json-ld cached doc loader

util/helpers.go

@@ -33,11 +33,15 @@ func IsValidStruct(data interface{}) error {
 func NewLDProcessor() LDProcessor {
 	// JSON LD processing
 	proc := ld.NewJsonLdProcessor()
+	// Initialize a new doc loader with caching capability
+	// LDProcessor is expected to be re-used for multiple json-ld operations
+	docLoader := ld.NewRFC7324CachingDocumentLoader(nil)
 	options := ld.NewJsonLdOptions("")
 	options.Format = "application/n-quads"
 	options.Algorithm = "URDNA2015"
 	options.ProcessingMode = ld.JsonLd_1_1
 	options.ProduceGeneralizedRdf = true
+	options.DocumentLoader = docLoader
 	return LDProcessor{
 		JsonLdProcessor: proc,
 		JsonLdOptions:   options,
@@ -48,6 +52,22 @@ func (l LDProcessor) GetOptions() *ld.JsonLdOptions {
 	return l.JsonLdOptions
 }
 
+func (l LDProcessor) GetContextFromMap(dataMap map[string]interface{}) (*ld.Context, error) {
+	var activeCtx *ld.Context
+	var err error
+	ldCtx := ld.NewContext(nil, l.JsonLdOptions)
+	contextMap, ok := dataMap["@context"].(map[string]interface{})
+	if !ok {
+		activeCtx, err = ldCtx.Parse(dataMap)
+	} else {
+		activeCtx, err = ldCtx.Parse(contextMap)
+	}
+	if err != nil {
+		return nil, err
+	}
+	return activeCtx, nil
+}
+
 func LDNormalize(document interface{}) (interface{}, error) {
 	processor := NewLDProcessor()
 	return processor.Normalize(document, processor.GetOptions())

util/helpers_test.go

@@ -2,7 +2,9 @@ package util
 
 import (
 	"testing"
+	"time"
 
+	"github.com/piprate/json-gold/ld"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -90,3 +92,48 @@ func TestMergeUniqueValues(t *testing.T) {
 		assert.True(tt, len(res) == len(a)+2)
 	})
 }
+
+func TestLDProcessor(t *testing.T) {
+	testJSONDLContextURLStr := "http://schema.org/"
+	ldProcessor := NewLDProcessor()
+
+	t.Run("caching document loader", func(tt *testing.T) {
+		numOfLoads := 5
+		nonCachedLoader := ld.NewDefaultDocumentLoader(nil)
+		t0 := time.Now()
+		for i := 0; i < numOfLoads; i++ {
+			doc, err := nonCachedLoader.LoadDocument(testJSONDLContextURLStr)
+			assert.NoError(tt, err)
+			assert.NotNil(tt, doc)
+		}
+		dtNonCached := time.Now().Sub(t0)
+		tt.Logf("non-cached document loader for %d tests dt: %v\n", numOfLoads, dtNonCached)
+
+		ldProcessor := NewLDProcessor()
+		t1 := time.Now()
+		for i := 0; i < numOfLoads; i++ {
+			doc, err := ldProcessor.DocumentLoader.LoadDocument(testJSONDLContextURLStr)
+			assert.NoError(tt, err)
+			assert.NotNil(tt, doc)
+		}
+		dtCached := time.Now().Sub(t1)
+		tt.Logf("caching document loader for %d tests dt: %v\n", numOfLoads, dtCached)
+
+		assert.True(tt, dtNonCached/dtCached > 2.0)
+	})
+
+	t.Run("get context from map", func(tt *testing.T) {
+		contextMap := map[string]interface{}{
+			"dc": "http://purl.org/dc/elements/1.1/",
+			"ex": "http://example.org/vocab#",
+			"ex:contains": map[string]interface{}{
+				"@type": "@id",
+			},
+		}
+
+		activeCtx, err := ldProcessor.GetContextFromMap(contextMap)
+		//expected activeCtx output is &{values:map[@base: processingMode:json-ld-1.1] options:0xc0001288f0 termDefinitions:map[dc:map[@id:http://purl.org/dc/elements/1.1/ @reverse:false _prefix:true] ex:map[@id:http://example.org/vocab# @reverse:false _prefix:true] ex:contains:map[@id:http://example.org/vocab#contains @reverse:false @type:@id]] inverse:map[] protected:map[] previousContext:<nil>}
+		assert.NoError(tt, err)
+		assert.NotNil(tt, activeCtx)
+	})
+}