Description

中文文档

this mod add wasm support for CC: Tweaked.

this mod uses chicory runtime (v1.7.5), and includes wasi support.

Mounted directories

• wasm — global program dir, read-only, .minecraft/wasm/
• wasm_save — per-save program dir, read-only, .minecraft/saves/<world>/computercraft/wasm/
• shared — per-save writable data dir (1 GB quota), .minecraft/saves/<world>/computercraft/shared/

Usage

put .wasm files (compiled from Rust, see cc_wasm_api) into the wasm folder (.minecraft/wasm/), then in game:

commands (shell)

• exec_wasm <name> — load wasm (interpreter) and drive its coroutine loop (tick/stopped)
• exec_wasm_aot <name> — load wasm with AOT + disk cache, then drive the coroutine loop
• wasm_compile_aot <name> [global|save|auto] — precompile a wasm to the AOT disk cache in background

lua api

• wasm.load_wasm(name, [useAoT], [source], [useStdio]) — load a module (no .wasm extension). useAoT defaults to true; source is "auto" (save first) / "global" / "save". with useStdio = true the module gets three extra methods:
  • stdin(...) — push strings into the WASI stdin (empty stdin = EOF, never blocks)
  • stdout() — return all output written to stdout since the last call (and clear it)
  • stderr() — same for stderr
• wasm.precompile(name, [source]) — start background AOT compilation (thread ccwasm-aot), writes result to the disk cache. Needed for large modules, because a single Lua call is limited by the computer thread timeout (~7.5s), while AOT compiling a big module (e.g. the python example) takes tens of seconds.
• wasm.precompile_done(name) — poll status: "compiling" / "done" / "failed" / nil. In Lua, poll with os.sleep to avoid the timeout.

after a module is precompiled once, wasm.load_wasm(name, true) loads it from the cache in ~1.4s no matter how big it is.

AOT disk cache

compiled machine code is cached in .minecraft/wasm_cache/ (keyed by the wasm content sha256, so changing the wasm invalidates the cache automatically; corrupted cache falls back to a cache-less recompile).

Wasm development

use this crate.

features (opt-in, Cargo features):

• coroutine — tick/stopped exports for driving a loop with exec_wasm/exec_wasm_aot
• eval — call back into Lua (eval_string/eval_result)
• addon — local monitor / vec2d / time helpers
• debug — debug output helpers

see the examples here: minesweeper, pic_display, txt_display, python, obj_demo, type_test.

Example

minesweeper example

• download this file and put it in .minecraft/wasm/

• place a monitor on top of a computer

• in computer craft's shell run exec_wasm minesweeper

picture display example

• download this file and put it in .minecraft/wasm/

• place a monitor on top of a computer

• in computer craft's shell run exec_wasm pic_display [path to picture file(in cc's fs)]

python interpreter example, download this file and put it in ./wasm/.

python.wasm is big (9.6MB): AOT compiling it takes ~11s, which exceeds the computer thread timeout for a single Lua call, so precompile it first (runs in a background thread and writes the AOT disk cache):

wasm_compile_aot python

then in computer craft lua run:

py = wasm.load_wasm("python") -- AOT, loads from disk cache in ~1.4s
py.init()
py.exec("import time as t")
print(py.eval("t.time()"))

note: when using stdio (load_wasm(..., true)), python's sys.stderr.write is line-buffered (chicory reports isatty), so call flush() explicitly if there is no newline; print flushes on its own.

Tests

test scripts live in wasm/test/ (dev run dir), entry point test.lua (run dofile from a computer, e.g. dofile("wasm/test/test.lua")). Results are written to shared/.