Windows: Use WriteFile to write to a UTF-8 console #134622
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rustbot has assigned @Mark-Simulacrum. Use |
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| /// Returns true if the attached console's code page is currently UTF-8. | ||
| #[cfg(not(target_vendor = "win7"))] | ||
| fn is_utf8_console() -> bool { | ||
| unsafe { c::GetConsoleOutputCP() == c::CP_UTF8 } |
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Is this cheap enough to call on every write? I guess we're already calling GetConsoleMode on every write...
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Yeah, I don't love it but it is cheap. Especially when compared to the previous code where if is_console is true then it will be doing a full UTF-8 to UTF-16 conversion using a small buffer (necessitating multiple calls to write).
| fn write(handle_id: u32, data: &[u8], incomplete_utf8: &mut IncompleteUtf8) -> io::Result<usize> { | ||
| if data.is_empty() { | ||
| return Ok(0); | ||
| } | ||
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| let handle = get_handle(handle_id)?; | ||
| if !is_console(handle) { | ||
| if !is_console(handle) || is_utf8_console() { |
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Should we be worried about race conditions at all with changes in the mode setting? My sense is probably no?
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Probably not. It is possible that the code page could be changed after is_utf8_console and before the write. But changing the console code page is like changing any global state (e.g. an environment variable or the current directory). That is, it's the sort of thing you maybe set once on startup and don't touch again (unless you're very careful).
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@bors r=Mark-Simulacrum |
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Rollup of 8 pull requests Successful merges: - rust-lang#134606 (ptr::copy: fix docs for the overlapping case) - rust-lang#134622 (Windows: Use WriteFile to write to a UTF-8 console) - rust-lang#134759 (compiletest: Remove the `-test` suffix from normalize directives) - rust-lang#134787 (Spruce up the docs of several queries related to the type/trait system and const eval) - rust-lang#134806 (rustdoc: use shorter paths as preferred canonical paths) - rust-lang#134815 (Sort triples by name in platform_support.md) - rust-lang#134816 (tools: fix build failure caused by PR rust-lang#134420) - rust-lang#134819 (Fix mistake in windows file open) r? `@ghost` `@rustbot` modify labels: rollup
Rollup merge of rust-lang#134622 - ChrisDenton:write-file-utf8, r=Mark-Simulacrum Windows: Use WriteFile to write to a UTF-8 console If the console code page is UTF-8 then we can simply write to it without needing to convert to UTF-16 and calling `WriteConsole`.
…k-Simulacrum Windows: Use WriteFile to write to a UTF-8 console If the console code page is UTF-8 then we can simply write to it without needing to convert to UTF-16 and calling `WriteConsole`.
Rollup of 8 pull requests Successful merges: - rust-lang#134606 (ptr::copy: fix docs for the overlapping case) - rust-lang#134622 (Windows: Use WriteFile to write to a UTF-8 console) - rust-lang#134759 (compiletest: Remove the `-test` suffix from normalize directives) - rust-lang#134787 (Spruce up the docs of several queries related to the type/trait system and const eval) - rust-lang#134806 (rustdoc: use shorter paths as preferred canonical paths) - rust-lang#134815 (Sort triples by name in platform_support.md) - rust-lang#134816 (tools: fix build failure caused by PR rust-lang#134420) - rust-lang#134819 (Fix mistake in windows file open) r? `@ghost` `@rustbot` modify labels: rollup
If the console code page is UTF-8 then we can simply write to it without needing to convert to UTF-16 and calling
WriteConsole.