Manage JS environment heap allocation

Author: kateinoigakukun

Diff for: src/swift/Sources/JavaScriptKit/JSObject.swift

@@ -42,13 +42,9 @@ public class JSObjectRef: Equatable {
         setJSValue(this: self, index: Int32(index), value: value)
     }
 
-    public static func global() -> JSObjectRef {
-        .init(id: _JS_Predef_Value_Global)
-    }
-
-    deinit {
+    public static let global = JSObjectRef(id: _JS_Predef_Value_Global)
 
-    }
+    deinit { _destroy_ref(id) }
 
     public static func == (lhs: JSObjectRef, rhs: JSObjectRef) -> Bool {
         return lhs.id == rhs.id

Diff for: src/swift/Sources/JavaScriptKit/JSValueConvertible.swift

@@ -28,7 +28,7 @@ extension JSFunctionRef: JSValueConvertible {
     public func jsValue() -> JSValue { .function(self) }
 }
 
-private let Object = JSObjectRef.global().Object.function!
+private let Object = JSObjectRef.global.Object.function!
 
 extension Dictionary where Value: JSValueConvertible, Key == String {
     public func jsValue() -> JSValue {
@@ -46,7 +46,7 @@ extension Dictionary: JSValueConvertible where Value == JSValueConvertible, Key
     }
 }
 
-private let Array = JSObjectRef.global().Array.function!
+private let Array = JSObjectRef.global.Array.function!
 
 extension Array where Element: JSValueConvertible {
     public func jsValue() -> JSValue {

Diff for: src/swift/Sources/JavaScriptKit/XcodeSupport.swift

@@ -53,4 +53,5 @@ func _call_new(
 func _create_function(
     _ host_func_id: JavaScriptHostFuncRef,
     _ func_ref_ptr: UnsafePointer<JavaScriptObjectRef>!) { fatalError() }
+func _destroy_ref(_ ref: JavaScriptObjectRef) { fatalError() }
 #endif

Diff for: src/swift/Sources/_CJavaScriptKit/include/_CJavaScriptKit.h

@@ -129,4 +129,12 @@ extern void _create_function(
     const JavaScriptObjectRef *func_ref_ptr
 );
 
+__attribute__((
+    __import_module__("javascript_kit"),
+    __import_name__("swjs_destroy_ref")
+))
+extern void _destroy_ref(
+    const JavaScriptObjectRef ref
+);
+
 #endif /* _CJavaScriptKit_h */

Diff for: src/web/src/index.ts

@@ -31,7 +31,8 @@ enum JavaScriptValueKind {
 
 export class SwiftRuntime {
     private instance: WebAssembly.Instance | null;
-    private _heapValues: any[]
+    private _heapValues: Map<number, any>;
+    private _heapNextKey: number;
 
     constructor() {
         this.instance = null;
@@ -41,9 +42,10 @@ export class SwiftRuntime {
         } else if (typeof global !== "undefined") {
             _global = global
         }
-        this._heapValues = [
-            _global,
-        ]
+        this._heapValues = new Map();
+        this._heapValues.set(0, _global);
+        // Note: 0 is preserved for global
+        this._heapNextKey = 1;
     }
 
     setInsance(instance: WebAssembly.Instance) {
@@ -57,13 +59,31 @@ export class SwiftRuntime {
             throw new Error("WebAssembly instance is not set yet");
         }
 
-        const allocValue = (value: any) => {
-            // TODO
-            const id = this._heapValues.length
-            this._heapValues.push(value)
+        const allocHeap = (value: any) => {
+            const isObject = typeof value == "object"
+            if (isObject && value.swjs_heap_id) {
+                return value.swjs_heap_id
+            }
+            const id = this._heapNextKey++;
+            this._heapValues.set(id, value)
+            if (isObject)
+                Reflect.set(value, "swjs_heap_id", id);
             return id
         }
 
+        const freeHeap = (ref: ref) => {
+            const value = this._heapValues.get(ref);
+            const isObject = typeof value == "object"
+            if (isObject && value.swjs_heap_id) {
+                delete value.swjs_heap_id;
+            }
+            this._heapValues.delete(ref)
+        }
+
+        const referenceHeap = (ref: ref) => {
+            return this._heapValues.get(ref)
+        }
+
         const callHostFunction = (host_func_id: number, args: any[]) => {
             if (!this.instance)
                 throw new Error("WebAssembly instance is not set yet");
@@ -79,7 +99,7 @@ export class SwiftRuntime {
                 writeUint32(base + 8, value.payload2)
             }
             let output: any;
-            const callback_func_ref = allocValue(function(result: any) {
+            const callback_func_ref = allocHeap(function(result: any) {
                 output = result
             })
             exports.swjs_call_host_function(host_func_id, argv, argc, callback_func_ref)
@@ -137,7 +157,7 @@ export class SwiftRuntime {
                     return readString(payload1, payload2)
                 }
                 case JavaScriptValueKind.Object: {
-                    return this._heapValues[payload1]
+                    return referenceHeap(payload1)
                 }
                 case JavaScriptValueKind.Null: {
                     return null
@@ -146,7 +166,7 @@ export class SwiftRuntime {
                     return undefined
                 }
                 case JavaScriptValueKind.Function: {
-                    return this._heapValues[payload1]
+                    return referenceHeap(payload1)
                 }
                 default:
                     throw new Error(`Type kind "${kind}" is not supported`)
@@ -179,7 +199,7 @@ export class SwiftRuntime {
                 case "string": {
                     return {
                         kind: JavaScriptValueKind.String,
-                        payload1: allocValue(value),
+                        payload1: allocHeap(value),
                         payload2: value.length,
                     }
                 }
@@ -193,14 +213,14 @@ export class SwiftRuntime {
                 case "object": {
                     return {
                         kind: JavaScriptValueKind.Object,
-                        payload1: allocValue(value),
+                        payload1: allocHeap(value),
                         payload2: 0,
                     }
                 }
                 case "function": {
                     return {
                         kind: JavaScriptValueKind.Function,
-                        payload1: allocValue(value),
+                        payload1: allocHeap(value),
                         payload2: 0,
                     }
                 }
@@ -230,15 +250,15 @@ export class SwiftRuntime {
                 kind: JavaScriptValueKind,
                 payload1: number, payload2: number
             ) => {
-                const obj = this._heapValues[ref];
+                const obj = referenceHeap(ref);
                 Reflect.set(obj, readString(name, length), decodeValue(kind, payload1, payload2))
             },
             swjs_get_prop: (
                 ref: ref, name: pointer, length: number,
                 kind_ptr: pointer,
                 payload1_ptr: pointer, payload2_ptr: pointer
             ) => {
-                const obj = this._heapValues[ref];
+                const obj = referenceHeap(ref);
                 const result = Reflect.get(obj, readString(name, length));
                 const { kind, payload1, payload2 } = encodeValue(result);
                 writeUint32(kind_ptr, kind);
@@ -250,31 +270,31 @@ export class SwiftRuntime {
                 kind: JavaScriptValueKind,
                 payload1: number, payload2: number
             ) => {
-                const obj = this._heapValues[ref];
+                const obj = referenceHeap(ref);
                 Reflect.set(obj, index, decodeValue(kind, payload1, payload2))
             },
             swjs_get_subscript: (
                 ref: ref, index: number,
                 kind_ptr: pointer,
                 payload1_ptr: pointer, payload2_ptr: pointer
             ) => {
-                const obj = this._heapValues[ref];
+                const obj = referenceHeap(ref);
                 const result = Reflect.get(obj, index);
                 const { kind, payload1, payload2 } = encodeValue(result);
                 writeUint32(kind_ptr, kind);
                 writeUint32(payload1_ptr, payload1);
                 writeUint32(payload2_ptr, payload2);
             },
             swjs_load_string: (ref: ref, buffer: pointer) => {
-                const string = this._heapValues[ref];
+                const string = referenceHeap(ref);
                 writeString(buffer, string);
             },
             swjs_call_function: (
                 ref: ref, argv: pointer, argc: number,
                 kind_ptr: pointer,
                 payload1_ptr: pointer, payload2_ptr: pointer
             ) => {
-                const func = this._heapValues[ref]
+                const func = referenceHeap(ref)
                 const result = Reflect.apply(func, undefined, decodeValues(argv, argc))
                 const { kind, payload1, payload2 } = encodeValue(result);
                 writeUint32(kind_ptr, kind);
@@ -287,8 +307,8 @@ export class SwiftRuntime {
                 kind_ptr: pointer,
                 payload1_ptr: pointer, payload2_ptr: pointer
             ) => {
-                const obj = this._heapValues[obj_ref]
-                const func = this._heapValues[func_ref]
+                const obj = referenceHeap(obj_ref)
+                const func = referenceHeap(func_ref)
                 const result = Reflect.apply(func, obj, decodeValues(argv, argc))
                 const { kind, payload1, payload2 } = encodeValue(result);
                 writeUint32(kind_ptr, kind);
@@ -299,7 +319,7 @@ export class SwiftRuntime {
                 host_func_id: number,
                 func_ref_ptr: pointer,
             ) => {
-                const func_ref = allocValue(function() {
+                const func_ref = allocHeap(function() {
                     return callHostFunction(host_func_id, Array.prototype.slice.call(arguments))
                 })
                 writeUint32(func_ref_ptr, func_ref)
@@ -308,12 +328,15 @@ export class SwiftRuntime {
                 ref: ref, argv: pointer, argc: number,
                 result_obj: pointer
             ) => {
-                const obj = this._heapValues[ref]
+                const obj = referenceHeap(ref)
                 const result = Reflect.construct(obj, decodeValues(argv, argc))
                 if (typeof result != "object")
                     throw Error(`Invalid result type of object constructor of "${obj}": "${result}"`)
-                writeUint32(result_obj, allocValue(result));
+                writeUint32(result_obj, allocHeap(result));
             },
+            swjs_destroy_ref: (ref: ref) => {
+                freeHeap(ref)
+            }
         }
     }
 }

Diff for: test/JavaScriptKitExec/Sources/JavaScriptKitExec/UnitTestUtils.swift

@@ -2,53 +2,62 @@ import JavaScriptKit
 
 struct MessageError: Error {
     let message: String
-    init(_ message: String) {
+    let file: StaticString
+    let line: UInt
+    let column: UInt
+    init(_ message: String, file: StaticString, line: UInt, column: UInt) {
         self.message = message
+        self.file = file
+        self.line = line
+        self.column = column
     }
 }
 
-func expectEqual<T: Equatable>(_ lhs: T, _ rhs: T) throws {
+func expectEqual<T: Equatable>(
+    _ lhs: T, _ rhs: T,
+    file: StaticString = #file, line: UInt = #line, column: UInt = #column
+) throws {
     if lhs != rhs {
-        throw MessageError("Expect to be equal \"\(lhs)\" and \"\(rhs)\"")
+        throw MessageError("Expect to be equal \"\(lhs)\" and \"\(rhs)\"", file: file, line: line, column: column)
     }
 }
 
-func expectObject(_ value: JSValue) throws -> JSObjectRef {
+func expectObject(_ value: JSValue, file: StaticString = #file, line: UInt = #line, column: UInt = #column) throws -> JSObjectRef {
     switch value {
     case .object(let ref): return ref
     default:
-        throw MessageError("Type of \(value) should be \"object\"")
+        throw MessageError("Type of \(value) should be \"object\"", file: file, line: line, column: column)
     }
 }
 
-func expectFunction(_ value: JSValue) throws -> JSFunctionRef {
+func expectFunction(_ value: JSValue, file: StaticString = #file, line: UInt = #line, column: UInt = #column) throws -> JSFunctionRef {
     switch value {
     case .function(let ref): return ref
     default:
-        throw MessageError("Type of \(value) should be \"function\"")
+        throw MessageError("Type of \(value) should be \"function\"", file: file, line: line, column: column)
     }
 }
 
-func expectBoolean(_ value: JSValue) throws -> Bool {
+func expectBoolean(_ value: JSValue, file: StaticString = #file, line: UInt = #line, column: UInt = #column) throws -> Bool {
     switch value {
     case .boolean(let bool): return bool
     default:
-        throw MessageError("Type of \(value) should be \"boolean\"")
+        throw MessageError("Type of \(value) should be \"boolean\"", file: file, line: line, column: column)
     }
 }
 
-func expectNumber(_ value: JSValue) throws -> Int32 {
+func expectNumber(_ value: JSValue, file: StaticString = #file, line: UInt = #line, column: UInt = #column) throws -> Int32 {
     switch value {
     case .number(let number): return number
     default:
-        throw MessageError("Type of \(value) should be \"number\"")
+        throw MessageError("Type of \(value) should be \"number\"", file: file, line: line, column: column)
     }
 }
 
-func expectString(_ value: JSValue) throws -> String {
+func expectString(_ value: JSValue, file: StaticString = #file, line: UInt = #line, column: UInt = #column) throws -> String {
     switch value {
     case .string(let string): return string
     default:
-        throw MessageError("Type of \(value) should be \"string\"")
+        throw MessageError("Type of \(value) should be \"string\"", file: file, line: line, column: column)
     }
 }

Diff for: test/JavaScriptKitExec/Sources/JavaScriptKitExec/main.swift

@@ -1,7 +1,7 @@
 import JavaScriptKit
 
 Literal_Conversion: do {
-    let global = JSObjectRef.global()
+    let global = JSObjectRef.global
     let inputs: [JSValue] = [
         .boolean(true),
         .boolean(false),
@@ -40,7 +40,7 @@ Object_Conversion: do {
     // ```
     //
 
-    let globalObject1 = getJSValue(this: .global(), name: "globalObject1")
+    let globalObject1 = getJSValue(this: .global, name: "globalObject1")
     let globalObject1Ref = try expectObject(globalObject1)
     let prop_1 = getJSValue(this: globalObject1Ref, name: "prop_1")
     let prop_1Ref = try expectObject(prop_1)
@@ -88,7 +88,7 @@ Function_Call: do {
     //
 
     // Notes: If the size of `RawJSValue` is updated, these test suites will fail.
-    let globalObject1 = getJSValue(this: .global(), name: "globalObject1")
+    let globalObject1 = getJSValue(this: .global, name: "globalObject1")
     let globalObject1Ref = try expectObject(globalObject1)
     let prop_5 = getJSValue(this: globalObject1Ref, name: "prop_5")
     let prop_5Ref = try expectObject(prop_5)
@@ -125,7 +125,7 @@ Host_Function_Registration: do {
     //   }
     // }
     // ```
-    let globalObject1 = getJSValue(this: .global(), name: "globalObject1")
+    let globalObject1 = getJSValue(this: .global, name: "globalObject1")
     let globalObject1Ref = try expectObject(globalObject1)
     let prop_6 = getJSValue(this: globalObject1Ref, name: "prop_6")
     let prop_6Ref = try expectObject(prop_6)
@@ -169,7 +169,7 @@ New_Object_Construction: do {
     //   }
     // }
     // ```
-    let objectConstructor = try expectFunction(getJSValue(this: .global(), name: "Animal"))
+    let objectConstructor = try expectFunction(getJSValue(this: .global, name: "Animal"))
     let cat1 = objectConstructor.new("Tama", 3, true)
     try expectEqual(getJSValue(this: cat1, name: "name"), .string("Tama"))
     try expectEqual(getJSValue(this: cat1, name: "age"), .number(3))
@@ -198,7 +198,7 @@ Call_Function_With_This: do {
     //   }
     // }
     // ```
-    let objectConstructor = try expectFunction(getJSValue(this: .global(), name: "Animal"))
+    let objectConstructor = try expectFunction(getJSValue(this: .global, name: "Animal"))
     let cat1 = objectConstructor.new("Tama", 3, true)
     let getIsCat = try expectFunction(getJSValue(this: cat1, name: "getIsCat"))