NetterSilverandClaude Opus 5.5 1db1635a88 Ask the composition cache once per story and page in PDF export ...

The PDF exporter called Cache::get twice for every text frame it drew.
Each call rebuilds the cache signature of the whole story, which looks up
every frame of the story with Document::find (a linear walk over all
spreads), and the anchored-frame placements walk them again. For a story
threaded through many frames this is O(frames^2 x items) per export.

The document doesn't change during an export, so the exporter now keeps
the composition it got for each (story, page) and reuses it. The cache
still decides what to compose; the output is byte-identical.

Add examples/pdf_export.rs to designcraft-cli: File > Export PDF through
a headless session on the `designcraft-cli perf` stress document (200
pages, 1M characters in 40 threaded stories, 500 placed images). The
stress document generator moves unchanged from src/perf.rs to a small
library module (src/stress.rs) that the binary and the example share.

Ryzen 16 threads, Linux, 12 runs each, interleaved:
  main     median 3485 ms, min 3427 ms
  patched  median 2016 ms, min 1656 ms  (-42 % median, -52 % min)
The exported PDF is byte-identical (12,075,744 bytes).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

2026-10-27 16:47:25 +01:00

..

pdf_export.rs

Ask the composition cache once per story and page in PDF export

2026-10-27 16:47:25 +01:00