windows: dynamically adjust the buffer size #5
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jazzdan
reviewed
Jul 27, 2020
| } | ||
| go w.readEvents() | ||
| return w, nil | ||
| } | ||
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| func (w *Watcher) SetBufferSize(bufSize int) { |
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i plan to call it from the tilt code!
| e := syscall.ReadDirectoryChanges(watch.ino.handle, &watch.buf[0], | ||
| uint32(unsafe.Sizeof(watch.buf)), w.recursive, mask, nil, &watch.ov, 0) | ||
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| hdr := (*reflect.SliceHeader)(unsafe.Pointer(&watch.buf)) |
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In Go, a slice is implemented as
- a pointer to some memory
- a length field
- a capacity field
https://golang.org/pkg/reflect/#SliceHeader
The windows syscall is all C. It needs a pointer to memory. So we unpack the slice, and pull the memory pointer out.
it's conceptually not that hard, but Go REALLY doesn't want you to do this (because it starts to mess with the Go garbage collector), so the syntax is pretty awkward
jazzdan
approved these changes
Jul 27, 2020
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Hello @jazzdan,
Please review the following commits I made in branch nicks/bufsize:
56f2b1e (2020-07-27 15:05:09 -0400)
windows: dynamically adjust the buffer size
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