/
numeric.go
600 lines (531 loc) · 14.4 KB
/
numeric.go
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package pgtype
import (
"database/sql/driver"
"encoding/binary"
"math"
"math/big"
"strconv"
"strings"
"github.com/jackc/pgx/pgio"
"github.com/pkg/errors"
)
// PostgreSQL internal numeric storage uses 16-bit "digits" with base of 10,000
const nbase = 10000
var big0 *big.Int = big.NewInt(0)
var big1 *big.Int = big.NewInt(1)
var big10 *big.Int = big.NewInt(10)
var big100 *big.Int = big.NewInt(100)
var big1000 *big.Int = big.NewInt(1000)
var bigMaxInt8 *big.Int = big.NewInt(math.MaxInt8)
var bigMinInt8 *big.Int = big.NewInt(math.MinInt8)
var bigMaxInt16 *big.Int = big.NewInt(math.MaxInt16)
var bigMinInt16 *big.Int = big.NewInt(math.MinInt16)
var bigMaxInt32 *big.Int = big.NewInt(math.MaxInt32)
var bigMinInt32 *big.Int = big.NewInt(math.MinInt32)
var bigMaxInt64 *big.Int = big.NewInt(math.MaxInt64)
var bigMinInt64 *big.Int = big.NewInt(math.MinInt64)
var bigMaxInt *big.Int = big.NewInt(int64(maxInt))
var bigMinInt *big.Int = big.NewInt(int64(minInt))
var bigMaxUint8 *big.Int = big.NewInt(math.MaxUint8)
var bigMaxUint16 *big.Int = big.NewInt(math.MaxUint16)
var bigMaxUint32 *big.Int = big.NewInt(math.MaxUint32)
var bigMaxUint64 *big.Int = (&big.Int{}).SetUint64(uint64(math.MaxUint64))
var bigMaxUint *big.Int = (&big.Int{}).SetUint64(uint64(maxUint))
var bigNBase *big.Int = big.NewInt(nbase)
var bigNBaseX2 *big.Int = big.NewInt(nbase * nbase)
var bigNBaseX3 *big.Int = big.NewInt(nbase * nbase * nbase)
var bigNBaseX4 *big.Int = big.NewInt(nbase * nbase * nbase * nbase)
type Numeric struct {
Int *big.Int
Exp int32
Status Status
}
func (dst *Numeric) Set(src interface{}) error {
if src == nil {
*dst = Numeric{Status: Null}
return nil
}
switch value := src.(type) {
case float32:
num, exp, err := parseNumericString(strconv.FormatFloat(float64(value), 'f', -1, 64))
if err != nil {
return err
}
*dst = Numeric{Int: num, Exp: exp, Status: Present}
case float64:
num, exp, err := parseNumericString(strconv.FormatFloat(value, 'f', -1, 64))
if err != nil {
return err
}
*dst = Numeric{Int: num, Exp: exp, Status: Present}
case int8:
*dst = Numeric{Int: big.NewInt(int64(value)), Status: Present}
case uint8:
*dst = Numeric{Int: big.NewInt(int64(value)), Status: Present}
case int16:
*dst = Numeric{Int: big.NewInt(int64(value)), Status: Present}
case uint16:
*dst = Numeric{Int: big.NewInt(int64(value)), Status: Present}
case int32:
*dst = Numeric{Int: big.NewInt(int64(value)), Status: Present}
case uint32:
*dst = Numeric{Int: big.NewInt(int64(value)), Status: Present}
case int64:
*dst = Numeric{Int: big.NewInt(value), Status: Present}
case uint64:
*dst = Numeric{Int: (&big.Int{}).SetUint64(value), Status: Present}
case int:
*dst = Numeric{Int: big.NewInt(int64(value)), Status: Present}
case uint:
*dst = Numeric{Int: (&big.Int{}).SetUint64(uint64(value)), Status: Present}
case string:
num, exp, err := parseNumericString(value)
if err != nil {
return err
}
*dst = Numeric{Int: num, Exp: exp, Status: Present}
default:
if originalSrc, ok := underlyingNumberType(src); ok {
return dst.Set(originalSrc)
}
return errors.Errorf("cannot convert %v to Numeric", value)
}
return nil
}
func (dst *Numeric) Get() interface{} {
switch dst.Status {
case Present:
return dst
case Null:
return nil
default:
return dst.Status
}
}
func (src *Numeric) AssignTo(dst interface{}) error {
switch src.Status {
case Present:
switch v := dst.(type) {
case *float32:
f, err := src.toFloat64()
if err != nil {
return err
}
return float64AssignTo(f, src.Status, dst)
case *float64:
f, err := src.toFloat64()
if err != nil {
return err
}
return float64AssignTo(f, src.Status, dst)
case *int:
normalizedInt, err := src.toBigInt()
if err != nil {
return err
}
if normalizedInt.Cmp(bigMaxInt) > 0 {
return errors.Errorf("%v is greater than maximum value for %T", normalizedInt, *v)
}
if normalizedInt.Cmp(bigMinInt) < 0 {
return errors.Errorf("%v is less than minimum value for %T", normalizedInt, *v)
}
*v = int(normalizedInt.Int64())
case *int8:
normalizedInt, err := src.toBigInt()
if err != nil {
return err
}
if normalizedInt.Cmp(bigMaxInt8) > 0 {
return errors.Errorf("%v is greater than maximum value for %T", normalizedInt, *v)
}
if normalizedInt.Cmp(bigMinInt8) < 0 {
return errors.Errorf("%v is less than minimum value for %T", normalizedInt, *v)
}
*v = int8(normalizedInt.Int64())
case *int16:
normalizedInt, err := src.toBigInt()
if err != nil {
return err
}
if normalizedInt.Cmp(bigMaxInt16) > 0 {
return errors.Errorf("%v is greater than maximum value for %T", normalizedInt, *v)
}
if normalizedInt.Cmp(bigMinInt16) < 0 {
return errors.Errorf("%v is less than minimum value for %T", normalizedInt, *v)
}
*v = int16(normalizedInt.Int64())
case *int32:
normalizedInt, err := src.toBigInt()
if err != nil {
return err
}
if normalizedInt.Cmp(bigMaxInt32) > 0 {
return errors.Errorf("%v is greater than maximum value for %T", normalizedInt, *v)
}
if normalizedInt.Cmp(bigMinInt32) < 0 {
return errors.Errorf("%v is less than minimum value for %T", normalizedInt, *v)
}
*v = int32(normalizedInt.Int64())
case *int64:
normalizedInt, err := src.toBigInt()
if err != nil {
return err
}
if normalizedInt.Cmp(bigMaxInt64) > 0 {
return errors.Errorf("%v is greater than maximum value for %T", normalizedInt, *v)
}
if normalizedInt.Cmp(bigMinInt64) < 0 {
return errors.Errorf("%v is less than minimum value for %T", normalizedInt, *v)
}
*v = normalizedInt.Int64()
case *uint:
normalizedInt, err := src.toBigInt()
if err != nil {
return err
}
if normalizedInt.Cmp(big0) < 0 {
return errors.Errorf("%d is less than zero for %T", normalizedInt, *v)
} else if normalizedInt.Cmp(bigMaxUint) > 0 {
return errors.Errorf("%d is greater than maximum value for %T", normalizedInt, *v)
}
*v = uint(normalizedInt.Uint64())
case *uint8:
normalizedInt, err := src.toBigInt()
if err != nil {
return err
}
if normalizedInt.Cmp(big0) < 0 {
return errors.Errorf("%d is less than zero for %T", normalizedInt, *v)
} else if normalizedInt.Cmp(bigMaxUint8) > 0 {
return errors.Errorf("%d is greater than maximum value for %T", normalizedInt, *v)
}
*v = uint8(normalizedInt.Uint64())
case *uint16:
normalizedInt, err := src.toBigInt()
if err != nil {
return err
}
if normalizedInt.Cmp(big0) < 0 {
return errors.Errorf("%d is less than zero for %T", normalizedInt, *v)
} else if normalizedInt.Cmp(bigMaxUint16) > 0 {
return errors.Errorf("%d is greater than maximum value for %T", normalizedInt, *v)
}
*v = uint16(normalizedInt.Uint64())
case *uint32:
normalizedInt, err := src.toBigInt()
if err != nil {
return err
}
if normalizedInt.Cmp(big0) < 0 {
return errors.Errorf("%d is less than zero for %T", normalizedInt, *v)
} else if normalizedInt.Cmp(bigMaxUint32) > 0 {
return errors.Errorf("%d is greater than maximum value for %T", normalizedInt, *v)
}
*v = uint32(normalizedInt.Uint64())
case *uint64:
normalizedInt, err := src.toBigInt()
if err != nil {
return err
}
if normalizedInt.Cmp(big0) < 0 {
return errors.Errorf("%d is less than zero for %T", normalizedInt, *v)
} else if normalizedInt.Cmp(bigMaxUint64) > 0 {
return errors.Errorf("%d is greater than maximum value for %T", normalizedInt, *v)
}
*v = normalizedInt.Uint64()
default:
if nextDst, retry := GetAssignToDstType(dst); retry {
return src.AssignTo(nextDst)
}
}
case Null:
return NullAssignTo(dst)
}
return nil
}
func (dst *Numeric) toBigInt() (*big.Int, error) {
if dst.Exp == 0 {
return dst.Int, nil
}
num := &big.Int{}
num.Set(dst.Int)
if dst.Exp > 0 {
mul := &big.Int{}
mul.Exp(big10, big.NewInt(int64(dst.Exp)), nil)
num.Mul(num, mul)
return num, nil
}
div := &big.Int{}
div.Exp(big10, big.NewInt(int64(-dst.Exp)), nil)
remainder := &big.Int{}
num.DivMod(num, div, remainder)
if remainder.Cmp(big0) != 0 {
return nil, errors.Errorf("cannot convert %v to integer", dst)
}
return num, nil
}
func (src *Numeric) toFloat64() (float64, error) {
f, err := strconv.ParseFloat(src.Int.String(), 64)
if err != nil {
return 0, err
}
if src.Exp > 0 {
for i := 0; i < int(src.Exp); i++ {
f *= 10
}
} else if src.Exp < 0 {
for i := 0; i > int(src.Exp); i-- {
f /= 10
}
}
return f, nil
}
func (dst *Numeric) DecodeText(ci *ConnInfo, src []byte) error {
if src == nil {
*dst = Numeric{Status: Null}
return nil
}
num, exp, err := parseNumericString(string(src))
if err != nil {
return err
}
*dst = Numeric{Int: num, Exp: exp, Status: Present}
return nil
}
func parseNumericString(str string) (n *big.Int, exp int32, err error) {
parts := strings.SplitN(str, ".", 2)
digits := strings.Join(parts, "")
if len(parts) > 1 {
exp = int32(-len(parts[1]))
} else {
for len(digits) > 1 && digits[len(digits)-1] == '0' && digits[len(digits)-2] != '-' {
digits = digits[:len(digits)-1]
exp++
}
}
accum := &big.Int{}
if _, ok := accum.SetString(digits, 10); !ok {
return nil, 0, errors.Errorf("%s is not a number", str)
}
return accum, exp, nil
}
func (dst *Numeric) DecodeBinary(ci *ConnInfo, src []byte) error {
if src == nil {
*dst = Numeric{Status: Null}
return nil
}
if len(src) < 8 {
return errors.Errorf("numeric incomplete %v", src)
}
rp := 0
ndigits := int16(binary.BigEndian.Uint16(src[rp:]))
rp += 2
if ndigits == 0 {
*dst = Numeric{Int: big.NewInt(0), Status: Present}
return nil
}
weight := int16(binary.BigEndian.Uint16(src[rp:]))
rp += 2
sign := int16(binary.BigEndian.Uint16(src[rp:]))
rp += 2
dscale := int16(binary.BigEndian.Uint16(src[rp:]))
rp += 2
if len(src[rp:]) < int(ndigits)*2 {
return errors.Errorf("numeric incomplete %v", src)
}
accum := &big.Int{}
for i := 0; i < int(ndigits+3)/4; i++ {
int64accum, bytesRead, digitsRead := nbaseDigitsToInt64(src[rp:])
rp += bytesRead
if i > 0 {
var mul *big.Int
switch digitsRead {
case 1:
mul = bigNBase
case 2:
mul = bigNBaseX2
case 3:
mul = bigNBaseX3
case 4:
mul = bigNBaseX4
default:
return errors.Errorf("invalid digitsRead: %d (this can't happen)", digitsRead)
}
accum.Mul(accum, mul)
}
accum.Add(accum, big.NewInt(int64accum))
}
exp := (int32(weight) - int32(ndigits) + 1) * 4
if dscale > 0 {
fracNBaseDigits := ndigits - weight - 1
fracDecimalDigits := fracNBaseDigits * 4
if dscale > fracDecimalDigits {
multCount := int(dscale - fracDecimalDigits)
for i := 0; i < multCount; i++ {
accum.Mul(accum, big10)
exp--
}
} else if dscale < fracDecimalDigits {
divCount := int(fracDecimalDigits - dscale)
for i := 0; i < divCount; i++ {
accum.Div(accum, big10)
exp++
}
}
}
reduced := &big.Int{}
remainder := &big.Int{}
if exp >= 0 {
for {
reduced.DivMod(accum, big10, remainder)
if remainder.Cmp(big0) != 0 {
break
}
accum.Set(reduced)
exp++
}
}
if sign != 0 {
accum.Neg(accum)
}
*dst = Numeric{Int: accum, Exp: exp, Status: Present}
return nil
}
func nbaseDigitsToInt64(src []byte) (accum int64, bytesRead, digitsRead int) {
digits := len(src) / 2
if digits > 4 {
digits = 4
}
rp := 0
for i := 0; i < digits; i++ {
if i > 0 {
accum *= nbase
}
accum += int64(binary.BigEndian.Uint16(src[rp:]))
rp += 2
}
return accum, rp, digits
}
func (src *Numeric) EncodeText(ci *ConnInfo, buf []byte) ([]byte, error) {
switch src.Status {
case Null:
return nil, nil
case Undefined:
return nil, errUndefined
}
buf = append(buf, src.Int.String()...)
buf = append(buf, 'e')
buf = append(buf, strconv.FormatInt(int64(src.Exp), 10)...)
return buf, nil
}
func (src *Numeric) EncodeBinary(ci *ConnInfo, buf []byte) ([]byte, error) {
switch src.Status {
case Null:
return nil, nil
case Undefined:
return nil, errUndefined
}
var sign int16
if src.Int.Cmp(big0) < 0 {
sign = 16384
}
absInt := &big.Int{}
wholePart := &big.Int{}
fracPart := &big.Int{}
remainder := &big.Int{}
absInt.Abs(src.Int)
// Normalize absInt and exp to where exp is always a multiple of 4. This makes
// converting to 16-bit base 10,000 digits easier.
var exp int32
switch src.Exp % 4 {
case 1, -3:
exp = src.Exp - 1
absInt.Mul(absInt, big10)
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)
fracPart.Add(fracPart, divisor)
} else {
wholePart = absInt
}
var wholeDigits, fracDigits []int16
for wholePart.Cmp(big0) != 0 {
wholePart.DivMod(wholePart, bigNBase, remainder)
wholeDigits = append(wholeDigits, int16(remainder.Int64()))
}
if fracPart.Cmp(big0) != 0 {
for fracPart.Cmp(big1) != 0 {
fracPart.DivMod(fracPart, bigNBase, remainder)
fracDigits = append(fracDigits, int16(remainder.Int64()))
}
}
buf = pgio.AppendInt16(buf, int16(len(wholeDigits)+len(fracDigits)))
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))
}
buf = pgio.AppendInt16(buf, weight)
buf = pgio.AppendInt16(buf, sign)
var dscale int16
if src.Exp < 0 {
dscale = int16(-src.Exp)
}
buf = pgio.AppendInt16(buf, dscale)
for i := len(wholeDigits) - 1; i >= 0; i-- {
buf = pgio.AppendInt16(buf, wholeDigits[i])
}
for i := len(fracDigits) - 1; i >= 0; i-- {
buf = pgio.AppendInt16(buf, fracDigits[i])
}
return buf, 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:
srcCopy := make([]byte, len(src))
copy(srcCopy, src)
return dst.DecodeText(nil, srcCopy)
}
return errors.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, err := src.EncodeText(nil, nil)
if err != nil {
return nil, err
}
return string(buf), nil
case Null:
return nil, nil
default:
return nil, errUndefined
}
}