Move back to data structure

- Uses less memory by creating for each language a map.

modules/translation/i18n/i18n.go

@@ -30,16 +30,22 @@ type locale struct {
 
 type LocaleStore struct {
 	// After initializing has finished, these fields are read-only.
-	langNames              []string
-	langDescs              []string
-	langOffsets            []int
-	offsetToTranslationMap []map[string]string
-	localeMap              map[string]*locale
-	defaultLang            string
+	langNames []string
+	langDescs []string
+
+	langOffsets       []int
+	translationKeys   []string
+	keyToOffset       map[string]int
+	translationValues []string
+
+	localeMap map[string]*locale
+
+	defaultLang        string
+	defaultLangKeysLen int
 }
 
 func NewLocaleStore() *LocaleStore {
-	return &LocaleStore{localeMap: make(map[string]*locale)}
+	return &LocaleStore{localeMap: make(map[string]*locale), keyToOffset: make(map[string]int)}
 }
 
 // AddLocaleByIni adds locale by ini into the store
@@ -63,15 +69,44 @@ func (ls *LocaleStore) AddLocaleByIni(langName, langDesc string, localeFile inte
 		// For development, live-reload of the translation files is important.
 		// For production, we can do some expensive work and then make the querying fast.
 		if setting.IsProd {
-			keyToValue := map[string]string{}
-			// Go trough all keys and store key->value into a map.
-			for _, section := range iniFile.Sections() {
-				for _, key := range section.Keys() {
-					keyToValue[strings.TrimPrefix(section.Name()+"."+key.Name(), "DEFAULT.")] = key.Value()
+			// If the language is the default language, then we go trough all keys. These keys
+			// will become the keys that we consider to support and take into account while going
+			// trough querying translation keys.
+			if langName == ls.defaultLang {
+				idx := 0
+				// Store all key, value into two slices.
+				for _, section := range iniFile.Sections() {
+					for _, key := range section.Keys() {
+						ls.translationKeys = append(ls.translationKeys, section.Name()+"#"+key.Name())
+						ls.translationValues = append(ls.translationValues, key.Value())
+
+						ls.keyToOffset[strings.TrimPrefix(section.Name()+"."+key.Name(), "DEFAULT.")] = idx
+						idx++
+					}
+				}
+
+				ls.defaultLangKeysLen = len(ls.translationKeys)
+			} else {
+				// Go trough all the keys that the defaultLang has and append it to translationValues.
+				// If the lang doesn't have a value for the translation, use the defaultLang's one.
+				for i := 0; i < ls.defaultLangKeysLen; i++ {
+					splitted := strings.SplitN(ls.translationKeys[i], "#", 2)
+					// TODO: optimize for repeated sequential access of section.
+					section, err := iniFile.GetSection(splitted[0])
+					if err != nil {
+						// Section not found? Use the defaultLang's value for this translation key.
+						ls.translationValues = append(ls.translationValues, ls.translationValues[i])
+						continue
+					}
+					key, err := section.GetKey(splitted[1])
+					if err != nil {
+						// Key not found? Use the defaultLang's value for this translation key.
+						ls.translationValues = append(ls.translationValues, ls.translationValues[i])
+						continue
+					}
+					ls.translationValues = append(ls.translationValues, key.Value())
 				}
 			}
-			// Append the key->value to the offsetToTranslationMap variable.
-			ls.offsetToTranslationMap = append(ls.offsetToTranslationMap, keyToValue)
 
 			// Help Go's GC.
 			iniFile = nil
@@ -175,12 +210,12 @@ func Tr(lang, trKey string, trArgs ...interface{}) string {
 }
 
 func TrOffset(offset int, trKey string, trArgs ...interface{}) string {
-	languageTranslationMap := DefaultLocales.offsetToTranslationMap[offset]
-	trMsg, ok := languageTranslationMap[trKey]
-	if !ok {
-		return trKey
-	}
+	// Get the offset of the translation key.
+	keyOffset := DefaultLocales.keyToOffset[trKey]
+	// Now adjust to use the language's translation of the key.
+	keyOffset += offset * DefaultLocales.defaultLangKeysLen
 
+	trMsg := DefaultLocales.translationValues[keyOffset]
 	if len(trArgs) > 0 {
 		fmtArgs := make([]interface{}, 0, len(trArgs))
 		for _, arg := range trArgs {