/
mod.rs
158 lines (128 loc) · 4.33 KB
/
mod.rs
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use deno_core::anyhow::Error;
use lazy_static::lazy_static;
use scryer_prolog::machine::parsed_results::QueryResult;
use std::collections::HashMap;
use std::sync::Arc;
use tokio::sync::RwLock;
pub(crate) mod engine;
pub(crate) mod prolog_service_extension;
use self::engine::PrologEngine;
#[derive(Clone)]
pub struct PrologService {
engines: Arc<RwLock<HashMap<String, PrologEngine>>>,
}
impl PrologService {
pub fn new() -> Self {
PrologService {
engines: Arc::new(RwLock::new(HashMap::new())),
}
}
pub async fn spawn_engine(&mut self, engine_name: String) -> Result<(), Error> {
if self.engines.read().await.contains_key(&engine_name) {
return Err(Error::msg("Engine already exists"));
}
let mut engine = PrologEngine::new();
engine.spawn().await?;
self.engines.write().await.insert(engine_name, engine);
Ok(())
}
pub async fn remove_engine(&mut self, engine_name: String) -> Result<(), Error> {
let mut engines = self.engines.write().await;
engines
.remove(&engine_name)
.ok_or_else(|| Error::msg("Engine not found"))?;
Ok(())
}
pub async fn run_query(
&self,
engine_name: String,
query: String,
) -> Result<QueryResult, Error> {
let engines = self.engines.read().await;
let engine = engines
.get(&engine_name)
.ok_or_else(|| Error::msg("Engine not found"))?;
let result = engine.run_query(query).await?;
Ok(result)
}
pub async fn load_module_string(
&self,
engine_name: String,
module_name: String,
program_lines: Vec<String>,
) -> Result<(), Error> {
let engines = self.engines.read().await;
let engine = engines
.get(&engine_name)
.ok_or_else(|| Error::msg("Engine not found"))?;
engine.load_module_string(module_name, program_lines).await
}
}
lazy_static! {
static ref PROLOG_SERVICE: Arc<RwLock<Option<PrologService>>> = Arc::new(RwLock::new(None));
}
pub async fn init_prolog_service() {
let mut lock = PROLOG_SERVICE.write().await;
*lock = Some(PrologService::new());
}
pub async fn get_prolog_service() -> PrologService {
let lock = PROLOG_SERVICE.read().await;
lock.clone().expect("PrologServiceInterface not set")
}
#[cfg(test)]
mod prolog_test {
use maplit::btreemap;
use scryer_prolog::machine::parsed_results::{QueryResolution, QueryMatch, Value};
use super::*;
#[tokio::test]
async fn test_init_prolog_engine() {
init_prolog_service().await;
let mut service = get_prolog_service().await;
let engine_name = "test".to_string();
assert!(service.spawn_engine(engine_name.clone()).await.is_ok());
let facts = String::from(
r#"
triple("a", "p1", "b").
triple("a", "p2", "b").
"#,
);
let load_facts = service
.load_module_string(engine_name.clone(), "facts".to_string(), vec![facts])
.await;
assert!(load_facts.is_ok());
let query = String::from("triple(\"a\",P,\"b\").");
let result = service
.run_query(engine_name.clone(), query)
.await
.expect("Error running query");
assert_eq!(
result,
Ok(QueryResolution::Matches(vec![
QueryMatch::from(btreemap! {
"P" => Value::from("p1"),
}),
QueryMatch::from(btreemap! {
"P" => Value::from("p2"),
}),
]))
);
let query = String::from("triple(\"a\",\"p1\",\"b\").");
let result = service
.run_query(engine_name.clone(), query)
.await
.expect("Error running query");
assert_eq!(
result,
Ok(QueryResolution::True)
);
let query = String::from("non_existant_predicate(\"a\",\"p1\",\"b\").");
let result = service
.run_query(engine_name.clone(), query)
.await
.expect("Error running query");
assert_eq!(
result,
Err(String::from("error existence_error procedure / non_existant_predicate 3 / non_existant_predicate 3"))
);
}
}