From 7e884fd04f0d6eb03cc1d1c667573aa1d96daa0d Mon Sep 17 00:00:00 2001
From: Eliot Whalan <ewhal@pantsu.cat>
Date: Mon, 8 May 2017 23:50:18 +1000
Subject: [PATCH] Optimize sql queries

---
 main.go                    |  2 --
 service/torrent/torrent.go | 16 +++++++++++-----
 util/search/search.go      | 30 +++++++++++++++---------------
 3 files changed, 26 insertions(+), 22 deletions(-)

diff --git a/main.go b/main.go
index 2784a9c5..f697cc9d 100644
--- a/main.go
+++ b/main.go
@@ -10,7 +10,6 @@ import (
 	"github.com/ewhal/nyaa/network"
 	"github.com/ewhal/nyaa/router"
 	"github.com/ewhal/nyaa/util/log"
-	"github.com/ewhal/nyaa/util/search" // super hacky fix
 	"github.com/ewhal/nyaa/util/signals"
 
 	"net/http"
@@ -61,7 +60,6 @@ func main() {
 		if len(config.TorrentFileStorage) > 0 {
 			os.MkdirAll(config.TorrentFileStorage, 0755)
 		}
-		search.Init(conf.DBType) // super hacky fix
 		RunServer(conf)
 	}
 }
diff --git a/service/torrent/torrent.go b/service/torrent/torrent.go
index 1e5260e7..40191c17 100644
--- a/service/torrent/torrent.go
+++ b/service/torrent/torrent.go
@@ -6,8 +6,8 @@ import (
 	"github.com/ewhal/nyaa/db"
 	"github.com/ewhal/nyaa/model"
 	"github.com/ewhal/nyaa/util"
-	"github.com/jinzhu/gorm"
 	"strings"
+	"strconv"
 )
 
 type WhereParams struct {
@@ -54,7 +54,6 @@ func GetTorrentById(id string) (model.Torrents, error) {
 
 func GetTorrentsOrderBy(parameters *WhereParams, orderBy string, limit int, offset int) ([]model.Torrents, int) {
 	var torrents []model.Torrents
-	var dbQuery *gorm.DB
 	var count int
 	conditions := "torrent_hash IS NOT NULL" // filter out broken entries
 	if strings.HasPrefix(orderBy, "filesize") {
@@ -69,15 +68,22 @@ func GetTorrentsOrderBy(parameters *WhereParams, orderBy string, limit int, offs
 		params = parameters.Params
 	}
 	db.ORM.Model(&torrents).Where(conditions, params...).Count(&count)
-	dbQuery = db.ORM.Model(&torrents).Where(conditions, params...)
+	dbQuery := "SELECT * FROM torrents"
+	if conditions != "" {
+		dbQuery = dbQuery + " WHERE " + conditions
+	}
+	if strings.Contains(conditions, "torrent_name") {
+		dbQuery = "WITH t AS (SELECT * FROM torrents WHERE " + conditions + ") SELECT * FROM t"
+	}
 
 	if orderBy == "" { // default OrderBy
 		orderBy = "torrent_id DESC"
 	}
+	dbQuery = dbQuery + " ORDER BY " + orderBy
 	if limit != 0 || offset != 0 { // if limits provided
-		dbQuery = dbQuery.Limit(limit).Offset(offset)
+		dbQuery = dbQuery + " LIMIT " + strconv.Itoa(limit) + " OFFSET " + strconv.Itoa(offset)
 	}
-	dbQuery.Order(orderBy).Find(&torrents)
+	db.ORM.Raw(dbQuery, params...).Find(&torrents)
 	return torrents, count
 }
 
diff --git a/util/search/search.go b/util/search/search.go
index 3872adff..12caa2ec 100644
--- a/util/search/search.go
+++ b/util/search/search.go
@@ -8,6 +8,8 @@ import (
 	"net/http"
 	"strconv"
 	"strings"
+	"unicode"
+	"unicode/utf8"
 )
 
 type SearchParam struct {
@@ -19,17 +21,6 @@ type SearchParam struct {
 	Sort     string
 }
 
-
-// super hacky fix:
-var search_op string
-func Init(backend string) {
-	if backend == "postgres" {
-		search_op = "ILIKE"
-	} else {
-		search_op = "LIKE"
-	}
-}
-
 func SearchByQuery(r *http.Request, pagenum int) (SearchParam, []model.Torrents, int) {
 	maxPerPage, errConv := strconv.Atoi(r.URL.Query().Get("max"))
 	if errConv != nil {
@@ -81,10 +72,19 @@ func SearchByQuery(r *http.Request, pagenum int) (SearchParam, []model.Torrents,
 		}
 		parameters.Params = append(parameters.Params, search_param.Status)
 	}
-	searchQuerySplit := strings.Split(search_param.Query, " ")
-	for i, _ := range searchQuerySplit {
-		conditions = append(conditions, "torrent_name " + search_op + " ?")
-		parameters.Params = append(parameters.Params, "%"+searchQuerySplit[i]+"%")
+	searchQuerySplit := strings.Fields(search_param.Query)
+	for i, word := range searchQuerySplit {
+		firstRune, _ := utf8.DecodeRuneInString(word)
+		if len(word) == 1 && unicode.IsPunct(firstRune) {
+			// some queries have a single punctuation character
+			// which causes a full scan instead of using the index
+			// and yields no meaningful results.
+			// due to len() == 1 we're just looking at 1-byte/ascii
+			// punctuation characters.
+			continue
+		}
+		conditions = append(conditions, "torrent_name %> ?")
+		parameters.Params = append(parameters.Params, searchQuerySplit[i])
 	}
 
 	parameters.Conditions = strings.Join(conditions[:], " AND ")