perf: add inplace decimal operations (#11004)

closes #9046

* add mutable decimal methods

* fix root

* gofmt

* add Clone(), rm assignment quo

* add SetInt64

* fix SetInt64

* More mut speedups

Co-authored-by: mconcat <monoidconcat@gmail.com>
Co-authored-by: ValarDragon <dojha12@gmail.com>




---

### Author Checklist

*All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.*

I have...

- [ ] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] added `!` to the type prefix if API or client breaking change
- [ ] targeted the correct branch (see [PR Targeting](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#pr-targeting))
- [ ] provided a link to the relevant issue or specification
- [ ] followed the guidelines for [building modules](https://github.com/cosmos/cosmos-sdk/blob/master/docs/building-modules)
- [ ] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#testing)
- [ ] added a changelog entry to `CHANGELOG.md`
- [ ] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [ ] updated the relevant documentation or specification
- [ ] reviewed "Files changed" and left comments if necessary
- [ ] confirmed all CI checks have passed

### Reviewers Checklist

*All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items.*

I have...

- [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] confirmed `!` in the type prefix if API or client breaking change
- [ ] confirmed all author checklist items have been addressed 
- [ ] reviewed state machine logic
- [ ] reviewed API design and naming
- [ ] reviewed documentation is accurate
- [ ] reviewed tests and test coverage
- [ ] manually tested (if applicable)

CHANGELOG.md

@@ -160,6 +160,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (deps) [\#10706](https://github.com/cosmos/cosmos-sdk/issues/10706) Bump rosetta-sdk-go to v0.7.2 and rosetta-cli to v0.7.3
 * (types/errors) [\#10779](https://github.com/cosmos/cosmos-sdk/pull/10779) Move most functionality in `types/errors` to a standalone `errors` go module, except the `RootCodespace` errors and ABCI response helpers. All functions and types that used to live in `types/errors` are now aliased so this is not a breaking change.
 * (gov) [\#10854](https://github.com/cosmos/cosmos-sdk/pull/10854) v1beta2's vote doesn't include the deprecate `option VoteOption` anymore. Instead, it only uses `WeightedVoteOption`.
+* (types) [\#11004](https://github.com/cosmos/cosmos-sdk/pull/11004) Added mutable versions of many of the sdk.Dec types operations.  This improves performance when used by avoiding reallocating a new bigint for each operation.
 
 ### Bug Fixes
 

types/decimal.go

@@ -208,7 +208,10 @@ func (d Dec) GTE(d2 Dec) bool   { return (d.i).Cmp(d2.i) >= 0 }       // greater
 func (d Dec) LT(d2 Dec) bool    { return (d.i).Cmp(d2.i) < 0 }        // less than
 func (d Dec) LTE(d2 Dec) bool   { return (d.i).Cmp(d2.i) <= 0 }       // less than or equal
 func (d Dec) Neg() Dec          { return Dec{new(big.Int).Neg(d.i)} } // reverse the decimal sign
+func (d Dec) NegMut() Dec       { d.i.Neg(d.i); return d }            // reverse the decimal sign, mutable
 func (d Dec) Abs() Dec          { return Dec{new(big.Int).Abs(d.i)} } // absolute value
+func (d Dec) Set(d2 Dec) Dec    { d.i.Set(d2.i); return d }           // set to existing dec value
+func (d Dec) Clone() Dec        { return Dec{new(big.Int).Set(d.i)} } // clone new dec
 
 // BigInt returns a copy of the underlying big.Int.
 func (d Dec) BigInt() *big.Int {
@@ -220,123 +223,192 @@ func (d Dec) BigInt() *big.Int {
 	return cp.Set(d.i)
 }
 
+func (d Dec) ImmutOp(op func(Dec, Dec) Dec, d2 Dec) Dec {
+	return op(d.Clone(), d2)
+}
+
+func (d Dec) ImmutOpInt(op func(Dec, Int) Dec, d2 Int) Dec {
+	return op(d.Clone(), d2)
+}
+
+func (d Dec) ImmutOpInt64(op func(Dec, int64) Dec, d2 int64) Dec {
+	// TODO: use already allocated operand bigint to avoid
+	// newint each time, add mutex for race condition
+	// Issue: https://github.com/cosmos/cosmos-sdk/issues/11166
+	return op(d.Clone(), d2)
+}
+
+func (d Dec) SetInt64(i int64) Dec {
+	d.i.SetInt64(i)
+	d.i.Mul(d.i, precisionReuse)
+	return d
+}
+
 // addition
 func (d Dec) Add(d2 Dec) Dec {
-	res := new(big.Int).Add(d.i, d2.i)
+	return d.ImmutOp(Dec.AddMut, d2)
+}
 
-	if res.BitLen() > maxDecBitLen {
+// mutable addition
+func (d Dec) AddMut(d2 Dec) Dec {
+	d.i.Add(d.i, d2.i)
+
+	if d.i.BitLen() > maxDecBitLen {
 		panic("Int overflow")
 	}
-	return Dec{res}
+	return d
 }
 
 // subtraction
 func (d Dec) Sub(d2 Dec) Dec {
-	res := new(big.Int).Sub(d.i, d2.i)
+	return d.ImmutOp(Dec.SubMut, d2)
+}
 
-	if res.BitLen() > maxDecBitLen {
+// mutable subtraction
+func (d Dec) SubMut(d2 Dec) Dec {
+	d.i.Sub(d.i, d2.i)
+
+	if d.i.BitLen() > maxDecBitLen {
 		panic("Int overflow")
 	}
-	return Dec{res}
+	return d
 }
 
 // multiplication
 func (d Dec) Mul(d2 Dec) Dec {
-	mul := new(big.Int).Mul(d.i, d2.i)
+	return d.ImmutOp(Dec.MulMut, d2)
-	chopped := chopPrecisionAndRound(mul)
+}
+
+// mutable multiplication
+func (d Dec) MulMut(d2 Dec) Dec {
+	d.i.Mul(d.i, d2.i)
+	chopped := chopPrecisionAndRound(d.i)
 
 	if chopped.BitLen() > maxDecBitLen {
 		panic("Int overflow")
 	}
-	return Dec{chopped}
+	*d.i = *chopped
+	return d
 }
 
 // multiplication truncate
 func (d Dec) MulTruncate(d2 Dec) Dec {
-	mul := new(big.Int).Mul(d.i, d2.i)
+	return d.ImmutOp(Dec.MulTruncateMut, d2)
-	chopped := chopPrecisionAndTruncate(mul)
+}
 
-	if chopped.BitLen() > maxDecBitLen {
+// mutable multiplication truncage
+func (d Dec) MulTruncateMut(d2 Dec) Dec {
+	d.i.Mul(d.i, d2.i)
+	chopPrecisionAndTruncate(d.i)
+
+	if d.i.BitLen() > maxDecBitLen {
 		panic("Int overflow")
 	}
-	return Dec{chopped}
+	return d
 }
 
 // multiplication
 func (d Dec) MulInt(i Int) Dec {
-	mul := new(big.Int).Mul(d.i, i.i)
+	return d.ImmutOpInt(Dec.MulIntMut, i)
+}
 
-	if mul.BitLen() > maxDecBitLen {
+func (d Dec) MulIntMut(i Int) Dec {
+	d.i.Mul(d.i, i.i)
+	if d.i.BitLen() > maxDecBitLen {
 		panic("Int overflow")
 	}
-	return Dec{mul}
+	return d
 }
 
 // MulInt64 - multiplication with int64
 func (d Dec) MulInt64(i int64) Dec {
-	mul := new(big.Int).Mul(d.i, big.NewInt(i))
+	return d.ImmutOpInt64(Dec.MulInt64Mut, i)
+}
 
-	if mul.BitLen() > maxDecBitLen {
+func (d Dec) MulInt64Mut(i int64) Dec {
+	d.i.Mul(d.i, big.NewInt(i))
+
+	if d.i.BitLen() > maxDecBitLen {
 		panic("Int overflow")
 	}
-	return Dec{mul}
+	return d
 }
 
 // quotient
 func (d Dec) Quo(d2 Dec) Dec {
+	return d.ImmutOp(Dec.QuoMut, d2)
+}
+
+// mutable quotient
+func (d Dec) QuoMut(d2 Dec) Dec {
 	// multiply precision twice
-	mul := new(big.Int).Mul(d.i, precisionReuse)
+	d.i.Mul(d.i, precisionReuse)
-	mul.Mul(mul, precisionReuse)
+	d.i.Mul(d.i, precisionReuse)
+	d.i.Quo(d.i, d2.i)
 
-	quo := new(big.Int).Quo(mul, d2.i)
+	chopPrecisionAndRound(d.i)
-	chopped := chopPrecisionAndRound(quo)
+	if d.i.BitLen() > maxDecBitLen {
-
-	if chopped.BitLen() > maxDecBitLen {
 		panic("Int overflow")
 	}
-	return Dec{chopped}
+	return d
 }
 
 // quotient truncate
 func (d Dec) QuoTruncate(d2 Dec) Dec {
+	return d.ImmutOp(Dec.QuoTruncateMut, d2)
+}
+
+// mutable quotient truncate
+func (d Dec) QuoTruncateMut(d2 Dec) Dec {
 	// multiply precision twice
-	mul := new(big.Int).Mul(d.i, precisionReuse)
+	d.i.Mul(d.i, precisionReuse)
-	mul.Mul(mul, precisionReuse)
+	d.i.Mul(d.i, precisionReuse)
+	d.i.Quo(d.i, d2.i)
 
-	quo := mul.Quo(mul, d2.i)
+	chopPrecisionAndTruncate(d.i)
-	chopped := chopPrecisionAndTruncate(quo)
+	if d.i.BitLen() > maxDecBitLen {
-
-	if chopped.BitLen() > maxDecBitLen {
 		panic("Int overflow")
 	}
-	return Dec{chopped}
+	return d
 }
 
 // quotient, round up
 func (d Dec) QuoRoundUp(d2 Dec) Dec {
+	return d.ImmutOp(Dec.QuoRoundupMut, d2)
+}
+
+// mutable quotient, round up
+func (d Dec) QuoRoundupMut(d2 Dec) Dec {
 	// multiply precision twice
-	mul := new(big.Int).Mul(d.i, precisionReuse)
+	d.i.Mul(d.i, precisionReuse)
-	mul.Mul(mul, precisionReuse)
+	d.i.Mul(d.i, precisionReuse)
+	d.i.Quo(d.i, d2.i)
 
-	quo := new(big.Int).Quo(mul, d2.i)
+	chopPrecisionAndRoundUp(d.i)
-	chopped := chopPrecisionAndRoundUp(quo)
+	if d.i.BitLen() > maxDecBitLen {
-
-	if chopped.BitLen() > maxDecBitLen {
 		panic("Int overflow")
 	}
-	return Dec{chopped}
+	return d
 }
 
 // quotient
 func (d Dec) QuoInt(i Int) Dec {
-	mul := new(big.Int).Quo(d.i, i.i)
+	return d.ImmutOpInt(Dec.QuoIntMut, i)
-	return Dec{mul}
+}
+
+func (d Dec) QuoIntMut(i Int) Dec {
+	d.i.Quo(d.i, i.i)
+	return d
 }
 
 // QuoInt64 - quotient with int64
 func (d Dec) QuoInt64(i int64) Dec {
-	mul := new(big.Int).Quo(d.i, big.NewInt(i))
+	return d.ImmutOpInt64(Dec.QuoInt64Mut, i)
-	return Dec{mul}
+}
+
+func (d Dec) QuoInt64Mut(i int64) Dec {
+	d.i.Quo(d.i, big.NewInt(i))
+	return d
 }
 
 // ApproxRoot returns an approximate estimation of a Dec's positive real nth root
@@ -357,8 +429,8 @@ func (d Dec) ApproxRoot(root uint64) (guess Dec, err error) {
 	}()
 
 	if d.IsNegative() {
-		absRoot, err := d.MulInt64(-1).ApproxRoot(root)
+		absRoot, err := d.Neg().ApproxRoot(root)
-		return absRoot.MulInt64(-1), err
+		return absRoot.NegMut(), err
 	}
 
 	if root == 1 || d.IsZero() || d.Equal(OneDec()) {
@@ -369,7 +441,6 @@ func (d Dec) ApproxRoot(root uint64) (guess Dec, err error) {
 		return OneDec(), nil
 	}
 
-	rootInt := NewIntFromUint64(root)
 	guess, delta := OneDec(), OneDec()
 
 	for iter := 0; delta.Abs().GT(SmallestDec()) && iter < maxApproxRootIterations; iter++ {
@@ -377,11 +448,11 @@ func (d Dec) ApproxRoot(root uint64) (guess Dec, err error) {
 		if prev.IsZero() {
 			prev = SmallestDec()
 		}
-		delta = d.Quo(prev)
+		delta.Set(d).QuoMut(prev)
-		delta = delta.Sub(guess)
+		delta.SubMut(guess)
-		delta = delta.QuoInt(rootInt)
+		delta.QuoInt64Mut(int64(root))
 
-		guess = guess.Add(delta)
+		guess.AddMut(delta)
 	}
 
 	return guess, nil
@@ -389,20 +460,26 @@ func (d Dec) ApproxRoot(root uint64) (guess Dec, err error) {
 
 // Power returns a the result of raising to a positive integer power
 func (d Dec) Power(power uint64) Dec {
+	res := Dec{new(big.Int).Set(d.i)}
+	return res.PowerMut(power)
+}
+
+func (d Dec) PowerMut(power uint64) Dec {
 	if power == 0 {
-		return OneDec()
+		d.SetInt64(1)
+		return d
 	}
 	tmp := OneDec()
 
 	for i := power; i > 1; {
 		if i%2 != 0 {
-			tmp = tmp.Mul(d)
+			tmp.MulMut(d)
 		}
 		i /= 2
-		d = d.Mul(d)
+		d.MulMut(d)
 	}
 
-	return d.Mul(tmp)
+	return d.MulMut(tmp)
 }
 
 // ApproxSqrt is a wrapper around ApproxRoot for the common special case
@@ -543,7 +620,7 @@ func chopPrecisionAndRoundUp(d *big.Int) *big.Int {
 		// make d positive, compute chopped value, and then un-mutate d
 		d = d.Neg(d)
 		// truncate since d is negative...
-		d = chopPrecisionAndTruncate(d)
+		chopPrecisionAndTruncate(d)
 		d = d.Neg(d)
 		return d
 	}
@@ -580,13 +657,19 @@ func (d Dec) RoundInt() Int {
 
 // chopPrecisionAndTruncate is similar to chopPrecisionAndRound,
 // but always rounds down. It does not mutate the input.
-func chopPrecisionAndTruncate(d *big.Int) *big.Int {
+func chopPrecisionAndTruncate(d *big.Int) {
-	return new(big.Int).Quo(d, precisionReuse)
+	d.Quo(d, precisionReuse)
+}
+
+func chopPrecisionAndTruncateNonMutative(d *big.Int) *big.Int {
+	tmp := new(big.Int).Set(d)
+	chopPrecisionAndTruncate(tmp)
+	return tmp
 }
 
 // TruncateInt64 truncates the decimals from the number and returns an int64
 func (d Dec) TruncateInt64() int64 {
-	chopped := chopPrecisionAndTruncate(d.i)
+	chopped := chopPrecisionAndTruncateNonMutative(d.i)
 	if !chopped.IsInt64() {
 		panic("Int64() out of bound")
 	}
@@ -595,12 +678,12 @@ func (d Dec) TruncateInt64() int64 {
 
 // TruncateInt truncates the decimals from the number and returns an Int
 func (d Dec) TruncateInt() Int {
-	return NewIntFromBigInt(chopPrecisionAndTruncate(d.i))
+	return NewIntFromBigInt(chopPrecisionAndTruncateNonMutative(d.i))
 }
 
 // TruncateDec truncates the decimals from the number and returns a Dec
 func (d Dec) TruncateDec() Dec {
-	return NewDecFromBigInt(chopPrecisionAndTruncate(d.i))
+	return NewDecFromBigInt(chopPrecisionAndTruncateNonMutative(d.i))
 }
 
 // Ceil returns the smallest interger value (as a decimal) that is greater than
@@ -625,7 +708,11 @@ func (d Dec) Ceil() Dec {
 
 // MaxSortableDec is the largest Dec that can be passed into SortableDecBytes()
 // Its negative form is the least Dec that can be passed in.
-var MaxSortableDec = OneDec().Quo(SmallestDec())
+var MaxSortableDec Dec
+
+func init() {
+	MaxSortableDec = OneDec().Quo(SmallestDec())
+}
 
 // ValidSortableDec ensures that a Dec is within the sortable bounds,
 // a Dec can't have a precision of less than 10^-18.

types/decimal_test.go

@@ -376,6 +376,7 @@ func (s *decimalTestSuite) TestPower() {
 		power    uint64
 		expected sdk.Dec
 	}{
+		{sdk.NewDec(100), 0, sdk.OneDec()},                                                 // 10 ^ (0) => 1.0
 		{sdk.OneDec(), 10, sdk.OneDec()},                                                   // 1.0 ^ (10) => 1.0
 		{sdk.NewDecWithPrec(5, 1), 2, sdk.NewDecWithPrec(25, 2)},                           // 0.5 ^ 2 => 0.25
 		{sdk.NewDecWithPrec(2, 1), 2, sdk.NewDecWithPrec(4, 2)},                            // 0.2 ^ 2 => 0.04
@@ -386,7 +387,13 @@ func (s *decimalTestSuite) TestPower() {
 
 	for i, tc := range testCases {
 		res := tc.input.Power(tc.power)
-		s.Require().True(tc.expected.Sub(res).Abs().LTE(sdk.SmallestDec()), "unexpected result for test case %d, input: %v", i, tc.input)
+		s.Require().True(tc.expected.Sub(res).Abs().LTE(sdk.SmallestDec()), "unexpected result for test case %d, normal power, input: %v", i, tc.input)
+
+		mutableInput := tc.input
+		mutableInput.PowerMut(tc.power)
+		s.Require().True(tc.expected.Sub(mutableInput).Abs().LTE(sdk.SmallestDec()),
+			"unexpected result for test case %d, input %v", i, tc.input)
+		s.Require().True(res.Equal(tc.input), "unexpected result for test case %d, mutable power, input: %v", i, tc.input)
 	}
 }