79 lines
1.5 KiB
Go
79 lines
1.5 KiB
Go
package ormfield
|
|
|
|
import (
|
|
"encoding/binary"
|
|
"io"
|
|
|
|
"google.golang.org/protobuf/reflect/protoreflect"
|
|
)
|
|
|
|
// Int64Codec encodes 64-bit integers as big-endian unsigned 64-bit integers
|
|
// by adding the maximum value of int32 (9223372036854775807) + 1 before encoding so
|
|
// that these values can be used for ordered iteration.
|
|
type Int64Codec struct{}
|
|
|
|
var int64Codec = Int64Codec{}
|
|
|
|
const int64Max = 9223372036854775807
|
|
|
|
func (i Int64Codec) Decode(r Reader) (protoreflect.Value, error) {
|
|
var x uint64
|
|
err := binary.Read(r, binary.BigEndian, &x)
|
|
if x >= int64Max {
|
|
x = x - int64Max - 1
|
|
return protoreflect.ValueOfInt64(int64(x)), err
|
|
}
|
|
|
|
y := int64(x) - int64Max - 1
|
|
return protoreflect.ValueOfInt64(y), err
|
|
}
|
|
|
|
func (i Int64Codec) Encode(value protoreflect.Value, w io.Writer) error {
|
|
var x int64
|
|
if value.IsValid() {
|
|
x = value.Int()
|
|
}
|
|
if x >= -1 {
|
|
y := uint64(x) + int64Max + 1
|
|
return binary.Write(w, binary.BigEndian, y)
|
|
}
|
|
|
|
x += int64Max
|
|
x++
|
|
return binary.Write(w, binary.BigEndian, uint64(x))
|
|
}
|
|
|
|
func (i Int64Codec) Compare(v1, v2 protoreflect.Value) int {
|
|
return compareInt(v1, v2)
|
|
}
|
|
|
|
func (i Int64Codec) IsOrdered() bool {
|
|
return true
|
|
}
|
|
|
|
func (i Int64Codec) FixedBufferSize() int {
|
|
return 8
|
|
}
|
|
|
|
func (i Int64Codec) ComputeBufferSize(protoreflect.Value) (int, error) {
|
|
return i.FixedBufferSize(), nil
|
|
}
|
|
|
|
func compareInt(v1, v2 protoreflect.Value) int {
|
|
var x, y int64
|
|
if v1.IsValid() {
|
|
x = v1.Int()
|
|
}
|
|
if v2.IsValid() {
|
|
y = v2.Int()
|
|
}
|
|
switch {
|
|
case x == y:
|
|
return 0
|
|
case x < y:
|
|
return -1
|
|
default:
|
|
return 1
|
|
}
|
|
}
|