Implement a singleton version of `napi_get_instance_data` and `napi_set_instance_data`

Still need to figure out how to do this without adding a layer of indirection to the global object as exposed to NAPI Addons

This code is not tested

3 files changed, 37 insertions, 0 deletions

diff --git a/src/bun.js/bindings/ZigGlobalObject.h b/src/bun.js/bindings/ZigGlobalObject.h
index 142065e35..1aee587cf 100644
--- a/src/bun.js/bindings/ZigGlobalObject.h
+++ b/src/bun.js/bindings/ZigGlobalObject.h
@@ -423,6 +423,13 @@ public:
     // To do that, we count the number of times we register a module.
     int napiModuleRegisterCallCount = 0;
 
+    // NAPI instance data
+    // This is not a correct implementation
+    // Addon modules can override each other's data
+    void* napiInstanceData = nullptr;
+    void* napiInstanceDataFinalizer = nullptr;
+    void* napiInstanceDataFinalizerHint = nullptr;
+
 #include "ZigGeneratedClasses+lazyStructureHeader.h"
 
 private:
diff --git a/src/bun.js/bindings/napi.cpp b/src/bun.js/bindings/napi.cpp
index 649b8bf50..943f37688 100644
--- a/src/bun.js/bindings/napi.cpp
+++ b/src/bun.js/bindings/napi.cpp
@@ -1480,3 +1480,31 @@ extern "C" napi_status napi_get_value_external(napi_env env, napi_value value,
     *result = jsCast<Bun::NapiExternal*>(object)->value();
     return napi_ok;
 }
+
+// TODO: make this per addon instead of globally shared for ALL addons
+extern "C" napi_status napi_get_instance_data(napi_env env,
+    void** data)
+{
+    Zig::GlobalObject* globalObject = toJS(env);
+    if (data == nullptr) {
+        return napi_invalid_arg;
+    }
+
+    *data = globalObject->napiInstanceData;
+    return napi_ok;
+}
+
+extern "C" napi_status napi_set_instance_data(napi_env env,
+    void* data,
+    napi_finalize finalize_cb,
+    void* finalize_hint)
+{
+    Zig::GlobalObject* globalObject = toJS(env);
+    if (data)
+        globalObject->napiInstanceData = data;
+
+    globalObject->napiInstanceDataFinalizer = reinterpret_cast<void*>(finalize_cb);
+    globalObject->napiInstanceDataFinalizerHint = finalize_hint;
+
+    return napi_ok;
+}
\ No newline at end of file
diff --git a/src/napi/napi.zig b/src/napi/napi.zig
index 260e5ba22..d7c7562b9 100644
--- a/src/napi/napi.zig
+++ b/src/napi/napi.zig
@@ -1508,6 +1508,8 @@ pub fn fixDeadCodeElimination() void {
     std.mem.doNotOptimizeAway(&napi_add_finalizer);
     std.mem.doNotOptimizeAway(&napi_create_external);
     std.mem.doNotOptimizeAway(&napi_get_value_external);
+    std.mem.doNotOptimizeAway(&napi_get_instance_data);
+    std.mem.doNotOptimizeAway(&napi_set_instance_data);
 
     std.mem.doNotOptimizeAway(&@import("../bun.js/node/buffer.zig").BufferVectorized.fill);
 }