diff --git a/.gitignore b/.gitignore index ff36b98..783412a 100644 --- a/.gitignore +++ b/.gitignore @@ -4,6 +4,7 @@ # IntelliJ .idea/ *.iml +*.sum # VS code *.code-workspace diff --git a/decimal_gen.go b/decimal_gen.go new file mode 100644 index 0000000..4378102 --- /dev/null +++ b/decimal_gen.go @@ -0,0 +1,90 @@ +package decimal + +import ( + "errors" +) + +var ( + errShortBytes = errors.New("msgp: too few bytes left to read object") +) + + +// MarshalMsg implements msgp.Marshaler +func (d Decimal) MarshalMsg(b []byte) (o []byte, err error) { + o = require(b, d.Msgsize()) + str := d.String() + sz := len(str) + if sz > 30 { + sz = 30 + if str[29] == '.' { + sz = 29 + } + + str = str[:sz] + } + + o, n := ensure(b, 1+sz) + o[n] = byte(0xa0 | sz) + n++ + + return o[:n+copy(o[n:], str)], nil +} + +// UnmarshalMsg implements msgp.Unmarshaler +func (d *Decimal) UnmarshalMsg(b []byte) (o []byte, err error) { + l := len(b) + if l < 1 { + return nil, errShortBytes + } + + sz := int(b[0] & 0x1f) + if len(b[1:]) < sz { + err = errShortBytes + return + } + if *d, err = NewFromString(string(b[1 : sz+1])); err == nil { + o = b[sz:] + } + return +} + +// Msgsize returns an upper bound estimate of the number of bytes occupied by the serialized message +func (d Decimal) Msgsize() int { + return 31 +} + +// Require ensures that cap(old)-len(old) >= extra. +func require(old []byte, extra int) []byte { + l := len(old) + c := cap(old) + r := l + extra + if c >= r { + return old + } else if l == 0 { + return make([]byte, 0, extra) + } + // the new size is the greater + // of double the old capacity + // and the sum of the old length + // and the number of new bytes + // necessary. + c <<= 1 + if c < r { + c = r + } + n := make([]byte, l, c) + copy(n, old) + return n +} + +// ensure 'sz' extra bytes in 'b' btw len(b) and cap(b) +func ensure(b []byte, sz int) ([]byte, int) { + l := len(b) + c := cap(b) + if c-l < sz { + o := make([]byte, (2*c)+sz) // exponential growth + n := copy(o, b) + return o[:n+sz], n + } + return b[:l+sz], l +} diff --git a/decimal_test.go b/decimal_test.go index 0905ce8..561fc3b 100644 --- a/decimal_test.go +++ b/decimal_test.go @@ -2,6 +2,7 @@ package decimal import ( "database/sql/driver" + "encoding/base64" "encoding/json" "encoding/xml" "fmt" @@ -3673,3 +3674,18 @@ func ExampleNewFromFloat() { //0.123123123123123 //-10000000000000 } + +func TestMsgPack(t *testing.T) { + d, _ := NewFromString("79228162514264337593543950334.123222") + out, err := d.MarshalMsg(nil) + if err != nil { + t.Fatal(err) + } + t.Log(base64.StdEncoding.EncodeToString(out)) + + var d2 = Decimal{} + if _, err = d2.UnmarshalMsg(out); err != nil { + t.Fatal(err) + } + t.Log(d2.String()) +} diff --git a/go.mod b/go.mod index 024d502..229d671 100644 --- a/go.mod +++ b/go.mod @@ -1,3 +1,3 @@ -module github.com/shopspring/decimal +module github.com/piyongcai/decimal go 1.7