//go:build linux

package host

import (
	"os"

	"golang.org/x/sys/unix"
)

// readHeadroom reads spare memory from /proc/meminfo and spare disk from
// the data directory's filesystem. A reading that fails is left at zero.
func readHeadroom(dataDir string, awake int) *edgeHeadroom {
	h := &edgeHeadroom{Awake: awake}
	if b, err := os.ReadFile("/proc/meminfo"); err == nil {
		h.MemFreeMiB = parseMemAvailableMiB(string(b))
	}
	var st unix.Statfs_t
	if err := unix.Statfs(dataDir, &st); err == nil {
		h.DiskFreeMiB = int64(st.Bavail) * int64(st.Bsize) / (1 << 20)
	}
	return h
}