from(&temp_dir.path());
384        let file_name = "test.json";
385        let file_path = config_path.join(file_name);
386        let config = fs::File::create(config_path.join(file_name)).unwrap();
387
388        let params: ParamType = ParamType {
389            days: 10,
390            diseases: 2,
391        };
392
393        define_global_property!(Parameters, ParamType);
394
395        let _ = serde_json::to_writer(config, &params);
396        let params_json = context
397            .load_parameters_from_json::<ParamType>(&file_path)
398            .unwrap();
399
400        context
401            .set_global_property_value(Parameters, params_json)
402            .unwrap();
403
404        let params_read = context
405            .get_global_property_value(Parameters)
406            .unwrap()
407            .clone();
408        assert_eq!(params_read.days, params.days);
409        assert_eq!(params_read.diseases, params.diseases);
410    }
411
412    #[derive(Serialize, Deserialize)]
413    pub struct Property1Type {
414        field_int: u32,
415        field_str: String,
416    }
417    define_global_property!(Property1, Property1Type);
418
419    #[derive(Serialize, Deserialize)]
420    pub struct Property2Type {
421        field_int: u32,
422    }
423    define_global_property!(Property2, Property2Type);
424
425    #[test]
426    fn read_global_properties() {
427        let mut context = Context::new();
428        let path = fixture_path("global_properties_test1.json");
429        context.load_global_properties(&path).unwrap();
430        let p1 = context.get_global_property_value(Property1).unwrap();
431        assert_eq!(p1.field_int, 1);
432        assert_eq!(p1.field_str, "test");
433        let p2 = context.get_global_property_value(Property2).unwrap();
434        assert_eq!(p2.field_int, 2);
435    }
436
437    #[test]
438    fn read_unknown_property() {
439        let mut context = Context::new();
440        let path = fixture_path("global_properties_missing.json");
441        match context.load_global_properties(&path) {
442            Err(IxaError::NoGlobalProperty { name }) => assert_eq!(name, "ixa.PropertyUnknown"),
443            _ => panic!("Unexpected error type"),
444        }
445    }
446
447    #[test]
448    fn read_malformed_property() {
449        let mut context = Context::new();
450        let path = fixture_path("global_properties_malformed.json");
451        let error = context.load_global_properties(&path);
452        match error {
453            Err(IxaError::JsonError(_)) => {}
454            _ => panic!("Unexpected error type"),
455        }
456    }
457
458    #[test]
459    fn read_duplicate_property() {
460        let mut context = Context::new();
461        let path = fixture_path("global_properties_test1.json");
462        context.load_global_properties(&path).unwrap();
463        let error = context.load_global_properties(&path);
464        match error {
465            Err(IxaError::DuplicateProperty { .. }) => {}
466            _ => panic!("Unexpected error type"),
467        }
468    }
469
470    #[derive(Serialize, Deserialize)]
471    pub struct Property3Type {
472        field_int: u32,
473    }
474    define_global_property!(Property3, Property3Type, |v: &Property3Type| {
475        match v.field_int {
476            0 => Ok(()),
477            _ => Err(Box::new(InvalidProperty3Value {
478                field_int: v.field_int,
479            }) as Box<dyn Error + Send + Sync + 'static>),
480        }
481    });
482
483    #[test]
484    fn validate_property_set_success() {
485        let mut context = Context::new();
486        context
487            .set_global_property_value(Property3, Property3Type { field_int: 0 })
488            .unwrap();
489    }
490
491    #[test]
492    fn validate_property_set_failure() {
493        let mut context = Context::new();
494        let error = context
495            .set_global_property_value(Property3, Property3Type { field_int: 1 })
496            .unwrap_err();
497        assert_eq!(
498            error.to_string(),
499            "illegal value for global property `Property3`: field_int must be zero, got 1"
500        );
501        match error {
502            IxaError::IllegalGlobalPropertyValue { name, source } => {
503                assert_eq!(name, "Property3");
504                assert_eq!(source.to_string(), "field_int must be zero, got 1");
505            }
506            _ => panic!("Unexpected error type"),
507        }
508    }
509
510    #[test]
511    fn validate_property_load_success() {
512        let mut context = Context::new();
513        let path = fixture_path("global_properties_valid.json");
514        context.load_global_properties(&path).unwrap();
515    }
516
517    #[test]
518    fn validate_property_load_failure() {
519        let mut context = Context::new();
520        let path = fixture_path("global_properties_invalid.json");
521        let error = context.load_global_properties(&path).unwrap_err();
522        assert_eq!(
523            error.to_string(),
524            "illegal value for global property `Property3`: field_int must be zero, got 42"
525        );
526        match error {
527            IxaError::IllegalGlobalPropertyValue { name, source } => {
528                assert_eq!(name, "Property3");
529                assert_eq!(source.to_string(), "field_int must be zero, got 42");
530            }
531            _ => panic!("Unexpected error type"),
532        }
533    }
534}
ixa/global_properties.rs

ixa/
global_properties.rs
