From e1e8d058a33f7566f9c565d04b0d8b56f9645c35 Mon Sep 17 00:00:00 2001 From: Dimitri Sokolyuk Date: Wed, 25 Apr 2018 09:28:54 +0200 Subject: add vendor --- .../x/net/webdav/internal/xml/typeinfo.go | 371 +++++++++++++++++++++ 1 file changed, 371 insertions(+) create mode 100644 vendor/golang.org/x/net/webdav/internal/xml/typeinfo.go (limited to 'vendor/golang.org/x/net/webdav/internal/xml/typeinfo.go') diff --git a/vendor/golang.org/x/net/webdav/internal/xml/typeinfo.go b/vendor/golang.org/x/net/webdav/internal/xml/typeinfo.go new file mode 100644 index 0000000..fdde288 --- /dev/null +++ b/vendor/golang.org/x/net/webdav/internal/xml/typeinfo.go @@ -0,0 +1,371 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package xml + +import ( + "fmt" + "reflect" + "strings" + "sync" +) + +// typeInfo holds details for the xml representation of a type. +type typeInfo struct { + xmlname *fieldInfo + fields []fieldInfo +} + +// fieldInfo holds details for the xml representation of a single field. +type fieldInfo struct { + idx []int + name string + xmlns string + flags fieldFlags + parents []string +} + +type fieldFlags int + +const ( + fElement fieldFlags = 1 << iota + fAttr + fCharData + fInnerXml + fComment + fAny + + fOmitEmpty + + fMode = fElement | fAttr | fCharData | fInnerXml | fComment | fAny +) + +var tinfoMap = make(map[reflect.Type]*typeInfo) +var tinfoLock sync.RWMutex + +var nameType = reflect.TypeOf(Name{}) + +// getTypeInfo returns the typeInfo structure with details necessary +// for marshalling and unmarshalling typ. +func getTypeInfo(typ reflect.Type) (*typeInfo, error) { + tinfoLock.RLock() + tinfo, ok := tinfoMap[typ] + tinfoLock.RUnlock() + if ok { + return tinfo, nil + } + tinfo = &typeInfo{} + if typ.Kind() == reflect.Struct && typ != nameType { + n := typ.NumField() + for i := 0; i < n; i++ { + f := typ.Field(i) + if f.PkgPath != "" || f.Tag.Get("xml") == "-" { + continue // Private field + } + + // For embedded structs, embed its fields. + if f.Anonymous { + t := f.Type + if t.Kind() == reflect.Ptr { + t = t.Elem() + } + if t.Kind() == reflect.Struct { + inner, err := getTypeInfo(t) + if err != nil { + return nil, err + } + if tinfo.xmlname == nil { + tinfo.xmlname = inner.xmlname + } + for _, finfo := range inner.fields { + finfo.idx = append([]int{i}, finfo.idx...) + if err := addFieldInfo(typ, tinfo, &finfo); err != nil { + return nil, err + } + } + continue + } + } + + finfo, err := structFieldInfo(typ, &f) + if err != nil { + return nil, err + } + + if f.Name == "XMLName" { + tinfo.xmlname = finfo + continue + } + + // Add the field if it doesn't conflict with other fields. + if err := addFieldInfo(typ, tinfo, finfo); err != nil { + return nil, err + } + } + } + tinfoLock.Lock() + tinfoMap[typ] = tinfo + tinfoLock.Unlock() + return tinfo, nil +} + +// structFieldInfo builds and returns a fieldInfo for f. +func structFieldInfo(typ reflect.Type, f *reflect.StructField) (*fieldInfo, error) { + finfo := &fieldInfo{idx: f.Index} + + // Split the tag from the xml namespace if necessary. + tag := f.Tag.Get("xml") + if i := strings.Index(tag, " "); i >= 0 { + finfo.xmlns, tag = tag[:i], tag[i+1:] + } + + // Parse flags. + tokens := strings.Split(tag, ",") + if len(tokens) == 1 { + finfo.flags = fElement + } else { + tag = tokens[0] + for _, flag := range tokens[1:] { + switch flag { + case "attr": + finfo.flags |= fAttr + case "chardata": + finfo.flags |= fCharData + case "innerxml": + finfo.flags |= fInnerXml + case "comment": + finfo.flags |= fComment + case "any": + finfo.flags |= fAny + case "omitempty": + finfo.flags |= fOmitEmpty + } + } + + // Validate the flags used. + valid := true + switch mode := finfo.flags & fMode; mode { + case 0: + finfo.flags |= fElement + case fAttr, fCharData, fInnerXml, fComment, fAny: + if f.Name == "XMLName" || tag != "" && mode != fAttr { + valid = false + } + default: + // This will also catch multiple modes in a single field. + valid = false + } + if finfo.flags&fMode == fAny { + finfo.flags |= fElement + } + if finfo.flags&fOmitEmpty != 0 && finfo.flags&(fElement|fAttr) == 0 { + valid = false + } + if !valid { + return nil, fmt.Errorf("xml: invalid tag in field %s of type %s: %q", + f.Name, typ, f.Tag.Get("xml")) + } + } + + // Use of xmlns without a name is not allowed. + if finfo.xmlns != "" && tag == "" { + return nil, fmt.Errorf("xml: namespace without name in field %s of type %s: %q", + f.Name, typ, f.Tag.Get("xml")) + } + + if f.Name == "XMLName" { + // The XMLName field records the XML element name. Don't + // process it as usual because its name should default to + // empty rather than to the field name. + finfo.name = tag + return finfo, nil + } + + if tag == "" { + // If the name part of the tag is completely empty, get + // default from XMLName of underlying struct if feasible, + // or field name otherwise. + if xmlname := lookupXMLName(f.Type); xmlname != nil { + finfo.xmlns, finfo.name = xmlname.xmlns, xmlname.name + } else { + finfo.name = f.Name + } + return finfo, nil + } + + if finfo.xmlns == "" && finfo.flags&fAttr == 0 { + // If it's an element no namespace specified, get the default + // from the XMLName of enclosing struct if possible. + if xmlname := lookupXMLName(typ); xmlname != nil { + finfo.xmlns = xmlname.xmlns + } + } + + // Prepare field name and parents. + parents := strings.Split(tag, ">") + if parents[0] == "" { + parents[0] = f.Name + } + if parents[len(parents)-1] == "" { + return nil, fmt.Errorf("xml: trailing '>' in field %s of type %s", f.Name, typ) + } + finfo.name = parents[len(parents)-1] + if len(parents) > 1 { + if (finfo.flags & fElement) == 0 { + return nil, fmt.Errorf("xml: %s chain not valid with %s flag", tag, strings.Join(tokens[1:], ",")) + } + finfo.parents = parents[:len(parents)-1] + } + + // If the field type has an XMLName field, the names must match + // so that the behavior of both marshalling and unmarshalling + // is straightforward and unambiguous. + if finfo.flags&fElement != 0 { + ftyp := f.Type + xmlname := lookupXMLName(ftyp) + if xmlname != nil && xmlname.name != finfo.name { + return nil, fmt.Errorf("xml: name %q in tag of %s.%s conflicts with name %q in %s.XMLName", + finfo.name, typ, f.Name, xmlname.name, ftyp) + } + } + return finfo, nil +} + +// lookupXMLName returns the fieldInfo for typ's XMLName field +// in case it exists and has a valid xml field tag, otherwise +// it returns nil. +func lookupXMLName(typ reflect.Type) (xmlname *fieldInfo) { + for typ.Kind() == reflect.Ptr { + typ = typ.Elem() + } + if typ.Kind() != reflect.Struct { + return nil + } + for i, n := 0, typ.NumField(); i < n; i++ { + f := typ.Field(i) + if f.Name != "XMLName" { + continue + } + finfo, err := structFieldInfo(typ, &f) + if finfo.name != "" && err == nil { + return finfo + } + // Also consider errors as a non-existent field tag + // and let getTypeInfo itself report the error. + break + } + return nil +} + +func min(a, b int) int { + if a <= b { + return a + } + return b +} + +// addFieldInfo adds finfo to tinfo.fields if there are no +// conflicts, or if conflicts arise from previous fields that were +// obtained from deeper embedded structures than finfo. In the latter +// case, the conflicting entries are dropped. +// A conflict occurs when the path (parent + name) to a field is +// itself a prefix of another path, or when two paths match exactly. +// It is okay for field paths to share a common, shorter prefix. +func addFieldInfo(typ reflect.Type, tinfo *typeInfo, newf *fieldInfo) error { + var conflicts []int +Loop: + // First, figure all conflicts. Most working code will have none. + for i := range tinfo.fields { + oldf := &tinfo.fields[i] + if oldf.flags&fMode != newf.flags&fMode { + continue + } + if oldf.xmlns != "" && newf.xmlns != "" && oldf.xmlns != newf.xmlns { + continue + } + minl := min(len(newf.parents), len(oldf.parents)) + for p := 0; p < minl; p++ { + if oldf.parents[p] != newf.parents[p] { + continue Loop + } + } + if len(oldf.parents) > len(newf.parents) { + if oldf.parents[len(newf.parents)] == newf.name { + conflicts = append(conflicts, i) + } + } else if len(oldf.parents) < len(newf.parents) { + if newf.parents[len(oldf.parents)] == oldf.name { + conflicts = append(conflicts, i) + } + } else { + if newf.name == oldf.name { + conflicts = append(conflicts, i) + } + } + } + // Without conflicts, add the new field and return. + if conflicts == nil { + tinfo.fields = append(tinfo.fields, *newf) + return nil + } + + // If any conflict is shallower, ignore the new field. + // This matches the Go field resolution on embedding. + for _, i := range conflicts { + if len(tinfo.fields[i].idx) < len(newf.idx) { + return nil + } + } + + // Otherwise, if any of them is at the same depth level, it's an error. + for _, i := range conflicts { + oldf := &tinfo.fields[i] + if len(oldf.idx) == len(newf.idx) { + f1 := typ.FieldByIndex(oldf.idx) + f2 := typ.FieldByIndex(newf.idx) + return &TagPathError{typ, f1.Name, f1.Tag.Get("xml"), f2.Name, f2.Tag.Get("xml")} + } + } + + // Otherwise, the new field is shallower, and thus takes precedence, + // so drop the conflicting fields from tinfo and append the new one. + for c := len(conflicts) - 1; c >= 0; c-- { + i := conflicts[c] + copy(tinfo.fields[i:], tinfo.fields[i+1:]) + tinfo.fields = tinfo.fields[:len(tinfo.fields)-1] + } + tinfo.fields = append(tinfo.fields, *newf) + return nil +} + +// A TagPathError represents an error in the unmarshalling process +// caused by the use of field tags with conflicting paths. +type TagPathError struct { + Struct reflect.Type + Field1, Tag1 string + Field2, Tag2 string +} + +func (e *TagPathError) Error() string { + return fmt.Sprintf("%s field %q with tag %q conflicts with field %q with tag %q", e.Struct, e.Field1, e.Tag1, e.Field2, e.Tag2) +} + +// value returns v's field value corresponding to finfo. +// It's equivalent to v.FieldByIndex(finfo.idx), but initializes +// and dereferences pointers as necessary. +func (finfo *fieldInfo) value(v reflect.Value) reflect.Value { + for i, x := range finfo.idx { + if i > 0 { + t := v.Type() + if t.Kind() == reflect.Ptr && t.Elem().Kind() == reflect.Struct { + if v.IsNil() { + v.Set(reflect.New(v.Type().Elem())) + } + v = v.Elem() + } + } + v = v.Field(x) + } + return v +} -- cgit v1.2.3