PI: Fix O(n²) performance in NameObject read/write#3679
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stefan6419846 merged 4 commits intopy-pdf:mainfrom Mar 12, 2026
Merged
PI: Fix O(n²) performance in NameObject read/write#3679stefan6419846 merged 4 commits intopy-pdf:mainfrom
stefan6419846 merged 4 commits intopy-pdf:mainfrom
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Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## main #3679 +/- ##
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Coverage 97.39% 97.39%
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Files 55 55
Lines 9964 9977 +13
Branches 1829 1830 +1
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+ Hits 9704 9717 +13
Misses 151 151
Partials 109 109 ☔ View full report in Codecov by Sentry. 🚀 New features to boost your workflow:
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Also added exponential chunk growth in And also added more tests for |
…ames Three functions had quadratic behavior that caused hangs on PDFs with extremely long Name objects (e.g. repeatedly mis-encoded UTF-8 names): - read_until_regex: searched entire accumulated buffer on each 16-byte chunk instead of only the new chunk, and used bytes concatenation - NameObject.unnumber: rebuilt entire bytes object on each # replacement - NameObject.renumber: used out += concatenation in a loop
TST: Add read_until_regex coverage tests
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stefan6419846
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Mar 12, 2026
stefan6419846
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Mar 15, 2026
## What's new ### New Features (ENH) - Expose /Perms verification result on Encryption object (#3672) by @costajohnt ### Performance Improvements (PI) - Fix O(n²) performance in NameObject read/write (#3679) by @dmitry-kostin - Batch-parse all objects in ObjStm on first access (#3677) by @dmitry-kostin ### Bug Fixes (BUG) - Avoid sharing array-based content streams between pages (#3681) by @stefan6419846 - Avoid accessing invalid page when inserting blank page under some conditions (#3529) by @j-t-1 [Full Changelog](6.8.0...6.9.0)
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Fixes #3678
read_until_regex: search only new chunk instead of rescanning entire buffer; use list accumulation instead of bytes concatenationNameObject.unnumber: use bytearray instead of rebuilding bytes on each#xxreplacementNameObject.renumber: useparts.append()+join()instead ofout +=A real-world PDF with a ~786KB pathologically encoded name (262,144 hex escapes from repeated UTF-8 mis-encoding) went from hanging indefinitely to completing in ~3 seconds.