desktop/scan.go

122 lines
1.8 KiB
Go

package desktop
import (
"os"
"path/filepath"
"runtime"
"strings"
"sync"
)
const bufferSize = 32 * 1024
type scan struct {
e map[int][]*Entry
errs chan error
in chan *scanEntry
sync.Mutex
sync.WaitGroup
}
type scanEntry struct {
i int
f *os.File
}
func Scan(dirs []string) (map[int][]*Entry, error) {
s := &scan{e: make(map[int][]*Entry), errs: make(chan error), in: make(chan *scanEntry)}
for i := 0; i < runtime.GOMAXPROCS(-1); i++ {
go scanner(s)
}
for i, dir := range dirs {
i, dir := i, dir
s.Add(1)
go scanDir(i, dir, s)
}
done := make(chan bool, 1)
go func() {
s.Wait()
close(s.in)
done <- true
}()
select {
case err := <-s.errs:
return nil, err
case <-done:
return s.e, nil
}
}
func scanner(s *scan) {
var (
buf = make([]byte, bufferSize)
scanEntry *scanEntry
entry *Entry
err error
)
for scanEntry = range s.in {
entry, err = Parse(scanEntry.f, buf)
scanEntry.f.Close()
if err != nil {
s.errs <- err
s.Done()
return
} else if entry == nil {
s.Done()
continue
}
s.Lock()
s.e[scanEntry.i] = append(s.e[scanEntry.i], entry)
s.Unlock()
s.Done()
}
}
func scanFunc(i int, s *scan) filepath.WalkFunc {
return func(path string, f os.FileInfo, err error) error {
s.Add(1)
go func() {
if err != nil {
s.errs <- err
s.Done()
return
}
if f == nil || f.IsDir() || !strings.HasSuffix(strings.ToLower(path), ".desktop") {
s.Done()
return
}
f, err := os.OpenFile(path, os.O_RDONLY, 0644)
if err != nil {
s.errs <- err
s.Done()
return
}
s.in <- &scanEntry{i: i, f: f}
}()
return nil
}
}
func scanDir(i int, dir string, s *scan) {
defer s.Done()
err := filepath.Walk(dir, scanFunc(i, s))
if err != nil {
s.errs <- err
}
}