star/hcache/winsize.go
2025-04-26 19:33:14 +08:00

51 lines
1.3 KiB
Go

//go:build linux
package hcache
/*
* Copyright 2015 Albert P. Tobey <atobey@datastax.com> @AlTobey
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* pcstat.go - page cache stat
*
* uses the mincore(2) syscall to find out which pages (almost always 4k)
* of a file are currently cached in memory
*
*/
import (
"log"
"syscall"
"unsafe"
"golang.org/x/sys/unix"
)
// adapted from https://groups.google.com/d/msg/golang-nuts/8d4pOPmSL9Q/H6WUqbGNELEJ
type winsize struct {
ws_row, ws_col uint16
ws_xpixel, ws_ypixel uint16
}
func getwinsize() winsize {
ws := winsize{}
_, _, err := unix.Syscall(syscall.SYS_IOCTL,
uintptr(0), uintptr(syscall.TIOCGWINSZ),
uintptr(unsafe.Pointer(&ws)))
if err != 0 {
log.Fatalf("TIOCGWINSZ failed to get terminal size: %s\n", err)
}
return ws
}