reader/csv: Use binary mode on Windows #2121
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On windows, when using `open()`, files are opened in Text mode by default. This causes automatic line conversion from `\r\n` to `\n`. We don't want this behaviour, and furthermore, it messes up our computation. If the file contents are `abc\r\n` and Windows is directed to read, it will return 4 bytes, `abc\n`. However, the file position as reported by `lseek` is 5, since we are five bytes into the file. This means we can miss rows if we get really unlucky with block offsets. Specifying `_O_BINARY` makes windows use binary mode, which is most compatible with the linux behaviour. Our CSV reader is prepared to handle carriage returns anyway.
Codecov ReportAll modified lines are covered by tests ✅
Additional details and impacted files@@ Coverage Diff @@
## master #2121 +/- ##
===========================================
+ Coverage 0 89.75% +89.75%
===========================================
Files 0 986 +986
Lines 0 35559 +35559
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+ Hits 0 31916 +31916
- Misses 0 3643 +3643
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andyfengHKU
approved these changes
Sep 30, 2023
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On windows, when using
open(), files are opened in Text mode by default. This causes automatic line conversion from\r\nto\n. We don't want this behaviour, and furthermore, it messes up our computation. If the file contents areabc\r\nand Windows is directed to read, it will return 4 bytes,abc\n. However, the file position as reported bylseekis 5, since we are five bytes into the file. This means we can miss rows if we get really unlucky with block offsets.Specifying
_O_BINARYmakes windows use binary mode, which is most compatible with the linux behaviour. Our CSV reader is prepared to handle carriage returns anyway.