change various func return type to pointer.

cpu_linux.go

@@ -18,18 +18,18 @@ func CPUTimes(percpu bool) ([]CPUTimesStat, error) {
 		if err != nil {
 			continue
 		}
-		ret = append(ret, ct)
+		ret = append(ret, *ct)
 
 	}
 	return ret, nil
 }
 
-func parseStatLine(line string) (CPUTimesStat, error) {
+func parseStatLine(line string) (*CPUTimesStat, error) {
 	fields := strings.Fields(line)
 
 	if strings.HasPrefix(fields[0], "cpu") == false {
 		//		return CPUTimesStat{}, e
-		return CPUTimesStat{}, errors.New("not contain cpu")
+		return nil, errors.New("not contain cpu")
 	}
 
 	cpu := fields[0]
@@ -44,7 +44,7 @@ func parseStatLine(line string) (CPUTimesStat, error) {
 	irq, _ := strconv.ParseFloat(fields[6], 32)
 	softirq, _ := strconv.ParseFloat(fields[7], 32)
 	stolen, _ := strconv.ParseFloat(fields[8], 32)
-	ct := CPUTimesStat{
+	ct := &CPUTimesStat{
 		CPU:     cpu,
 		User:    float32(user),
 		Nice:    float32(nice),

host_linux.go

@@ -11,15 +11,15 @@ import (
 	"unsafe"
 )
 
-func HostInfo() (HostInfoStat, error) {
-	ret := HostInfoStat{}
-
+func HostInfo() (*HostInfoStat, error) {
 	hostname, err := os.Hostname()
-	ret.Hostname = hostname
 	if err != nil {
-		return ret, err
+		return nil, err
 	}
 
+	ret := &HostInfoStat{
+		Hostname: hostname,
+	}
 	return ret, nil
 }
 

load_linux.go

@@ -8,29 +8,29 @@ import (
 	"strings"
 )
 
-func LoadAvg() (LoadAvgStat, error) {
+func LoadAvg() (*LoadAvgStat, error) {
 	filename := "/proc/loadavg"
 	line, err := ioutil.ReadFile(filename)
 	if err != nil {
-		return LoadAvgStat{}, err
+		return nil, err
 	}
 
 	values := strings.Fields(string(line))
 
 	load1, err := strconv.ParseFloat(values[0], 64)
 	if err != nil {
-		return LoadAvgStat{}, err
+		return nil, err
 	}
 	load5, err := strconv.ParseFloat(values[1], 64)
 	if err != nil {
-		return LoadAvgStat{}, err
+		return nil, err
 	}
 	load15, err := strconv.ParseFloat(values[2], 64)
 	if err != nil {
-		return LoadAvgStat{}, err
+		return nil, err
 	}
 
-	ret := LoadAvgStat{
+	ret := &LoadAvgStat{
 		Load1:  load1,
 		Load5:  load5,
 		Load15: load15,

mem_freebsd.go

@@ -2,14 +2,14 @@
 
 package gopsutil
 
-func VirtualMemory() (VirtualMemoryStat, error) {
-	ret := VirtualMemoryStat{}
+func VirtualMemory() (*VirtualMemoryStat, error) {
+	ret := &VirtualMemoryStat{}
 
 	return ret, nil
 }
 
-func SwapMemory() (SwapMemoryStat, error) {
-	ret := SwapMemoryStat{}
+func SwapMemory() (*SwapMemoryStat, error) {
+	ret := &SwapMemoryStat{}
 
 	return ret, nil
 }

mem_linux.go

@@ -6,17 +6,19 @@ import (
 	"syscall"
 )
 
-func VirtualMemory() (VirtualMemoryStat, error) {
-	ret := VirtualMemoryStat{}
+func VirtualMemory() (*VirtualMemoryStat, error) {
 	sysinfo := &syscall.Sysinfo_t{}
 
 	if err := syscall.Sysinfo(sysinfo); err != nil {
-		return ret, err
+		return nil, err
+	}
+
+	ret := &VirtualMemoryStat{
+		Total:   uint64(sysinfo.Totalram),
+		Free:    uint64(sysinfo.Freeram),
+		Shared:  uint64(sysinfo.Sharedram),
+		Buffers: uint64(sysinfo.Bufferram),
 	}
-	ret.Total = uint64(sysinfo.Totalram)
-	ret.Free = uint64(sysinfo.Freeram)
-	ret.Shared = uint64(sysinfo.Sharedram)
-	ret.Buffers = uint64(sysinfo.Bufferram)
 
 	ret.Used = ret.Total - ret.Free
 
@@ -35,15 +37,16 @@ func VirtualMemory() (VirtualMemoryStat, error) {
 	return ret, nil
 }
 
-func SwapMemory() (SwapMemoryStat, error) {
-	ret := SwapMemoryStat{}
+func SwapMemory() (*SwapMemoryStat, error) {
 	sysinfo := &syscall.Sysinfo_t{}
 
 	if err := syscall.Sysinfo(sysinfo); err != nil {
-		return ret, err
+		return nil, err
+	}
+	ret := &SwapMemoryStat{
+		Total: sysinfo.Totalswap,
+		Free:  sysinfo.Freeswap,
 	}
-	ret.Total = sysinfo.Totalswap
-	ret.Free = sysinfo.Freeswap
 	ret.Used = ret.Total - ret.Free
 	ret.UsedPercent = float64(ret.Total-ret.Free) / float64(ret.Total) * 100.0
 

mem_windows.go

@@ -23,25 +23,26 @@ type MEMORYSTATUSEX struct {
 	ullAvailExtendedVirtual uint64
 }
 
-func VirtualMemory() (VirtualMemoryStat, error) {
-	ret := VirtualMemoryStat{}
-
+func VirtualMemory() (*VirtualMemoryStat, error) {
 	var memInfo MEMORYSTATUSEX
 	memInfo.cbSize = uint32(unsafe.Sizeof(memInfo))
 	mem, _, _ := procGlobalMemoryStatusEx.Call(uintptr(unsafe.Pointer(&memInfo)))
 	if mem == 0 {
-		return ret, syscall.GetLastError()
+		return nil, syscall.GetLastError()
+	}
+
+	ret := &VirtualMemoryStat{
+		Total:       memInfo.ullTotalPhys,
+		Available:   memInfo.ullAvailPhys,
+		UsedPercent: float64(memInfo.dwMemoryLoad),
 	}
 
-	ret.Total = memInfo.ullTotalPhys
-	ret.Available = memInfo.ullAvailPhys
-	ret.UsedPercent = float64(memInfo.dwMemoryLoad)
 	ret.Used = ret.Total - ret.Available
 	return ret, nil
 }
 
-func SwapMemory() (SwapMemoryStat, error) {
-	ret := SwapMemoryStat{}
+func SwapMemory() (*SwapMemoryStat, error) {
+	ret := &SwapMemoryStat{}
 
 	return ret, nil
 }

net_linux.go

@@ -10,7 +10,7 @@ func NetIOCounters(pernic bool) ([]NetIOCountersStat, error) {
 	filename := "/proc/net/dev"
 	lines, err := readLines(filename)
 	if err != nil {
-		return make([]NetIOCountersStat, 0), err
+		return nil, err
 	}
 
 	statlen := len(lines) - 1