Numeric: refactoring and truncate for BigQuery

flow/connectors/bigquery/qrep_avro_sync.go

@@ -14,7 +14,6 @@ import (
 	"go.temporal.io/sdk/activity"
 
 	avro "github.com/PeerDB-io/peer-flow/connectors/utils/avro"
-	numeric "github.com/PeerDB-io/peer-flow/datatypes"
 	"github.com/PeerDB-io/peer-flow/generated/protos"
 	"github.com/PeerDB-io/peer-flow/model"
 	"github.com/PeerDB-io/peer-flow/model/qvalue"
@@ -281,12 +280,8 @@ func DefineAvroSchema(dstTableName string,
 }
 
 func GetAvroType(bqField *bigquery.FieldSchema) (interface{}, error) {
-	avroNumericPrecision := int16(bqField.Precision)
-	avroNumericScale := int16(bqField.Scale)
-	bqNumeric := numeric.BigQueryNumericCompatibility{}
-	if !bqNumeric.IsValidPrevisionAndScale(avroNumericPrecision, avroNumericScale) {
-		avroNumericPrecision, avroNumericScale = bqNumeric.DefaultPrecisionAndScale()
-	}
+	avroNumericPrecision, avroNumericScale := qvalue.DetermineNumericSettingForDWH(
+		int16(bqField.Precision), int16(bqField.Scale), protos.DBType_BIGQUERY)
 
 	considerRepeated := func(typ string, repeated bool) interface{} {
 		if repeated {

flow/datatypes/bigint.go

@@ -0,0 +1,33 @@
+package datatypes
+
+import (
+	"math"
+	"math/big"
+)
+
+var tenInt = big.NewInt(10)
+
+func CountDigits(bi *big.Int) int {
+	if bi.IsInt64() {
+		i64 := bi.Int64()
+		// restrict fast path to integers with exact conversion to float64
+		if i64 <= (1<<53) && i64 >= -(1<<53) {
+			if i64 == 0 {
+				return 1
+			}
+			return int(math.Log10(math.Abs(float64(i64)))) + 1
+		}
+	}
+
+	estimatedNumDigits := int(float64(bi.BitLen()) / math.Log2(10))
+
+	// estimatedNumDigits (lg10) may be off by 1, need to verify
+	digitsBigInt := big.NewInt(int64(estimatedNumDigits))
+	errorCorrectionUnit := digitsBigInt.Exp(tenInt, digitsBigInt, nil)
+
+	if bi.CmpAbs(errorCorrectionUnit) >= 0 {
+		return estimatedNumDigits + 1
+	}
+
+	return estimatedNumDigits
+}

flow/datatypes/bigint_test.go

@@ -0,0 +1,38 @@
+package datatypes
+
+import (
+	"math/big"
+	"testing"
+)
+
+func TestCountDigits(t *testing.T) {
+	bi := big.NewInt(-0)
+	expected := 1
+	result := CountDigits(bi)
+	if result != expected {
+		t.Errorf("Unexpected result. Expected: %v, but got: %v", expected, result)
+	}
+
+	bi = big.NewInt(0)
+	expected = 1
+	result = CountDigits(bi)
+	if result != expected {
+		t.Errorf("Unexpected result. Expected: %v, but got: %v", expected, result)
+	}
+
+	// 18 nines
+	bi = big.NewInt(999999999999999999)
+	result = CountDigits(bi)
+	expected = 18
+	if result != expected {
+		t.Errorf("Unexpected result. Expected: %v, but got: %v", expected, result)
+	}
+
+	// 18 nines
+	bi = big.NewInt(-999999999999999999)
+	result = CountDigits(bi)
+	expected = 18
+	if result != expected {
+		t.Errorf("Unexpected result. Expected: %v, but got: %v", expected, result)
+	}
+}

flow/datatypes/numeric.go

@@ -15,7 +15,7 @@ type WarehouseNumericCompatibility interface {
 	MaxPrecision() int16
 	MaxScale() int16
 	DefaultPrecisionAndScale() (int16, int16)
-	IsValidPrevisionAndScale(precision, scale int16) bool
+	IsValidPrecisionAndScale(precision, scale int16) bool
 }
 
 type ClickHouseNumericCompatibility struct{}
@@ -32,7 +32,7 @@ func (ClickHouseNumericCompatibility) DefaultPrecisionAndScale() (int16, int16)
 	return PeerDBClickhousePrecision, PeerDBClickhouseScale
 }
 
-func (ClickHouseNumericCompatibility) IsValidPrevisionAndScale(precision, scale int16) bool {
+func (ClickHouseNumericCompatibility) IsValidPrecisionAndScale(precision, scale int16) bool {
 	return precision > 0 && precision <= PeerDBClickhousePrecision && scale < precision
 }
 
@@ -50,7 +50,7 @@ func (SnowflakeNumericCompatibility) DefaultPrecisionAndScale() (int16, int16) {
 	return PeerDBSnowflakePrecision, PeerDBSnowflakeScale
 }
 
-func (SnowflakeNumericCompatibility) IsValidPrevisionAndScale(precision, scale int16) bool {
+func (SnowflakeNumericCompatibility) IsValidPrecisionAndScale(precision, scale int16) bool {
 	return precision > 0 && precision <= 38 && scale < precision
 }
 
@@ -68,8 +68,9 @@ func (BigQueryNumericCompatibility) DefaultPrecisionAndScale() (int16, int16) {
 	return PeerDBBigQueryPrecision, PeerDBBigQueryScale
 }
 
-func (BigQueryNumericCompatibility) IsValidPrevisionAndScale(precision, scale int16) bool {
-	return precision > 0 && precision <= 38 && scale <= 20 && scale < precision
+func (BigQueryNumericCompatibility) IsValidPrecisionAndScale(precision, scale int16) bool {
+	return precision > 0 && precision <= PeerDBBigQueryPrecision &&
+		scale <= PeerDBBigQueryScale && scale < precision
 }
 
 type DefaultNumericCompatibility struct{}
@@ -86,7 +87,7 @@ func (DefaultNumericCompatibility) DefaultPrecisionAndScale() (int16, int16) {
 	return 38, 20
 }
 
-func (DefaultNumericCompatibility) IsValidPrevisionAndScale(precision, scale int16) bool {
+func (DefaultNumericCompatibility) IsValidPrecisionAndScale(precision, scale int16) bool {
 	return true
 }
 
@@ -112,7 +113,7 @@ func GetNumericTypeForWarehouse(typmod int32, warehouseNumeric WarehouseNumericC
 	}
 
 	precision, scale := ParseNumericTypmod(typmod)
-	if !warehouseNumeric.IsValidPrevisionAndScale(precision, scale) {
+	if !warehouseNumeric.IsValidPrecisionAndScale(precision, scale) {
 		return warehouseNumeric.DefaultPrecisionAndScale()
 	}
 

flow/model/qvalue/avro_converter.go

@@ -4,8 +4,6 @@ import (
 	"errors"
 	"fmt"
 	"log/slog"
-	"math"
-	"math/big"
 	"time"
 
 	"github.com/google/uuid"
@@ -52,6 +50,21 @@ type AvroSchemaField struct {
 	LogicalType string      `json:"logicalType,omitempty"`
 }
 
+func TruncateOrLogNumeric(num decimal.Decimal, precision int16, scale int16, targetDB protos.DBType) (decimal.Decimal, error) {
+	if targetDB == protos.DBType_SNOWFLAKE || targetDB == protos.DBType_BIGQUERY {
+		bidigi := datatypes.CountDigits(num.BigInt())
+		avroPrecision, avroScale := DetermineNumericSettingForDWH(precision, scale, targetDB)
+		if bidigi+int(avroScale) > int(avroPrecision) {
+			slog.Warn("Clearing NUMERIC value with too many digits", slog.Any("number", num))
+			return num, errors.New("invalid numeric")
+		} else if num.Exponent() < -int32(avroScale) {
+			num = num.Truncate(int32(avroScale))
+			slog.Warn("Truncated NUMERIC value", slog.Any("number", num))
+		}
+	}
+	return num, nil
+}
+
 // GetAvroSchemaFromQValueKind returns the Avro schema for a given QValueKind.
 // The function takes in two parameters, a QValueKind and a boolean indicating if the
 // Avro schema should respect null values. It returns a QValueKindAvroSchema object
@@ -430,45 +443,12 @@ func (c *QValueAvroConverter) processNullableUnion(
 	return value, nil
 }
 
-var tenInt = big.NewInt(10)
-
-func countDigits(bi *big.Int) int {
-	if bi.IsInt64() {
-		i64 := bi.Int64()
-		// restrict fast path to integers with exact conversion to float64
-		if i64 <= (1<<53) && i64 >= -(1<<53) {
-			if i64 == 0 {
-				return 1
-			}
-			return int(math.Log10(math.Abs(float64(i64)))) + 1
-		}
-	}
-
-	estimatedNumDigits := int(float64(bi.BitLen()) / math.Log2(10))
-
-	// estimatedNumDigits (lg10) may be off by 1, need to verify
-	digitsBigInt := big.NewInt(int64(estimatedNumDigits))
-	errorCorrectionUnit := digitsBigInt.Exp(tenInt, digitsBigInt, nil)
-
-	if bi.CmpAbs(errorCorrectionUnit) >= 0 {
-		return estimatedNumDigits + 1
-	}
-
-	return estimatedNumDigits
-}
-
 func (c *QValueAvroConverter) processNumeric(num decimal.Decimal) interface{} {
-	if c.TargetDWH == protos.DBType_SNOWFLAKE {
-		bidigi := countDigits(num.BigInt())
-		avroPrecision, avroScale := DetermineNumericSettingForDWH(c.Precision, c.Scale, c.TargetDWH)
-
-		if bidigi+int(avroScale) > int(avroPrecision) {
-			slog.Warn("Clearing NUMERIC value with too many digits for Snowflake!", slog.Any("number", num))
-			return nil
-		} else if num.Exponent() < -int32(avroScale) {
-			num = num.Round(int32(avroScale))
-		}
+	num, err := TruncateOrLogNumeric(num, c.Precision, c.Scale, c.TargetDWH)
+	if err != nil {
+		return nil
 	}
+
 	rat := num.Rat()
 	if c.Nullable {
 		return goavro.Union("bytes.decimal", rat)

flow/model/qvalue/dwh.go

@@ -22,7 +22,7 @@ func DetermineNumericSettingForDWH(precision int16, scale int16, dwh protos.DBTy
 		warehouseNumeric = numeric.DefaultNumericCompatibility{}
 	}
 
-	if !warehouseNumeric.IsValidPrevisionAndScale(precision, scale) {
+	if !warehouseNumeric.IsValidPrecisionAndScale(precision, scale) {
 		precision, scale = warehouseNumeric.DefaultPrecisionAndScale()
 	}