micropython/ports/webassembly/api.js

/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2023-2024 Damien P. George
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

// Options:
// - heapsize: size in bytes of the MicroPython GC heap.
// - url: location to load `micropython.mjs`.
// - stdin: function to return input characters.
// - stdout: function that takes one argument, and is passed lines of stdout
//   output as they are produced.  By default this is handled by Emscripten
//   and in a browser goes to console, in node goes to process.stdout.write.
// - stderr: same behaviour as stdout but for error output.
// - linebuffer: whether to buffer line-by-line to stdout/stderr.
export async function loadMicroPython(options) {
    const { heapsize, url, stdin, stdout, stderr, linebuffer } = Object.assign(
        { heapsize: 1024 * 1024, linebuffer: true },
        options,
    );
    const Module = {};
    Module.locateFile = (path, scriptDirectory) =>
        url || scriptDirectory + path;
    Module._textDecoder = new TextDecoder();
    if (stdin !== undefined) {
        Module.stdin = stdin;
    }
    if (stdout !== undefined) {
        if (linebuffer) {
            Module._stdoutBuffer = [];
            Module.stdout = (c) => {
                if (c === 10) {
                    stdout(
                        Module._textDecoder.decode(
                            new Uint8Array(Module._stdoutBuffer),
                        ),
                    );
                    Module._stdoutBuffer = [];
                } else {
                    Module._stdoutBuffer.push(c);
                }
            };
        } else {
            Module.stdout = (c) => stdout(new Uint8Array([c]));
        }
    }
    if (stderr !== undefined) {
        if (linebuffer) {
            Module._stderrBuffer = [];
            Module.stderr = (c) => {
                if (c === 10) {
                    stderr(
                        Module._textDecoder.decode(
                            new Uint8Array(Module._stderrBuffer),
                        ),
                    );
                    Module._stderrBuffer = [];
                } else {
                    Module._stderrBuffer.push(c);
                }
            };
        } else {
            Module.stderr = (c) => stderr(new Uint8Array([c]));
        }
    }
    const moduleLoaded = new Promise((r) => {
        Module.postRun = r;
    });
    _createMicroPythonModule(Module);
    await moduleLoaded;
    globalThis.Module = Module;
    proxy_js_init();
    const pyimport = (name) => {
        const value = Module._malloc(3 * 4);
        Module.ccall(
            "mp_js_do_import",
            "null",
            ["string", "pointer"],
            [name, value],
        );
        return proxy_convert_mp_to_js_obj_jsside_with_free(value);
    };
    Module.ccall("mp_js_init", "null", ["number"], [heapsize]);
    Module.ccall("proxy_c_init", "null", [], []);
    return {
        _module: Module,
        PyProxy: PyProxy,
        FS: Module.FS,
        globals: {
            __dict__: pyimport("__main__").__dict__,
            get(key) {
                return this.__dict__[key];
            },
            set(key, value) {
                this.__dict__[key] = value;
            },
            delete(key) {
                delete this.__dict__[key];
            },
        },
        registerJsModule(name, module) {
            const value = Module._malloc(3 * 4);
            proxy_convert_js_to_mp_obj_jsside(module, value);
            Module.ccall(
                "mp_js_register_js_module",
                "null",
                ["string", "pointer"],
                [name, value],
            );
            Module._free(value);
        },
        pyimport: pyimport,
        runPython(code) {
            const value = Module._malloc(3 * 4);
            Module.ccall(
                "mp_js_do_exec",
                "number",
                ["string", "pointer"],
                [code, value],
            );
            return proxy_convert_mp_to_js_obj_jsside_with_free(value);
        },
    };
}

globalThis.loadMicroPython = loadMicroPython;