Even if the file is cached, fread has to do a memcpy. mmap doesn't. | Hacker News

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		do_not_redeem 4 months ago \| parent \| context \| favorite \| on: How memory maps (mmap) deliver faster file access ... Even if the file is cached, fread has to do a memcpy. mmap doesn't.

gpderetta 4 months ago [–]

fread is (usually) buffered io, so it actually does two additional mem copies (kernel to FILE buffer then to user buffer)

assbuttbuttass 4 months ago | [–]

Not in Go

gpderetta 4 months ago | | [–]

oh, right, this is Go (https://pkg.go.dev/github.com/odeke-em/go-utils/fread#sectio...). Do the strings it return share memory with the internal buffer?

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