User rules -- hold them as a slice of strings, which is how dns forwarding server will expect them.

app.go

@@ -149,7 +149,7 @@ func main() {
 			log.Printf("Couldn't load filter %d contents due to %s", filter.ID, err)
 			// clear LastUpdated so it gets fetched right away
 		}
-		if len(filter.Contents) == 0 {
+		if len(filter.Rules) == 0 {
 			filter.LastUpdated = time.Time{}
 		}
 	}

config.go

@@ -76,7 +76,7 @@ type filter struct {
 	LastUpdated time.Time `json:"lastUpdated,omitempty" yaml:"last_updated,omitempty"`
 	ID          int64     `json:"id"` // auto-assigned when filter is added (see nextFilterID), json by default keeps ID uppercase but we need lowercase
 
-	Contents []byte `json:"-" yaml:"-"` // not in yaml or json
+	Rules []string `json:"-" yaml:"-"` // not in yaml or json
 }
 
 var defaultDNS = []string{"tls://1.1.1.1", "tls://1.0.0.1"}
@@ -112,21 +112,12 @@ var config = configuration{
 
 // Creates a helper object for working with the user rules
 func userFilter() filter {
-	// TODO: This should be calculated when UserRules are set
-	var contents []byte
-	for _, rule := range config.UserRules {
-		contents = append(contents, []byte(rule)...)
-		contents = append(contents, '\n')
-	}
-
-	userFilter := filter{
+	return filter{
 		// User filter always has constant ID=0
-		ID:       userFilterID,
-		Contents: contents,
-		Enabled:  true,
+		ID:      userFilterID,
+		Rules:   config.UserRules,
+		Enabled: true,
 	}
-
-	return userFilter
 }
 
 // Loads configuration from the YAML file

control.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"bytes"
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
@@ -9,6 +8,7 @@ import (
 	"net/http"
 	"os"
 	"path/filepath"
+	"reflect"
 	"regexp"
 	"strconv"
 	"strings"
@@ -577,7 +577,7 @@ func refreshFiltersIfNeccessary(force bool) int {
 }
 
 // A helper function that parses filter contents and returns a number of rules and a filter name (if there's any)
-func parseFilterContents(contents []byte) (int, string) {
+func parseFilterContents(contents []byte) (int, string, []string) {
 	lines := strings.Split(string(contents), "\n")
 	rulesCount := 0
 	name := ""
@@ -596,7 +596,7 @@ func parseFilterContents(contents []byte) (int, string) {
 		}
 	}
 
-	return rulesCount, name
+	return rulesCount, name, lines
 }
 
 // Checks for filters updates
@@ -645,21 +645,21 @@ func (filter *filter) update(force bool) (bool, error) {
 	}
 
 	// Extract filter name and count number of rules
-	rulesCount, filterName := parseFilterContents(body)
+	rulesCount, filterName, rules := parseFilterContents(body)
 
 	if filterName != "" {
 		filter.Name = filterName
 	}
 
 	// Check if the filter has been really changed
-	if bytes.Equal(filter.Contents, body) {
+	if reflect.DeepEqual(filter.Rules, rules) {
 		log.Printf("The filter %d text has not changed", filter.ID)
 		return false, nil
 	}
 
 	log.Printf("Filter %d has been updated: %d bytes, %d rules", filter.ID, len(body), rulesCount)
 	filter.RulesCount = rulesCount
-	filter.Contents = body
+	filter.Rules = rules
 
 	return true, nil
 }
@@ -668,8 +668,9 @@ func (filter *filter) update(force bool) (bool, error) {
 func (filter *filter) save() error {
 	filterFilePath := filter.Path()
 	log.Printf("Saving filter %d contents to: %s", filter.ID, filterFilePath)
+	body := []byte(strings.Join(filter.Rules, "\n"))
 
-	return safeWriteFile(filterFilePath, filter.Contents)
+	return safeWriteFile(filterFilePath, body)
 }
 
 // loads filter contents from the file in dataDir
@@ -692,12 +693,11 @@ func (filter *filter) load() error {
 		return err
 	}
 
-	log.Printf("Filter %d length is %d", filter.ID, len(filterFileContents))
-	filter.Contents = filterFileContents
+	log.Printf("File %s, id %d, length %d", filterFilePath, filter.ID, len(filterFileContents))
+	rulesCount, _, rules := parseFilterContents(filterFileContents)
 
-	// Now extract the rules count
-	rulesCount, _ := parseFilterContents(filter.Contents)
 	filter.RulesCount = rulesCount
+	filter.Rules = rules
 
 	return nil
 }