Add an int64 quantity implementation

Provides fast transformations of int64 scaled values with overflow to
inf.Dec as needed. Attempts to reduce allocations and expensive
operations in the critical path.

Alters the public signature of Quantity to encourage more efficient use
This commit is contained in:
Clayton Coleman
2016-05-17 00:35:40 -04:00
parent c63ac4e664
commit b2a01d4d94
11 changed files with 2364 additions and 952 deletions

View File

@@ -17,62 +17,268 @@ limitations under the License.
package resource
import (
"math/big"
"fmt"
"io"
inf "gopkg.in/inf.v0"
"github.com/gogo/protobuf/proto"
)
// QuantityProto is a struct that is equivalent to Quantity, but intended for
// protobuf marshalling/unmarshalling. It is generated into a serialization
// that matches Quantity. Do not use in Go structs.
//
// +protobuf=true
type QuantityProto struct {
// The format of the quantity
Format Format `protobuf:"bytes,1,opt,name=format,casttype=Format"`
// The scale dimension of the value
Scale int32 `protobuf:"varint,2,opt,name=scale"`
// Bigint is serialized as a raw bytes array
Bigint []byte `protobuf:"bytes,3,opt,name=bigint"`
var _ proto.Sizer = &Quantity{}
func (m *Quantity) Marshal() (data []byte, err error) {
size := m.Size()
data = make([]byte, size)
n, err := m.MarshalTo(data)
if err != nil {
return nil, err
}
return data[:n], nil
}
// ProtoTime returns the Time as a new ProtoTime value.
func (q *Quantity) QuantityProto() *QuantityProto {
if q == nil {
return &QuantityProto{}
}
p := &QuantityProto{
Format: q.Format,
}
if q.Amount != nil {
p.Scale = int32(q.Amount.Scale())
p.Bigint = q.Amount.UnscaledBig().Bytes()
}
return p
// MarshalTo is a customized version of the generated Protobuf unmarshaler for a struct
// with a single string field.
func (m *Quantity) MarshalTo(data []byte) (int, error) {
var i int
_ = i
var l int
_ = l
data[i] = 0xa
i++
// BEGIN CUSTOM MARSHAL
out := m.toBytes()
i = encodeVarintGenerated(data, i, uint64(len(out)))
i += copy(data[i:], out)
// END CUSTOM MARSHAL
return i, nil
}
// Size implements the protobuf marshalling interface.
func (q *Quantity) Size() (n int) { return q.QuantityProto().Size() }
// Reset implements the protobuf marshalling interface.
func (q *Quantity) Unmarshal(data []byte) error {
p := QuantityProto{}
if err := p.Unmarshal(data); err != nil {
return err
func encodeVarintGenerated(data []byte, offset int, v uint64) int {
for v >= 1<<7 {
data[offset] = uint8(v&0x7f | 0x80)
v >>= 7
offset++
}
data[offset] = uint8(v)
return offset + 1
}
func (m *Quantity) Size() (n int) {
var l int
_ = l
// BEGIN CUSTOM SIZE
l = len(m.toBytes())
// END CUSTOM SIZE
n += 1 + l + sovGenerated(uint64(l))
return n
}
func sovGenerated(x uint64) (n int) {
for {
n++
x >>= 7
if x == 0 {
break
}
}
return n
}
// Unmarshal is a customized version of the generated Protobuf unmarshaler for a struct
// with a single string field.
func (m *Quantity) Unmarshal(data []byte) error {
l := len(data)
iNdEx := 0
for iNdEx < l {
preIndex := iNdEx
var wire uint64
for shift := uint(0); ; shift += 7 {
if shift >= 64 {
return ErrIntOverflowGenerated
}
if iNdEx >= l {
return io.ErrUnexpectedEOF
}
b := data[iNdEx]
iNdEx++
wire |= (uint64(b) & 0x7F) << shift
if b < 0x80 {
break
}
}
fieldNum := int32(wire >> 3)
wireType := int(wire & 0x7)
if wireType == 4 {
return fmt.Errorf("proto: Quantity: wiretype end group for non-group")
}
if fieldNum <= 0 {
return fmt.Errorf("proto: Quantity: illegal tag %d (wire type %d)", fieldNum, wire)
}
switch fieldNum {
case 1:
if wireType != 2 {
return fmt.Errorf("proto: wrong wireType = %d for field String_", wireType)
}
var stringLen uint64
for shift := uint(0); ; shift += 7 {
if shift >= 64 {
return ErrIntOverflowGenerated
}
if iNdEx >= l {
return io.ErrUnexpectedEOF
}
b := data[iNdEx]
iNdEx++
stringLen |= (uint64(b) & 0x7F) << shift
if b < 0x80 {
break
}
}
intStringLen := int(stringLen)
if intStringLen < 0 {
return ErrInvalidLengthGenerated
}
postIndex := iNdEx + intStringLen
if postIndex > l {
return io.ErrUnexpectedEOF
}
s := string(data[iNdEx:postIndex])
// BEGIN CUSTOM DECODE
p, err := ParseQuantity(s)
if err != nil {
return err
}
*m = p
// END CUSTOM DECODE
iNdEx = postIndex
default:
iNdEx = preIndex
skippy, err := skipGenerated(data[iNdEx:])
if err != nil {
return err
}
if skippy < 0 {
return ErrInvalidLengthGenerated
}
if (iNdEx + skippy) > l {
return io.ErrUnexpectedEOF
}
iNdEx += skippy
}
}
if iNdEx > l {
return io.ErrUnexpectedEOF
}
q.Format = p.Format
b := big.NewInt(0)
b.SetBytes(p.Bigint)
q.Amount = inf.NewDecBig(b, inf.Scale(p.Scale))
return nil
}
// Marshal implements the protobuf marshalling interface.
func (q *Quantity) Marshal() (data []byte, err error) {
return q.QuantityProto().Marshal()
func skipGenerated(data []byte) (n int, err error) {
l := len(data)
iNdEx := 0
for iNdEx < l {
var wire uint64
for shift := uint(0); ; shift += 7 {
if shift >= 64 {
return 0, ErrIntOverflowGenerated
}
if iNdEx >= l {
return 0, io.ErrUnexpectedEOF
}
b := data[iNdEx]
iNdEx++
wire |= (uint64(b) & 0x7F) << shift
if b < 0x80 {
break
}
}
wireType := int(wire & 0x7)
switch wireType {
case 0:
for shift := uint(0); ; shift += 7 {
if shift >= 64 {
return 0, ErrIntOverflowGenerated
}
if iNdEx >= l {
return 0, io.ErrUnexpectedEOF
}
iNdEx++
if data[iNdEx-1] < 0x80 {
break
}
}
return iNdEx, nil
case 1:
iNdEx += 8
return iNdEx, nil
case 2:
var length int
for shift := uint(0); ; shift += 7 {
if shift >= 64 {
return 0, ErrIntOverflowGenerated
}
if iNdEx >= l {
return 0, io.ErrUnexpectedEOF
}
b := data[iNdEx]
iNdEx++
length |= (int(b) & 0x7F) << shift
if b < 0x80 {
break
}
}
iNdEx += length
if length < 0 {
return 0, ErrInvalidLengthGenerated
}
return iNdEx, nil
case 3:
for {
var innerWire uint64
var start int = iNdEx
for shift := uint(0); ; shift += 7 {
if shift >= 64 {
return 0, ErrIntOverflowGenerated
}
if iNdEx >= l {
return 0, io.ErrUnexpectedEOF
}
b := data[iNdEx]
iNdEx++
innerWire |= (uint64(b) & 0x7F) << shift
if b < 0x80 {
break
}
}
innerWireType := int(innerWire & 0x7)
if innerWireType == 4 {
break
}
next, err := skipGenerated(data[start:])
if err != nil {
return 0, err
}
iNdEx = start + next
}
return iNdEx, nil
case 4:
return iNdEx, nil
case 5:
iNdEx += 4
return iNdEx, nil
default:
return 0, fmt.Errorf("proto: illegal wireType %d", wireType)
}
}
panic("unreachable")
}
// MarshalTo implements the protobuf marshalling interface.
func (q *Quantity) MarshalTo(data []byte) (int, error) {
return q.QuantityProto().MarshalTo(data)
}
var (
ErrInvalidLengthGenerated = fmt.Errorf("proto: negative length found during unmarshaling")
ErrIntOverflowGenerated = fmt.Errorf("proto: integer overflow")
)