func cachedReadFile(path string) ([]byte, error) {
key := []byte(path)
if v, err := fileCache.Get(key); err == nil {
metrics.IncrCounter(hitMetricsKey, 1.0)
return v, nil
}
buf, err := fs.ReadFile(path)
fileCache.Set(key, buf, generalTimeout)
metrics.IncrCounter(missMetricsKey, 1.0)
return buf, err
}
func (p dir) ReadFile(path string) ([]byte, error) {
if path == "/" {
return nil, fmt.Errorf("I'm a directory!")
}
head, tail := split(path)
fs, ok := p.entries[head]
if !ok {
return nil, fmt.Errorf("Not found: %s", path)
}
return fs.ReadFile(tail)
}
func readStats(path string) (ppid, threads int, jiffies, rss uint64, err error) {
var (
buf []byte
userJiffies, sysJiffies, rssPages uint64
)
buf, err = fs.ReadFile(path)
if err != nil {
return
}
splits := strings.Fields(string(buf))
if len(splits) < 24 {
err = fmt.Errorf("Invalid /proc/PID/stat")
return
}
ppid, err = strconv.Atoi(splits[3])
if err != nil {
return
}
threads, err = strconv.Atoi(splits[19])
if err != nil {
return
}
userJiffies, err = strconv.ParseUint(splits[13], 10, 64)
if err != nil {
return
}
sysJiffies, err = strconv.ParseUint(splits[14], 10, 64)
if err != nil {
return
}
jiffies = userJiffies + sysJiffies
rssPages, err = strconv.ParseUint(splits[23], 10, 64)
if err != nil {
return
}
rss = rssPages * uint64(os.Getpagesize())
return
}