feat(crypto-nodejs) Implement OlmMachine.close

feat(crypto-nodejs) Implement `OlmMachine.close`

bindings/matrix-sdk-crypto-nodejs/src/machine.rs

@@ -2,6 +2,7 @@
 
 use std::{
     collections::{BTreeMap, HashMap},
+    ops::Deref,
     sync::Arc,
 };
 
@@ -16,11 +17,38 @@ use crate::{
     sync_events, types, vodozemac,
 };
 
+/// The value used by the `OlmMachine` JS class.
+///
+/// It has 2 states: `Opened` and `Closed`. Why maintaining the state here?
+/// Because NodeJS has no way to drop an object explicitly, and we want to be
+/// able to “close” the `OlmMachine` to free all associated data. More over,
+/// `napi-rs` doesn't allow a function to take the ownership of the type itself
+/// (`fn close(self) { … }`). So we manage the state ourselves.
+///
+/// Using the `OlmMachine` when its state is `Closed` will panic.
+enum OlmMachineInner {
+    Opened(matrix_sdk_crypto::OlmMachine),
+    Closed,
+}
+
+impl Deref for OlmMachineInner {
+    type Target = matrix_sdk_crypto::OlmMachine;
+
+    #[inline]
+    fn deref(&self) -> &Self::Target {
+        match self {
+            Self::Opened(machine) => machine,
+            Self::Closed => panic!("The `OlmMachine` has been closed, cannot use it anymore"),
+        }
+    }
+}
+
 /// State machine implementation of the Olm/Megolm encryption protocol
 /// used for Matrix end to end encryption.
+// #[napi(custom_finalize)]
 #[napi]
 pub struct OlmMachine {
-    inner: matrix_sdk_crypto::OlmMachine,
+    inner: OlmMachineInner,
 }
 
 #[napi]
@@ -77,7 +105,7 @@ impl OlmMachine {
         store_passphrase.zeroize();
 
         Ok(OlmMachine {
-            inner: match store {
+            inner: OlmMachineInner::Opened(match store {
                 Some(store) => matrix_sdk_crypto::OlmMachine::with_store(
                     user_id.inner.as_ref(),
                     device_id.inner.as_ref(),
@@ -92,7 +120,7 @@ impl OlmMachine {
                     )
                     .await
                 }
-            },
+            }),
         })
     }
 
@@ -409,4 +437,21 @@ impl OlmMachine {
     pub async fn sign(&self, message: String) -> types::Signatures {
         self.inner.sign(message.as_str()).await.into()
     }
+
+    /// Shut down the `OlmMachine`.
+    ///
+    /// The `OlmMachine` cannot be used after this method has been called,
+    /// otherwise it will panic.
+    ///
+    /// All associated resources will be closed too, like the crypto storage
+    /// connections.
+    ///
+    /// # Safety
+    ///
+    /// The caller is responsible to **not** use any objects that came from this
+    /// `OlmMachine` after this `close` method has been called.
+    #[napi(strict)]
+    pub fn close(&mut self) {
+        self.inner = OlmMachineInner::Closed;
+    }
 }

bindings/matrix-sdk-crypto-nodejs/tests/machine.test.js

@@ -25,7 +25,7 @@ describe(OlmMachine.name, () => {
             expect(await OlmMachine.initialize(new UserId('@foo:bar.org'), new DeviceId('baz'), temp_directory, 'hello')).toBeInstanceOf(OlmMachine);
         });
     });
-    
+
     const user = new UserId('@alice:example.org');
     const device = new DeviceId('foobar');
     const room = new RoomId('!baz:matrix.org');
@@ -34,6 +34,16 @@ describe(OlmMachine.name, () => {
         return OlmMachine.initialize(new_user || user, new_device || device);
     }
 
+    test('can drop/close, and then re-open', async () => {
+        const temp_directory = await fs.mkdtemp(path.join(os.tmpdir(), 'matrix-sdk-crypto--'));
+
+        let m1 = await OlmMachine.initialize(new UserId('@test:bar.org'), new DeviceId('device'), temp_directory, 'hello')
+        m1.close();
+
+        let m2 = await OlmMachine.initialize(new UserId('@test:bar.org'), new DeviceId('device'), temp_directory, 'hello')
+        m2.close();
+    });
+
     test('can read user ID', async () => {
         expect((await machine()).userId.toString()).toStrictEqual(user.toString());
     });
@@ -179,7 +189,7 @@ describe(OlmMachine.name, () => {
         beforeAll(async () => {
             m = await machine(user, device);
         });
-        
+
         test('can pass keysquery and keysclaim requests directly', async () => {
             {
                 // derived from https://github.com/matrix-org/matrix-rust-sdk/blob/7f49618d350fab66b7e1dc4eaf64ec25ceafd658/benchmarks/benches/crypto_bench/keys_query.json