Fix File#pos, File#seek and File#truncate over 2G on Windows #9015
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straight-shoota
added
platform:windows
src/crystal/system/win32/file.cr
Outdated
| @@ -212,8 +212,8 @@ module Crystal::System::File | |||
| end | |||
| end | |||
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| private def system_truncate(size : Int) : Nil | |||
| if LibC._chsize(fd, size) != 0 | |||
| private def system_truncate(size) : Nil | |||
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Why is the Int restriction gone?
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That's because I'm a newbie about crystal and I didn't know that Int was the base type of all integer types.
I thought that Int was 32-bit by analogy with C and changed the restriction from Int to Int64 at first because the size argument is passed to the Int64 argument of LibC._chsize_s(). However I got an error by the following code.
File.open("test-file.txt", "w") do |file|
file << "123456789012345678901234567890"
file.truncate(20)
end$ ./crystal/.build/crystal build --cross-compile --target x86_64-pc-windows-msvc "$@" trunc-test.cr
Showing last frame. Use --error-trace for full trace.
In crystal/src/file.cr:763:5
763 | system_truncate(size)
^--------------
Error: no overload matches 'File#system_truncate' with type Int32
Overloads are:
- Crystal::System::File#system_truncate(size : Int64)I could not imagine the error reason. I checked the definition of system_truncate in src/crystal/system/unix/file.cr and found that it didn't have such restriction. So I removed the restriction and it worked. I made a pull request after that.
I just now checked that it worked with the Int restriction. Should I revert the change at the line and push a commit?
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Yes, please!
Int is not well named, it should be named Integer. I hope we can rename it in the future.
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I pushed 5c20b89. Is it Okay?
_lseek and _chsize cannot handle files bigger than 2G because they use Long, whose maximum size is 2G on Windows. This commit uses _lseeki64 and _chsize_s instead.
…-lang#9015) _lseek and _chsize cannot handle files bigger than 2G because they use Long, whose maximum size is 2G on Windows. This commit uses _lseeki64 and _chsize_s instead.
_lseek and _chsize cannot handle files bigger than 2G because they use Long, whose maximum size is 2G on Windows. This commit uses _lseeki64 and _chsize_s instead.