Cleanup

server.go

@@ -117,7 +117,12 @@ func handleExecuteQuery(rw http.ResponseWriter, req *http.Request) {
 		geo = &geoData{request.Geo.Latitude, request.Geo.Longitude}
 	}
 
-	allEntries := getRecords(queryContext{geo, request.Profile, request.WalkingDist})
+	allEntries, err := fetchRecords(db, queryContext{geo, request.Profile, request.WalkingDist})
+	if err != nil {
+		http.Error(rw, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
 	features := fixFeatures(request.Features)
 	modes := fixModes(request.Modes)
 
@@ -241,13 +246,13 @@ func handleAddCategory(rw http.ResponseWriter, req *http.Request) {
 			return
 		}
 
-		affectedRows, err := result.RowsAffected()
+		rows, err := result.RowsAffected()
 		if err != nil {
 			http.Error(rw, err.Error(), http.StatusInternalServerError)
 			return
 		}
 
-		response.Success = affectedRows > 0
+		response.Success = rows > 0
 		response.Id = int(insertId)
 	}
 
@@ -315,6 +320,7 @@ func handleAccessReview(rw http.ResponseWriter, req *http.Request) {
 	}
 
 	if rowsAffected == 0 || len(request.Profile) == 0 {
+		http.Error(rw, err.Error(), http.StatusInternalServerError)
 		return
 	}
 

util.go

@@ -23,10 +23,9 @@
 package main
 
 import (
-	"log"
+	"database/sql"
 	"math"
 	"strconv"
-	"sync"
 
 	"github.com/kellydunn/golang-geo"
 )
@@ -69,7 +68,7 @@ func fixModes(modes map[string]string) map[string]modeType {
 	return fixedModes
 }
 
-func similarity(features1 map[string]float64, features2 map[string]float64) float64 {
+func semanticSimilarity(features1 map[string]float64, features2 map[string]float64) float64 {
 	var result float64
 
 	for key, value1 := range features1 {
@@ -81,7 +80,7 @@ func similarity(features1 map[string]float64, features2 map[string]float64) floa
 	return result
 }
 
-func compare(features1 map[string]float64, features2 map[string]float64, modes map[string]modeType) float64 {
+func semanticCompare(features1 map[string]float64, features2 map[string]float64, modes map[string]modeType) float64 {
 	var result float64
 
 	for key, value1 := range features1 {
@@ -92,8 +91,6 @@ func compare(features1 map[string]float64, features2 map[string]float64, modes m
 			result += 1 - math.Abs(value1-value2)
 		case modeTypeProd:
 			result += value1 * value2
-		default:
-			log.Fatal("unsupported compare mode")
 		}
 	}
 
@@ -102,7 +99,7 @@ func compare(features1 map[string]float64, features2 map[string]float64, modes m
 
 func walkMatches(entries []record, features map[string]float64, modes map[string]modeType, minScore float64, callback func(record, float64)) {
 	for _, entry := range entries {
-		if score := compare(features, entry.features, modes); score >= minScore {
+		if score := semanticCompare(features, entry.features, modes); score >= minScore {
 			callback(entry, score)
 		}
 	}
@@ -163,7 +160,7 @@ func project(entries []record, features map[string]float64, modes map[string]mod
 	return projections
 }
 
-func computeRecordsGeo(entries []record, context queryContext) {
+func computeRecordGeo(entries []record, context queryContext) {
 	distUserMin := math.MaxFloat64
 	distUserMax := 0.0
 
@@ -199,12 +196,13 @@ func computeRecordsGeo(entries []record, context queryContext) {
 	}
 }
 
-func computeRecordCompat(entry *record, context queryContext, wg *sync.WaitGroup) {
+func computeRecordCompat(db *sql.DB, entries []record, context queryContext) error {
-	defer wg.Done()
+	for i := range entries {
+		entry := &entries[i]
 
 		historyRows, err := db.Query("SELECT id FROM history WHERE reviewId = (?)", entry.Id)
 		if err != nil {
-		log.Fatal(err)
+			return err
 		}
 		defer historyRows.Close()
 
@@ -216,12 +214,12 @@ func computeRecordCompat(entry *record, context queryContext, wg *sync.WaitGroup
 		for historyRows.Next() {
 			var historyId int
 			if err := historyRows.Scan(&historyId); err != nil {
-			log.Fatal(err)
+				return err
 			}
 
 			groupRows, err := db.Query("SELECT categoryId, categoryValue FROM historyGroups WHERE historyId = (?)", historyId)
 			if err != nil {
-			log.Fatal(err)
+				return err
 			}
 			defer groupRows.Close()
 
@@ -233,57 +231,39 @@ func computeRecordCompat(entry *record, context queryContext, wg *sync.WaitGroup
 				)
 
 				if err := groupRows.Scan(&categoryId, &categoryValue); err != nil {
-				log.Fatal(err)
+					return err
 				}
 
 				recordProfile[strconv.Itoa(categoryId)] = categoryValue
 			}
 			if err := groupRows.Err(); err != nil {
-			log.Fatal(err)
+				return err
 			}
 
-		groupSum += similarity(recordProfile, context.profile)
+			groupSum += semanticSimilarity(recordProfile, context.profile)
 			groupCount++
 		}
 		if err := historyRows.Err(); err != nil {
-		log.Fatal(err)
+			return err
 		}
 
 		if groupCount > 0 {
 			entry.Compatibility = groupSum / float64(groupCount)
 		}
+	}
+
+	return nil
 }
 
-func computeRecordsCompat(entries []record, context queryContext) {
+func fetchRecords(db *sql.DB, context queryContext) ([]record, error) {
-	count := len(entries)
+	rows, err := db.Query("SELECT name, url, delicious, accommodating, affordable, atmospheric, latitude, longitude, closestStnDist, closestStnName, accessCount, id FROM reviews")
-	limit := 32
-
-	for i := 0; i < count; i += limit {
-		batch := count - i
-		if batch > limit {
-			batch = limit
-		}
-
-		var wg sync.WaitGroup
-		wg.Add(batch)
-
-		for j := 0; j < batch; j++ {
-			go computeRecordCompat(&entries[i+j], context, &wg)
-		}
-
-		wg.Wait()
-	}
-}
-
-func getRecords(context queryContext) []record {
-	recordRows, err := db.Query("SELECT name, url, delicious, accommodating, affordable, atmospheric, latitude, longitude, closestStnDist, closestStnName, accessCount, id FROM reviews")
 	if err != nil {
-		log.Fatal(err)
+		return nil, err
 	}
-	defer recordRows.Close()
+	defer rows.Close()
 
 	var entries []record
-	for recordRows.Next() {
+	for rows.Next() {
 		var (
 			name, url, closestStn                             string
 			delicious, accommodating, affordable, atmospheric float64
@@ -291,7 +271,7 @@ func getRecords(context queryContext) []record {
 			accessCount, id                                   int
 		)
 
-		recordRows.Scan(
+		rows.Scan(
 			&name,
 			&url,
 			&delicious,
@@ -322,12 +302,14 @@ func getRecords(context queryContext) []record {
 
 		entries = append(entries, entry)
 	}
-	if err := recordRows.Err(); err != nil {
+	if err := rows.Err(); err != nil {
-		log.Fatal(err)
+		return nil, err
 	}
 
-	computeRecordsCompat(entries, context)
+	computeRecordGeo(entries, context)
-	computeRecordsGeo(entries, context)
+	if err := computeRecordCompat(db, entries, context); err != nil {
+		return nil, err
+	}
 
-	return entries
+	return entries, nil
 }