optimize expandQuery and ReplaceWithDollarSign

adapter/postgresql/database.go

@@ -99,7 +99,7 @@ func (*database) CompileStatement(sess sqladapter.Session, stmt *exql.Statement,
 	}
 
 	query, args := sqlbuilder.Preprocess(compiled, args)
-	query = sqladapter.ReplaceWithDollarSign(query)
+	query = string(sqladapter.ReplaceWithDollarSign([]byte(query)))
 	return query, args, nil
 }
 

internal/sqladapter/exql/column_value_test.go

@@ -76,10 +76,10 @@ func BenchmarkJoinColumnValues(b *testing.B) {
 func BenchmarkColumnValuesHash(b *testing.B) {
 	cvs := JoinColumnValues(
 		&ColumnValue{Column: ColumnWithName("id"), Operator: ">", Value: NewValue(8)},
-		&ColumnValue{Column: ColumnWithName("other.id"), Operator: "<", Value: NewValue(Raw{Value: "100"})},
+		&ColumnValue{Column: ColumnWithName("other.id"), Operator: "<", Value: NewValue(&Raw{Value: "100"})},
 		&ColumnValue{Column: ColumnWithName("name"), Operator: "=", Value: NewValue("Haruki Murakami")},
-		&ColumnValue{Column: ColumnWithName("created"), Operator: ">=", Value: NewValue(Raw{Value: "NOW()"})},
-		&ColumnValue{Column: ColumnWithName("modified"), Operator: "<=", Value: NewValue(Raw{Value: "NOW()"})},
+		&ColumnValue{Column: ColumnWithName("created"), Operator: ">=", Value: NewValue(&Raw{Value: "NOW()"})},
+		&ColumnValue{Column: ColumnWithName("modified"), Operator: "<=", Value: NewValue(&Raw{Value: "NOW()"})},
 	)
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -90,10 +90,10 @@ func BenchmarkColumnValuesHash(b *testing.B) {
 func BenchmarkColumnValuesCompile(b *testing.B) {
 	cvs := JoinColumnValues(
 		&ColumnValue{Column: ColumnWithName("id"), Operator: ">", Value: NewValue(8)},
-		&ColumnValue{Column: ColumnWithName("other.id"), Operator: "<", Value: NewValue(Raw{Value: "100"})},
+		&ColumnValue{Column: ColumnWithName("other.id"), Operator: "<", Value: NewValue(&Raw{Value: "100"})},
 		&ColumnValue{Column: ColumnWithName("name"), Operator: "=", Value: NewValue("Haruki Murakami")},
-		&ColumnValue{Column: ColumnWithName("created"), Operator: ">=", Value: NewValue(Raw{Value: "NOW()"})},
-		&ColumnValue{Column: ColumnWithName("modified"), Operator: "<=", Value: NewValue(Raw{Value: "NOW()"})},
+		&ColumnValue{Column: ColumnWithName("created"), Operator: ">=", Value: NewValue(&Raw{Value: "NOW()"})},
+		&ColumnValue{Column: ColumnWithName("modified"), Operator: "<=", Value: NewValue(&Raw{Value: "NOW()"})},
 	)
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -105,10 +105,10 @@ func BenchmarkColumnValuesCompileNoCache(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		cvs := JoinColumnValues(
 			&ColumnValue{Column: ColumnWithName("id"), Operator: ">", Value: NewValue(8)},
-			&ColumnValue{Column: ColumnWithName("other.id"), Operator: "<", Value: NewValue(Raw{Value: "100"})},
+			&ColumnValue{Column: ColumnWithName("other.id"), Operator: "<", Value: NewValue(&Raw{Value: "100"})},
 			&ColumnValue{Column: ColumnWithName("name"), Operator: "=", Value: NewValue("Haruki Murakami")},
-			&ColumnValue{Column: ColumnWithName("created"), Operator: ">=", Value: NewValue(Raw{Value: "NOW()"})},
-			&ColumnValue{Column: ColumnWithName("modified"), Operator: "<=", Value: NewValue(Raw{Value: "NOW()"})},
+			&ColumnValue{Column: ColumnWithName("created"), Operator: ">=", Value: NewValue(&Raw{Value: "NOW()"})},
+			&ColumnValue{Column: ColumnWithName("modified"), Operator: "<=", Value: NewValue(&Raw{Value: "NOW()"})},
 		)
 		_, _ = cvs.Compile(defaultTemplate)
 	}

internal/sqladapter/session.go

 package sqladapter
 
 import (
+	"bytes"
 	"context"
 	"database/sql"
 	"database/sql/driver"
 	"errors"
 	"fmt"
-	"log"
 	"math"
 	"reflect"
 	"strconv"
@@ -657,7 +657,6 @@ func (sess *sessionWithContext) Collection(name string) db.Collection {
 	h := cache.NewHashable(hashTypeCollection, name)
 
 	cachedCol, ok := sess.cachedCollections.ReadRaw(h)
-	log.Printf("CACHED: %v, ok: %v", cachedCol, ok)
 	if ok {
 		return cachedCol.(db.Collection)
 	}
@@ -1004,29 +1003,37 @@ func (sess *sessionWithContext) WaitForConnection(connectFn func() error) error
 
 // ReplaceWithDollarSign turns a SQL statament with '?' placeholders into
 // dollar placeholders, like $1, $2, ..., $n
-func ReplaceWithDollarSign(in string) string {
-	buf := []byte(in)
-	out := make([]byte, 0, len(buf))
-
-	i, j, k, t := 0, 1, 0, len(buf)
-
-	for i < t {
+func ReplaceWithDollarSign(buf []byte) []byte {
+	z := bytes.Count(buf, []byte{'?'})
+	// the capacity is a quick estimation of the total memory required, this
+	// reduces reallocations
+	out := make([]byte, 0, len(buf)+z*3)
+
+	var i, k = 0, 1
+	for i < len(buf) {
 		if buf[i] == '?' {
-			out = append(out, buf[k:i]...)
-			k = i + 1
+			out = append(out, buf[:i]...)
+			buf = buf[i+1:]
+			i = 0
 
-			if k < t && buf[k] == '?' {
-				i = k
-			} else {
-				out = append(out, []byte("$"+strconv.Itoa(j))...)
-				j++
+			if len(buf) > 0 && buf[0] == '?' {
+				out = append(out, '?')
+				buf = buf[1:]
+				continue
 			}
+
+			out = append(out, '$')
+			out = append(out, []byte(strconv.Itoa(k))...)
+			k = k + 1
+			continue
 		}
-		i++
+		i = i + 1
 	}
-	out = append(out, buf[k:i]...)
 
-	return string(out)
+	out = append(out, buf[:len(buf)]...)
+	buf = nil
+
+	return out
 }
 
 func copySettings(from Session, into Session) {

internal/sqlbuilder/convert.go

 package sqlbuilder
 
 import (
+	"bytes"
 	"database/sql/driver"
 	"reflect"
-	"strings"
 
 	"github.com/upper/db/v4/internal/adapter"
 	"github.com/upper/db/v4/internal/sqladapter/exql"
@@ -13,31 +13,75 @@ var (
 	sqlDefault = &exql.Raw{Value: "DEFAULT"}
 )
 
-func expandQuery(in string, args []interface{}, fn func(interface{}) (string, []interface{})) (string, []interface{}) {
-	argn := 0
-	argx := make([]interface{}, 0, len(args))
-	for i := 0; i < len(in); i++ {
-		if in[i] != '?' {
+func expandQuery(in []byte, inArgs []interface{}) ([]byte, []interface{}) {
+	out := make([]byte, 0, len(in))
+	outArgs := make([]interface{}, 0, len(inArgs))
+
+	i := 0
+	for i < len(in) && len(inArgs) > 0 {
+		if in[i] == '?' {
+			out = append(out, in[:i]...)
+			in = in[i+1:]
+			i = 0
+
+			replace, replaceArgs := expandArgument(inArgs[0])
+			inArgs = inArgs[1:]
+
+			if len(replace) > 0 {
+				replace, replaceArgs = expandQuery(replace, replaceArgs)
+				out = append(out, replace...)
+			} else {
+				out = append(out, '?')
+			}
+
+			outArgs = append(outArgs, replaceArgs...)
 			continue
 		}
-		if len(args) > argn {
-			k, values := fn(args[argn])
-			k, values = expandQuery(k, values, fn)
+		i = i + 1
+	}
+
+	if len(out) < 1 {
+		return in, inArgs
+	}
+
+	out = append(out, in[:len(in)]...)
+	in = nil
+
+	outArgs = append(outArgs, inArgs[:len(inArgs)]...)
+	inArgs = nil
+
+	return out, outArgs
+}
 
-			if k != "" {
-				in = in[:i] + k + in[i+1:]
-				i += len(k) - 1
+func expandArgument(arg interface{}) ([]byte, []interface{}) {
+	values, isSlice := toInterfaceArguments(arg)
+
+	if isSlice {
+		if len(values) == 0 {
+			return []byte("(NULL)"), nil
 		}
-			if len(values) > 0 {
-				argx = append(argx, values...)
+		buf := bytes.Repeat([]byte(" ?,"), len(values))
+		buf[0] = '('
+		buf[len(buf)-1] = ')'
+		return buf, values
 	}
-			argn++
+
+	if len(values) == 1 {
+		switch t := arg.(type) {
+		case *adapter.RawExpr:
+			return expandQuery([]byte(t.Raw()), t.Arguments())
+		case compilable:
+			s, err := t.Compile()
+			if err == nil {
+				return append([]byte{'('}, append([]byte(s), ')')...), t.Arguments()
 			}
+			panic(err.Error())
 		}
-	if len(argx) < len(args) {
-		argx = append(argx, args[argn:]...)
+	} else if len(values) == 0 {
+		return []byte("NULL"), nil
 	}
-	return in, argx
+
+	return nil, []interface{}{arg}
 }
 
 // toInterfaceArguments converts the given value into an array of interfaces.
@@ -145,5 +189,6 @@ func preprocessFn(arg interface{}) (string, []interface{}) {
 // Preprocess expands arguments that needs to be expanded and compiles a query
 // into a single string.
 func Preprocess(in string, args []interface{}) (string, []interface{}) {
-	return expandQuery(in, args, preprocessFn)
+	b, args := expandQuery([]byte(in), args)
+	return string(b), args
 }