mirror of
https://github.com/fluencelabs/assemblyscript
synced 2025-04-25 15:12:12 +00:00
143 lines
4.6 KiB
Markdown
143 lines
4.6 KiB
Markdown
 loader
|
|
======================
|
|
|
|
A convenient loader for AssemblyScript modules. Demangles module exports to a friendly object structure compatible with WebIDL and TypeScript definitions and provides some useful utility to read/write data from/to memory.
|
|
|
|
Usage
|
|
-----
|
|
|
|
```js
|
|
const loader = require("@assemblyscript/loader");
|
|
...
|
|
```
|
|
|
|
API
|
|
---
|
|
|
|
* **instantiate**<`T`>(module: `WebAssembly.Module`, imports?: `WasmImports`): `ASUtil & T`<br />
|
|
Instantiates an AssemblyScript module using the specified imports.
|
|
|
|
* **instantiateBuffer**<`T`>(buffer: `Uint8Array`, imports?: `WasmImports`): `ASUtil & T`<br />
|
|
Instantiates an AssemblyScript module from a buffer using the specified imports.
|
|
|
|
* **instantiateStreaming**<`T`>(response: `Response`, imports?: `WasmImports`): `Promise<ASUtil & T>`<br />
|
|
Instantiates an AssemblyScript module from a response using the specified imports.
|
|
|
|
* **demangle**<`T`>(exports: `WasmExports`): `T`<br />
|
|
Demangles an AssemblyScript module's exports to a friendly object structure. You usually don't have to call this manually as instantiation does this implicitly.
|
|
|
|
**Note:** `T` above can either be omitted if the structure of the module is unknown, or can reference a `.d.ts` (i.e. `typeof MyModule`) as produced by the compiler with the `-d` option.
|
|
|
|
Instances are automatically populated with useful utility:
|
|
|
|
* **I8**: `Int8Array`<br />
|
|
An 8-bit signed integer view on the memory.
|
|
|
|
* **U8**: `Uint8Array`<br />
|
|
An 8-bit unsigned integer view on the memory.
|
|
|
|
* **I16**: `Int16Array`<br />
|
|
A 16-bit signed integer view on the memory.
|
|
|
|
* **U16**: `Uint16Array`<br />
|
|
A 16-bit unsigned integer view on the memory.
|
|
|
|
* **I32**: `Int32Array`<br />
|
|
A 32-bit signed integer view on the memory.
|
|
|
|
* **U32**: `Uint32Array`<br />
|
|
A 32-bit unsigned integer view on the memory.
|
|
|
|
* **I64**: `BigInt64Array`<br />
|
|
A 64-bit signed integer view on the memory<sup>1</sup>.
|
|
|
|
* **U64**: `BigUint64Array`<br />
|
|
A 64-bit unsigned integer view on the memory<sup>1</sup>.
|
|
|
|
* **F32**: `Float32Array`<br />
|
|
A 32-bit float view on the memory.
|
|
|
|
* **F64**: `Float64Array`<br />
|
|
A 64-bit float view on the memory.
|
|
|
|
* **newString**(str: `string`): `number`<br />
|
|
Allocates a new string in the module's memory and returns its pointer. Requires `allocate_memory` to be exported from your module's entry file, i.e.:
|
|
|
|
```js
|
|
import "allocator/tlsf";
|
|
export { allocate_memory, free_memory };
|
|
```
|
|
|
|
* **getString**(ptr: `number`): `string`<br />
|
|
Gets a string from the module's memory by its pointer.
|
|
|
|
<sup>1</sup> This feature has not yet landed in any VM as of this writing.
|
|
|
|
Examples
|
|
--------
|
|
|
|
### Instantiating a module
|
|
|
|
```js
|
|
// From a module provided as a buffer, i.e. as returned by fs.readFileSync
|
|
const myModule = loader.instatiateBuffer(fs.readFileSync("myModule.wasm"), myImports);
|
|
|
|
// From a response object, i.e. as returned by window.fetch
|
|
const myModule = await loader.instantiateStreaming(fetch("myModule.wasm"), myImports);
|
|
```
|
|
|
|
### Reading/writing basic values to/from memory
|
|
|
|
```js
|
|
var ptrToInt8 = ...;
|
|
var value = myModule.I8[ptrToInt8]; // alignment of log2(1)=0
|
|
|
|
var ptrToInt16 = ...;
|
|
var value = myModule.I16[ptrToInt16 >>> 1]; // alignment of log2(2)=1
|
|
|
|
var ptrToInt32 = ...;
|
|
var value = myModule.I32[ptrToInt32 >>> 2]; // alignment of log2(4)=2
|
|
|
|
var ptrToInt64 = ...;
|
|
var value = myModule.I64[ptrToInt64 >>> 3]; // alignment of log2(8)=3
|
|
|
|
var ptrToFloat32 = ...;
|
|
var value = myModule.F32[ptrToFloat32 >>> 2]; // alignment of log2(4)=2
|
|
|
|
var ptrToFloat64 = ...;
|
|
var value = myModule.F64[ptrToFloat64 >>> 3]; // alignment of log2(8)=3
|
|
|
|
// Likewise, for writing
|
|
myModule.I8[ptrToInt8] = newValue;
|
|
myModule.I16[ptrToInt16 >>> 1] = newValue;
|
|
myModule.I32[ptrToInt32 >>> 2] = newValue;
|
|
myModule.I64[ptrToInt64 >>> 3] = newValue;
|
|
myModule.F32[ptrToFloat32 >>> 2] = newValue;
|
|
myModule.F64[ptrToFloat64 >>> 3] = newValue;
|
|
```
|
|
|
|
**Note:** Make sure to reference the views as shown above as these will automatically be updated when the module's memory grows.
|
|
|
|
### Allocating/obtaining strings to/from memory
|
|
|
|
```js
|
|
// Allocating a string, i.e. to be passed to an export expecting one
|
|
var str = "Hello world!";
|
|
var ptr = module.newString(str);
|
|
|
|
// Disposing a string that is no longer needed (requires free_memory to be exported)
|
|
module.free_memory(ptr);
|
|
|
|
// Obtaining a string, i.e. as returned by an export
|
|
var ptrToString = ...;
|
|
var str = module.getString(ptrToString);
|
|
```
|
|
|
|
### Usage with TypeScript definitions produced by the compiler
|
|
|
|
```ts
|
|
import MyModule from "myModule"; // pointing at the d.ts
|
|
|
|
const myModule = loader.instatiateBuffer<typeof MyModule>(fs.readFileSync("myModule.wasm"), myImports);
|
|
```
|