Class FFILibrary

web/src/runtime.ts:58–151

* @internal * FFI Library wrapper, maintains most runtime states.

 * FFI Library wrapper, maintains most runtime states.
 */
class FFILibrary implements Disposable {
  wasm32: boolean;
  memory: Memory;
  exports: Record<string, Function>;
  webGPUContext?: WebGPUContext;
  private wasmInstance: WebAssembly.Instance;
  private recycledCallStacks: Array<CachedCallStack> = [];

  constructor(
    wasmInstance: WebAssembly.Instance,
    imports: Record<string, any>
  ) {
    this.wasmInstance = wasmInstance;
    this.memory = new Memory(this.detectWasmMemory(this.wasmInstance, imports));
    assert(
      this.wasmInstance.exports !== undefined,
      "Expect the library module contains exports"
    );
    this.exports = this.wasmInstance.exports as Record<string, Function>;
    this.wasm32 = this.memory.wasm32;
    this.validateInstance();
  }

  dispose(): void {
    while (this.recycledCallStacks.length != 0) {
      (this.recycledCallStacks.pop() as Disposable).dispose();
    }
    this.webGPUContext?.dispose();
  }

  sizeofPtr(): number {
    return this.memory.sizeofPtr();
  }

  checkCall(code: number): void {
    if (code != 0) {
      const msgPtr = (this.exports
        .TVMFFIWasmGetLastError as ctypes.FTVMFFIWasmGetLastError)();
      throw new Error(this.memory.loadCString(msgPtr));
    }
  }

  getOrAllocCallStack(): CachedCallStack {
    if (this.recycledCallStacks.length != 0) {
      return this.recycledCallStacks.pop() as CachedCallStack;
    }
    return new CachedCallStack(
      this.memory,
      this.exports.TVMWasmAllocSpace as ctypes.FTVMWasmAllocSpace,
      this.exports.TVMWasmFreeSpace as ctypes.FTVMWasmFreeSpace
    );
  }

  recycleCallStack(callstack: CachedCallStack): void {
    callstack.reset();
    this.recycledCallStacks.push(callstack);
  }