Fix memory leak (#3887)

* Fix memory leak

* Remove an extra copy

* Further fixes

---------

Co-authored-by: Jarred Sumner <709451+Jarred-Sumner@users.noreply.github.com>

1 files changed, 114 insertions, 0 deletions

diff --git a/src/bun.js/Strong.zig b/src/bun.js/Strong.zig
new file mode 100644
index 000000000..d2ed3afbd
--- /dev/null
+++ b/src/bun.js/Strong.zig
@@ -0,0 +1,114 @@
+const bun = @import("root").bun;
+const JSC = bun.JSC;
+
+const StrongImpl = opaque {
+    pub fn init(globalThis: *JSC.JSGlobalObject, value: JSC.JSValue) *StrongImpl {
+        JSC.markBinding(@src());
+        return Bun__StrongRef__new(globalThis, value);
+    }
+
+    pub fn get(this: *StrongImpl) JSC.JSValue {
+        JSC.markBinding(@src());
+        return Bun__StrongRef__get(this);
+    }
+
+    pub fn set(this: *StrongImpl, globalThis: *JSC.JSGlobalObject, value: JSC.JSValue) void {
+        JSC.markBinding(@src());
+        Bun__StrongRef__set(this, globalThis, value);
+    }
+
+    pub fn clear(this: *StrongImpl) void {
+        JSC.markBinding(@src());
+        Bun__StrongRef__clear(this);
+    }
+
+    pub fn deinit(
+        this: *StrongImpl,
+    ) void {
+        JSC.markBinding(@src());
+        Bun__StrongRef__delete(this);
+    }
+
+    extern fn Bun__StrongRef__delete(this: *StrongImpl) void;
+    extern fn Bun__StrongRef__new(*JSC.JSGlobalObject, JSC.JSValue) *StrongImpl;
+    extern fn Bun__StrongRef__get(this: *StrongImpl) JSC.JSValue;
+    extern fn Bun__StrongRef__set(this: *StrongImpl, *JSC.JSGlobalObject, JSC.JSValue) void;
+    extern fn Bun__StrongRef__clear(this: *StrongImpl) void;
+};
+
+pub const Strong = struct {
+    ref: ?*StrongImpl = null,
+    globalThis: ?*JSC.JSGlobalObject = null,
+
+    pub fn init() Strong {
+        return .{};
+    }
+
+    pub fn create(
+        value: JSC.JSValue,
+        globalThis: *JSC.JSGlobalObject,
+    ) Strong {
+        if (value != .zero) {
+            return .{ .ref = StrongImpl.init(globalThis, value), .globalThis = globalThis };
+        }
+
+        return .{ .globalThis = globalThis };
+    }
+
+    pub fn get(this: *Strong) ?JSC.JSValue {
+        var ref = this.ref orelse return null;
+        const result = ref.get();
+        if (result == .zero) {
+            return null;
+        }
+
+        return result;
+    }
+
+    pub fn swap(this: *Strong) JSC.JSValue {
+        var ref = this.ref orelse return .zero;
+        const result = ref.get();
+        if (result == .zero) {
+            return .zero;
+        }
+
+        ref.clear();
+        return result;
+    }
+
+    pub fn has(this: *Strong) bool {
+        var ref = this.ref orelse return false;
+        return ref.get() != .zero;
+    }
+
+    pub fn trySwap(this: *Strong) ?JSC.JSValue {
+        const result = this.swap();
+        if (result == .zero) {
+            return null;
+        }
+
+        return result;
+    }
+
+    pub fn set(this: *Strong, globalThis: *JSC.JSGlobalObject, value: JSC.JSValue) void {
+        var ref: *StrongImpl = this.ref orelse {
+            if (value == .zero) return;
+            this.ref = StrongImpl.init(globalThis, value);
+            this.globalThis = globalThis;
+            return;
+        };
+        this.globalThis = globalThis;
+        ref.set(globalThis, value);
+    }
+
+    pub fn clear(this: *Strong) void {
+        var ref: *StrongImpl = this.ref orelse return;
+        ref.clear();
+    }
+
+    pub fn deinit(this: *Strong) void {
+        var ref: *StrongImpl = this.ref orelse return;
+        this.ref = null;
+        ref.deinit();
+    }
+};