import os import sys import subprocess import tempfile import wasmtime import platform import click from pathlib import Path import hashlib import lzma import appdirs from importlib import resources as importlib_resources try: importlib_resources.files # py3.9+ stdlib except AttributeError: import importlib_resources # py3.8- shim # ============================== # Note on wasmtime path handling # ============================== # # Hack: Right now, wasmtime's preopen_dir / --map functionality is completely borked. AFAICT only the first mapping is # even considered, and preopening both / and . simply does not work: Either all paths open'ed by the executable must be # absolute, or all paths must be relative. I spent some hours trying to track down where exactly this borkage originates # from, but I found the code confusing and did not succeed. # # FOR NOW we work around this issue the dumb way: We simply have click parse enough of the command line to transform any # paths given on the command line to absolute paths. The actual path resolution is done by click because of # resolve_path=True. # def _run_wasm_app(wasm_filename, argv, cachedir="svg-flatten-wasi"): module_binary = importlib_resources.read_binary(__package__, wasm_filename) module_path_digest = hashlib.sha256(__file__.encode()).hexdigest() module_digest = hashlib.sha256(module_binary).hexdigest() cache_path = Path(os.getenv("SVG_FLATTEN_WASI_CACHE_DIR", appdirs.user_cache_dir(cachedir))) cache_path.mkdir(parents=True, exist_ok=True) cache_filename = (cache_path / f'{wasm_filename}-{module_path_digest[:8]}-{module_digest[:16]}') wasi_cfg = wasmtime.WasiConfig() wasi_cfg.argv = argv wasi_cfg.preopen_dir('/', '/') wasi_cfg.inherit_stdin() wasi_cfg.inherit_stdout() wasi_cfg.inherit_stderr() engine = wasmtime.Engine() import time try: with cache_filename.open("rb") as cache_file: module = wasmtime.Module.deserialize(engine, lzma.decompress(cache_file.read())) except: print("Preparing to run {}. This might take a while...".format(argv[0]), file=sys.stderr) module = wasmtime.Module(engine, module_binary) with cache_filename.open("wb") as cache_file: cache_file.write(lzma.compress(module.serialize(), preset=0)) linker = wasmtime.Linker(engine) linker.define_wasi() store = wasmtime.Store(engine) store.set_wasi(wasi_cfg) app = linker.instantiate(store, module) linker.define_instance(store, "app", app) try: app.exports(store)["_start"](store) return 0 except wasmtime.ExitTrap as trap: return trap.code def run_usvg(input_file, output_file, dpi=96): args = ['--keep-named-groups', '--dpi', str(dpi), input_file, output_file] # By default, try a number of options: candidates = [ # somewhere in $PATH 'usvg', 'wasi-usvg', # in user-local cargo installation Path.home() / '.cargo' / 'bin' / 'usvg', # wasi-usvg in user-local pip installation Path.home() / '.local' / 'bin' / 'wasi-usvg', # next to our current python interpreter (e.g. in virtualenv) str(Path(sys.executable).parent / 'wasi-usvg') ] # if USVG envvar is set, try that first. if 'USVG' in os.environ: exec_candidates = [os.environ['USVG'], *exec_candidates] for candidate in candidates: try: res = subprocess.run([candidate, *args], check=True) print('used usvg:', candidate) break except FileNotFoundError: continue else: raise SystemError('usvg executable not found') @click.command(context_settings={'ignore_unknown_options': True}) @click.option('--no-usvg', is_flag=True) @click.option('--usvg-dpi', type=int, default=96) @click.argument('other_args', nargs=-1, type=click.UNPROCESSED) @click.argument('input_file', type=click.Path(resolve_path=True, dir_okay=False)) @click.argument('output_file', type=click.Path(resolve_path=True, dir_okay=False, writable=True)) def run_svg_flatten(input_file, output_file, other_args, usvg_dpi, no_usvg): with tempfile.NamedTemporaryFile() as f: if not no_usvg: run_usvg(input_file, f.name, dpi=usvg_dpi) input_file = f.name cmdline = ['svg-flatten', '--force-svg', '--no-usvg', *other_args, input_file, output_file] sys.exit(_run_wasm_app("svg-flatten.wasm", cmdline))