From a5ad6b56332c27dfa435ab26c60d65f3798c9368 Mon Sep 17 00:00:00 2001
From: Ziyang Hu <hu.ziyang@cantab.net>
Date: Fri, 13 Jan 2023 18:22:46 +0800
Subject: [PATCH] change language APIs to match the new Rust API

---
 cozo-core/src/runtime/callback.rs | 10 ++++++++++
 cozo-lib-java/src/lib.rs          |  8 ++++----
 cozo-lib-nodejs/src/lib.rs        |  6 +++---
 cozo-lib-python/src/lib.rs        | 19 +++++++++++++++++++
 4 files changed, 36 insertions(+), 7 deletions(-)

diff --git a/cozo-core/src/runtime/callback.rs b/cozo-core/src/runtime/callback.rs
index c04f20e1..075574be 100644
--- a/cozo-core/src/runtime/callback.rs
+++ b/cozo-core/src/runtime/callback.rs
@@ -7,6 +7,7 @@
  */
 
 use std::collections::{BTreeMap, BTreeSet};
+use std::fmt::{Display, Formatter};
 
 use smartstring::{LazyCompact, SmartString};
 
@@ -21,6 +22,15 @@ pub enum CallbackOp {
     Rm,
 }
 
+impl Display for CallbackOp {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        match self {
+            CallbackOp::Put => f.write_str("Put"),
+            CallbackOp::Rm => f.write_str("Rm"),
+        }
+    }
+}
+
 #[cfg(not(target_arch = "wasm32"))]
 pub struct CallbackDeclaration {
     pub(crate) dependent: SmartString<LazyCompact>,
diff --git a/cozo-lib-java/src/lib.rs b/cozo-lib-java/src/lib.rs
index c42a4e17..d61ea221 100644
--- a/cozo-lib-java/src/lib.rs
+++ b/cozo-lib-java/src/lib.rs
@@ -7,7 +7,7 @@
  */
 use std::collections::BTreeMap;
 use std::sync::atomic::{AtomicI32, Ordering};
-use std::sync::Mutex;
+use std::sync::{Arc, Mutex};
 
 use jni::objects::{JClass, JString};
 use jni::sys::{jboolean, jint, jstring};
@@ -19,7 +19,7 @@ use cozo::*;
 #[derive(Default)]
 struct Handles {
     current: AtomicI32,
-    dbs: Mutex<BTreeMap<i32, DbInstance>>,
+    dbs: Mutex<BTreeMap<i32, Arc<DbInstance>>>,
 }
 
 lazy_static! {
@@ -29,7 +29,7 @@ lazy_static! {
     };
 }
 
-fn get_db(id: i32) -> Option<DbInstance> {
+fn get_db(id: i32) -> Option<Arc<DbInstance>> {
     let dbs = HANDLES.dbs.lock().unwrap();
     dbs.get(&id).cloned()
 }
@@ -49,7 +49,7 @@ pub extern "system" fn Java_org_cozodb_CozoJavaBridge_openDb(
         Ok(db) => {
             let id = HANDLES.current.fetch_add(1, Ordering::AcqRel);
             let mut dbs = HANDLES.dbs.lock().unwrap();
-            dbs.insert(id, db);
+            dbs.insert(id, Arc::new(db));
             id
         }
         Err(err) => {
diff --git a/cozo-lib-nodejs/src/lib.rs b/cozo-lib-nodejs/src/lib.rs
index fc18dfde..ddc2e81d 100644
--- a/cozo-lib-nodejs/src/lib.rs
+++ b/cozo-lib-nodejs/src/lib.rs
@@ -7,7 +7,7 @@
  */
 use std::collections::BTreeMap;
 use std::sync::atomic::{AtomicU32, Ordering};
-use std::sync::Mutex;
+use std::sync::{Arc, Mutex};
 
 use lazy_static::lazy_static;
 use neon::prelude::*;
@@ -17,7 +17,7 @@ use cozo::*;
 #[derive(Default)]
 struct Handles {
     current: AtomicU32,
-    dbs: Mutex<BTreeMap<u32, DbInstance>>,
+    dbs: Mutex<BTreeMap<u32, Arc<DbInstance>>>,
 }
 
 lazy_static! {
@@ -32,7 +32,7 @@ fn open_db(mut cx: FunctionContext) -> JsResult<JsNumber> {
         Ok(db) => {
             let id = HANDLES.current.fetch_add(1, Ordering::AcqRel);
             let mut dbs = HANDLES.dbs.lock().unwrap();
-            dbs.insert(id, db);
+            dbs.insert(id, Arc::new(db));
             Ok(cx.number(id))
         }
         Err(err) => {
diff --git a/cozo-lib-python/src/lib.rs b/cozo-lib-python/src/lib.rs
index 7d749b17..aedfa8a2 100644
--- a/cozo-lib-python/src/lib.rs
+++ b/cozo-lib-python/src/lib.rs
@@ -127,6 +127,25 @@ impl CozoDbPy {
             Err(PyException::new_err(DB_CLOSED_MSG))
         }
     }
+    pub fn register_callback(&self, rel: &str, callback: &PyAny) -> PyResult<u32> {
+        if let Some(db) = &self.db {
+            let cb: Py<PyAny> = callback.into();
+            match db.register_callback(rel, move |op, new, old| {
+                Python::with_gil(|py| {
+                    let callable = cb.as_ref(py);
+                    let _ = callable.call0();
+                })
+            }) {
+                Ok(id) => Ok(id),
+                Err(err) => {
+                    let reports = format_error_as_json(err, None).to_string();
+                    Err(PyException::new_err(reports))
+                }
+            }
+        } else {
+            Err(PyException::new_err(DB_CLOSED_MSG))
+        }
+    }
     pub fn run_query(&self, py: Python<'_>, query: &str, params: &str) -> String {
         if let Some(db) = &self.db {
             py.allow_threads(|| db.run_script_str(query, params))