Add fast methods for reading typed arrays to the loader (#794)

lib/loader/index.d.ts

@@ -55,14 +55,30 @@ interface ASUtil {
   __getArray(ref: number): number[];
   /** Gets a view on the values of an array in the module's memory. */
   __getArrayView(ref: number): TypedArray;
+  /** Reads (copies) the values of Uint8Array from the module's memory. */
+  __getUint8Array(ref: number): Uint8Array;
+  /** Reads (copies) the values of Int8Array from the module's memory. */
+  __getInt8Array(ref: number): Int8Array;
+  /** Reads (copies) the values of Uint16Array from the module's memory. */
+  __getUint16Array(ref: number): Uint16Array;
+  /** Reads (copies) the values of Int16Array from the module's memory. */
+  __getInt16Array(ref: number): Int16Array;
+  /** Reads (copies) the values of Uint32Array from the module's memory. */
+  __getUint32Array(ref: number): Uint32Array;
+  /** Reads (copies) the values of Int32Array from the module's memory. */
+  __getInt32Array(ref: number): Int32Array;
+  /** Reads (copies) the values of Float32Array from the module's memory. */
+  __getFloat32Array(ref: number): Float32Array;
+    /** Reads (copies) the values of Float64Array from the module's memory. */
+  __getFloat64Array(ref: number): Float64Array;
   /** Retains a reference externally, making sure that it doesn't become collected prematurely. Returns the reference. */
   __retain(ref: number): number;
   /** Releases a previously retained reference to an object, allowing the runtime to collect it once its reference count reaches zero. */
   __release(ref: number): void;
   /** Allocates an instance of the class represented by the specified id. */
   __alloc(size: number, id: number): number;
   /** Tests whether an object is an instance of the class represented by the specified base id. */
-  __instanceof(ref: number, baseId: number): boolean;  
+  __instanceof(ref: number, baseId: number): boolean;
   /** Forces a cycle collection. Only relevant if objects potentially forming reference cycles are used. */
   __collect(): void;
 }

lib/loader/index.js

@@ -24,6 +24,8 @@ const KEY_SIGNED = 1 << 19;
 const KEY_FLOAT = 1 << 20;
 const KEY_NULLABLE = 1 << 21;
 const KEY_MANAGED = 1 << 22;
+const KEY_ALIGN_OFFSET = 14;
+const VAL_ALIGN_OFFSET = 5;
 
 // Array(BufferView) layout
 const ARRAYBUFFERVIEW_BUFFER_OFFSET = 0;
@@ -109,6 +111,7 @@ function postInstantiate(baseModule, instance) {
       F64 = new Float64Array(buffer);
     }
   }
+
   checkMem();
 
   /** Gets the runtime type info for the given id. */
@@ -125,28 +128,43 @@ function postInstantiate(baseModule, instance) {
     return U32[(rttiBase + 4 >>> 2) + id * 2 + 1];
   }
 
-  /** Gets the runtime alignment of a collection's values or keys. */
-  function getAlign(which, info) {
-    return 31 - Math.clz32((info / which) & 31); // -1 if none
+  /** Gets the runtime alignment of a collection's values. */
+  function getAlignValue(info) {
+    return 31 - Math.clz32((info >>> VAL_ALIGN_OFFSET) & 31); // -1 if none
+  }
+
+  /** Gets the runtime alignment of a collection's keys. */
+  function getAlignKey(info) {
+    return 31 - Math.clz32((info >>> KEY_ALIGN_OFFSET) & 31); // -1 if none
+  }
+
+  function getTypedArray(Type, shift, arr) {
+    var buffer = memory.buffer;
+    var u32 = new Uint32Array(buffer);
+    var buf = u32[arr + ARRAYBUFFERVIEW_DATASTART_OFFSET >>> 2];
+    var length = u32[buf + SIZE_OFFSET >>> 2];
+    return new Type(buffer).slice(buf >>> shift, buf + length >>> shift);
   }
 
   /** Allocates a new string in the module's memory and returns its retained pointer. */
   function __allocString(str) {
-    const length = str.length;
-    const ref = alloc(length << 1, STRING_ID);
-    checkMem();
-    for (let i = 0, j = ref >>> 1; i < length; ++i) U16[j + i] = str.charCodeAt(i);
+    var length = str.length;
+    var ref = alloc(length << 1, STRING_ID);
+    var u16 = new Uint16Array(memory.buffer);
+    for (var i = 0, p = ref >>> 1; i < length; ++i) u16[p + i] = str.charCodeAt(i);
     return ref;
   }
 
   baseModule.__allocString = __allocString;
 
   /** Reads a string from the module's memory by its pointer. */
   function __getString(ref) {
-    checkMem();
-    const id = U32[ref + ID_OFFSET >>> 2];
+    var buf = memory.buffer;
+    var u16 = new Uint16Array(buf);
+    var u32 = new Uint32Array(buf);
+    var id = u32[ref + ID_OFFSET >>> 2];
     if (id !== STRING_ID) throw Error("not a string: " + ref);
-    return getStringImpl(U32, U16, ref);
+    return getStringImpl(u32, u16, ref);
   }
 
   baseModule.__getString = __getString;
@@ -173,7 +191,7 @@ function postInstantiate(baseModule, instance) {
   function __allocArray(id, values) {
     const info = getInfo(id);
     if (!(info & (ARRAYBUFFERVIEW | ARRAY))) throw Error("not an array: " + id + " @ " + info);
-    const align = getAlign(VAL_ALIGN, info);
+    const align = getAlignValue(info);
     const length = values.length;
     const buf = alloc(length << align, ARRAYBUFFER_ID);
     const arr = alloc(info & ARRAY ? ARRAY_SIZE : ARRAYBUFFERVIEW_SIZE, id);
@@ -183,8 +201,11 @@ function postInstantiate(baseModule, instance) {
     U32[arr + ARRAYBUFFERVIEW_DATALENGTH_OFFSET >>> 2] = length << align;
     if (info & ARRAY) U32[arr + ARRAY_LENGTH_OFFSET >>> 2] = length;
     const view = getView(align, info & VAL_SIGNED, info & VAL_FLOAT);
-    for (let i = 0; i < length; ++i) view[(buf >> align) + i] = values[i];
-    if (info & VAL_MANAGED) for (let i = 0; i < length; ++i) retain(values[i]);
+    if (info & VAL_MANAGED) {
+      for (let i = 0; i < length; ++i) view[(buf >>> align) + i] = retain(values[i]);
+    } else {
+      view.set(values, buf >>> align);
+    }
     return arr;
   }
 
@@ -196,7 +217,7 @@ function postInstantiate(baseModule, instance) {
     const id = U32[arr + ID_OFFSET >>> 2];
     const info = getInfo(id);
     if (!(info & ARRAYBUFFERVIEW)) throw Error("not an array: " + id);
-    const align = getAlign(VAL_ALIGN, info);
+    const align = getAlignValue(info);
     var buf = U32[arr + ARRAYBUFFERVIEW_DATASTART_OFFSET >>> 2];
     const length = info & ARRAY
       ? U32[arr + ARRAY_LENGTH_OFFSET >>> 2]
@@ -214,6 +235,23 @@ function postInstantiate(baseModule, instance) {
 
   baseModule.__getArray = __getArray;
 
+  function __getArrayBuffer(buf) {
+    var buffer = memory.buffer;
+    var length = (new Uint32Array(buffer))[buf + SIZE_OFFSET >>> 2];
+    return buffer.slice(buf, buf + length);
+  }
+
+  baseModule.__getArrayBuffer = __getArrayBuffer;
+
+  baseModule.__getUint8Array = getTypedArray.bind(null, Uint8Array, 0);
+  baseModule.__getInt8Array = getTypedArray.bind(null, Int8Array, 0);
+  baseModule.__getUint16Array = getTypedArray.bind(null, Uint16Array, 1);
+  baseModule.__getInt16Array = getTypedArray.bind(null, Int16Array, 1);
+  baseModule.__getUint32Array = getTypedArray.bind(null, Uint32Array, 2);
+  baseModule.__getInt32Array = getTypedArray.bind(null, Int32Array, 2);
+  baseModule.__getFloat32Array = getTypedArray.bind(null, Float32Array, 2);
+  baseModule.__getFloat64Array = getTypedArray.bind(null, Float64Array, 3);
+
   /** Tests whether an object is an instance of the class represented by the specified base id. */
   function __instanceof(ref, baseId) {
     var id = U32[(ref + ID_OFFSET) >>> 2];
@@ -228,7 +266,7 @@ function postInstantiate(baseModule, instance) {
 
   // Pull basic exports to baseModule so code in preInstantiate can use them
   baseModule.memory = baseModule.memory || memory;
-  baseModule.table = baseModule.table || table;
+  baseModule.table  = baseModule.table  || table;
 
   // Demangle exports and provide the usual utility on the prototype
   return demangle(rawExports, Object.defineProperties(baseModule, {

lib/loader/tests/assembly/index.ts

@@ -63,6 +63,9 @@ export function dotrace(num: f64): void {
   trace("The answer is", 1, num);
 }
 
+export const UINT8ARRAY_ID = idof<Uint8Array>();
+export const INT16ARRAY_ID = idof<Int16Array>();
+export const UINT16ARRAY_ID = idof<Uint16Array>();
 export const INT32ARRAY_ID = idof<Int32Array>();
 export const UINT32ARRAY_ID = idof<Uint32Array>();
 export const FLOAT32ARRAY_ID = idof<Float32Array>();

lib/loader/tests/index.js

@@ -55,11 +55,57 @@ assert.strictEqual(module.__getString(module.COLOR), "red");
   try { module.__release(ref); assert(false); } catch (e) {};
 }
 
+/*
+{
+  let arrU8Arr = new Uint8Array([0, 1, 2]);
+  let refU8Arr = module.__retain(module.__allocUint8Array(arrU8Arr));
+  assert(module.__instanceof(refU8Arr, module.UINT8ARRAY_ID));
+  assert.deepEqual(module.__getUint8Array(refU8Arr), arrU8Arr);
+  module.__release(refU8Arr);
+  try { module.__release(refU8Arr); assert(false); } catch (e) {};
+
+  let arrU16Arr = new Uint16Array([0, 0x7FFF, 0xFFFF]);
+  let refU16Arr = module.__retain(module.__allocUint16Array(arrU16Arr));
+  assert(module.__instanceof(refU16Arr, module.UINT16ARRAY_ID));
+  assert.deepEqual(module.__getUint16Array(refU16Arr), arrU16Arr);
+  module.__release(refU16Arr);
+  try { module.__release(refU16Arr); assert(false); } catch (e) {};
+
+  let arrI16Arr = new Int16Array([0, -1, -2]);
+  let refI16Arr = module.__retain(module.__allocInt16Array(arrI16Arr));
+  assert(module.__instanceof(refI16Arr, module.INT16ARRAY_ID));
+  assert.deepEqual(module.__getInt16Array(refI16Arr), arrI16Arr);
+  module.__release(refI16Arr);
+  try { module.__release(refI16Arr); assert(false); } catch (e) {};
+}
+*/
+
+// should be able to distinguish between signed and unsigned
+{
+  let arr = new Uint8Array([0, 255, 127]);
+  let ref = module.__retain(module.__allocArray(module.UINT8ARRAY_ID, arr));
+  assert(module.__instanceof(ref, module.UINT8ARRAY_ID));
+  assert.deepEqual(module.__getUint8Array(ref), arr);
+  module.__release(ref);
+  try { module.__release(ref); assert(false); } catch (e) {};
+}
+
+// should be able to distinguish between signed and unsigned
+{
+  let arr = new Int16Array([0, 0xFFFF, -0x00FF]);
+  let ref = module.__retain(module.__allocArray(module.INT16ARRAY_ID, arr));
+  assert(module.__instanceof(ref, module.INT16ARRAY_ID));
+  assert.deepEqual(module.__getInt16Array(ref), arr);
+  module.__release(ref);
+  try { module.__release(ref); assert(false); } catch (e) {};
+}
+
 // should be able to distinguish between signed and unsigned
 {
   let arr = [1, -1 >>> 0, 0x80000000];
   let ref = module.__retain(module.__allocArray(module.UINT32ARRAY_ID, arr));
   assert(module.__instanceof(ref, module.UINT32ARRAY_ID));
+  assert.deepEqual(module.__getUint32Array(ref), new Uint32Array(arr));
   assert.deepEqual(module.__getArray(ref), arr);
   module.__release(ref);
   try { module.__release(ref); assert(false); } catch (e) {};
@@ -70,6 +116,7 @@ assert.strictEqual(module.__getString(module.COLOR), "red");
   let arr = [0.0, 1.5, 2.5];
   let ref = module.__retain(module.__allocArray(module.FLOAT32ARRAY_ID, arr));
   assert(module.__instanceof(ref, module.FLOAT32ARRAY_ID));
+  assert.deepEqual(module.__getFloat32Array(ref), new Float32Array(arr));
   assert.deepEqual(module.__getArray(ref), arr);
   module.__release(ref);
   try { module.__release(ref); assert(false); } catch (e) {};