lumbda/wasm/dist-repl/python/lumbda-py.js
russell@unturf.com ff2ef382c7
gc diagnostics: per-tier heap pressure surfaced in repl tabbar
Step 1 of the GC effort. Each tier loader now exposes heapStats():
  - asm-wasm — lumbda_heap_used / lumbda_heap_total wat exports
  - c-wasm   — emscripten linear memory size (no free path right now,
               so used = total; documented in the loader)
  - python   — pyodide module linear memory size; CPython GC cycles
               this naturally

Worker handles a "heap" message kind that round-trips the active tab's
loaded tiers; repl tabbar shows a compact "py 12M · c 32M · asm 4M"
strip next to the buttons. Polls every 2s.

Doesn't solve the leak — just makes pressure visible so the user knows
when to use "reboot tier". Real GC (Cheney over the WAT bump allocator,
Boehm-em or custom mark-sweep for c-wasm) coming next.
2026-06-14 17:32:48 -04:00

76 lines
2.7 KiB
JavaScript

// wasm/python/lumbda-py.js
// Python tier loader — Pyodide (CPython-in-WASM) hosting lumbda.py.
//
// ES module form so it works in both window and Web Worker contexts.
// Exports createPythonTier() -> Promise<{ evalLisp(src) -> Promise<string> }>.
const PYODIDE_VERSION = "0.27.2";
const PYODIDE_INDEX_URL = `https://cdn.jsdelivr.net/pyodide/v${PYODIDE_VERSION}/full/`;
async function _bootstrap() {
// Dynamic ES-module import works in both window and Worker (module type)
// contexts. The CDN ships pyodide.mjs alongside pyodide.js.
const { loadPyodide } = await import(PYODIDE_INDEX_URL + "pyodide.mjs");
const pyodide = await loadPyodide({ indexURL: PYODIDE_INDEX_URL });
// Pull lumbda.py + stdlib.lsp into Pyodide's virtual FS. Paths resolve
// relative to THIS loader (under python/) for both window and Worker.
const pyURL = new URL("./lumbda.py", import.meta.url).href;
const stdlibURL = new URL("./stdlib.lsp", import.meta.url).href;
const lumbdaSrc = await (await fetch(pyURL)).text();
const stdlibSrc = await (await fetch(stdlibURL)).text();
pyodide.FS.writeFile("/home/pyodide/lumbda.py", lumbdaSrc);
pyodide.FS.writeFile("/home/pyodide/stdlib.lsp", stdlibSrc);
await pyodide.runPythonAsync(`
import sys, io
sys.path.insert(0, "/home/pyodide")
import lumbda
_env = lumbda.make_global_env()
for _e in lumbda.read_all(lumbda.PRELUDE):
lumbda.leval(_e, _env)
def _lumbda_eval(src):
buf = io.StringIO()
old = sys.stdout
sys.stdout = buf
last = None
try:
for e in lumbda.read_all(src):
last = lumbda.leval(e, _env)
except Exception as ex:
sys.stdout = old
return f"{buf.getvalue()}error: {ex}"
sys.stdout = old
out = buf.getvalue()
if last is not None and not isinstance(last, lumbda._Void):
rep = lumbda.show(last)
if out and not out.endswith("\\n"):
out += "\\n"
out += rep
return out
`);
return {
async evalLisp(src) {
pyodide.globals.set("_src_in", src);
return await pyodide.runPythonAsync("_lumbda_eval(_src_in)");
},
heapStats() {
// Pyodide's runtime memory is the Emscripten linear memory.
// CPython's GC reclaims behind the scenes, so this number
// rises and falls naturally as objects die.
const total = pyodide._module.HEAPU8.byteLength;
return { used: total, total };
},
};
}
// Closure-encapsulated singleton (see lumbda-c.loader.js for rationale).
export const createPythonTier = (() => {
let tier = null;
return async () => {
if (!tier) tier = await _bootstrap();
return tier;
};
})();