Improve performance of n-quads parsing

.github/workflows/ci.yml

@@ -16,7 +16,7 @@ jobs:
     steps:
       - uses: actions/setup-go@v3
         with:
-          go-version: 1.18
+          go-version: 1.21
 
       - name: Checkout code
         uses: actions/checkout@v2
@@ -53,7 +53,7 @@ jobs:
         uses: actions/checkout@v3
       - uses: actions/setup-go@v3
         with:
-          go-version: 1.18
+          go-version: 1.21
       - uses: actions/cache@v3
         with:
           path: |
@@ -65,7 +65,7 @@ jobs:
       - uses: zencargo/github-action-go-mod-tidy@v1
         with:
           path: .
-          go-version: 1.18
+          go-version: 1.21
 
   test:
     runs-on: ubuntu-latest
@@ -75,7 +75,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v3
         with:
-          go-version: 1.18
+          go-version: 1.21
       - name: Set up Cache
         uses: actions/cache@v3
         with:

go.mod

@@ -1,10 +1,11 @@
 module github.com/piprate/json-gold
 
-go 1.18
+go 1.21
 
 require (
-	github.com/pquerna/cachecontrol v0.0.0-20180517163645-1555304b9b35
-	github.com/stretchr/testify v1.8.3
+	github.com/cayleygraph/quad v1.3.0
+	github.com/pquerna/cachecontrol v0.2.0
+	github.com/stretchr/testify v1.9.0
 )
 
 require (

go.sum

@@ -1,12 +1,18 @@
+github.com/cayleygraph/quad v1.3.0 h1:xg7HOLWWPgvZ4CcvzEpfCwq42L8mzYUR+8V0jtYoBzc=
+github.com/cayleygraph/quad v1.3.0/go.mod h1:NadtM7uMm78FskmX++XiOOrNvgkq0E1KvvhQdMseMz4=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/pquerna/cachecontrol v0.0.0-20180517163645-1555304b9b35 h1:J9b7z+QKAmPf4YLrFg6oQUotqHQeUNWwkvo7jZp1GLU=
-github.com/pquerna/cachecontrol v0.0.0-20180517163645-1555304b9b35/go.mod h1:prYjPmNq4d1NPVmpShWobRqXY3q7Vp+80DqgxxUrUIA=
-github.com/stretchr/testify v1.8.3 h1:RP3t2pwF7cMEbC1dqtB6poj3niw/9gnV4Cjg5oW5gtY=
-github.com/stretchr/testify v1.8.3/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+github.com/pquerna/cachecontrol v0.2.0 h1:vBXSNuE5MYP9IJ5kjsdo8uq+w41jSPgvba2DEnkRx9k=
+github.com/pquerna/cachecontrol v0.2.0/go.mod h1:NrUG3Z7Rdu85UNR3vm7SOsl1nFIeSiQnrHV5K9mBcUI=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

ld/serialize_nquads.go

@@ -19,8 +19,10 @@ import (
 	"bytes"
 	"fmt"
 	"io"
-	"regexp"
 	"strings"
+
+	"github.com/cayleygraph/quad"
+	"github.com/cayleygraph/quad/nquads"
 )
 
 // NQuadRDFSerializer parses and serializes N-Quads.
@@ -108,15 +110,6 @@ func toNQuad(triple *Quad, graphName string) string {
 	return quad
 }
 
-func unescape(str string) string {
-	str = strings.ReplaceAll(str, "\\\\", "\\")
-	str = strings.ReplaceAll(str, "\\\"", "\"")
-	str = strings.ReplaceAll(str, "\\n", "\n")
-	str = strings.ReplaceAll(str, "\\r", "\r")
-	str = strings.ReplaceAll(str, "\\t", "\t")
-	return str
-}
-
 func escape(str string) string {
 	str = strings.ReplaceAll(str, "\\", "\\\\")
 	str = strings.ReplaceAll(str, "\"", "\\\"")
@@ -126,66 +119,6 @@ func escape(str string) string {
 	return str
 }
 
-const (
-	wso = "[ \\t]*"
-	iri = "(?:<([^:]+:[^>]*)>)"
-
-	// https://www.w3.org/TR/turtle/#grammar-production-BLANK_NODE_LABEL
-
-	pnCharsBase = "A-Z" + "a-z" +
-		"\u00C0-\u00D6" +
-		"\u00D8-\u00F6" +
-		"\u00F8-\u02FF" +
-		"\u0370-\u037D" +
-		"\u037F-\u1FFF" +
-		"\u200C-\u200D" +
-		"\u2070-\u218F" +
-		"\u2C00-\u2FEF" +
-		"\u3001-\uD7FF" +
-		"\uF900-\uFDCF" +
-		"\uFDF0-\uFFFD"
-	// TODO:
-	//"\u10000-\uEFFFF"
-
-	pnCharsU = pnCharsBase + "_"
-
-	pnChars = pnCharsU +
-		"0-9" +
-		"-" +
-		"\u00B7" +
-		"\u0300-\u036F" +
-		"\u203F-\u2040"
-
-	blankNodeLabel = "(_:" +
-		"(?:[" + pnCharsU + "0-9])" +
-		"(?:(?:[" + pnChars + ".])*(?:[" + pnChars + "]))?" +
-		")"
-
-	//   '(_:' +
-	//     '(?:[' + PN_CHARS_U + '0-9])' +
-	//     '(?:(?:[' + PN_CHARS + '.])*(?:[' + PN_CHARS + ']))?' +
-	//   ')';
-
-	bnode = blankNodeLabel
-
-	plain    = "\"([^\"\\\\]*(?:\\\\.[^\"\\\\]*)*)\""
-	datatype = "(?:\\^\\^" + iri + ")"
-	language = "(?:@([a-z]+(?:-[a-zA-Z0-9]+)*))"
-	literal  = "(?:" + plain + "(?:" + datatype + "|" + language + ")?)"
-	ws       = "[ \\t]+"
-
-	subject  = "(?:" + iri + "|" + bnode + ")" + ws
-	property = iri + ws
-	object   = "(?:" + iri + "|" + bnode + "|" + literal + ")" + wso
-	graph    = "(?:\\.|(?:(?:" + iri + "|" + bnode + ")" + wso + "\\.))"
-)
-
-var regexEmpty = regexp.MustCompile("^" + wso + "$")
-
-// full quad regex
-
-var regexQuad = regexp.MustCompile("^" + wso + subject + property + object + graph + wso + "$") //nolint:gocritic
-
 type lineScanner interface {
 	Bytes() []byte
 	Scan() bool
@@ -253,53 +186,63 @@ func ParseNQuadsFrom(o interface{}) (*RDFDataset, error) {
 		lineNumber++
 
 		// skip empty lines
-		if regexEmpty.Match(line) {
+		if isEmpty(line) {
 			continue
 		}
 
 		// parse quad
-		if !regexQuad.Match(line) {
-			return nil, NewJsonLdError(SyntaxError, fmt.Errorf("error while parsing N-Quads; invalid quad. line: %d", lineNumber))
+		q, err := nquads.ParseRaw(string(line))
+		if err != nil {
+			return nil, NewJsonLdError(SyntaxError, fmt.Errorf("error while parsing N-Quads; invalid quad. line: %d. reason: %w", lineNumber, err))
 		}
-		match := regexQuad.FindStringSubmatch(string(line))
 
 		// get subject
 		var subject Node
-		if match[1] != "" {
-			subject = NewIRI(unescape(match[1]))
-		} else {
-			subject = NewBlankNode(unescape(match[2]))
+		switch v := q.Subject.(type) {
+		case quad.IRI:
+			subject = NewIRI(string(v))
+		case quad.BNode:
+			subject = NewBlankNode(v.String())
+		default:
+			return nil, fmt.Errorf("invalid subject: %s", q.Subject.String())
 		}
 
 		// get predicate
-		predicate := NewIRI(unescape(match[3]))
+		var predicate Node
+		if iri, ok := q.Predicate.(quad.IRI); ok {
+			predicate = NewIRI(string(iri))
+		} else {
+			return nil, fmt.Errorf("invalid predicate: %s", q.Predicate.String())
+		}
 
 		// get object
 		var object Node
-		if match[4] != "" {
-			object = NewIRI(unescape(match[4]))
-		} else if match[5] != "" {
-			object = NewBlankNode(unescape(match[5]))
-		} else {
-			language := unescape(match[8])
-			var datatype string
-			if match[7] != "" {
-				datatype = unescape(match[7])
-			} else if match[8] != "" {
-				datatype = RDFLangString
-			} else {
-				datatype = XSDString
-			}
-			unescaped := unescape(match[6])
-			object = NewLiteral(unescaped, datatype, language)
+		switch obj := q.Object.(type) {
+		case quad.IRI:
+			object = NewIRI(string(obj))
+		case quad.BNode:
+			object = NewBlankNode(obj.String())
+		case quad.TypedString:
+			object = NewLiteral(string(obj.Value), string(obj.Type), "")
+		case quad.LangString:
+			object = NewLiteral(string(obj.Value), RDFLangString, obj.Lang)
+		case quad.String:
+			object = NewLiteral(string(obj), XSDString, "")
+		default:
+			return nil, fmt.Errorf("invalid object: %s", q.Object.String())
 		}
 
 		// get graph name ('@default' is used for the default graph)
 		name := "@default"
-		if match[9] != "" {
-			name = unescape(match[9])
-		} else if match[10] != "" {
-			name = unescape(match[10])
+		if label := q.Label; label != nil {
+			switch label := label.(type) {
+			case quad.IRI:
+				name = string(label)
+			case quad.BNode:
+				name = label.String()
+			default:
+				return nil, fmt.Errorf("invalid label: %s", q.Label.String())
+			}
 		}
 
 		triple := NewQuad(subject, predicate, object, name)
@@ -331,3 +274,12 @@ func ParseNQuadsFrom(o interface{}) (*RDFDataset, error) {
 func ParseNQuads(input string) (*RDFDataset, error) {
 	return ParseNQuadsFrom(input)
 }
+
+func isEmpty(line []byte) bool {
+	for _, b := range line {
+		if b != ' ' && b != '\t' {
+			return false
+		}
+	}
+	return true
+}

ld/serialize_nquads_bench_test.go

@@ -0,0 +1,51 @@
+// Copyright 2026 Siemens AG
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ld
+
+import (
+	"testing"
+)
+
+var benchInput string = `
+<http://example.org/subject> <http://example.org/predicate> <http://example.org/object> .
+
+_:b0 <http://example.org/predicate> <http://example.org/object> .
+
+<http://example.org/subject> <http://example.org/predicate> _:b0 .
+
+<http://example.org/subject> <http://example.org/predicate> "literal value" .
+
+<http://example.org/subject> <http://example.org/predicate> "Hello World"@en .
+
+<http://example.org/subject> <http://example.org/predicate> "42"^^<http://www.w3.org/2001/XMLSchema#integer> .
+
+<http://example.org/subject> <http://example.org/predicate> "Line 1\\nLine 2\\tTabbed" .
+
+<http://example.org/subject> <http://example.org/predicate> <http://example.org/object> <http://example.org/graph> .
+
+<http://example.org/subject> <http://example.org/predicate> <http://example.org/object> _:graph .
+
+<http://example.org/subject> <http://example.org/predicate> "Quote: \"nested\" and backslash: \\\\" .
+`
+
+func BenchmarkParseNQuadsFrom(b *testing.B) {
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		_, err := ParseNQuads(benchInput)
+		if err != nil {
+			b.Fatalf("failed to parse benchInput: %s", err)
+		}
+	}
+}