stackchain-dashboard/src/frontend_bundle.py
timmy 740e91a615
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perf: precompress immutable dashboard runtime (#431)
2026-08-09 22:12:00 +00:00

74 lines
2.4 KiB
Python

"""Build the content-addressed browser shell served by the dashboard."""
from __future__ import annotations
import gzip
import hashlib
import re
from dataclasses import dataclass
from pathlib import Path
SCRIPT_TAG = re.compile(r'^<script src="(static/[^"?]+\.js)"></script>$', re.MULTILINE)
WORKER_RUNTIME_SOURCE = "static/background-issue-sync.js"
@dataclass(frozen=True)
class FrontendBuild:
dashboard_html: str
runtime_bytes: bytes
runtime_gzip_bytes: bytes
runtime_digest: str
runtime_name: str
page_sources: tuple[str, ...]
service_worker_source: str
def _bundle(frontend_dir: Path, sources: tuple[str, ...]) -> bytes:
chunks = []
for source in sources:
path = frontend_dir / source.removeprefix("static/")
chunks.append(f"/* {source} */\n".encode() + path.read_bytes() + b"\n;\n")
return b"".join(chunks)
def build_frontend(frontend_dir: Path) -> FrontendBuild:
"""Return one internally consistent HTML, runtime, and offline-worker build."""
source_html = (frontend_dir / "index.html").read_text()
sources = tuple(SCRIPT_TAG.findall(source_html))
if not sources:
raise ValueError("dashboard entry document has no page scripts")
runtime = _bundle(frontend_dir, sources)
runtime_gzip = gzip.compress(runtime, compresslevel=6, mtime=0)
digest = hashlib.sha256(runtime).hexdigest()[:16]
runtime_name = f"runtime-{digest}.js"
dashboard_html = SCRIPT_TAG.sub("", source_html)
dashboard_html = dashboard_html.replace(
"</body>", f'<script src="{runtime_name}"></script>\n</body>'
)
worker = (frontend_dir / "service-worker.js").read_text()
for source in sources:
if source != WORKER_RUNTIME_SOURCE:
worker = worker.replace(f" BASE + '{source}',\n", "")
worker = worker.replace(
" BASE + 'static/dashboard.css',\n",
f" BASE + 'static/dashboard.css',\n BASE + '{runtime_name}',\n",
)
worker = re.sub(
r"const CACHE = 'stackchain-dashboard-shell-v\d+';",
f"const CACHE = 'stackchain-dashboard-shell-{digest}';",
worker,
count=1,
)
return FrontendBuild(
dashboard_html=dashboard_html,
runtime_bytes=runtime,
runtime_gzip_bytes=runtime_gzip,
runtime_digest=digest,
runtime_name=runtime_name,
page_sources=sources,
service_worker_source=worker,
)