package validator import ( "fmt" "reflect" "strings" "sync" "sync/atomic" ) type tagType uint8 const ( typeDefault tagType = iota typeOmitEmpty typeIsDefault typeNoStructLevel typeStructOnly typeDive typeOr typeKeys typeEndKeys ) const ( invalidValidation = "Invalid validation tag on field '%s'" undefinedValidation = "Undefined validation function '%s' on field '%s'" keysTagNotDefined = "'" + endKeysTag + "' tag encountered without a corresponding '" + keysTag + "' tag" ) type structCache struct { lock sync.Mutex m atomic.Value // map[reflect.Type]*cStruct } func (sc *structCache) Get(key reflect.Type) (c *cStruct, found bool) { c, found = sc.m.Load().(map[reflect.Type]*cStruct)[key] return } func (sc *structCache) Set(key reflect.Type, value *cStruct) { m := sc.m.Load().(map[reflect.Type]*cStruct) nm := make(map[reflect.Type]*cStruct, len(m)+1) for k, v := range m { nm[k] = v } nm[key] = value sc.m.Store(nm) } type tagCache struct { lock sync.Mutex m atomic.Value // map[string]*cTag } func (tc *tagCache) Get(key string) (c *cTag, found bool) { c, found = tc.m.Load().(map[string]*cTag)[key] return } func (tc *tagCache) Set(key string, value *cTag) { m := tc.m.Load().(map[string]*cTag) nm := make(map[string]*cTag, len(m)+1) for k, v := range m { nm[k] = v } nm[key] = value tc.m.Store(nm) } type cStruct struct { name string fields []*cField fn StructLevelFuncCtx } type cField struct { idx int name string altName string namesEqual bool cTags *cTag } type cTag struct { tag string aliasTag string actualAliasTag string param string keys *cTag // only populated when using tag's 'keys' and 'endkeys' for map key validation next *cTag fn FuncCtx typeof tagType hasTag bool hasAlias bool hasParam bool // true if parameter used eg. eq= where the equal sign has been set isBlockEnd bool // indicates the current tag represents the last validation in the block } func (v *Validate) extractStructCache(current reflect.Value, sName string) *cStruct { v.structCache.lock.Lock() defer v.structCache.lock.Unlock() // leave as defer! because if inner panics, it will never get unlocked otherwise! typ := current.Type() // could have been multiple trying to access, but once first is done this ensures struct // isn't parsed again. cs, ok := v.structCache.Get(typ) if ok { return cs } cs = &cStruct{name: sName, fields: make([]*cField, 0), fn: v.structLevelFuncs[typ]} numFields := current.NumField() var ctag *cTag var fld reflect.StructField var tag string var customName string for i := 0; i < numFields; i++ { fld = typ.Field(i) if !fld.Anonymous && len(fld.PkgPath) > 0 { continue } tag = fld.Tag.Get(v.tagName) if tag == skipValidationTag { continue } customName = fld.Name if v.hasTagNameFunc { name := v.tagNameFunc(fld) if len(name) > 0 { customName = name } } // NOTE: cannot use shared tag cache, because tags may be equal, but things like alias may be different // and so only struct level caching can be used instead of combined with Field tag caching if len(tag) > 0 { ctag, _ = v.parseFieldTagsRecursive(tag, fld.Name, "", false) } else { // even if field doesn't have validations need cTag for traversing to potential inner/nested // elements of the field. ctag = new(cTag) } cs.fields = append(cs.fields, &cField{ idx: i, name: fld.Name, altName: customName, cTags: ctag, namesEqual: fld.Name == customName, }) } v.structCache.Set(typ, cs) return cs } func (v *Validate) parseFieldTagsRecursive(tag string, fieldName string, alias string, hasAlias bool) (firstCtag *cTag, current *cTag) { var t string var ok bool noAlias := len(alias) == 0 tags := strings.Split(tag, tagSeparator) for i := 0; i < len(tags); i++ { t = tags[i] if noAlias { alias = t } // check map for alias and process new tags, otherwise process as usual if tagsVal, found := v.aliases[t]; found { if i == 0 { firstCtag, current = v.parseFieldTagsRecursive(tagsVal, fieldName, t, true) } else { next, curr := v.parseFieldTagsRecursive(tagsVal, fieldName, t, true) current.next, current = next, curr } continue } var prevTag tagType if i == 0 { current = &cTag{aliasTag: alias, hasAlias: hasAlias, hasTag: true} firstCtag = current } else { prevTag = current.typeof current.next = &cTag{aliasTag: alias, hasAlias: hasAlias, hasTag: true} current = current.next } switch t { case diveTag: current.typeof = typeDive continue case keysTag: current.typeof = typeKeys if i == 0 || prevTag != typeDive { panic(fmt.Sprintf("'%s' tag must be immediately preceeded by the '%s' tag", keysTag, diveTag)) } current.typeof = typeKeys // need to pass along only keys tag // need to increment i to skip over the keys tags b := make([]byte, 0, 64) i++ for ; i < len(tags); i++ { b = append(b, tags[i]...) b = append(b, ',') if tags[i] == endKeysTag { break } } current.keys, _ = v.parseFieldTagsRecursive(string(b[:len(b)-1]), fieldName, "", false) continue case endKeysTag: current.typeof = typeEndKeys // if there are more in tags then there was no keysTag defined // and an error should be thrown if i != len(tags)-1 { panic(keysTagNotDefined) } return case omitempty: current.typeof = typeOmitEmpty continue case structOnlyTag: current.typeof = typeStructOnly continue case noStructLevelTag: current.typeof = typeNoStructLevel continue default: if t == isdefault { current.typeof = typeIsDefault } // if a pipe character is needed within the param you must use the utf8Pipe representation "0x7C" orVals := strings.Split(t, orSeparator) for j := 0; j < len(orVals); j++ { vals := strings.SplitN(orVals[j], tagKeySeparator, 2) if noAlias { alias = vals[0] current.aliasTag = alias } else { current.actualAliasTag = t } if j > 0 { current.next = &cTag{aliasTag: alias, actualAliasTag: current.actualAliasTag, hasAlias: hasAlias, hasTag: true} current = current.next } current.hasParam = len(vals) > 1 current.tag = vals[0] if len(current.tag) == 0 { panic(strings.TrimSpace(fmt.Sprintf(invalidValidation, fieldName))) } if current.fn, ok = v.validations[current.tag]; !ok { panic(strings.TrimSpace(fmt.Sprintf(undefinedValidation, current.tag, fieldName))) } if len(orVals) > 1 { current.typeof = typeOr } if len(vals) > 1 { current.param = strings.Replace(strings.Replace(vals[1], utf8HexComma, ",", -1), utf8Pipe, "|", -1) } } current.isBlockEnd = true } } return } func (v *Validate) fetchCacheTag(tag string) *cTag { // find cached tag ctag, found := v.tagCache.Get(tag) if !found { v.tagCache.lock.Lock() defer v.tagCache.lock.Unlock() // could have been multiple trying to access, but once first is done this ensures tag // isn't parsed again. ctag, found = v.tagCache.Get(tag) if !found { ctag, _ = v.parseFieldTagsRecursive(tag, "", "", false) v.tagCache.Set(tag, ctag) } } return ctag }