diff options
Diffstat (limited to 'vendor/github.com/BurntSushi/toml/decode.go')
-rw-r--r-- | vendor/github.com/BurntSushi/toml/decode.go | 613 |
1 files changed, 613 insertions, 0 deletions
diff --git a/vendor/github.com/BurntSushi/toml/decode.go b/vendor/github.com/BurntSushi/toml/decode.go new file mode 100644 index 0000000..7aaf462 --- /dev/null +++ b/vendor/github.com/BurntSushi/toml/decode.go @@ -0,0 +1,613 @@ +package toml + +import ( + "bytes" + "encoding" + "encoding/json" + "fmt" + "io" + "io/fs" + "math" + "os" + "reflect" + "strconv" + "strings" + "time" +) + +// Unmarshaler is the interface implemented by objects that can unmarshal a +// TOML description of themselves. +type Unmarshaler interface { + UnmarshalTOML(any) error +} + +// Unmarshal decodes the contents of data in TOML format into a pointer v. +// +// See [Decoder] for a description of the decoding process. +func Unmarshal(data []byte, v any) error { + _, err := NewDecoder(bytes.NewReader(data)).Decode(v) + return err +} + +// Decode the TOML data in to the pointer v. +// +// See [Decoder] for a description of the decoding process. +func Decode(data string, v any) (MetaData, error) { + return NewDecoder(strings.NewReader(data)).Decode(v) +} + +// DecodeFile reads the contents of a file and decodes it with [Decode]. +func DecodeFile(path string, v any) (MetaData, error) { + fp, err := os.Open(path) + if err != nil { + return MetaData{}, err + } + defer fp.Close() + return NewDecoder(fp).Decode(v) +} + +// DecodeFS reads the contents of a file from [fs.FS] and decodes it with +// [Decode]. +func DecodeFS(fsys fs.FS, path string, v any) (MetaData, error) { + fp, err := fsys.Open(path) + if err != nil { + return MetaData{}, err + } + defer fp.Close() + return NewDecoder(fp).Decode(v) +} + +// Primitive is a TOML value that hasn't been decoded into a Go value. +// +// This type can be used for any value, which will cause decoding to be delayed. +// You can use [PrimitiveDecode] to "manually" decode these values. +// +// NOTE: The underlying representation of a `Primitive` value is subject to +// change. Do not rely on it. +// +// NOTE: Primitive values are still parsed, so using them will only avoid the +// overhead of reflection. They can be useful when you don't know the exact type +// of TOML data until runtime. +type Primitive struct { + undecoded any + context Key +} + +// The significand precision for float32 and float64 is 24 and 53 bits; this is +// the range a natural number can be stored in a float without loss of data. +const ( + maxSafeFloat32Int = 16777215 // 2^24-1 + maxSafeFloat64Int = int64(9007199254740991) // 2^53-1 +) + +// Decoder decodes TOML data. +// +// TOML tables correspond to Go structs or maps; they can be used +// interchangeably, but structs offer better type safety. +// +// TOML table arrays correspond to either a slice of structs or a slice of maps. +// +// TOML datetimes correspond to [time.Time]. Local datetimes are parsed in the +// local timezone. +// +// [time.Duration] types are treated as nanoseconds if the TOML value is an +// integer, or they're parsed with time.ParseDuration() if they're strings. +// +// All other TOML types (float, string, int, bool and array) correspond to the +// obvious Go types. +// +// An exception to the above rules is if a type implements the TextUnmarshaler +// interface, in which case any primitive TOML value (floats, strings, integers, +// booleans, datetimes) will be converted to a []byte and given to the value's +// UnmarshalText method. See the Unmarshaler example for a demonstration with +// email addresses. +// +// # Key mapping +// +// TOML keys can map to either keys in a Go map or field names in a Go struct. +// The special `toml` struct tag can be used to map TOML keys to struct fields +// that don't match the key name exactly (see the example). A case insensitive +// match to struct names will be tried if an exact match can't be found. +// +// The mapping between TOML values and Go values is loose. That is, there may +// exist TOML values that cannot be placed into your representation, and there +// may be parts of your representation that do not correspond to TOML values. +// This loose mapping can be made stricter by using the IsDefined and/or +// Undecoded methods on the MetaData returned. +// +// This decoder does not handle cyclic types. Decode will not terminate if a +// cyclic type is passed. +type Decoder struct { + r io.Reader +} + +// NewDecoder creates a new Decoder. +func NewDecoder(r io.Reader) *Decoder { + return &Decoder{r: r} +} + +var ( + unmarshalToml = reflect.TypeOf((*Unmarshaler)(nil)).Elem() + unmarshalText = reflect.TypeOf((*encoding.TextUnmarshaler)(nil)).Elem() + primitiveType = reflect.TypeOf((*Primitive)(nil)).Elem() +) + +// Decode TOML data in to the pointer `v`. +func (dec *Decoder) Decode(v any) (MetaData, error) { + rv := reflect.ValueOf(v) + if rv.Kind() != reflect.Ptr { + s := "%q" + if reflect.TypeOf(v) == nil { + s = "%v" + } + + return MetaData{}, fmt.Errorf("toml: cannot decode to non-pointer "+s, reflect.TypeOf(v)) + } + if rv.IsNil() { + return MetaData{}, fmt.Errorf("toml: cannot decode to nil value of %q", reflect.TypeOf(v)) + } + + // Check if this is a supported type: struct, map, any, or something that + // implements UnmarshalTOML or UnmarshalText. + rv = indirect(rv) + rt := rv.Type() + if rv.Kind() != reflect.Struct && rv.Kind() != reflect.Map && + !(rv.Kind() == reflect.Interface && rv.NumMethod() == 0) && + !rt.Implements(unmarshalToml) && !rt.Implements(unmarshalText) { + return MetaData{}, fmt.Errorf("toml: cannot decode to type %s", rt) + } + + // TODO: parser should read from io.Reader? Or at the very least, make it + // read from []byte rather than string + data, err := io.ReadAll(dec.r) + if err != nil { + return MetaData{}, err + } + + p, err := parse(string(data)) + if err != nil { + return MetaData{}, err + } + + md := MetaData{ + mapping: p.mapping, + keyInfo: p.keyInfo, + keys: p.ordered, + decoded: make(map[string]struct{}, len(p.ordered)), + context: nil, + data: data, + } + return md, md.unify(p.mapping, rv) +} + +// PrimitiveDecode is just like the other Decode* functions, except it decodes a +// TOML value that has already been parsed. Valid primitive values can *only* be +// obtained from values filled by the decoder functions, including this method. +// (i.e., v may contain more [Primitive] values.) +// +// Meta data for primitive values is included in the meta data returned by the +// Decode* functions with one exception: keys returned by the Undecoded method +// will only reflect keys that were decoded. Namely, any keys hidden behind a +// Primitive will be considered undecoded. Executing this method will update the +// undecoded keys in the meta data. (See the example.) +func (md *MetaData) PrimitiveDecode(primValue Primitive, v any) error { + md.context = primValue.context + defer func() { md.context = nil }() + return md.unify(primValue.undecoded, rvalue(v)) +} + +// unify performs a sort of type unification based on the structure of `rv`, +// which is the client representation. +// +// Any type mismatch produces an error. Finding a type that we don't know +// how to handle produces an unsupported type error. +func (md *MetaData) unify(data any, rv reflect.Value) error { + // Special case. Look for a `Primitive` value. + // TODO: #76 would make this superfluous after implemented. + if rv.Type() == primitiveType { + // Save the undecoded data and the key context into the primitive + // value. + context := make(Key, len(md.context)) + copy(context, md.context) + rv.Set(reflect.ValueOf(Primitive{ + undecoded: data, + context: context, + })) + return nil + } + + rvi := rv.Interface() + if v, ok := rvi.(Unmarshaler); ok { + err := v.UnmarshalTOML(data) + if err != nil { + return md.parseErr(err) + } + return nil + } + if v, ok := rvi.(encoding.TextUnmarshaler); ok { + return md.unifyText(data, v) + } + + // TODO: + // The behavior here is incorrect whenever a Go type satisfies the + // encoding.TextUnmarshaler interface but also corresponds to a TOML hash or + // array. In particular, the unmarshaler should only be applied to primitive + // TOML values. But at this point, it will be applied to all kinds of values + // and produce an incorrect error whenever those values are hashes or arrays + // (including arrays of tables). + + k := rv.Kind() + + if k >= reflect.Int && k <= reflect.Uint64 { + return md.unifyInt(data, rv) + } + switch k { + case reflect.Struct: + return md.unifyStruct(data, rv) + case reflect.Map: + return md.unifyMap(data, rv) + case reflect.Array: + return md.unifyArray(data, rv) + case reflect.Slice: + return md.unifySlice(data, rv) + case reflect.String: + return md.unifyString(data, rv) + case reflect.Bool: + return md.unifyBool(data, rv) + case reflect.Interface: + if rv.NumMethod() > 0 { /// Only empty interfaces are supported. + return md.e("unsupported type %s", rv.Type()) + } + return md.unifyAnything(data, rv) + case reflect.Float32, reflect.Float64: + return md.unifyFloat64(data, rv) + } + return md.e("unsupported type %s", rv.Kind()) +} + +func (md *MetaData) unifyStruct(mapping any, rv reflect.Value) error { + tmap, ok := mapping.(map[string]any) + if !ok { + if mapping == nil { + return nil + } + return md.e("type mismatch for %s: expected table but found %s", rv.Type().String(), fmtType(mapping)) + } + + for key, datum := range tmap { + var f *field + fields := cachedTypeFields(rv.Type()) + for i := range fields { + ff := &fields[i] + if ff.name == key { + f = ff + break + } + if f == nil && strings.EqualFold(ff.name, key) { + f = ff + } + } + if f != nil { + subv := rv + for _, i := range f.index { + subv = indirect(subv.Field(i)) + } + + if isUnifiable(subv) { + md.decoded[md.context.add(key).String()] = struct{}{} + md.context = append(md.context, key) + + err := md.unify(datum, subv) + if err != nil { + return err + } + md.context = md.context[0 : len(md.context)-1] + } else if f.name != "" { + return md.e("cannot write unexported field %s.%s", rv.Type().String(), f.name) + } + } + } + return nil +} + +func (md *MetaData) unifyMap(mapping any, rv reflect.Value) error { + keyType := rv.Type().Key().Kind() + if keyType != reflect.String && keyType != reflect.Interface { + return fmt.Errorf("toml: cannot decode to a map with non-string key type (%s in %q)", + keyType, rv.Type()) + } + + tmap, ok := mapping.(map[string]any) + if !ok { + if tmap == nil { + return nil + } + return md.badtype("map", mapping) + } + if rv.IsNil() { + rv.Set(reflect.MakeMap(rv.Type())) + } + for k, v := range tmap { + md.decoded[md.context.add(k).String()] = struct{}{} + md.context = append(md.context, k) + + rvval := reflect.Indirect(reflect.New(rv.Type().Elem())) + + err := md.unify(v, indirect(rvval)) + if err != nil { + return err + } + md.context = md.context[0 : len(md.context)-1] + + rvkey := indirect(reflect.New(rv.Type().Key())) + + switch keyType { + case reflect.Interface: + rvkey.Set(reflect.ValueOf(k)) + case reflect.String: + rvkey.SetString(k) + } + + rv.SetMapIndex(rvkey, rvval) + } + return nil +} + +func (md *MetaData) unifyArray(data any, rv reflect.Value) error { + datav := reflect.ValueOf(data) + if datav.Kind() != reflect.Slice { + if !datav.IsValid() { + return nil + } + return md.badtype("slice", data) + } + if l := datav.Len(); l != rv.Len() { + return md.e("expected array length %d; got TOML array of length %d", rv.Len(), l) + } + return md.unifySliceArray(datav, rv) +} + +func (md *MetaData) unifySlice(data any, rv reflect.Value) error { + datav := reflect.ValueOf(data) + if datav.Kind() != reflect.Slice { + if !datav.IsValid() { + return nil + } + return md.badtype("slice", data) + } + n := datav.Len() + if rv.IsNil() || rv.Cap() < n { + rv.Set(reflect.MakeSlice(rv.Type(), n, n)) + } + rv.SetLen(n) + return md.unifySliceArray(datav, rv) +} + +func (md *MetaData) unifySliceArray(data, rv reflect.Value) error { + l := data.Len() + for i := 0; i < l; i++ { + err := md.unify(data.Index(i).Interface(), indirect(rv.Index(i))) + if err != nil { + return err + } + } + return nil +} + +func (md *MetaData) unifyString(data any, rv reflect.Value) error { + _, ok := rv.Interface().(json.Number) + if ok { + if i, ok := data.(int64); ok { + rv.SetString(strconv.FormatInt(i, 10)) + } else if f, ok := data.(float64); ok { + rv.SetString(strconv.FormatFloat(f, 'f', -1, 64)) + } else { + return md.badtype("string", data) + } + return nil + } + + if s, ok := data.(string); ok { + rv.SetString(s) + return nil + } + return md.badtype("string", data) +} + +func (md *MetaData) unifyFloat64(data any, rv reflect.Value) error { + rvk := rv.Kind() + + if num, ok := data.(float64); ok { + switch rvk { + case reflect.Float32: + if num < -math.MaxFloat32 || num > math.MaxFloat32 { + return md.parseErr(errParseRange{i: num, size: rvk.String()}) + } + fallthrough + case reflect.Float64: + rv.SetFloat(num) + default: + panic("bug") + } + return nil + } + + if num, ok := data.(int64); ok { + if (rvk == reflect.Float32 && (num < -maxSafeFloat32Int || num > maxSafeFloat32Int)) || + (rvk == reflect.Float64 && (num < -maxSafeFloat64Int || num > maxSafeFloat64Int)) { + return md.parseErr(errUnsafeFloat{i: num, size: rvk.String()}) + } + rv.SetFloat(float64(num)) + return nil + } + + return md.badtype("float", data) +} + +func (md *MetaData) unifyInt(data any, rv reflect.Value) error { + _, ok := rv.Interface().(time.Duration) + if ok { + // Parse as string duration, and fall back to regular integer parsing + // (as nanosecond) if this is not a string. + if s, ok := data.(string); ok { + dur, err := time.ParseDuration(s) + if err != nil { + return md.parseErr(errParseDuration{s}) + } + rv.SetInt(int64(dur)) + return nil + } + } + + num, ok := data.(int64) + if !ok { + return md.badtype("integer", data) + } + + rvk := rv.Kind() + switch { + case rvk >= reflect.Int && rvk <= reflect.Int64: + if (rvk == reflect.Int8 && (num < math.MinInt8 || num > math.MaxInt8)) || + (rvk == reflect.Int16 && (num < math.MinInt16 || num > math.MaxInt16)) || + (rvk == reflect.Int32 && (num < math.MinInt32 || num > math.MaxInt32)) { + return md.parseErr(errParseRange{i: num, size: rvk.String()}) + } + rv.SetInt(num) + case rvk >= reflect.Uint && rvk <= reflect.Uint64: + unum := uint64(num) + if rvk == reflect.Uint8 && (num < 0 || unum > math.MaxUint8) || + rvk == reflect.Uint16 && (num < 0 || unum > math.MaxUint16) || + rvk == reflect.Uint32 && (num < 0 || unum > math.MaxUint32) { + return md.parseErr(errParseRange{i: num, size: rvk.String()}) + } + rv.SetUint(unum) + default: + panic("unreachable") + } + return nil +} + +func (md *MetaData) unifyBool(data any, rv reflect.Value) error { + if b, ok := data.(bool); ok { + rv.SetBool(b) + return nil + } + return md.badtype("boolean", data) +} + +func (md *MetaData) unifyAnything(data any, rv reflect.Value) error { + rv.Set(reflect.ValueOf(data)) + return nil +} + +func (md *MetaData) unifyText(data any, v encoding.TextUnmarshaler) error { + var s string + switch sdata := data.(type) { + case Marshaler: + text, err := sdata.MarshalTOML() + if err != nil { + return err + } + s = string(text) + case encoding.TextMarshaler: + text, err := sdata.MarshalText() + if err != nil { + return err + } + s = string(text) + case fmt.Stringer: + s = sdata.String() + case string: + s = sdata + case bool: + s = fmt.Sprintf("%v", sdata) + case int64: + s = fmt.Sprintf("%d", sdata) + case float64: + s = fmt.Sprintf("%f", sdata) + default: + return md.badtype("primitive (string-like)", data) + } + if err := v.UnmarshalText([]byte(s)); err != nil { + return md.parseErr(err) + } + return nil +} + +func (md *MetaData) badtype(dst string, data any) error { + return md.e("incompatible types: TOML value has type %s; destination has type %s", fmtType(data), dst) +} + +func (md *MetaData) parseErr(err error) error { + k := md.context.String() + return ParseError{ + LastKey: k, + Position: md.keyInfo[k].pos, + Line: md.keyInfo[k].pos.Line, + err: err, + input: string(md.data), + } +} + +func (md *MetaData) e(format string, args ...any) error { + f := "toml: " + if len(md.context) > 0 { + f = fmt.Sprintf("toml: (last key %q): ", md.context) + p := md.keyInfo[md.context.String()].pos + if p.Line > 0 { + f = fmt.Sprintf("toml: line %d (last key %q): ", p.Line, md.context) + } + } + return fmt.Errorf(f+format, args...) +} + +// rvalue returns a reflect.Value of `v`. All pointers are resolved. +func rvalue(v any) reflect.Value { + return indirect(reflect.ValueOf(v)) +} + +// indirect returns the value pointed to by a pointer. +// +// Pointers are followed until the value is not a pointer. New values are +// allocated for each nil pointer. +// +// An exception to this rule is if the value satisfies an interface of interest +// to us (like encoding.TextUnmarshaler). +func indirect(v reflect.Value) reflect.Value { + if v.Kind() != reflect.Ptr { + if v.CanSet() { + pv := v.Addr() + pvi := pv.Interface() + if _, ok := pvi.(encoding.TextUnmarshaler); ok { + return pv + } + if _, ok := pvi.(Unmarshaler); ok { + return pv + } + } + return v + } + if v.IsNil() { + v.Set(reflect.New(v.Type().Elem())) + } + return indirect(reflect.Indirect(v)) +} + +func isUnifiable(rv reflect.Value) bool { + if rv.CanSet() { + return true + } + rvi := rv.Interface() + if _, ok := rvi.(encoding.TextUnmarshaler); ok { + return true + } + if _, ok := rvi.(Unmarshaler); ok { + return true + } + return false +} + +// fmt %T with "interface {}" replaced with "any", which is far more readable. +func fmtType(t any) string { + return strings.ReplaceAll(fmt.Sprintf("%T", t), "interface {}", "any") +} |