Merge pull request #1235 from ydb-platform/revert-decimal

Revert decimal to latest working version.

Author: asmyasnikov

CHANGELOG.md

@@ -1,3 +1,5 @@
+* Fixed incorrect formatting of decimal. Implementation of decimal has been reverted to latest working version
+
 ## v3.67.1
 * Fixed race of stop internal processes on close topic writer
 * Fixed goroutines leak within topic reader on network problems

internal/decimal/decimal.go

@@ -3,6 +3,8 @@ package decimal
 import (
 	"math/big"
 	"math/bits"
+
+	"github.com/ydb-platform/ydb-go-sdk/v3/internal/xstring"
 )
 
 const (
@@ -97,56 +99,27 @@ func Parse(s string, precision, scale uint32) (*big.Int, error) {
 		return v, nil
 	}
 
-	s, neg, specialValue := setSpecialValue(s, v)
-	if specialValue != nil {
-		return specialValue, nil
-	}
-	var err error
-	v, err = parseNumber(s, v, precision, scale, neg)
-	if err != nil {
-		return nil, err
-	}
-
-	return v, nil
-}
-
-func setSpecialValue(s string, v *big.Int) (string, bool, *big.Int) {
-	s, neg := parseSign(s)
-
-	return parseSpecialValue(s, neg, v)
-}
-
-func parseSign(s string) (string, bool) {
 	neg := s[0] == '-'
 	if neg || s[0] == '+' {
 		s = s[1:]
 	}
-
-	return s, neg
-}
-
-func parseSpecialValue(s string, neg bool, v *big.Int) (string, bool, *big.Int) {
 	if isInf(s) {
 		if neg {
-			return s, neg, v.Set(neginf)
+			return v.Set(neginf), nil
 		}
 
-		return s, neg, v.Set(inf)
+		return v.Set(inf), nil
 	}
 	if isNaN(s) {
 		if neg {
-			return s, neg, v.Set(negnan)
+			return v.Set(negnan), nil
 		}
 
-		return s, neg, v.Set(nan)
+		return v.Set(nan), nil
 	}
 
-	return s, neg, nil
-}
-
-func parseNumber(s string, v *big.Int, precision, scale uint32, neg bool) (*big.Int, error) {
-	var err error
 	integral := precision - scale
+
 	var dot bool
 	for ; len(s) > 0; s = s[1:] {
 		c := s[0]
@@ -158,10 +131,12 @@ func parseNumber(s string, v *big.Int, precision, scale uint32, neg bool) (*big.
 
 			continue
 		}
-		if dot && scale > 0 {
-			scale--
-		} else if dot {
-			break
+		if dot {
+			if scale > 0 {
+				scale--
+			} else {
+				break
+			}
 		}
 
 		if !isDigit(c) {
@@ -180,10 +155,30 @@ func parseNumber(s string, v *big.Int, precision, scale uint32, neg bool) (*big.
 		}
 		integral--
 	}
+	//nolint:nestif
 	if len(s) > 0 { // Characters remaining.
-		v, err = handleRemainingDigits(s, v, precision)
-		if err != nil {
-			return nil, err
+		c := s[0]
+		if !isDigit(c) {
+			return nil, syntaxError(s)
+		}
+		plus := c > '5'
+		if !plus && c == '5' {
+			var x big.Int
+			plus = x.And(v, one).Cmp(zero) != 0 // Last digit is not a zero.
+			for !plus && len(s) > 1 {
+				s = s[1:]
+				c := s[0]
+				if !isDigit(c) {
+					return nil, syntaxError(s)
+				}
+				plus = c != '0'
+			}
+		}
+		if plus {
+			v.Add(v, one)
+			if v.Cmp(pow(ten, precision)) >= 0 {
+				v.Set(inf)
+			}
 		}
 	}
 	v.Mul(v, pow(ten, scale))
@@ -194,56 +189,26 @@ func parseNumber(s string, v *big.Int, precision, scale uint32, neg bool) (*big.
 	return v, nil
 }
 
-func handleRemainingDigits(s string, v *big.Int, precision uint32) (*big.Int, error) {
-	c := s[0]
-	if !isDigit(c) {
-		return nil, syntaxError(s)
-	}
-	plus := c > '5'
-	if !plus && c == '5' {
-		var x big.Int
-		plus = x.And(v, one).Cmp(zero) != 0 // Last digit is not a zero.
-		for !plus && len(s) > 1 {
-			s = s[1:]
-			c := s[0]
-			if !isDigit(c) {
-				return nil, syntaxError(s)
-			}
-			plus = c != '0'
-		}
-	}
-	if plus {
-		v.Add(v, one)
-		if v.Cmp(pow(ten, precision)) >= 0 {
-			v.Set(inf)
-		}
-	}
-
-	return v, nil
-}
-
 // Format returns the string representation of x with the given precision and
 // scale.
-//
-//nolint:funlen
 func Format(x *big.Int, precision, scale uint32) string {
-	// Check for special values and nil pointer upfront.
-	if x == nil {
-		return "0"
-	}
-	if x.CmpAbs(inf) == 0 {
+	switch {
+	case x.CmpAbs(inf) == 0:
 		if x.Sign() < 0 {
 			return "-inf"
 		}
 
 		return "inf"
-	}
-	if x.CmpAbs(nan) == 0 {
+
+	case x.CmpAbs(nan) == 0:
 		if x.Sign() < 0 {
 			return "-nan"
 		}
 
 		return "nan"
+
+	case x == nil:
+		return "0"
 	}
 
 	v := big.NewInt(0).Set(x)
@@ -267,59 +232,42 @@ func Format(x *big.Int, precision, scale uint32) string {
 
 		digit.Mod(v, ten)
 		d := int(digit.Int64())
-
-		pos--
-		if d != 0 || scale == 0 || pos >= 0 {
-			setDigitAtPosition(bts, pos, d)
+		if d != 0 || scale == 0 || pos > 0 {
+			const numbers = "0123456789"
+			pos--
+			bts[pos] = numbers[d]
 		}
-
 		if scale > 0 {
 			scale--
 			if scale == 0 && pos > 0 {
-				bts[pos-1] = '.'
 				pos--
+				bts[pos] = '.'
 			}
 		}
 	}
-
-	for ; scale > 0; scale-- {
-		if precision == 0 {
-			pos = 0
-
-			break
+	if scale > 0 {
+		for ; scale > 0; scale-- {
+			if precision == 0 {
+				return errorTag
+			}
+			precision--
+			pos--
+			bts[pos] = '0'
 		}
-		precision--
+
 		pos--
-		bts[pos] = '0'
+		bts[pos] = '.'
 	}
-
 	if bts[pos] == '.' {
 		pos--
 		bts[pos] = '0'
 	}
-
 	if neg {
 		pos--
 		bts[pos] = '-'
 	}
 
-	return string(bts[pos:])
-}
-
-func abs(x *big.Int) (*big.Int, bool) {
-	v := big.NewInt(0).Set(x)
-	neg := x.Sign() < 0
-	if neg {
-		// Convert negative to positive.
-		v.Neg(x)
-	}
-
-	return v, neg
-}
-
-func setDigitAtPosition(bts []byte, pos, digit int) {
-	const numbers = "0123456789"
-	bts[pos] = numbers[digit]
+	return xstring.FromBytes(bts[pos:])
 }
 
 // BigIntToByte returns the 16-byte array representation of x.