add rutor api

server/rutor/torrsearch/index.go

@@ -0,0 +1,76 @@
+package torrsearch
+
+import (
+	"log"
+	"server/rutor/models"
+	"strconv"
+)
+
+// Index is an inverted Index. It maps tokens to document IDs.
+type Index map[string][]int
+
+var idx Index
+
+func NewIndex(torrs []*models.TorrentDetails) {
+	log.Println("Index torrs")
+	idx = make(Index)
+	idx.add(torrs)
+}
+
+func Search(text string) []int {
+	return idx.search(text)
+}
+
+func (idx Index) add(torrs []*models.TorrentDetails) {
+	for ID, torr := range torrs {
+		for _, token := range analyze(torr.Name + " " + torr.GetNames() + " " + strconv.Itoa(torr.Year)) {
+			ids := idx[token]
+			if ids != nil && ids[len(ids)-1] == ID {
+				// Don't add same ID twice.
+				continue
+			}
+			idx[token] = append(ids, ID)
+		}
+	}
+}
+
+// intersection returns the set intersection between a and b.
+// a and b have to be sorted in ascending order and contain no duplicates.
+func intersection(a []int, b []int) []int {
+	maxLen := len(a)
+	if len(b) > maxLen {
+		maxLen = len(b)
+	}
+	r := make([]int, 0, maxLen)
+	var i, j int
+	for i < len(a) && j < len(b) {
+		if a[i] < b[j] {
+			i++
+		} else if a[i] > b[j] {
+			j++
+		} else {
+			r = append(r, a[i])
+			i++
+			j++
+		}
+	}
+	return r
+}
+
+// Search queries the Index for the given text.
+func (idx Index) search(text string) []int {
+	var r []int
+	for _, token := range analyze(text) {
+		if ids, ok := idx[token]; ok {
+			if r == nil {
+				r = ids
+			} else {
+				r = intersection(r, ids)
+			}
+		} else {
+			// Token doesn't exist.
+			return nil
+		}
+	}
+	return r
+}