Files
cista-storage/cista/preview_worker.py
T
Leo Vasanko fb0ddd20e0 Add OnlyOffice-based preview for office documents
Replace Aspose.Words with OnlyOffice Document Server for generating
bitmap previews of office documents (Word, Excel, PowerPoint, etc.).

Backend:
- Add cista/onlyoffice.py conversion client
- Convert office docs directly to PNG via OnlyOffice, then AVIF via pyvips
- Make office previews optional based on OnlyOffice availability
- Remove Aspose.Words dependency and all related code
- Add spreadsheet and presentation format support

Frontend:
- Mark office files as previewable in Document.ts
- Add office extensions to MediaPreview.vue preview list
- Fix pre-existing @ts-ignore in HeaderMain.vue

Tests:
- Fix test_lrucache.py parameter name (open -> opener)

Also run ruff format across the codebase to satisfy linter checks.
2026-04-26 06:59:01 +00:00

117 lines
3.3 KiB
Python

"""Preview generation worker subprocess.
Two modes are supported:
1) Legacy one-shot mode: argv has path/quality/maxsize/maxzoom.
2) Long-lived mode: read JSONL commands from stdin and write framed responses.
Framed response format:
(blake3(packet))(uint32 json size)(uint32 payload size)(json)(binary payload)
where packet = (uint32 json size)(uint32 payload size)(json)(binary payload).
"""
import contextlib
import io
import logging
import struct
import sys
from pathlib import Path
import msgspec
from blake3 import blake3
class PreviewRequest(msgspec.Struct, omit_defaults=True):
path: str
quality: int
maxsize: int
maxzoom: float
class PreviewResponse(msgspec.Struct, omit_defaults=True):
ok: bool
mime: str | None = None
backend: str | None = None
timings: list[float] | None = None
error: str | None = None
stderr: str | None = None
_enc = msgspec.json.Encoder()
_dec_req = msgspec.json.Decoder(PreviewRequest)
def _write_response(resp: PreviewResponse, payload: bytes) -> None:
meta_bytes = _enc.encode(resp)
packet = struct.pack("<II", len(meta_bytes), len(payload)) + meta_bytes + payload
checksum = blake3(packet).digest()
sys.stdout.buffer.write(checksum)
sys.stdout.buffer.write(packet)
sys.stdout.buffer.flush()
def _run_once() -> None:
if len(sys.argv) != 5:
sys.stderr.write(f"Usage: {sys.argv[0]} <path> <quality> <maxsize> <maxzoom>\n")
sys.exit(1)
from cista.preview import dispatch
path = Path(sys.argv[1])
quality = int(sys.argv[2])
maxsize = int(sys.argv[3])
maxzoom = float(sys.argv[4])
result, _ = dispatch(path, quality, maxsize, maxzoom)
if result:
sys.stdout.buffer.write(result)
sys.stdout.buffer.flush()
def _run_loop() -> None:
from cista.preview import dispatch
while True:
line = sys.stdin.buffer.readline()
if not line:
return
stderr_capture = io.StringIO()
handler = logging.StreamHandler(stderr_capture)
root_logger = logging.getLogger()
root_logger.addHandler(handler)
try:
with contextlib.redirect_stderr(stderr_capture):
req = _dec_req.decode(line)
result, resp = dispatch(
Path(req.path), req.quality, req.maxsize, req.maxzoom
)
if not resp.ok:
captured = stderr_capture.getvalue().strip()
if captured:
resp = PreviewResponse(
ok=False,
backend=resp.backend,
error=resp.error,
stderr=captured,
)
_write_response(resp, result or b"")
except Exception as e:
captured = stderr_capture.getvalue().strip()
_write_response(
PreviewResponse(ok=False, error=str(e), stderr=captured or None), b""
)
finally:
root_logger.removeHandler(handler)
handler.close()
def main() -> None:
# Configure all log output to stderr before any imports that may emit logs.
logging.basicConfig(stream=sys.stderr, level=logging.INFO)
if len(sys.argv) > 1:
_run_once()
return
_run_loop()
if __name__ == "__main__":
main()