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-rw-r--r--vendor/github.com/DmitriyVTitov/size/size.go142
1 files changed, 142 insertions, 0 deletions
diff --git a/vendor/github.com/DmitriyVTitov/size/size.go b/vendor/github.com/DmitriyVTitov/size/size.go
new file mode 100644
index 000000000..b52e2c41d
--- /dev/null
+++ b/vendor/github.com/DmitriyVTitov/size/size.go
@@ -0,0 +1,142 @@
+// Package size implements run-time calculation of size of the variable.
+// Source code is based on "binary.Size()" function from Go standard library.
+// size.Of() omits size of slices, arrays and maps containers itself (24, 24 and 8 bytes).
+// When counting maps separate calculations are done for keys and values.
+package size
+
+import (
+ "reflect"
+ "unsafe"
+)
+
+// Of returns the size of 'v' in bytes.
+// If there is an error during calculation, Of returns -1.
+func Of(v interface{}) int {
+ // Cache with every visited pointer so we don't count two pointers
+ // to the same memory twice.
+ cache := make(map[uintptr]bool)
+ return sizeOf(reflect.Indirect(reflect.ValueOf(v)), cache)
+}
+
+// sizeOf returns the number of bytes the actual data represented by v occupies in memory.
+// If there is an error, sizeOf returns -1.
+func sizeOf(v reflect.Value, cache map[uintptr]bool) int {
+ switch v.Kind() {
+
+ case reflect.Array:
+ sum := 0
+ for i := 0; i < v.Len(); i++ {
+ s := sizeOf(v.Index(i), cache)
+ if s < 0 {
+ return -1
+ }
+ sum += s
+ }
+
+ return sum + (v.Cap()-v.Len())*int(v.Type().Elem().Size())
+
+ case reflect.Slice:
+ // return 0 if this node has been visited already
+ if cache[v.Pointer()] {
+ return 0
+ }
+ cache[v.Pointer()] = true
+
+ sum := 0
+ for i := 0; i < v.Len(); i++ {
+ s := sizeOf(v.Index(i), cache)
+ if s < 0 {
+ return -1
+ }
+ sum += s
+ }
+
+ sum += (v.Cap() - v.Len()) * int(v.Type().Elem().Size())
+
+ return sum + int(v.Type().Size())
+
+ case reflect.Struct:
+ sum := 0
+ for i, n := 0, v.NumField(); i < n; i++ {
+ s := sizeOf(v.Field(i), cache)
+ if s < 0 {
+ return -1
+ }
+ sum += s
+ }
+
+ // Look for struct padding.
+ padding := int(v.Type().Size())
+ for i, n := 0, v.NumField(); i < n; i++ {
+ padding -= int(v.Field(i).Type().Size())
+ }
+
+ return sum + padding
+
+ case reflect.String:
+ s := v.String()
+ hdr := (*reflect.StringHeader)(unsafe.Pointer(&s))
+ if cache[hdr.Data] {
+ return int(v.Type().Size())
+ }
+ cache[hdr.Data] = true
+ return len(s) + int(v.Type().Size())
+
+ case reflect.Ptr:
+ // return Ptr size if this node has been visited already (infinite recursion)
+ if cache[v.Pointer()] {
+ return int(v.Type().Size())
+ }
+ cache[v.Pointer()] = true
+ if v.IsNil() {
+ return int(reflect.New(v.Type()).Type().Size())
+ }
+ s := sizeOf(reflect.Indirect(v), cache)
+ if s < 0 {
+ return -1
+ }
+ return s + int(v.Type().Size())
+
+ case reflect.Bool,
+ reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64,
+ reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
+ reflect.Int, reflect.Uint,
+ reflect.Chan,
+ reflect.Uintptr,
+ reflect.Float32, reflect.Float64, reflect.Complex64, reflect.Complex128,
+ reflect.Func:
+ return int(v.Type().Size())
+
+ case reflect.Map:
+ // return 0 if this node has been visited already (infinite recursion)
+ if cache[v.Pointer()] {
+ return 0
+ }
+ cache[v.Pointer()] = true
+ sum := 0
+ keys := v.MapKeys()
+ for i := range keys {
+ val := v.MapIndex(keys[i])
+ // calculate size of key and value separately
+ sv := sizeOf(val, cache)
+ if sv < 0 {
+ return -1
+ }
+ sum += sv
+ sk := sizeOf(keys[i], cache)
+ if sk < 0 {
+ return -1
+ }
+ sum += sk
+ }
+ // Include overhead due to unused map buckets. 10.79 comes
+ // from https://golang.org/src/runtime/map.go.
+ return sum + int(v.Type().Size()) + int(float64(len(keys))*10.79)
+
+ case reflect.Interface:
+ return sizeOf(v.Elem(), cache) + int(v.Type().Size())
+
+ }
+
+ return -1
+}