36 lines
1.4 KiB
Markdown
36 lines
1.4 KiB
Markdown
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# atomic
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import "github.com/natefinch/atomic"
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atomic is a go package for atomic file writing
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By default, writing to a file in go (and generally any language) can fail
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partway through... you then have a partially written file, which probably was
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truncated when the write began, and bam, now you've lost data.
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This go package avoids this problem, by writing first to a temp file, and then
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overwriting the target file in an atomic way. This is easy on linux, os.Rename
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just is atomic. However, on Windows, os.Rename is not atomic, and so bad things
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can happen. By wrapping the windows API moveFileEx, we can ensure that the move
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is atomic, and we can be safe in knowing that either the move succeeds entirely,
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or neither file will be modified.
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## func ReplaceFile
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``` go
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func ReplaceFile(source, destination string) error
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```
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ReplaceFile atomically replaces the destination file or directory with the
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source. It is guaranteed to either replace the target file entirely, or not
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change either file.
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## func WriteFile
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``` go
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func WriteFile(filename string, r io.Reader) (err error)
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```
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WriteFile atomically writes the contents of r to the specified filepath. If
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an error occurs, the target file is guaranteed to be either fully written, or
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not written at all. WriteFile overwrites any file that exists at the
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location (but only if the write fully succeeds, otherwise the existing file
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is unmodified).
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