Cache splitOffsets list to avoid repeated allocations#15625
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kuldeep27396 wants to merge 4 commits intoapache:mainfrom
Open
Cache splitOffsets list to avoid repeated allocations#15625kuldeep27396 wants to merge 4 commits intoapache:mainfrom
kuldeep27396 wants to merge 4 commits intoapache:mainfrom
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BaseFile.splitOffsets() was creating a new List<Long> wrapper on every invocation via ArrayUtil.toUnmodifiableLongList(). When file metadata is read and rewritten (e.g., during manifest rewriting or format conversion), each entry needlessly allocates a list that is immediately consumed and discarded. This change caches the List<Long> representation after the first conversion, similar to how other fields like partitionData are handled. The cache is transient so it won't be serialized. Fixes apache#15622
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Why this change
Resolves #15622
Problem: BaseFile.splitOffsets() was creating a new List wrapper on every invocation via ArrayUtil.toUnmodifiableLongList(). When file metadata is read and rewritten (e.g., during manifest rewriting or format conversion), each entry needlessly allocates a list that is immediately consumed and discarded.
Solution: Cache the List representation after the first conversion, similar to how other fields like partitionData are handled. The cache is transient so it won't be serialized.
Changes
Performance Impact
This eliminates unnecessary object allocations when:
The change is minimal and focused, following the existing pattern used for other cached fields in the class.