Add pgtype.Numeric
This commit is contained in:
Jack Christensen
@@ -0,0 +1,602 @@
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package pgtype
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import (
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"bytes"
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"database/sql/driver"
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"encoding/binary"
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"fmt"
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"io"
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"math"
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"math/big"
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"strconv"
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"strings"
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"github.com/jackc/pgx/pgio"
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)
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// PostgreSQL internal numeric storage uses 16-bit "digits" with base of 10,000
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const nbase = 10000
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var big0 *big.Int = big.NewInt(0)
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var big10 *big.Int = big.NewInt(10)
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var big100 *big.Int = big.NewInt(100)
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var big1000 *big.Int = big.NewInt(1000)
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var bigMaxInt8 *big.Int = big.NewInt(math.MaxInt8)
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var bigMinInt8 *big.Int = big.NewInt(math.MinInt8)
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var bigMaxInt16 *big.Int = big.NewInt(math.MaxInt16)
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var bigMinInt16 *big.Int = big.NewInt(math.MinInt16)
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var bigMaxInt32 *big.Int = big.NewInt(math.MaxInt32)
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var bigMinInt32 *big.Int = big.NewInt(math.MinInt32)
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var bigMaxInt64 *big.Int = big.NewInt(math.MaxInt64)
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var bigMinInt64 *big.Int = big.NewInt(math.MinInt64)
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var bigMaxInt *big.Int = big.NewInt(int64(maxInt))
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var bigMinInt *big.Int = big.NewInt(int64(minInt))
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var bigMaxUint8 *big.Int = big.NewInt(math.MaxUint8)
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var bigMaxUint16 *big.Int = big.NewInt(math.MaxUint16)
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var bigMaxUint32 *big.Int = big.NewInt(math.MaxUint32)
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var bigMaxUint64 *big.Int = (&big.Int{}).SetUint64(uint64(math.MaxUint64))
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var bigMaxUint *big.Int = (&big.Int{}).SetUint64(uint64(maxUint))
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var bigNBase *big.Int = big.NewInt(nbase)
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var bigNBaseX2 *big.Int = big.NewInt(nbase * nbase)
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var bigNBaseX3 *big.Int = big.NewInt(nbase * nbase * nbase)
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var bigNBaseX4 *big.Int = big.NewInt(nbase * nbase * nbase * nbase)
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type Numeric struct {
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Int *big.Int
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Exp int32
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Status Status
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}
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func (dst *Numeric) Set(src interface{}) error {
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if src == nil {
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*dst = Numeric{Status: Null}
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return nil
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}
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switch value := src.(type) {
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case float32:
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num, exp, err := parseNumericString(strconv.FormatFloat(float64(value), 'f', -1, 64))
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if err != nil {
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return err
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}
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*dst = Numeric{Int: num, Exp: exp, Status: Present}
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case float64:
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num, exp, err := parseNumericString(strconv.FormatFloat(value, 'f', -1, 64))
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if err != nil {
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return err
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}
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*dst = Numeric{Int: num, Exp: exp, Status: Present}
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case int8:
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*dst = Numeric{Int: big.NewInt(int64(value)), Status: Present}
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case uint8:
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*dst = Numeric{Int: big.NewInt(int64(value)), Status: Present}
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case int16:
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*dst = Numeric{Int: big.NewInt(int64(value)), Status: Present}
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case uint16:
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*dst = Numeric{Int: big.NewInt(int64(value)), Status: Present}
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case int32:
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*dst = Numeric{Int: big.NewInt(int64(value)), Status: Present}
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case uint32:
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*dst = Numeric{Int: big.NewInt(int64(value)), Status: Present}
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case int64:
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*dst = Numeric{Int: big.NewInt(value), Status: Present}
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case uint64:
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*dst = Numeric{Int: (&big.Int{}).SetUint64(value), Status: Present}
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case int:
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*dst = Numeric{Int: big.NewInt(int64(value)), Status: Present}
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case uint:
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*dst = Numeric{Int: (&big.Int{}).SetUint64(uint64(value)), Status: Present}
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case string:
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num, exp, err := parseNumericString(value)
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if err != nil {
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return err
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}
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*dst = Numeric{Int: num, Exp: exp, Status: Present}
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default:
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if originalSrc, ok := underlyingNumberType(src); ok {
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return dst.Set(originalSrc)
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}
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return fmt.Errorf("cannot convert %v to Numeric", value)
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}
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return nil
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}
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func (dst *Numeric) Get() interface{} {
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switch dst.Status {
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case Present:
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return dst
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case Null:
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return nil
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default:
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return dst.Status
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}
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}
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func (src *Numeric) AssignTo(dst interface{}) error {
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switch src.Status {
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case Present:
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switch v := dst.(type) {
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case *float32:
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f, err := strconv.ParseFloat(src.Int.String(), 64)
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if err != nil {
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return err
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}
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return float64AssignTo(f, src.Status, dst)
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case *float64:
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f, err := strconv.ParseFloat(src.Int.String(), 64)
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if err != nil {
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return err
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}
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return float64AssignTo(f, src.Status, dst)
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case *int:
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normalizedInt, err := src.toBigInt()
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if err != nil {
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return err
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}
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if normalizedInt.Cmp(bigMaxInt) > 0 {
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return fmt.Errorf("%v is greater than maximum value for %T", normalizedInt, *v)
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}
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if normalizedInt.Cmp(bigMinInt) < 0 {
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return fmt.Errorf("%v is less than minimum value for %T", normalizedInt, *v)
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}
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*v = int(normalizedInt.Int64())
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case *int8:
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normalizedInt, err := src.toBigInt()
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if err != nil {
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return err
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}
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if normalizedInt.Cmp(bigMaxInt8) > 0 {
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return fmt.Errorf("%v is greater than maximum value for %T", normalizedInt, *v)
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}
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if normalizedInt.Cmp(bigMinInt8) < 0 {
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return fmt.Errorf("%v is less than minimum value for %T", normalizedInt, *v)
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}
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*v = int8(normalizedInt.Int64())
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case *int16:
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normalizedInt, err := src.toBigInt()
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if err != nil {
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return err
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}
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if normalizedInt.Cmp(bigMaxInt16) > 0 {
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return fmt.Errorf("%v is greater than maximum value for %T", normalizedInt, *v)
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}
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if normalizedInt.Cmp(bigMinInt16) < 0 {
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return fmt.Errorf("%v is less than minimum value for %T", normalizedInt, *v)
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}
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*v = int16(normalizedInt.Int64())
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case *int32:
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normalizedInt, err := src.toBigInt()
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if err != nil {
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return err
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}
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if normalizedInt.Cmp(bigMaxInt32) > 0 {
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return fmt.Errorf("%v is greater than maximum value for %T", normalizedInt, *v)
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}
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if normalizedInt.Cmp(bigMinInt32) < 0 {
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return fmt.Errorf("%v is less than minimum value for %T", normalizedInt, *v)
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}
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*v = int32(normalizedInt.Int64())
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case *int64:
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normalizedInt, err := src.toBigInt()
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if err != nil {
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return err
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}
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if normalizedInt.Cmp(bigMaxInt64) > 0 {
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return fmt.Errorf("%v is greater than maximum value for %T", normalizedInt, *v)
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}
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if normalizedInt.Cmp(bigMinInt64) < 0 {
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return fmt.Errorf("%v is less than minimum value for %T", normalizedInt, *v)
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}
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*v = normalizedInt.Int64()
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case *uint:
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normalizedInt, err := src.toBigInt()
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if err != nil {
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return err
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}
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if normalizedInt.Cmp(big0) < 0 {
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return fmt.Errorf("%d is less than zero for %T", normalizedInt, *v)
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} else if normalizedInt.Cmp(bigMaxUint) > 0 {
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return fmt.Errorf("%d is greater than maximum value for %T", normalizedInt, *v)
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}
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*v = uint(normalizedInt.Uint64())
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case *uint8:
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normalizedInt, err := src.toBigInt()
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if err != nil {
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return err
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}
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if normalizedInt.Cmp(big0) < 0 {
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return fmt.Errorf("%d is less than zero for %T", normalizedInt, *v)
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} else if normalizedInt.Cmp(bigMaxUint8) > 0 {
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return fmt.Errorf("%d is greater than maximum value for %T", normalizedInt, *v)
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}
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*v = uint8(normalizedInt.Uint64())
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case *uint16:
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normalizedInt, err := src.toBigInt()
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if err != nil {
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return err
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}
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if normalizedInt.Cmp(big0) < 0 {
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return fmt.Errorf("%d is less than zero for %T", normalizedInt, *v)
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} else if normalizedInt.Cmp(bigMaxUint16) > 0 {
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return fmt.Errorf("%d is greater than maximum value for %T", normalizedInt, *v)
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}
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*v = uint16(normalizedInt.Uint64())
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case *uint32:
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normalizedInt, err := src.toBigInt()
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if err != nil {
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return err
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}
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if normalizedInt.Cmp(big0) < 0 {
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return fmt.Errorf("%d is less than zero for %T", normalizedInt, *v)
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} else if normalizedInt.Cmp(bigMaxUint32) > 0 {
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return fmt.Errorf("%d is greater than maximum value for %T", normalizedInt, *v)
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}
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*v = uint32(normalizedInt.Uint64())
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case *uint64:
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normalizedInt, err := src.toBigInt()
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if err != nil {
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return err
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}
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if normalizedInt.Cmp(big0) < 0 {
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return fmt.Errorf("%d is less than zero for %T", normalizedInt, *v)
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} else if normalizedInt.Cmp(bigMaxUint64) > 0 {
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return fmt.Errorf("%d is greater than maximum value for %T", normalizedInt, *v)
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}
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*v = normalizedInt.Uint64()
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default:
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if nextDst, retry := GetAssignToDstType(dst); retry {
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return src.AssignTo(nextDst)
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}
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}
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case Null:
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return nullAssignTo(dst)
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}
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return nil
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}
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func (dst *Numeric) toBigInt() (*big.Int, error) {
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if dst.Exp == 0 {
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return dst.Int, nil
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}
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num := &big.Int{}
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num.Set(dst.Int)
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if dst.Exp > 0 {
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mul := &big.Int{}
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mul.Exp(big10, big.NewInt(int64(dst.Exp)), nil)
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num.Mul(num, mul)
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return num, nil
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}
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div := &big.Int{}
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div.Exp(big10, big.NewInt(int64(-dst.Exp)), nil)
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remainder := &big.Int{}
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num.DivMod(num, div, remainder)
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if remainder.Cmp(big0) != 0 {
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return nil, fmt.Errorf("cannot convert %v to integer", dst)
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}
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return num, nil
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}
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func (dst *Numeric) DecodeText(ci *ConnInfo, src []byte) error {
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if src == nil {
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*dst = Numeric{Status: Null}
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return nil
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}
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num, exp, err := parseNumericString(string(src))
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if err != nil {
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return err
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}
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*dst = Numeric{Int: num, Exp: exp, Status: Present}
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return nil
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}
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func parseNumericString(str string) (n *big.Int, exp int32, err error) {
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parts := strings.SplitN(str, ".", 2)
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digits := strings.Join(parts, "")
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if len(parts) > 1 {
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exp = int32(-len(parts[1]))
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} else {
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for len(digits) > 1 && digits[len(digits)-1] == '0' {
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digits = digits[:len(digits)-1]
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exp++
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}
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}
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accum := &big.Int{}
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if _, ok := accum.SetString(digits, 10); !ok {
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return nil, 0, fmt.Errorf("%s is not a number", str)
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}
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return accum, exp, nil
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}
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func (dst *Numeric) DecodeBinary(ci *ConnInfo, src []byte) error {
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if src == nil {
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*dst = Numeric{Status: Null}
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return nil
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}
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if len(src) < 8 {
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return fmt.Errorf("numeric incomplete %v", src)
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}
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rp := 0
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ndigits := int16(binary.BigEndian.Uint16(src[rp:]))
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rp += 2
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if ndigits == 0 {
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*dst = Numeric{Int: big.NewInt(0), Status: Present}
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return nil
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}
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weight := int16(binary.BigEndian.Uint16(src[rp:]))
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rp += 2
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sign := int16(binary.BigEndian.Uint16(src[rp:]))
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rp += 2
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dscale := int16(binary.BigEndian.Uint16(src[rp:]))
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rp += 2
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if len(src[rp:]) < int(ndigits)*2 {
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return fmt.Errorf("numeric incomplete %v", src)
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}
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accum := &big.Int{}
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for i := 0; i < int(ndigits+3)/4; i++ {
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int64accum, bytesRead, digitsRead := nbaseDigitsToInt64(src[rp:])
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rp += bytesRead
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if i > 0 {
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var mul *big.Int
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switch digitsRead {
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case 1:
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mul = bigNBase
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case 2:
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mul = bigNBaseX2
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case 3:
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mul = bigNBaseX3
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case 4:
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mul = bigNBaseX4
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default:
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return fmt.Errorf("invalid digitsRead: %d (this can't happen)", digitsRead)
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}
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accum.Mul(accum, mul)
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}
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accum.Add(accum, big.NewInt(int64accum))
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}
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exp := (int32(weight) - int32(ndigits) + 1) * 4
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if dscale > 0 {
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fracNBaseDigits := ndigits - weight - 1
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fracDecimalDigits := fracNBaseDigits * 4
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if dscale > fracDecimalDigits {
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multCount := int(dscale - fracDecimalDigits)
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for i := 0; i < multCount; i++ {
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accum.Mul(accum, big10)
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exp--
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}
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} else if dscale < fracDecimalDigits {
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divCount := int(fracDecimalDigits - dscale)
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for i := 0; i < divCount; i++ {
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accum.Div(accum, big10)
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exp++
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}
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}
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}
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reduced := &big.Int{}
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remainder := &big.Int{}
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if exp >= 0 {
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for {
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reduced.DivMod(accum, big10, remainder)
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if remainder.Cmp(big0) != 0 {
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break
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}
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accum.Set(reduced)
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exp++
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}
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}
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if sign != 0 {
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accum.Neg(accum)
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}
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*dst = Numeric{Int: accum, Exp: exp, Status: Present}
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return nil
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}
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func nbaseDigitsToInt64(src []byte) (accum int64, bytesRead, digitsRead int) {
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digits := len(src) / 2
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if digits > 4 {
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digits = 4
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}
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rp := 0
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for i := 0; i < digits; i++ {
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if i > 0 {
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accum *= nbase
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}
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accum += int64(binary.BigEndian.Uint16(src[rp:]))
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rp += 2
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}
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return accum, rp, digits
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}
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func (src *Numeric) EncodeText(ci *ConnInfo, w io.Writer) (bool, error) {
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switch src.Status {
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case Null:
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return true, nil
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case Undefined:
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return false, errUndefined
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}
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if _, err := io.WriteString(w, src.Int.String()); err != nil {
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return false, err
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}
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if err := pgio.WriteByte(w, 'e'); err != nil {
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return false, err
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}
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if _, err := io.WriteString(w, strconv.FormatInt(int64(src.Exp), 10)); err != nil {
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return false, err
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}
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return false, nil
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}
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func (src *Numeric) EncodeBinary(ci *ConnInfo, w io.Writer) (bool, error) {
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switch src.Status {
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case Null:
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return true, nil
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case Undefined:
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return false, errUndefined
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}
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var sign int16
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if src.Int.Cmp(big0) < 0 {
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sign = 16384
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}
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absInt := &big.Int{}
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wholePart := &big.Int{}
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fracPart := &big.Int{}
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remainder := &big.Int{}
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absInt.Abs(src.Int)
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// Normalize absInt and exp to where exp is always a multiple of 4. This makes
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// converting to 16-bit base 10,000 digits easier.
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var exp int32
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switch src.Exp % 4 {
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case 1, -3:
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exp = src.Exp - 1
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absInt.Mul(absInt, big10)
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case 2, -2:
|
||||
exp = src.Exp - 2
|
||||
absInt.Mul(absInt, big100)
|
||||
case 3, -1:
|
||||
exp = src.Exp - 3
|
||||
absInt.Mul(absInt, big1000)
|
||||
default:
|
||||
exp = src.Exp
|
||||
}
|
||||
|
||||
if exp < 0 {
|
||||
divisor := &big.Int{}
|
||||
divisor.Exp(big10, big.NewInt(int64(-exp)), nil)
|
||||
wholePart.DivMod(absInt, divisor, fracPart)
|
||||
} else {
|
||||
wholePart = absInt
|
||||
}
|
||||
|
||||
var wholeDigits, fracDigits []int16
|
||||
|
||||
for wholePart.Cmp(big0) != 0 {
|
||||
wholePart.DivMod(wholePart, bigNBase, remainder)
|
||||
wholeDigits = append(wholeDigits, int16(remainder.Int64()))
|
||||
}
|
||||
|
||||
for fracPart.Cmp(big0) != 0 {
|
||||
fracPart.DivMod(fracPart, bigNBase, remainder)
|
||||
fracDigits = append(fracDigits, int16(remainder.Int64()))
|
||||
}
|
||||
|
||||
if _, err := pgio.WriteInt16(w, int16(len(wholeDigits)+len(fracDigits))); err != nil {
|
||||
return false, err
|
||||
}
|
||||
|
||||
var weight int16
|
||||
if len(wholeDigits) > 0 {
|
||||
weight = int16(len(wholeDigits) - 1)
|
||||
if exp > 0 {
|
||||
weight += int16(exp / 4)
|
||||
}
|
||||
} else {
|
||||
weight = int16(exp/4) - 1 + int16(len(fracDigits))
|
||||
}
|
||||
if _, err := pgio.WriteInt16(w, weight); err != nil {
|
||||
return false, err
|
||||
}
|
||||
|
||||
if _, err := pgio.WriteInt16(w, sign); err != nil {
|
||||
return false, err
|
||||
}
|
||||
|
||||
var dscale int16
|
||||
if src.Exp < 0 {
|
||||
dscale = int16(-src.Exp)
|
||||
}
|
||||
if _, err := pgio.WriteInt16(w, dscale); err != nil {
|
||||
return false, err
|
||||
}
|
||||
|
||||
for i := len(wholeDigits) - 1; i >= 0; i-- {
|
||||
if _, err := pgio.WriteInt16(w, wholeDigits[i]); err != nil {
|
||||
return false, err
|
||||
}
|
||||
}
|
||||
|
||||
for i := len(fracDigits) - 1; i >= 0; i-- {
|
||||
if _, err := pgio.WriteInt16(w, fracDigits[i]); err != nil {
|
||||
return false, err
|
||||
}
|
||||
}
|
||||
|
||||
return false, nil
|
||||
}
|
||||
|
||||
// Scan implements the database/sql Scanner interface.
|
||||
func (dst *Numeric) Scan(src interface{}) error {
|
||||
if src == nil {
|
||||
*dst = Numeric{Status: Null}
|
||||
return nil
|
||||
}
|
||||
|
||||
switch src := src.(type) {
|
||||
case float64:
|
||||
// TODO
|
||||
// *dst = Numeric{Float: src, Status: Present}
|
||||
return nil
|
||||
case string:
|
||||
return dst.DecodeText(nil, []byte(src))
|
||||
case []byte:
|
||||
return dst.DecodeText(nil, src)
|
||||
}
|
||||
|
||||
return fmt.Errorf("cannot scan %T", src)
|
||||
}
|
||||
|
||||
// Value implements the database/sql/driver Valuer interface.
|
||||
func (src *Numeric) Value() (driver.Value, error) {
|
||||
switch src.Status {
|
||||
case Present:
|
||||
buf := &bytes.Buffer{}
|
||||
_, err := src.EncodeText(nil, buf)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
return buf.String(), nil
|
||||
case Null:
|
||||
return nil, nil
|
||||
default:
|
||||
return nil, errUndefined
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user