ncdu: refactor accumulated attributes into a struct

cmd/ncdu/ncdu.go

@@ -299,9 +299,9 @@ func (u *UI) biggestEntry() (biggest int64) {
 		return
 	}
 	for i := range u.entries {
-		size, _, _, _, _, _, _ := u.d.AttrI(u.sortPerm[i])
+		attrs, _ := u.d.AttrI(u.sortPerm[i])
-		if size > biggest {
+		if attrs.Size > biggest {
-			biggest = size
+			biggest = attrs.Size
 		}
 	}
 	return
@@ -313,8 +313,8 @@ func (u *UI) hasEmptyDir() bool {
 		return false
 	}
 	for i := range u.entries {
-		_, count, _, isDir, _, _, _ := u.d.AttrI(u.sortPerm[i])
+		attrs, _ := u.d.AttrI(u.sortPerm[i])
-		if isDir && count == 0 {
+		if attrs.IsDir && attrs.Count == 0 {
 			return true
 		}
 	}
@@ -359,9 +359,9 @@ func (u *UI) Draw() error {
 			if y >= h-1 {
 				break
 			}
-			size, count, countUnknownSize, isDir, readable, entriesHaveErrors, err := u.d.AttrI(u.sortPerm[n])
+			attrs, err := u.d.AttrI(u.sortPerm[n])
 			fg := termbox.ColorWhite
-			if entriesHaveErrors {
+			if attrs.EntriesHaveErrors {
 				fg = termbox.ColorYellow
 			}
 			if err != nil {
@@ -372,19 +372,19 @@ func (u *UI) Draw() error {
 				fg, bg = bg, fg
 			}
 			mark := ' '
-			if isDir {
+			if attrs.IsDir {
 				mark = '/'
 			}
 			fileFlag := ' '
 			message := ""
-			if !readable {
+			if !attrs.Readable {
 				message = " [not read yet]"
 			}
-			if countUnknownSize > 0 {
+			if attrs.CountUnknownSize > 0 {
-				message = fmt.Sprintf(" [%d of %d files have unknown size, size may be underestimated]", countUnknownSize, count)
+				message = fmt.Sprintf(" [%d of %d files have unknown size, size may be underestimated]", attrs.CountUnknownSize, attrs.Count)
 				fileFlag = '~'
 			}
-			if entriesHaveErrors {
+			if attrs.EntriesHaveErrors {
 				message = " [some subdirectories could not be read, size may be underestimated]"
 				fileFlag = '.'
 			}
@@ -394,35 +394,29 @@ func (u *UI) Draw() error {
 			}
 			extras := ""
 			if u.showCounts {
-				ss := operations.CountStringField(count, u.humanReadable, 9) + " "
+				ss := operations.CountStringField(attrs.Count, u.humanReadable, 9) + " "
-				if count > 0 {
+				if attrs.Count > 0 {
 					extras += ss
 				} else {
 					extras += strings.Repeat(" ", len(ss))
 				}
 			}
-			var averageSize float64
-			if count > 0 {
-				countForAverage := count - countUnknownSize
-				if countForAverage > 0 {
-					averageSize = float64(size) / float64(countForAverage)
-				}
-			}
 			if u.showDirAverageSize {
-				ss := operations.SizeStringField(int64(averageSize), u.humanReadable, 9) + " "
+				avg := attrs.AverageSize()
-				if averageSize > 0 {
+				ss := operations.SizeStringField(int64(avg), u.humanReadable, 9) + " "
+				if avg > 0 {
 					extras += ss
 				} else {
 					extras += strings.Repeat(" ", len(ss))
 				}
 			}
 			if showEmptyDir {
-				if isDir && count == 0 && fileFlag == ' ' {
+				if attrs.IsDir && attrs.Count == 0 && fileFlag == ' ' {
 					fileFlag = 'e'
 				}
 			}
 			if u.showGraph {
-				bars := (size + perBar/2 - 1) / perBar
+				bars := (attrs.Size + perBar/2 - 1) / perBar
 				// clip if necessary - only happens during startup
 				if bars > 10 {
 					bars = 10
@@ -431,7 +425,7 @@ func (u *UI) Draw() error {
 				}
 				extras += "[" + graph[graphBars-bars:2*graphBars-bars] + "] "
 			}
-			Linef(0, y, w, fg, bg, ' ', "%c %s %s%c%s%s", fileFlag, operations.SizeStringField(size, u.humanReadable, 12), extras, mark, path.Base(entry.Remote()), message)
+			Linef(0, y, w, fg, bg, ' ', "%c %s %s%c%s%s", fileFlag, operations.SizeStringField(attrs.Size, u.humanReadable, 12), extras, mark, path.Base(entry.Remote()), message)
 			y++
 		}
 	}
@@ -582,14 +576,14 @@ type ncduSort struct {
 // Less is part of sort.Interface.
 func (ds *ncduSort) Less(i, j int) bool {
 	var iAvgSize, jAvgSize float64
-	isize, icount, _, _, _, _, _ := ds.d.AttrI(ds.sortPerm[i])
+	iattrs, _ := ds.d.AttrI(ds.sortPerm[i])
-	jsize, jcount, _, _, _, _, _ := ds.d.AttrI(ds.sortPerm[j])
+	jattrs, _ := ds.d.AttrI(ds.sortPerm[j])
 	iname, jname := ds.entries[ds.sortPerm[i]].Remote(), ds.entries[ds.sortPerm[j]].Remote()
-	if icount > 0 {
+	if iattrs.Count > 0 {
-		iAvgSize = float64(isize / icount)
+		iAvgSize = iattrs.AverageSize()
 	}
-	if jcount > 0 {
+	if jattrs.Count > 0 {
-		jAvgSize = float64(jsize / jcount)
+		jAvgSize = jattrs.AverageSize()
 	}
 
 	switch {
@@ -598,33 +592,33 @@ func (ds *ncduSort) Less(i, j int) bool {
 	case ds.u.sortByName > 0:
 		break
 	case ds.u.sortBySize < 0:
-		if isize != jsize {
+		if iattrs.Size != jattrs.Size {
-			return isize < jsize
+			return iattrs.Size < jattrs.Size
 		}
 	case ds.u.sortBySize > 0:
-		if isize != jsize {
+		if iattrs.Size != jattrs.Size {
-			return isize > jsize
+			return iattrs.Size > jattrs.Size
 		}
 	case ds.u.sortByCount < 0:
-		if icount != jcount {
+		if iattrs.Count != jattrs.Count {
-			return icount < jcount
+			return iattrs.Count < jattrs.Count
 		}
 	case ds.u.sortByCount > 0:
-		if icount != jcount {
+		if iattrs.Count != jattrs.Count {
-			return icount > jcount
+			return iattrs.Count > jattrs.Count
 		}
 	case ds.u.sortByAverageSize < 0:
 		if iAvgSize != jAvgSize {
 			return iAvgSize < jAvgSize
 		}
 		// if avgSize is equal, sort by size
-		return isize < jsize
+		return iattrs.Size < jattrs.Size
 	case ds.u.sortByAverageSize > 0:
 		if iAvgSize != jAvgSize {
 			return iAvgSize > jAvgSize
 		}
 		// if avgSize is equal, sort by size
-		return isize > jsize
+		return iattrs.Size > jattrs.Size
 	}
 	// if everything equal, sort by name
 	return iname < jname

cmd/ncdu/scan/scan.go

@@ -25,6 +25,33 @@ type Dir struct {
 	entriesHaveErrors bool
 }
 
+// Attrs contains accumulated properties for a directory entry
+//
+// Files with unknown size are counted separately but also included
+// in the total count. They are not included in the size, i.e. treated
+// as empty files, which means the size may be underestimated.
+type Attrs struct {
+	Size              int64
+	Count             int64
+	CountUnknownSize  int64
+	IsDir             bool
+	Readable          bool
+	EntriesHaveErrors bool
+}
+
+// AverageSize calculates average size of files in directory
+//
+// If there are files with unknown size, this returns the average over
+// files with known sizes, which means it may be under- or
+// overestimated.
+func (a *Attrs) AverageSize() float64 {
+	countKnownSize := a.Count - a.CountUnknownSize
+	if countKnownSize > 0 {
+		return float64(a.Size) / float64(countKnownSize)
+	}
+	return 0
+}
+
 // Parent returns the directory above this one
 func (d *Dir) Parent() *Dir {
 	// no locking needed since these are write once in newDir()
@@ -167,19 +194,19 @@ func (d *Dir) Attr() (size int64, count int64) {
 }
 
 // AttrI returns the size, count and flags for the i-th directory entry
-func (d *Dir) AttrI(i int) (size int64, count int64, countUnknownSize int64, isDir bool, readable bool, entriesHaveErrors bool, err error) {
+func (d *Dir) AttrI(i int) (attrs Attrs, err error) {
 	d.mu.Lock()
 	defer d.mu.Unlock()
 	subDir, isDir := d.getDir(i)
 
 	if !isDir {
-		return d.entries[i].Size(), 0, 0, false, true, d.entriesHaveErrors, d.readError
+		return Attrs{d.entries[i].Size(), 0, 0, false, true, d.entriesHaveErrors}, d.readError
 	}
 	if subDir == nil {
-		return 0, 0, 0, true, false, false, nil
+		return Attrs{0, 0, 0, true, false, false}, nil
 	}
-	size, count = subDir.Attr()
+	size, count := subDir.Attr()
-	return size, count, subDir.countUnknownSize, true, true, subDir.entriesHaveErrors, subDir.readError
+	return Attrs{size, count, subDir.countUnknownSize, true, true, subDir.entriesHaveErrors}, subDir.readError
 }
 
 // Scan the Fs passed in, returning a root directory channel and an