msgpack: add string() for decimal, datetime. interval

Added a benchmark, which shows that the code for decimal is optimized two or more times for string conversion than the code from the library. Added a datetime Interval type conversion function to a string, added tests for this function.

Added #322

Author: babyTsakhes

decimal/decimal.go

@@ -99,7 +99,7 @@ func (d Decimal) MarshalMsgpack() ([]byte, error) {
 	//  +--------+-------------------+------------+===============+
 	//  | MP_EXT | length (optional) | MP_DECIMAL | PackedDecimal |
 	//  +--------+-------------------+------------+===============+
-	strBuf := d.String()
+	strBuf := d.Decimal.String()
 	bcdBuf, err := encodeStringToBCD(strBuf)
 	if err != nil {
 		return nil, fmt.Errorf("msgpack: can't encode string (%s) to a BCD buffer: %w", strBuf, err)
@@ -149,14 +149,14 @@ func decimalDecoder(d *msgpack.Decoder, v reflect.Value, extLen int) error {
 
 // This method converts the decimal type to a string.
 // Use shopspring/decimal by default.
-// StringOptimized - optimized version for Tarantool Decimal
+// String - optimized version for Tarantool Decimal
 // taking into account the limitations of int64 and support for large numbers via fallback
 // Tarantool decimal has 38 digits, which can exceed int64.
 // Therefore, we cannot use int64 for all cases.
 // For the general case, use shopspring/decimal.String().
 // For cases where it is known that numbers contain less than 26 characters,
 // you can use the optimized version.
-func (d Decimal) StringOptimized() string {
+func (d Decimal) String() string {
 	coefficient := d.Decimal.Coefficient() // Note: In shopspring/decimal, the number is stored as coefficient *10^exponent, where exponent can be negative.
 	exponent := d.Decimal.Exponent()
 

decimal/decimal_bench_test.go

@@ -12,9 +12,9 @@ import (
 func BenchmarkMinimal(b *testing.B) {
 	dec := MustMakeDecimal("123.45")
 
-	b.Run("StringOptimized", func(b *testing.B) {
+	b.Run("String", func(b *testing.B) {
 		for i := 0; i < b.N; i++ {
-			_ = dec.StringOptimized()
+			_ = dec.String()
 		}
 	})
 
@@ -46,10 +46,10 @@ func BenchmarkDecimalString_SmallNumbers(b *testing.B) {
 	}
 
 	b.ResetTimer()
-	b.Run("StringOptimized", func(b *testing.B) {
+	b.Run("String", func(b *testing.B) {
 		for i := 0; i < b.N; i++ {
 			for _, dec := range decimals {
-				_ = dec.StringOptimized()
+				_ = dec.String()
 			}
 		}
 	})
@@ -78,10 +78,10 @@ func BenchmarkDecimalString_Int64Boundaries(b *testing.B) {
 	}
 
 	b.ResetTimer()
-	b.Run("StringOptimized", func(b *testing.B) {
+	b.Run("String", func(b *testing.B) {
 		for i := 0; i < b.N; i++ {
 			for _, dec := range decimals {
-				_ = dec.StringOptimized()
+				_ = dec.String()
 			}
 		}
 	})
@@ -110,10 +110,10 @@ func BenchmarkDecimalString_LargeNumbers(b *testing.B) {
 	}
 
 	b.ResetTimer()
-	b.Run("StringOptimized", func(b *testing.B) {
+	b.Run("String", func(b *testing.B) {
 		for i := 0; i < b.N; i++ {
 			for _, dec := range decimals {
-				_ = dec.StringOptimized()
+				_ = dec.String()
 			}
 		}
 	})
@@ -147,10 +147,10 @@ func BenchmarkDecimalString_Mixed(b *testing.B) {
 	}
 
 	b.ResetTimer()
-	b.Run("StringOptimized", func(b *testing.B) {
+	b.Run("String", func(b *testing.B) {
 		for i := 0; i < b.N; i++ {
 			for _, dec := range decimals {
-				_ = dec.StringOptimized()
+				_ = dec.String()
 			}
 		}
 	})
@@ -180,9 +180,9 @@ func BenchmarkDecimalString_DifferentPrecision(b *testing.B) {
 		b.Run(tc.name, func(b *testing.B) {
 			dec := MustMakeDecimal(tc.value)
 
-			b.Run("StringOptimized", func(b *testing.B) {
+			b.Run("String", func(b *testing.B) {
 				for i := 0; i < b.N; i++ {
-					_ = dec.StringOptimized()
+					_ = dec.String()
 				}
 			})
 
@@ -275,11 +275,11 @@ func BenchmarkDecimalString_Random(b *testing.B) {
 	}
 
 	b.ResetTimer()
-	b.Run("StringOptimized", func(b *testing.B) {
+	b.Run("String", func(b *testing.B) {
 		total := 0
 		for i := 0; i < b.N; i++ {
 			dec := generateRandomDecimal()
-			result := dec.StringOptimized()
+			result := dec.String()
 			total += len(result)
 		}
 		_ = total
@@ -312,10 +312,10 @@ func BenchmarkDecimalString_MemoryAllocations(b *testing.B) {
 
 	b.ResetTimer()
 
-	b.Run("StringOptimized", func(b *testing.B) {
+	b.Run("String", func(b *testing.B) {
 		for i := 0; i < b.N; i++ {
 			for _, dec := range decimals {
-				_ = dec.StringOptimized()
+				_ = dec.String()
 			}
 		}
 	})

decimal/decimal_test.go

@@ -703,7 +703,7 @@ func TestMain(m *testing.M) {
 	os.Exit(code)
 }
 
-func TestDecimalStringOptimized(t *testing.T) {
+func TestDecimalString(t *testing.T) {
 	tests := []struct {
 		name             string
 		input            string
@@ -770,7 +770,7 @@ func TestDecimalStringOptimized(t *testing.T) {
 			dec, err := MakeDecimalFromString(tt.input)
 			assert.NoError(t, err)
 
-			result := dec.StringOptimized()
+			result := dec.String()
 
 			assert.Equal(t, tt.expected, result)
 
@@ -802,8 +802,8 @@ func TestTarantoolBCDCompatibility(t *testing.T) {
 			err = dec2.UnmarshalMsgpack(msgpackData)
 			assert.NoError(t, err)
 
-			originalStr := dec.StringOptimized()
-			roundtripStr := dec2.StringOptimized()
+			originalStr := dec.String()
+			roundtripStr := dec2.String()
 
 			assert.Equal(t, originalStr, roundtripStr,
 				"BCD roundtrip failed for input: %s", input)
@@ -863,11 +863,11 @@ func Test100_00(t *testing.T) {
 	if coefficient.IsInt64() {
 		t.Logf("Int64: %v", coefficient.Int64())
 	}
-	result := dec.StringOptimized()
-	t.Logf("StringOptimized: %q", result)
+	result := dec.String()
+	t.Logf("String: %q", result)
 }
 
-func TestLargeNumberStringOptimized(t *testing.T) {
+func TestLargeNumberString(t *testing.T) {
 	largeNumber := "123456789012345678901234567890.123456789"
 	dec, err := MakeDecimalFromString(largeNumber)
 	if err != nil {
@@ -880,7 +880,7 @@ func TestLargeNumberStringOptimized(t *testing.T) {
 		t.Error("Expected coefficient to be too large for int64")
 	}
 
-	optimized := dec.StringOptimized()
+	optimized := dec.String()
 	standard := dec.Decimal.String()
 
 	if optimized != standard {
@@ -910,7 +910,7 @@ func TestDecimalTrailingZeros(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.input, func(t *testing.T) {
 			dec := MustMakeDecimal(tt.input)
-			result := dec.StringOptimized()
+			result := dec.String()
 			if result != tt.expected {
 				t.Errorf("For %s: expected %s, got %s", tt.input, tt.expected, result)
 			}