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JiriUhlirandClaude Opus 5 156289fe2d Implementace prevodu HTML na PDF
Sluzba prijme adresu HTML dokumentu nebo HTML v tele requestu a vrati PDF.
Navrzena pro dokumenty o stovkach az tisicich stranek.

Rendering:
- WeasyPrint jako vychozi engine, spravne CSS Paged Media, nizka pametova
  narocnost, bez JavaScriptu
- Chromium pres Playwright pro dokumenty dokreslovane skripty
- rezim auto s detekci skriptu a fallbackem pri selhani WeasyPrintu

Velke dokumenty:
- deleni na casti na strukturalnich hranicich, rez nikdy uvnitr tabulky
  nebo odstavce
- dvoupruchodovy render obsahu se skutecnymi cisly stranek, pozice nadpisu
  se ctou z kotev hlasenych u kazde stranky
- cislovani stranek bud pres CSS countery, nebo pres cislovaci vrstvu
  nastampovanou na hotove PDF, rozmer stranky se cte z vysledneho souboru
- Chromium se restartuje po N jobech, nikdy vsak behem beziciho renderu

API:
- POST /convert synchronne, POST /jobs asynchronne se sledovanim stavu,
  stahovanim vysledku, rusenim a volitelnym callbackem
- GET /health s overenim dostupnosti obou enginu a stavem fronty
- OpenAPI respektuje prefix reverse proxy pres root_path

Bezpecnost a provoz:
- SSRF kontrola po DNS resolvu, na kazdem presmerovani a u vsech pozadavku
  prohlizece
- nedostupne assety render nezastavi, ale hlasi se v odpovedi i v logu
- fronta s omezenym poctem workeru, rozpracovane joby se pri ukonceni
  oznaci jako failed, nezmizi potichu
- strukturovane JSON logovani s job_id
- vsechny limity vypnute ve vychozim stavu

Dockerfile je dvoufazovy, obsahuje zavislosti WeasyPrintu, Chromium
a fonty s ceskou diakritikou.

Autentizace zamerne neni implementovana, zpusob predavani neni domluveny.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-27 14:50:10 +02:00

49 lines
1.2 KiB
Python

"""Common interface of the render engines."""
from __future__ import annotations
from abc import ABC, abstractmethod
from dataclasses import dataclass, field
from pathlib import Path
from ..models import ConvertRequest
@dataclass
class ChunkRender:
"""Result of rendering a single chunk."""
path: Path
page_count: int
# Anchor name to zero based page index inside this chunk.
anchor_pages: dict[str, int] = field(default_factory=dict)
class RenderEngine(ABC):
name: str
@abstractmethod
async def available(self) -> bool:
"""True when the engine can render right now."""
@abstractmethod
async def render_chunk(
self,
html: str,
base_url: str | None,
request: ConvertRequest,
output_path: Path,
total_pages: int | None = None,
asset_gate=None,
) -> ChunkRender:
"""Render one chunk into output_path."""
async def shutdown(self) -> None:
"""Release engine resources. Default is a no-op."""
return None
@property
def supports_anchor_pages(self) -> bool:
"""True when the engine can report on which page an anchor landed."""
return False