added field score calcualtions giving the title a higher weight

3 files changed, 40 insertions, 11 deletions

diff --git a/index/index.go b/index/index.go
index 53f9fca..cceabeb 100644
--- a/index/index.go
+++ b/index/index.go
@@ -1,10 +1,14 @@
 package index
 
-import "sync"
+import (
+	"searchEngine/analyzer"
+	"sync"
+)
 
 type Posting struct {
-	DocId int
-	Count int
+	DocId      int
+	Count      int
+	TitleCount int
 }
 type InvertedIndex struct {
 	Mu       sync.RWMutex
@@ -19,11 +23,25 @@ func New() *InvertedIndex {
 	}
 }
 
-func (idx *InvertedIndex) Add(docID int, title string, tokens []string) {
+func (idx *InvertedIndex) Add(docID int, title string, bodyTokens []string) {
+	titleTokens := analyzer.ProcessText(title)
 
-	tokenCounts := make(map[string]int)
-	for _, token := range tokens {
-		tokenCounts[token]++
+	type fieldStats struct {
+		body  int
+		title int
+	}
+	docStats := make(map[string]fieldStats)
+
+	for _, token := range titleTokens {
+		stats := docStats[token]
+		stats.title++
+		docStats[token] = stats
+	}
+
+	for _, token := range bodyTokens {
+		stats := docStats[token]
+		stats.body++
+		docStats[token] = stats
 	}
 
 	idx.Mu.Lock()
@@ -31,10 +49,11 @@ func (idx *InvertedIndex) Add(docID int, title string, tokens []string) {
 
 	idx.DocNames[docID] = title
 
-	for token, count := range tokenCounts {
+	for token, stats := range docStats {
 		idx.Data[token] = append(idx.Data[token], Posting{
-			DocId: docID,
-			Count: count,
+			DocId:      docID,
+			Count:      stats.body,
+			TitleCount: stats.title,
 		})
 	}
 }
diff --git a/scoring/field.go b/scoring/field.go
new file mode 100644
index 0000000..9637950
--- /dev/null
+++ b/scoring/field.go
@@ -0,0 +1,10 @@
+package scoring
+
+import "searchEngine/index"
+
+var TitleWeight = 5.0
+var BodyWeight = 1.0
+
+func FieldScore(p index.Posting) float64 {
+	return (float64(p.TitleCount) * TitleWeight) + (float64(p.Count) * BodyWeight)
+}
diff --git a/scoring/idf.go b/scoring/idf.go
index 6d96089..5c85ba3 100644
--- a/scoring/idf.go
+++ b/scoring/idf.go
@@ -13,5 +13,5 @@ func CalculateIDF(totalDocs int, docFrequency int) float64 {
 }
 func ScoreTFIDF(p index.Posting, idf float64) float64 {
 
-	return float64(p.Count) * idf
+	return FieldScore(p) * idf
 }