diff options
Diffstat (limited to 'vendor/github.com/BurntSushi/toml/decode.go')
-rw-r--r-- | vendor/github.com/BurntSushi/toml/decode.go | 505 |
1 files changed, 505 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 000000000..c26b00c01 --- /dev/null +++ b/vendor/github.com/BurntSushi/toml/decode.go @@ -0,0 +1,505 @@ +package toml + +import ( + "fmt" + "io" + "io/ioutil" + "math" + "reflect" + "strings" + "time" +) + +var e = fmt.Errorf + +// Unmarshaler is the interface implemented by objects that can unmarshal a +// TOML description of themselves. +type Unmarshaler interface { + UnmarshalTOML(interface{}) error +} + +// Unmarshal decodes the contents of `p` in TOML format into a pointer `v`. +func Unmarshal(p []byte, v interface{}) error { + _, err := Decode(string(p), v) + return err +} + +// Primitive is a TOML value that hasn't been decoded into a Go value. +// When using the various `Decode*` functions, the type `Primitive` may +// be given to any value, and its decoding will be delayed. +// +// A `Primitive` value can be decoded using the `PrimitiveDecode` function. +// +// The underlying representation of a `Primitive` value is subject to change. +// Do not rely on it. +// +// N.B. 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 run time. +type Primitive struct { + undecoded interface{} + context Key +} + +// DEPRECATED! +// +// Use MetaData.PrimitiveDecode instead. +func PrimitiveDecode(primValue Primitive, v interface{}) error { + md := MetaData{decoded: make(map[string]bool)} + return md.unify(primValue.undecoded, rvalue(v)) +} + +// 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 interface{}) error { + md.context = primValue.context + defer func() { md.context = nil }() + return md.unify(primValue.undecoded, rvalue(v)) +} + +// Decode will decode the contents of `data` in TOML format into a pointer +// `v`. +// +// TOML hashes correspond to Go structs or maps. (Dealer's choice. They can be +// used interchangeably.) +// +// TOML arrays of tables correspond to either a slice of structs or a slice +// of maps. +// +// TOML datetimes correspond to Go `time.Time` values. +// +// 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 +// encoding.TextUnmarshaler interface. In this case, any primitive TOML value +// (floats, strings, integers, booleans and datetimes) will be converted to +// a byte string and given to the value's UnmarshalText method. See the +// Unmarshaler example for a demonstration with time duration strings. +// +// 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 may 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 will not handle cyclic types. If a cyclic type is passed, +// `Decode` will not terminate. +func Decode(data string, v interface{}) (MetaData, error) { + p, err := parse(data) + if err != nil { + return MetaData{}, err + } + md := MetaData{ + p.mapping, p.types, p.ordered, + make(map[string]bool, len(p.ordered)), nil, + } + return md, md.unify(p.mapping, rvalue(v)) +} + +// DecodeFile is just like Decode, except it will automatically read the +// contents of the file at `fpath` and decode it for you. +func DecodeFile(fpath string, v interface{}) (MetaData, error) { + bs, err := ioutil.ReadFile(fpath) + if err != nil { + return MetaData{}, err + } + return Decode(string(bs), v) +} + +// DecodeReader is just like Decode, except it will consume all bytes +// from the reader and decode it for you. +func DecodeReader(r io.Reader, v interface{}) (MetaData, error) { + bs, err := ioutil.ReadAll(r) + if err != nil { + return MetaData{}, err + } + return Decode(string(bs), 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 interface{}, rv reflect.Value) error { + + // Special case. Look for a `Primitive` value. + if rv.Type() == reflect.TypeOf((*Primitive)(nil)).Elem() { + // 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 + } + + // Special case. Unmarshaler Interface support. + if rv.CanAddr() { + if v, ok := rv.Addr().Interface().(Unmarshaler); ok { + return v.UnmarshalTOML(data) + } + } + + // Special case. Handle time.Time values specifically. + // TODO: Remove this code when we decide to drop support for Go 1.1. + // This isn't necessary in Go 1.2 because time.Time satisfies the encoding + // interfaces. + if rv.Type().AssignableTo(rvalue(time.Time{}).Type()) { + return md.unifyDatetime(data, rv) + } + + // Special case. Look for a value satisfying the TextUnmarshaler interface. + if v, ok := rv.Interface().(TextUnmarshaler); ok { + return md.unifyText(data, v) + } + // BUG(burntsushi) + // 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() + + // laziness + if k >= reflect.Int && k <= reflect.Uint64 { + return md.unifyInt(data, rv) + } + switch k { + case reflect.Ptr: + elem := reflect.New(rv.Type().Elem()) + err := md.unify(data, reflect.Indirect(elem)) + if err != nil { + return err + } + rv.Set(elem) + return nil + 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: + // we only support empty interfaces. + if rv.NumMethod() > 0 { + return e("Unsupported type '%s'.", rv.Kind()) + } + return md.unifyAnything(data, rv) + case reflect.Float32: + fallthrough + case reflect.Float64: + return md.unifyFloat64(data, rv) + } + return e("Unsupported type '%s'.", rv.Kind()) +} + +func (md *MetaData) unifyStruct(mapping interface{}, rv reflect.Value) error { + tmap, ok := mapping.(map[string]interface{}) + if !ok { + if mapping == nil { + return nil + } + return mismatch(rv, "map", 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()] = true + md.context = append(md.context, key) + if err := md.unify(datum, subv); err != nil { + return e("Type mismatch for '%s.%s': %s", + rv.Type().String(), f.name, err) + } + md.context = md.context[0 : len(md.context)-1] + } else if f.name != "" { + // Bad user! No soup for you! + return e("Field '%s.%s' is unexported, and therefore cannot "+ + "be loaded with reflection.", rv.Type().String(), f.name) + } + } + } + return nil +} + +func (md *MetaData) unifyMap(mapping interface{}, rv reflect.Value) error { + tmap, ok := mapping.(map[string]interface{}) + if !ok { + if tmap == nil { + return nil + } + return badtype("map", mapping) + } + if rv.IsNil() { + rv.Set(reflect.MakeMap(rv.Type())) + } + for k, v := range tmap { + md.decoded[md.context.add(k).String()] = true + md.context = append(md.context, k) + + rvkey := indirect(reflect.New(rv.Type().Key())) + rvval := reflect.Indirect(reflect.New(rv.Type().Elem())) + if err := md.unify(v, rvval); err != nil { + return err + } + md.context = md.context[0 : len(md.context)-1] + + rvkey.SetString(k) + rv.SetMapIndex(rvkey, rvval) + } + return nil +} + +func (md *MetaData) unifyArray(data interface{}, rv reflect.Value) error { + datav := reflect.ValueOf(data) + if datav.Kind() != reflect.Slice { + if !datav.IsValid() { + return nil + } + return badtype("slice", data) + } + sliceLen := datav.Len() + if sliceLen != rv.Len() { + return e("expected array length %d; got TOML array of length %d", + rv.Len(), sliceLen) + } + return md.unifySliceArray(datav, rv) +} + +func (md *MetaData) unifySlice(data interface{}, rv reflect.Value) error { + datav := reflect.ValueOf(data) + if datav.Kind() != reflect.Slice { + if !datav.IsValid() { + return nil + } + return 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 { + sliceLen := data.Len() + for i := 0; i < sliceLen; i++ { + v := data.Index(i).Interface() + sliceval := indirect(rv.Index(i)) + if err := md.unify(v, sliceval); err != nil { + return err + } + } + return nil +} + +func (md *MetaData) unifyDatetime(data interface{}, rv reflect.Value) error { + if _, ok := data.(time.Time); ok { + rv.Set(reflect.ValueOf(data)) + return nil + } + return badtype("time.Time", data) +} + +func (md *MetaData) unifyString(data interface{}, rv reflect.Value) error { + if s, ok := data.(string); ok { + rv.SetString(s) + return nil + } + return badtype("string", data) +} + +func (md *MetaData) unifyFloat64(data interface{}, rv reflect.Value) error { + if num, ok := data.(float64); ok { + switch rv.Kind() { + case reflect.Float32: + fallthrough + case reflect.Float64: + rv.SetFloat(num) + default: + panic("bug") + } + return nil + } + return badtype("float", data) +} + +func (md *MetaData) unifyInt(data interface{}, rv reflect.Value) error { + if num, ok := data.(int64); ok { + if rv.Kind() >= reflect.Int && rv.Kind() <= reflect.Int64 { + switch rv.Kind() { + case reflect.Int, reflect.Int64: + // No bounds checking necessary. + case reflect.Int8: + if num < math.MinInt8 || num > math.MaxInt8 { + return e("Value '%d' is out of range for int8.", num) + } + case reflect.Int16: + if num < math.MinInt16 || num > math.MaxInt16 { + return e("Value '%d' is out of range for int16.", num) + } + case reflect.Int32: + if num < math.MinInt32 || num > math.MaxInt32 { + return e("Value '%d' is out of range for int32.", num) + } + } + rv.SetInt(num) + } else if rv.Kind() >= reflect.Uint && rv.Kind() <= reflect.Uint64 { + unum := uint64(num) + switch rv.Kind() { + case reflect.Uint, reflect.Uint64: + // No bounds checking necessary. + case reflect.Uint8: + if num < 0 || unum > math.MaxUint8 { + return e("Value '%d' is out of range for uint8.", num) + } + case reflect.Uint16: + if num < 0 || unum > math.MaxUint16 { + return e("Value '%d' is out of range for uint16.", num) + } + case reflect.Uint32: + if num < 0 || unum > math.MaxUint32 { + return e("Value '%d' is out of range for uint32.", num) + } + } + rv.SetUint(unum) + } else { + panic("unreachable") + } + return nil + } + return badtype("integer", data) +} + +func (md *MetaData) unifyBool(data interface{}, rv reflect.Value) error { + if b, ok := data.(bool); ok { + rv.SetBool(b) + return nil + } + return badtype("boolean", data) +} + +func (md *MetaData) unifyAnything(data interface{}, rv reflect.Value) error { + rv.Set(reflect.ValueOf(data)) + return nil +} + +func (md *MetaData) unifyText(data interface{}, v TextUnmarshaler) error { + var s string + switch sdata := data.(type) { + case 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 badtype("primitive (string-like)", data) + } + if err := v.UnmarshalText([]byte(s)); err != nil { + return err + } + return nil +} + +// rvalue returns a reflect.Value of `v`. All pointers are resolved. +func rvalue(v interface{}) 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.CanAddr() { + pv := v.Addr() + if _, ok := pv.Interface().(TextUnmarshaler); 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 + } + if _, ok := rv.Interface().(TextUnmarshaler); ok { + return true + } + return false +} + +func badtype(expected string, data interface{}) error { + return e("Expected %s but found '%T'.", expected, data) +} + +func mismatch(user reflect.Value, expected string, data interface{}) error { + return e("Type mismatch for %s. Expected %s but found '%T'.", + user.Type().String(), expected, data) +} |