Add HW 7

homework/07-kv-sharding/tests/src/shared_state.rs

@@ -0,0 +1,78 @@
+use std::ffi::CString;
+
+use pyo3::prelude::*;
+use pyo3::types::{PyList, PyModule};
+
+const VALIDATOR_CODE: &str = include_str!("../shared_state_validator.py");
+
+fn validator_module<'py>(py: Python<'py>) -> PyResult<Bound<'py, PyModule>> {
+    let code = CString::new(VALIDATOR_CODE).expect("validator source contains a null byte");
+    PyModule::from_code(
+        py,
+        &code,
+        c"shared_state_validator.py",
+        c"shared_state_validator",
+    )
+}
+
+#[cfg(test)]
+fn validate_source(
+    source: &str,
+    filename: &str,
+    class_names: &[&str],
+) -> Result<Vec<String>, String> {
+    Python::attach(|py| {
+        let module = validator_module(py).map_err(|error| error.to_string())?;
+        let class_names = PyList::new(py, class_names).map_err(|error| error.to_string())?;
+        module
+            .getattr("validate_source")
+            .and_then(|function| function.call1((source, filename, class_names)))
+            .and_then(|result| result.extract::<Vec<String>>())
+            .map_err(|error| error.to_string())
+    })
+}
+
+fn validate_solution(path: &str, class_names: &[&str]) -> Result<Vec<String>, String> {
+    Python::attach(|py| {
+        let module = validator_module(py).map_err(|error| error.to_string())?;
+        let class_names = PyList::new(py, class_names).map_err(|error| error.to_string())?;
+        module
+            .getattr("validate_solution")
+            .and_then(|function| function.call1((path, class_names)))
+            .and_then(|result| result.extract::<Vec<String>>())
+            .map_err(|error| error.to_string())
+    })
+}
+
+pub fn validate_or_report(path: &str, class_names: &[&str]) -> bool {
+    match validate_solution(path, class_names) {
+        Ok(violations) if violations.is_empty() => true,
+        Ok(violations) => {
+            println!("ERROR: shared state between AnySystem processes is forbidden");
+            for violation in violations {
+                println!("{violation}");
+            }
+            println!("\nSCORE: 0\n");
+            false
+        }
+        Err(error) => panic!("failed to validate solution for shared state: {error}"),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::validate_source;
+
+    #[test]
+    fn embeds_validator_and_rejects_shared_state() {
+        let violations = validate_source(
+            "class ProcessImpl:\n    shared = {}\n",
+            "solution.py",
+            &["ProcessImpl"],
+        )
+        .unwrap();
+
+        assert_eq!(violations.len(), 1);
+        assert!(violations[0].contains("ProcessImpl.shared"));
+    }
+}