diff options
Diffstat (limited to 'vendor/github.com/BurntSushi/toml/encode.go')
-rw-r--r-- | vendor/github.com/BurntSushi/toml/encode.go | 568 |
1 files changed, 568 insertions, 0 deletions
diff --git a/vendor/github.com/BurntSushi/toml/encode.go b/vendor/github.com/BurntSushi/toml/encode.go new file mode 100644 index 00000000..0f2558b2 --- /dev/null +++ b/vendor/github.com/BurntSushi/toml/encode.go @@ -0,0 +1,568 @@ +package toml + +import ( + "bufio" + "errors" + "fmt" + "io" + "reflect" + "sort" + "strconv" + "strings" + "time" +) + +type tomlEncodeError struct{ error } + +var ( + errArrayMixedElementTypes = errors.New( + "toml: cannot encode array with mixed element types") + errArrayNilElement = errors.New( + "toml: cannot encode array with nil element") + errNonString = errors.New( + "toml: cannot encode a map with non-string key type") + errAnonNonStruct = errors.New( + "toml: cannot encode an anonymous field that is not a struct") + errArrayNoTable = errors.New( + "toml: TOML array element cannot contain a table") + errNoKey = errors.New( + "toml: top-level values must be Go maps or structs") + errAnything = errors.New("") // used in testing +) + +var quotedReplacer = strings.NewReplacer( + "\t", "\\t", + "\n", "\\n", + "\r", "\\r", + "\"", "\\\"", + "\\", "\\\\", +) + +// Encoder controls the encoding of Go values to a TOML document to some +// io.Writer. +// +// The indentation level can be controlled with the Indent field. +type Encoder struct { + // A single indentation level. By default it is two spaces. + Indent string + + // hasWritten is whether we have written any output to w yet. + hasWritten bool + w *bufio.Writer +} + +// NewEncoder returns a TOML encoder that encodes Go values to the io.Writer +// given. By default, a single indentation level is 2 spaces. +func NewEncoder(w io.Writer) *Encoder { + return &Encoder{ + w: bufio.NewWriter(w), + Indent: " ", + } +} + +// Encode writes a TOML representation of the Go value to the underlying +// io.Writer. If the value given cannot be encoded to a valid TOML document, +// then an error is returned. +// +// The mapping between Go values and TOML values should be precisely the same +// as for the Decode* functions. Similarly, the TextMarshaler interface is +// supported by encoding the resulting bytes as strings. (If you want to write +// arbitrary binary data then you will need to use something like base64 since +// TOML does not have any binary types.) +// +// When encoding TOML hashes (i.e., Go maps or structs), keys without any +// sub-hashes are encoded first. +// +// If a Go map is encoded, then its keys are sorted alphabetically for +// deterministic output. More control over this behavior may be provided if +// there is demand for it. +// +// Encoding Go values without a corresponding TOML representation---like map +// types with non-string keys---will cause an error to be returned. Similarly +// for mixed arrays/slices, arrays/slices with nil elements, embedded +// non-struct types and nested slices containing maps or structs. +// (e.g., [][]map[string]string is not allowed but []map[string]string is OK +// and so is []map[string][]string.) +func (enc *Encoder) Encode(v interface{}) error { + rv := eindirect(reflect.ValueOf(v)) + if err := enc.safeEncode(Key([]string{}), rv); err != nil { + return err + } + return enc.w.Flush() +} + +func (enc *Encoder) safeEncode(key Key, rv reflect.Value) (err error) { + defer func() { + if r := recover(); r != nil { + if terr, ok := r.(tomlEncodeError); ok { + err = terr.error + return + } + panic(r) + } + }() + enc.encode(key, rv) + return nil +} + +func (enc *Encoder) encode(key Key, rv reflect.Value) { + // Special case. Time needs to be in ISO8601 format. + // Special case. If we can marshal the type to text, then we used that. + // Basically, this prevents the encoder for handling these types as + // generic structs (or whatever the underlying type of a TextMarshaler is). + switch rv.Interface().(type) { + case time.Time, TextMarshaler: + enc.keyEqElement(key, rv) + return + } + + k := rv.Kind() + switch k { + case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, + reflect.Int64, + reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, + reflect.Uint64, + reflect.Float32, reflect.Float64, reflect.String, reflect.Bool: + enc.keyEqElement(key, rv) + case reflect.Array, reflect.Slice: + if typeEqual(tomlArrayHash, tomlTypeOfGo(rv)) { + enc.eArrayOfTables(key, rv) + } else { + enc.keyEqElement(key, rv) + } + case reflect.Interface: + if rv.IsNil() { + return + } + enc.encode(key, rv.Elem()) + case reflect.Map: + if rv.IsNil() { + return + } + enc.eTable(key, rv) + case reflect.Ptr: + if rv.IsNil() { + return + } + enc.encode(key, rv.Elem()) + case reflect.Struct: + enc.eTable(key, rv) + default: + panic(e("unsupported type for key '%s': %s", key, k)) + } +} + +// eElement encodes any value that can be an array element (primitives and +// arrays). +func (enc *Encoder) eElement(rv reflect.Value) { + switch v := rv.Interface().(type) { + case time.Time: + // Special case time.Time as a primitive. Has to come before + // TextMarshaler below because time.Time implements + // encoding.TextMarshaler, but we need to always use UTC. + enc.wf(v.UTC().Format("2006-01-02T15:04:05Z")) + return + case TextMarshaler: + // Special case. Use text marshaler if it's available for this value. + if s, err := v.MarshalText(); err != nil { + encPanic(err) + } else { + enc.writeQuoted(string(s)) + } + return + } + switch rv.Kind() { + case reflect.Bool: + enc.wf(strconv.FormatBool(rv.Bool())) + case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, + reflect.Int64: + enc.wf(strconv.FormatInt(rv.Int(), 10)) + case reflect.Uint, reflect.Uint8, reflect.Uint16, + reflect.Uint32, reflect.Uint64: + enc.wf(strconv.FormatUint(rv.Uint(), 10)) + case reflect.Float32: + enc.wf(floatAddDecimal(strconv.FormatFloat(rv.Float(), 'f', -1, 32))) + case reflect.Float64: + enc.wf(floatAddDecimal(strconv.FormatFloat(rv.Float(), 'f', -1, 64))) + case reflect.Array, reflect.Slice: + enc.eArrayOrSliceElement(rv) + case reflect.Interface: + enc.eElement(rv.Elem()) + case reflect.String: + enc.writeQuoted(rv.String()) + default: + panic(e("unexpected primitive type: %s", rv.Kind())) + } +} + +// By the TOML spec, all floats must have a decimal with at least one +// number on either side. +func floatAddDecimal(fstr string) string { + if !strings.Contains(fstr, ".") { + return fstr + ".0" + } + return fstr +} + +func (enc *Encoder) writeQuoted(s string) { + enc.wf("\"%s\"", quotedReplacer.Replace(s)) +} + +func (enc *Encoder) eArrayOrSliceElement(rv reflect.Value) { + length := rv.Len() + enc.wf("[") + for i := 0; i < length; i++ { + elem := rv.Index(i) + enc.eElement(elem) + if i != length-1 { + enc.wf(", ") + } + } + enc.wf("]") +} + +func (enc *Encoder) eArrayOfTables(key Key, rv reflect.Value) { + if len(key) == 0 { + encPanic(errNoKey) + } + for i := 0; i < rv.Len(); i++ { + trv := rv.Index(i) + if isNil(trv) { + continue + } + panicIfInvalidKey(key) + enc.newline() + enc.wf("%s[[%s]]", enc.indentStr(key), key.maybeQuotedAll()) + enc.newline() + enc.eMapOrStruct(key, trv) + } +} + +func (enc *Encoder) eTable(key Key, rv reflect.Value) { + panicIfInvalidKey(key) + if len(key) == 1 { + // Output an extra new line between top-level tables. + // (The newline isn't written if nothing else has been written though.) + enc.newline() + } + if len(key) > 0 { + enc.wf("%s[%s]", enc.indentStr(key), key.maybeQuotedAll()) + enc.newline() + } + enc.eMapOrStruct(key, rv) +} + +func (enc *Encoder) eMapOrStruct(key Key, rv reflect.Value) { + switch rv := eindirect(rv); rv.Kind() { + case reflect.Map: + enc.eMap(key, rv) + case reflect.Struct: + enc.eStruct(key, rv) + default: + panic("eTable: unhandled reflect.Value Kind: " + rv.Kind().String()) + } +} + +func (enc *Encoder) eMap(key Key, rv reflect.Value) { + rt := rv.Type() + if rt.Key().Kind() != reflect.String { + encPanic(errNonString) + } + + // Sort keys so that we have deterministic output. And write keys directly + // underneath this key first, before writing sub-structs or sub-maps. + var mapKeysDirect, mapKeysSub []string + for _, mapKey := range rv.MapKeys() { + k := mapKey.String() + if typeIsHash(tomlTypeOfGo(rv.MapIndex(mapKey))) { + mapKeysSub = append(mapKeysSub, k) + } else { + mapKeysDirect = append(mapKeysDirect, k) + } + } + + var writeMapKeys = func(mapKeys []string) { + sort.Strings(mapKeys) + for _, mapKey := range mapKeys { + mrv := rv.MapIndex(reflect.ValueOf(mapKey)) + if isNil(mrv) { + // Don't write anything for nil fields. + continue + } + enc.encode(key.add(mapKey), mrv) + } + } + writeMapKeys(mapKeysDirect) + writeMapKeys(mapKeysSub) +} + +func (enc *Encoder) eStruct(key Key, rv reflect.Value) { + // Write keys for fields directly under this key first, because if we write + // a field that creates a new table, then all keys under it will be in that + // table (not the one we're writing here). + rt := rv.Type() + var fieldsDirect, fieldsSub [][]int + var addFields func(rt reflect.Type, rv reflect.Value, start []int) + addFields = func(rt reflect.Type, rv reflect.Value, start []int) { + for i := 0; i < rt.NumField(); i++ { + f := rt.Field(i) + // skip unexported fields + if f.PkgPath != "" && !f.Anonymous { + continue + } + frv := rv.Field(i) + if f.Anonymous { + t := f.Type + switch t.Kind() { + case reflect.Struct: + // Treat anonymous struct fields with + // tag names as though they are not + // anonymous, like encoding/json does. + if getOptions(f.Tag).name == "" { + addFields(t, frv, f.Index) + continue + } + case reflect.Ptr: + if t.Elem().Kind() == reflect.Struct && + getOptions(f.Tag).name == "" { + if !frv.IsNil() { + addFields(t.Elem(), frv.Elem(), f.Index) + } + continue + } + // Fall through to the normal field encoding logic below + // for non-struct anonymous fields. + } + } + + if typeIsHash(tomlTypeOfGo(frv)) { + fieldsSub = append(fieldsSub, append(start, f.Index...)) + } else { + fieldsDirect = append(fieldsDirect, append(start, f.Index...)) + } + } + } + addFields(rt, rv, nil) + + var writeFields = func(fields [][]int) { + for _, fieldIndex := range fields { + sft := rt.FieldByIndex(fieldIndex) + sf := rv.FieldByIndex(fieldIndex) + if isNil(sf) { + // Don't write anything for nil fields. + continue + } + + opts := getOptions(sft.Tag) + if opts.skip { + continue + } + keyName := sft.Name + if opts.name != "" { + keyName = opts.name + } + if opts.omitempty && isEmpty(sf) { + continue + } + if opts.omitzero && isZero(sf) { + continue + } + + enc.encode(key.add(keyName), sf) + } + } + writeFields(fieldsDirect) + writeFields(fieldsSub) +} + +// tomlTypeName returns the TOML type name of the Go value's type. It is +// used to determine whether the types of array elements are mixed (which is +// forbidden). If the Go value is nil, then it is illegal for it to be an array +// element, and valueIsNil is returned as true. + +// Returns the TOML type of a Go value. The type may be `nil`, which means +// no concrete TOML type could be found. +func tomlTypeOfGo(rv reflect.Value) tomlType { + if isNil(rv) || !rv.IsValid() { + return nil + } + switch rv.Kind() { + case reflect.Bool: + return tomlBool + case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, + reflect.Int64, + reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, + reflect.Uint64: + return tomlInteger + case reflect.Float32, reflect.Float64: + return tomlFloat + case reflect.Array, reflect.Slice: + if typeEqual(tomlHash, tomlArrayType(rv)) { + return tomlArrayHash + } + return tomlArray + case reflect.Ptr, reflect.Interface: + return tomlTypeOfGo(rv.Elem()) + case reflect.String: + return tomlString + case reflect.Map: + return tomlHash + case reflect.Struct: + switch rv.Interface().(type) { + case time.Time: + return tomlDatetime + case TextMarshaler: + return tomlString + default: + return tomlHash + } + default: + panic("unexpected reflect.Kind: " + rv.Kind().String()) + } +} + +// tomlArrayType returns the element type of a TOML array. The type returned +// may be nil if it cannot be determined (e.g., a nil slice or a zero length +// slize). This function may also panic if it finds a type that cannot be +// expressed in TOML (such as nil elements, heterogeneous arrays or directly +// nested arrays of tables). +func tomlArrayType(rv reflect.Value) tomlType { + if isNil(rv) || !rv.IsValid() || rv.Len() == 0 { + return nil + } + firstType := tomlTypeOfGo(rv.Index(0)) + if firstType == nil { + encPanic(errArrayNilElement) + } + + rvlen := rv.Len() + for i := 1; i < rvlen; i++ { + elem := rv.Index(i) + switch elemType := tomlTypeOfGo(elem); { + case elemType == nil: + encPanic(errArrayNilElement) + case !typeEqual(firstType, elemType): + encPanic(errArrayMixedElementTypes) + } + } + // If we have a nested array, then we must make sure that the nested + // array contains ONLY primitives. + // This checks arbitrarily nested arrays. + if typeEqual(firstType, tomlArray) || typeEqual(firstType, tomlArrayHash) { + nest := tomlArrayType(eindirect(rv.Index(0))) + if typeEqual(nest, tomlHash) || typeEqual(nest, tomlArrayHash) { + encPanic(errArrayNoTable) + } + } + return firstType +} + +type tagOptions struct { + skip bool // "-" + name string + omitempty bool + omitzero bool +} + +func getOptions(tag reflect.StructTag) tagOptions { + t := tag.Get("toml") + if t == "-" { + return tagOptions{skip: true} + } + var opts tagOptions + parts := strings.Split(t, ",") + opts.name = parts[0] + for _, s := range parts[1:] { + switch s { + case "omitempty": + opts.omitempty = true + case "omitzero": + opts.omitzero = true + } + } + return opts +} + +func isZero(rv reflect.Value) bool { + switch rv.Kind() { + case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: + return rv.Int() == 0 + case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64: + return rv.Uint() == 0 + case reflect.Float32, reflect.Float64: + return rv.Float() == 0.0 + } + return false +} + +func isEmpty(rv reflect.Value) bool { + switch rv.Kind() { + case reflect.Array, reflect.Slice, reflect.Map, reflect.String: + return rv.Len() == 0 + case reflect.Bool: + return !rv.Bool() + } + return false +} + +func (enc *Encoder) newline() { + if enc.hasWritten { + enc.wf("\n") + } +} + +func (enc *Encoder) keyEqElement(key Key, val reflect.Value) { + if len(key) == 0 { + encPanic(errNoKey) + } + panicIfInvalidKey(key) + enc.wf("%s%s = ", enc.indentStr(key), key.maybeQuoted(len(key)-1)) + enc.eElement(val) + enc.newline() +} + +func (enc *Encoder) wf(format string, v ...interface{}) { + if _, err := fmt.Fprintf(enc.w, format, v...); err != nil { + encPanic(err) + } + enc.hasWritten = true +} + +func (enc *Encoder) indentStr(key Key) string { + return strings.Repeat(enc.Indent, len(key)-1) +} + +func encPanic(err error) { + panic(tomlEncodeError{err}) +} + +func eindirect(v reflect.Value) reflect.Value { + switch v.Kind() { + case reflect.Ptr, reflect.Interface: + return eindirect(v.Elem()) + default: + return v + } +} + +func isNil(rv reflect.Value) bool { + switch rv.Kind() { + case reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice: + return rv.IsNil() + default: + return false + } +} + +func panicIfInvalidKey(key Key) { + for _, k := range key { + if len(k) == 0 { + encPanic(e("Key '%s' is not a valid table name. Key names "+ + "cannot be empty.", key.maybeQuotedAll())) + } + } +} + +func isValidKeyName(s string) bool { + return len(s) != 0 +} |