Specialized implementation of Equal for RulesConfig

Fixes 6d4f8be

Author: jml

pkg/configs/configs.go

@@ -44,6 +44,22 @@ func (v View) GetVersionedRulesConfig() *VersionedRulesConfig {
 // RulesConfig are the set of rules files for a particular organization.
 type RulesConfig map[string]string
 
+// Equal compares two RulesConfigs for equality.
+//
+// instance Eq RulesConfig
+func (c RulesConfig) Equal(o RulesConfig) bool {
+	if len(o) != len(c) {
+		return false
+	}
+	for k, v1 := range c {
+		v2, ok := o[k]
+		if !ok || v1 != v2 {
+			return false
+		}
+	}
+	return true
+}
+
 // Parse rules from the Cortex configuration.
 //
 // Strongly inspired by `loadGroups` in Prometheus.

pkg/configs/db/memory/memory.go

@@ -2,7 +2,6 @@ package memory
 
 import (
 	"database/sql"
-	"reflect"
 
 	"github.com/weaveworks/cortex/pkg/configs"
 )
@@ -77,7 +76,7 @@ func (d *DB) SetRulesConfig(userID string, oldConfig, newConfig configs.RulesCon
 	if !ok {
 		return true, d.SetConfig(userID, configs.Config{RulesFiles: newConfig})
 	}
-	if !reflect.DeepEqual(c.Config.RulesFiles, oldConfig) {
+	if !oldConfig.Equal(c.Config.RulesFiles) {
 		return false, nil
 	}
 	return true, d.SetConfig(userID, configs.Config{

pkg/configs/db/postgres/postgres.go

@@ -4,7 +4,6 @@ import (
 	"database/sql"
 	"encoding/json"
 	"errors"
-	"reflect"
 
 	"github.com/Masterminds/squirrel"
 	"github.com/go-kit/kit/log/level"
@@ -159,7 +158,7 @@ func (d DB) SetRulesConfig(userID string, oldConfig, newConfig configs.RulesConf
 		// The supplied oldConfig must match the current config. If no config
 		// exists, then oldConfig must be nil. Otherwise, it must exactly
 		// equal the existing config.
-		if !((err == sql.ErrNoRows && oldConfig == nil) || reflect.DeepEqual(current.Config.RulesFiles, oldConfig)) {
+		if !((err == sql.ErrNoRows && oldConfig == nil) || oldConfig.Equal(current.Config.RulesFiles)) {
 			return nil
 		}
 		new := configs.Config{