Reuse preprocessed EPUB HTML when reopening files - #416
Merged
cary-rowen merged 1 commit intoJul 31, 2026
Merged
Conversation
cary-rowen
marked this pull request as ready for review
July 31, 2026 10:59
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Link to issue number:
N/A
Summary of the issue:
Reopening an unchanged EPUB repeats the expensive HTML preprocessing step, which slows down file opening.
Description of how this pull request fixes the issue:
The existing EPUB cache now stores preprocessed HTML under a versioned key. Cache misses keep the current behavior, while cache hits skip the repeated preprocessing. Existing file-change detection and fallback handling remain unchanged.
A regression test verifies that repeated opens reuse the cached result without changing the document text.
Testing performed:
Manually opened the provided EPUB samples once to populate the cache and reopened them from the cache. The document text, storage text, and anchor positions matched between both opens. Cached opens were approximately 23–40% faster, saving about 0.3–1.6 seconds depending on the sample.
Known issues with pull request:
The improvement applies to reopening unchanged EPUB files; first-open time is unchanged. No known functional issues.