fix: report logical bytes for zero-copy clonefile/FICLONE/ReFS paths#3394
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fix: report logical bytes for zero-copy clonefile/FICLONE/ReFS paths#3394
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Zero-copy reflink methods (clonefile, FICLONE, ReFS DUPLICATE_EXTENTS) return bytes_copied=0 from the platform_copy dispatch layer because no data physically traversed userspace. The user-facing copy_file_optimized_with wrapper was passing this through unchanged, causing macOS test failures (test_copy_large_file, test_copy_file_optimized_result_type) and under-reporting transfer statistics. Substitute the source file size_hint when CopyResult::is_zero_copy() so progress and statistics reflect the data made available at the destination. The lower-layer dispatch contract is preserved (it still reports 0 for zero-copy methods, as required by platform_copy/tests.rs).
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Summary
copy_file_optimized_withincrates/engine/src/local_copy/win_copy.rsto report the logical file size (viasize_hint) when the underlying platform copy used a zero-copy reflink method (clonefile/FICLONE/ReFSDUPLICATE_EXTENTS).test_copy_large_fileandtest_copy_file_optimized_result_typethat have been blocking master and several open PRs (feat: add AdaptiveLevelStrategy for runtime compression level tuning #3391, feat: add adaptive capacity scaling to ReorderBuffer #3392, docs: audit SIMD/scalar parity coverage across checksums crate #3393).platform_copystill returnsbytes_copied=0for zero-copy methods (verified bycrates/fast_io/src/platform_copy/tests.rs).Root cause
dispatch::platform_copy_implcorrectly returnsCopyResult { bytes_copied: 0, method: Clonefile }because no bytes physically traversed userspace. Thewin_copyuser-facing wrapper passed this through, soWinCopyResult::StandardCopy(0)was reported even when a multi-MB file was cloned.Fix
Use
CopyResult::is_zero_copy()(already exists for exactly this distinction) to substitute the sourcesize_hintfor the user-facing byte count when the operation went through a zero-copy path. Statistics and progress now reflect the data made available at the destination, matching upstream rsync's accounting.Test plan