1 files changed, 243 insertions, 0 deletions
diff --git a/vendor/github.com/fjl/memsize/memsize.go b/vendor/github.com/fjl/memsize/memsize.go
new file mode 100644
index 000000000..2664e87c4
--- /dev/null
+++ b/vendor/github.com/fjl/memsize/memsize.go
@@ -0,0 +1,243 @@
+package memsize
+
+import (
+	"bytes"
+	"fmt"
+	"reflect"
+	"sort"
+	"strings"
+	"text/tabwriter"
+	"unsafe"
+)
+
+// Scan traverses all objects reachable from v and counts how much memory
+// is used per type. The value must be a non-nil pointer to any value.
+func Scan(v interface{}) Sizes {
+	rv := reflect.ValueOf(v)
+	if rv.Kind() != reflect.Ptr || rv.IsNil() {
+		panic("value to scan must be non-nil pointer")
+	}
+
+	stopTheWorld("memsize scan")
+	defer startTheWorld()
+
+	ctx := newContext()
+	ctx.scan(invalidAddr, rv, false)
+	ctx.s.BitmapSize = ctx.seen.size()
+	ctx.s.BitmapUtilization = ctx.seen.utilization()
+	return *ctx.s
+}
+
+// Sizes is the result of a scan.
+type Sizes struct {
+	Total  uintptr
+	ByType map[reflect.Type]*TypeSize
+	// Internal stats (for debugging)
+	BitmapSize        uintptr
+	BitmapUtilization float32
+}
+
+type TypeSize struct {
+	Total uintptr
+	Count uintptr
+}
+
+func newSizes() *Sizes {
+	return &Sizes{ByType: make(map[reflect.Type]*TypeSize)}
+}
+
+// Report returns a human-readable report.
+func (s Sizes) Report() string {
+	type typLine struct {
+		name  string
+		count uintptr
+		total uintptr
+	}
+	tab := []typLine{{"ALL", 0, s.Total}}
+	for _, typ := range s.ByType {
+		tab[0].count += typ.Count
+	}
+	maxname := 0
+	for typ, s := range s.ByType {
+		line := typLine{typ.String(), s.Count, s.Total}
+		tab = append(tab, line)
+		if len(line.name) > maxname {
+			maxname = len(line.name)
+		}
+	}
+	sort.Slice(tab, func(i, j int) bool { return tab[i].total > tab[j].total })
+
+	buf := new(bytes.Buffer)
+	w := tabwriter.NewWriter(buf, 0, 0, 0, ' ', tabwriter.AlignRight)
+	for _, line := range tab {
+		namespace := strings.Repeat(" ", maxname-len(line.name))
+		fmt.Fprintf(w, "%s%s\t  %v\t  %s\t\n", line.name, namespace, line.count, HumanSize(line.total))
+	}
+	w.Flush()
+	return buf.String()
+}
+
+// addValue is called during scan and adds the memory of given object.
+func (s *Sizes) addValue(v reflect.Value, size uintptr) {
+	s.Total += size
+	rs := s.ByType[v.Type()]
+	if rs == nil {
+		rs = new(TypeSize)
+		s.ByType[v.Type()] = rs
+	}
+	rs.Total += size
+	rs.Count++
+}
+
+type context struct {
+	// We track previously scanned objects to prevent infinite loops
+	// when scanning cycles and to prevent counting objects more than once.
+	seen *bitmap
+	tc   typCache
+	s    *Sizes
+}
+
+func newContext() *context {
+	return &context{seen: newBitmap(), tc: make(typCache), s: newSizes()}
+}
+
+// scan walks all objects below v, determining their size. All scan* functions return the
+// amount of 'extra' memory (e.g. slice data) that is referenced by the object.
+func (c *context) scan(addr address, v reflect.Value, add bool) (extraSize uintptr) {
+	size := v.Type().Size()
+	var marked uintptr
+	if addr.valid() {
+		marked = c.seen.countRange(uintptr(addr), size)
+		if marked == size {
+			return 0 // Skip if we have already seen the whole object.
+		}
+		c.seen.markRange(uintptr(addr), size)
+	}
+	// fmt.Printf("%v: %v ⮑ (marked %d)\n", addr, v.Type(), marked)
+	if c.tc.needScan(v.Type()) {
+		extraSize = c.scanContent(addr, v)
+	}
+	// fmt.Printf("%v: %v %d (add %v, size %d, marked %d, extra %d)\n", addr, v.Type(), size+extraSize, add, v.Type().Size(), marked, extraSize)
+	if add {
+		size -= marked
+		size += extraSize
+		c.s.addValue(v, size)
+	}
+	return extraSize
+}
+
+func (c *context) scanContent(addr address, v reflect.Value) uintptr {
+	switch v.Kind() {
+	case reflect.Array:
+		return c.scanArray(addr, v)
+	case reflect.Chan:
+		return c.scanChan(v)
+	case reflect.Func:
+		// can't do anything here
+		return 0
+	case reflect.Interface:
+		return c.scanInterface(v)
+	case reflect.Map:
+		return c.scanMap(v)
+	case reflect.Ptr:
+		if !v.IsNil() {
+			c.scan(address(v.Pointer()), v.Elem(), true)
+		}
+		return 0
+	case reflect.Slice:
+		return c.scanSlice(v)
+	case reflect.String:
+		return uintptr(v.Len())
+	case reflect.Struct:
+		return c.scanStruct(addr, v)
+	default:
+		unhandledKind(v.Kind())
+		return 0
+	}
+}
+
+func (c *context) scanChan(v reflect.Value) uintptr {
+	etyp := v.Type().Elem()
+	extra := uintptr(0)
+	if c.tc.needScan(etyp) {
+		// Scan the channel buffer. This is unsafe but doesn't race because
+		// the world is stopped during scan.
+		hchan := unsafe.Pointer(v.Pointer())
+		for i := uint(0); i < uint(v.Cap()); i++ {
+			addr := chanbuf(hchan, i)
+			elem := reflect.NewAt(etyp, addr).Elem()
+			extra += c.scanContent(address(addr), elem)
+		}
+	}
+	return uintptr(v.Cap())*etyp.Size() + extra
+}
+
+func (c *context) scanStruct(base address, v reflect.Value) uintptr {
+	extra := uintptr(0)
+	for i := 0; i < v.NumField(); i++ {
+		f := v.Type().Field(i)
+		if c.tc.needScan(f.Type) {
+			addr := base.addOffset(f.Offset)
+			extra += c.scanContent(addr, v.Field(i))
+		}
+	}
+	return extra
+}
+
+func (c *context) scanArray(addr address, v reflect.Value) uintptr {
+	esize := v.Type().Elem().Size()
+	extra := uintptr(0)
+	for i := 0; i < v.Len(); i++ {
+		extra += c.scanContent(addr, v.Index(i))
+		addr = addr.addOffset(esize)
+	}
+	return extra
+}
+
+func (c *context) scanSlice(v reflect.Value) uintptr {
+	slice := v.Slice(0, v.Cap())
+	esize := slice.Type().Elem().Size()
+	base := slice.Pointer()
+	// Add size of the unscanned portion of the backing array to extra.
+	blen := uintptr(slice.Len()) * esize
+	marked := c.seen.countRange(base, blen)
+	extra := blen - marked
+	c.seen.markRange(uintptr(base), blen)
+	if c.tc.needScan(slice.Type().Elem()) {
+		// Elements may contain pointers, scan them individually.
+		addr := address(base)
+		for i := 0; i < slice.Len(); i++ {
+			extra += c.scanContent(addr, slice.Index(i))
+			addr = addr.addOffset(esize)
+		}
+	}
+	return extra
+}
+
+func (c *context) scanMap(v reflect.Value) uintptr {
+	var (
+		typ   = v.Type()
+		len   = uintptr(v.Len())
+		extra = uintptr(0)
+	)
+	if c.tc.needScan(typ.Key()) || c.tc.needScan(typ.Elem()) {
+		for _, k := range v.MapKeys() {
+			extra += c.scan(invalidAddr, k, false)
+			extra += c.scan(invalidAddr, v.MapIndex(k), false)
+		}
+	}
+	return len*typ.Key().Size() + len*typ.Elem().Size() + extra
+}
+
+func (c *context) scanInterface(v reflect.Value) uintptr {
+	elem := v.Elem()
+	if !elem.IsValid() {
+		return 0 // nil interface
+	}
+	c.scan(invalidAddr, elem, false)
+	if !c.tc.isPointer(elem.Type()) {
+		// Account for non-pointer size of the value.
+		return elem.Type().Size()
+	}
+	return 0
+}