diff options
Diffstat (limited to 'vendor/gopkg.in/yaml.v2/decode.go')
-rw-r--r-- | vendor/gopkg.in/yaml.v2/decode.go | 775 |
1 files changed, 775 insertions, 0 deletions
diff --git a/vendor/gopkg.in/yaml.v2/decode.go b/vendor/gopkg.in/yaml.v2/decode.go new file mode 100644 index 0000000..e4e56e2 --- /dev/null +++ b/vendor/gopkg.in/yaml.v2/decode.go @@ -0,0 +1,775 @@ +package yaml + +import ( + "encoding" + "encoding/base64" + "fmt" + "io" + "math" + "reflect" + "strconv" + "time" +) + +const ( + documentNode = 1 << iota + mappingNode + sequenceNode + scalarNode + aliasNode +) + +type node struct { + kind int + line, column int + tag string + // For an alias node, alias holds the resolved alias. + alias *node + value string + implicit bool + children []*node + anchors map[string]*node +} + +// ---------------------------------------------------------------------------- +// Parser, produces a node tree out of a libyaml event stream. + +type parser struct { + parser yaml_parser_t + event yaml_event_t + doc *node + doneInit bool +} + +func newParser(b []byte) *parser { + p := parser{} + if !yaml_parser_initialize(&p.parser) { + panic("failed to initialize YAML emitter") + } + if len(b) == 0 { + b = []byte{'\n'} + } + yaml_parser_set_input_string(&p.parser, b) + return &p +} + +func newParserFromReader(r io.Reader) *parser { + p := parser{} + if !yaml_parser_initialize(&p.parser) { + panic("failed to initialize YAML emitter") + } + yaml_parser_set_input_reader(&p.parser, r) + return &p +} + +func (p *parser) init() { + if p.doneInit { + return + } + p.expect(yaml_STREAM_START_EVENT) + p.doneInit = true +} + +func (p *parser) destroy() { + if p.event.typ != yaml_NO_EVENT { + yaml_event_delete(&p.event) + } + yaml_parser_delete(&p.parser) +} + +// expect consumes an event from the event stream and +// checks that it's of the expected type. +func (p *parser) expect(e yaml_event_type_t) { + if p.event.typ == yaml_NO_EVENT { + if !yaml_parser_parse(&p.parser, &p.event) { + p.fail() + } + } + if p.event.typ == yaml_STREAM_END_EVENT { + failf("attempted to go past the end of stream; corrupted value?") + } + if p.event.typ != e { + p.parser.problem = fmt.Sprintf("expected %s event but got %s", e, p.event.typ) + p.fail() + } + yaml_event_delete(&p.event) + p.event.typ = yaml_NO_EVENT +} + +// peek peeks at the next event in the event stream, +// puts the results into p.event and returns the event type. +func (p *parser) peek() yaml_event_type_t { + if p.event.typ != yaml_NO_EVENT { + return p.event.typ + } + if !yaml_parser_parse(&p.parser, &p.event) { + p.fail() + } + return p.event.typ +} + +func (p *parser) fail() { + var where string + var line int + if p.parser.problem_mark.line != 0 { + line = p.parser.problem_mark.line + // Scanner errors don't iterate line before returning error + if p.parser.error == yaml_SCANNER_ERROR { + line++ + } + } else if p.parser.context_mark.line != 0 { + line = p.parser.context_mark.line + } + if line != 0 { + where = "line " + strconv.Itoa(line) + ": " + } + var msg string + if len(p.parser.problem) > 0 { + msg = p.parser.problem + } else { + msg = "unknown problem parsing YAML content" + } + failf("%s%s", where, msg) +} + +func (p *parser) anchor(n *node, anchor []byte) { + if anchor != nil { + p.doc.anchors[string(anchor)] = n + } +} + +func (p *parser) parse() *node { + p.init() + switch p.peek() { + case yaml_SCALAR_EVENT: + return p.scalar() + case yaml_ALIAS_EVENT: + return p.alias() + case yaml_MAPPING_START_EVENT: + return p.mapping() + case yaml_SEQUENCE_START_EVENT: + return p.sequence() + case yaml_DOCUMENT_START_EVENT: + return p.document() + case yaml_STREAM_END_EVENT: + // Happens when attempting to decode an empty buffer. + return nil + default: + panic("attempted to parse unknown event: " + p.event.typ.String()) + } +} + +func (p *parser) node(kind int) *node { + return &node{ + kind: kind, + line: p.event.start_mark.line, + column: p.event.start_mark.column, + } +} + +func (p *parser) document() *node { + n := p.node(documentNode) + n.anchors = make(map[string]*node) + p.doc = n + p.expect(yaml_DOCUMENT_START_EVENT) + n.children = append(n.children, p.parse()) + p.expect(yaml_DOCUMENT_END_EVENT) + return n +} + +func (p *parser) alias() *node { + n := p.node(aliasNode) + n.value = string(p.event.anchor) + n.alias = p.doc.anchors[n.value] + if n.alias == nil { + failf("unknown anchor '%s' referenced", n.value) + } + p.expect(yaml_ALIAS_EVENT) + return n +} + +func (p *parser) scalar() *node { + n := p.node(scalarNode) + n.value = string(p.event.value) + n.tag = string(p.event.tag) + n.implicit = p.event.implicit + p.anchor(n, p.event.anchor) + p.expect(yaml_SCALAR_EVENT) + return n +} + +func (p *parser) sequence() *node { + n := p.node(sequenceNode) + p.anchor(n, p.event.anchor) + p.expect(yaml_SEQUENCE_START_EVENT) + for p.peek() != yaml_SEQUENCE_END_EVENT { + n.children = append(n.children, p.parse()) + } + p.expect(yaml_SEQUENCE_END_EVENT) + return n +} + +func (p *parser) mapping() *node { + n := p.node(mappingNode) + p.anchor(n, p.event.anchor) + p.expect(yaml_MAPPING_START_EVENT) + for p.peek() != yaml_MAPPING_END_EVENT { + n.children = append(n.children, p.parse(), p.parse()) + } + p.expect(yaml_MAPPING_END_EVENT) + return n +} + +// ---------------------------------------------------------------------------- +// Decoder, unmarshals a node into a provided value. + +type decoder struct { + doc *node + aliases map[*node]bool + mapType reflect.Type + terrors []string + strict bool +} + +var ( + mapItemType = reflect.TypeOf(MapItem{}) + durationType = reflect.TypeOf(time.Duration(0)) + defaultMapType = reflect.TypeOf(map[interface{}]interface{}{}) + ifaceType = defaultMapType.Elem() + timeType = reflect.TypeOf(time.Time{}) + ptrTimeType = reflect.TypeOf(&time.Time{}) +) + +func newDecoder(strict bool) *decoder { + d := &decoder{mapType: defaultMapType, strict: strict} + d.aliases = make(map[*node]bool) + return d +} + +func (d *decoder) terror(n *node, tag string, out reflect.Value) { + if n.tag != "" { + tag = n.tag + } + value := n.value + if tag != yaml_SEQ_TAG && tag != yaml_MAP_TAG { + if len(value) > 10 { + value = " `" + value[:7] + "...`" + } else { + value = " `" + value + "`" + } + } + d.terrors = append(d.terrors, fmt.Sprintf("line %d: cannot unmarshal %s%s into %s", n.line+1, shortTag(tag), value, out.Type())) +} + +func (d *decoder) callUnmarshaler(n *node, u Unmarshaler) (good bool) { + terrlen := len(d.terrors) + err := u.UnmarshalYAML(func(v interface{}) (err error) { + defer handleErr(&err) + d.unmarshal(n, reflect.ValueOf(v)) + if len(d.terrors) > terrlen { + issues := d.terrors[terrlen:] + d.terrors = d.terrors[:terrlen] + return &TypeError{issues} + } + return nil + }) + if e, ok := err.(*TypeError); ok { + d.terrors = append(d.terrors, e.Errors...) + return false + } + if err != nil { + fail(err) + } + return true +} + +// d.prepare initializes and dereferences pointers and calls UnmarshalYAML +// if a value is found to implement it. +// It returns the initialized and dereferenced out value, whether +// unmarshalling was already done by UnmarshalYAML, and if so whether +// its types unmarshalled appropriately. +// +// If n holds a null value, prepare returns before doing anything. +func (d *decoder) prepare(n *node, out reflect.Value) (newout reflect.Value, unmarshaled, good bool) { + if n.tag == yaml_NULL_TAG || n.kind == scalarNode && n.tag == "" && (n.value == "null" || n.value == "~" || n.value == "" && n.implicit) { + return out, false, false + } + again := true + for again { + again = false + if out.Kind() == reflect.Ptr { + if out.IsNil() { + out.Set(reflect.New(out.Type().Elem())) + } + out = out.Elem() + again = true + } + if out.CanAddr() { + if u, ok := out.Addr().Interface().(Unmarshaler); ok { + good = d.callUnmarshaler(n, u) + return out, true, good + } + } + } + return out, false, false +} + +func (d *decoder) unmarshal(n *node, out reflect.Value) (good bool) { + switch n.kind { + case documentNode: + return d.document(n, out) + case aliasNode: + return d.alias(n, out) + } + out, unmarshaled, good := d.prepare(n, out) + if unmarshaled { + return good + } + switch n.kind { + case scalarNode: + good = d.scalar(n, out) + case mappingNode: + good = d.mapping(n, out) + case sequenceNode: + good = d.sequence(n, out) + default: + panic("internal error: unknown node kind: " + strconv.Itoa(n.kind)) + } + return good +} + +func (d *decoder) document(n *node, out reflect.Value) (good bool) { + if len(n.children) == 1 { + d.doc = n + d.unmarshal(n.children[0], out) + return true + } + return false +} + +func (d *decoder) alias(n *node, out reflect.Value) (good bool) { + if d.aliases[n] { + // TODO this could actually be allowed in some circumstances. + failf("anchor '%s' value contains itself", n.value) + } + d.aliases[n] = true + good = d.unmarshal(n.alias, out) + delete(d.aliases, n) + return good +} + +var zeroValue reflect.Value + +func resetMap(out reflect.Value) { + for _, k := range out.MapKeys() { + out.SetMapIndex(k, zeroValue) + } +} + +func (d *decoder) scalar(n *node, out reflect.Value) bool { + var tag string + var resolved interface{} + if n.tag == "" && !n.implicit { + tag = yaml_STR_TAG + resolved = n.value + } else { + tag, resolved = resolve(n.tag, n.value) + if tag == yaml_BINARY_TAG { + data, err := base64.StdEncoding.DecodeString(resolved.(string)) + if err != nil { + failf("!!binary value contains invalid base64 data") + } + resolved = string(data) + } + } + if resolved == nil { + if out.Kind() == reflect.Map && !out.CanAddr() { + resetMap(out) + } else { + out.Set(reflect.Zero(out.Type())) + } + return true + } + if resolvedv := reflect.ValueOf(resolved); out.Type() == resolvedv.Type() { + // We've resolved to exactly the type we want, so use that. + out.Set(resolvedv) + return true + } + // Perhaps we can use the value as a TextUnmarshaler to + // set its value. + if out.CanAddr() { + u, ok := out.Addr().Interface().(encoding.TextUnmarshaler) + if ok { + var text []byte + if tag == yaml_BINARY_TAG { + text = []byte(resolved.(string)) + } else { + // We let any value be unmarshaled into TextUnmarshaler. + // That might be more lax than we'd like, but the + // TextUnmarshaler itself should bowl out any dubious values. + text = []byte(n.value) + } + err := u.UnmarshalText(text) + if err != nil { + fail(err) + } + return true + } + } + switch out.Kind() { + case reflect.String: + if tag == yaml_BINARY_TAG { + out.SetString(resolved.(string)) + return true + } + if resolved != nil { + out.SetString(n.value) + return true + } + case reflect.Interface: + if resolved == nil { + out.Set(reflect.Zero(out.Type())) + } else if tag == yaml_TIMESTAMP_TAG { + // It looks like a timestamp but for backward compatibility + // reasons we set it as a string, so that code that unmarshals + // timestamp-like values into interface{} will continue to + // see a string and not a time.Time. + // TODO(v3) Drop this. + out.Set(reflect.ValueOf(n.value)) + } else { + out.Set(reflect.ValueOf(resolved)) + } + return true + case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: + switch resolved := resolved.(type) { + case int: + if !out.OverflowInt(int64(resolved)) { + out.SetInt(int64(resolved)) + return true + } + case int64: + if !out.OverflowInt(resolved) { + out.SetInt(resolved) + return true + } + case uint64: + if resolved <= math.MaxInt64 && !out.OverflowInt(int64(resolved)) { + out.SetInt(int64(resolved)) + return true + } + case float64: + if resolved <= math.MaxInt64 && !out.OverflowInt(int64(resolved)) { + out.SetInt(int64(resolved)) + return true + } + case string: + if out.Type() == durationType { + d, err := time.ParseDuration(resolved) + if err == nil { + out.SetInt(int64(d)) + return true + } + } + } + case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: + switch resolved := resolved.(type) { + case int: + if resolved >= 0 && !out.OverflowUint(uint64(resolved)) { + out.SetUint(uint64(resolved)) + return true + } + case int64: + if resolved >= 0 && !out.OverflowUint(uint64(resolved)) { + out.SetUint(uint64(resolved)) + return true + } + case uint64: + if !out.OverflowUint(uint64(resolved)) { + out.SetUint(uint64(resolved)) + return true + } + case float64: + if resolved <= math.MaxUint64 && !out.OverflowUint(uint64(resolved)) { + out.SetUint(uint64(resolved)) + return true + } + } + case reflect.Bool: + switch resolved := resolved.(type) { + case bool: + out.SetBool(resolved) + return true + } + case reflect.Float32, reflect.Float64: + switch resolved := resolved.(type) { + case int: + out.SetFloat(float64(resolved)) + return true + case int64: + out.SetFloat(float64(resolved)) + return true + case uint64: + out.SetFloat(float64(resolved)) + return true + case float64: + out.SetFloat(resolved) + return true + } + case reflect.Struct: + if resolvedv := reflect.ValueOf(resolved); out.Type() == resolvedv.Type() { + out.Set(resolvedv) + return true + } + case reflect.Ptr: + if out.Type().Elem() == reflect.TypeOf(resolved) { + // TODO DOes this make sense? When is out a Ptr except when decoding a nil value? + elem := reflect.New(out.Type().Elem()) + elem.Elem().Set(reflect.ValueOf(resolved)) + out.Set(elem) + return true + } + } + d.terror(n, tag, out) + return false +} + +func settableValueOf(i interface{}) reflect.Value { + v := reflect.ValueOf(i) + sv := reflect.New(v.Type()).Elem() + sv.Set(v) + return sv +} + +func (d *decoder) sequence(n *node, out reflect.Value) (good bool) { + l := len(n.children) + + var iface reflect.Value + switch out.Kind() { + case reflect.Slice: + out.Set(reflect.MakeSlice(out.Type(), l, l)) + case reflect.Array: + if l != out.Len() { + failf("invalid array: want %d elements but got %d", out.Len(), l) + } + case reflect.Interface: + // No type hints. Will have to use a generic sequence. + iface = out + out = settableValueOf(make([]interface{}, l)) + default: + d.terror(n, yaml_SEQ_TAG, out) + return false + } + et := out.Type().Elem() + + j := 0 + for i := 0; i < l; i++ { + e := reflect.New(et).Elem() + if ok := d.unmarshal(n.children[i], e); ok { + out.Index(j).Set(e) + j++ + } + } + if out.Kind() != reflect.Array { + out.Set(out.Slice(0, j)) + } + if iface.IsValid() { + iface.Set(out) + } + return true +} + +func (d *decoder) mapping(n *node, out reflect.Value) (good bool) { + switch out.Kind() { + case reflect.Struct: + return d.mappingStruct(n, out) + case reflect.Slice: + return d.mappingSlice(n, out) + case reflect.Map: + // okay + case reflect.Interface: + if d.mapType.Kind() == reflect.Map { + iface := out + out = reflect.MakeMap(d.mapType) + iface.Set(out) + } else { + slicev := reflect.New(d.mapType).Elem() + if !d.mappingSlice(n, slicev) { + return false + } + out.Set(slicev) + return true + } + default: + d.terror(n, yaml_MAP_TAG, out) + return false + } + outt := out.Type() + kt := outt.Key() + et := outt.Elem() + + mapType := d.mapType + if outt.Key() == ifaceType && outt.Elem() == ifaceType { + d.mapType = outt + } + + if out.IsNil() { + out.Set(reflect.MakeMap(outt)) + } + l := len(n.children) + for i := 0; i < l; i += 2 { + if isMerge(n.children[i]) { + d.merge(n.children[i+1], out) + continue + } + k := reflect.New(kt).Elem() + if d.unmarshal(n.children[i], k) { + kkind := k.Kind() + if kkind == reflect.Interface { + kkind = k.Elem().Kind() + } + if kkind == reflect.Map || kkind == reflect.Slice { + failf("invalid map key: %#v", k.Interface()) + } + e := reflect.New(et).Elem() + if d.unmarshal(n.children[i+1], e) { + d.setMapIndex(n.children[i+1], out, k, e) + } + } + } + d.mapType = mapType + return true +} + +func (d *decoder) setMapIndex(n *node, out, k, v reflect.Value) { + if d.strict && out.MapIndex(k) != zeroValue { + d.terrors = append(d.terrors, fmt.Sprintf("line %d: key %#v already set in map", n.line+1, k.Interface())) + return + } + out.SetMapIndex(k, v) +} + +func (d *decoder) mappingSlice(n *node, out reflect.Value) (good bool) { + outt := out.Type() + if outt.Elem() != mapItemType { + d.terror(n, yaml_MAP_TAG, out) + return false + } + + mapType := d.mapType + d.mapType = outt + + var slice []MapItem + var l = len(n.children) + for i := 0; i < l; i += 2 { + if isMerge(n.children[i]) { + d.merge(n.children[i+1], out) + continue + } + item := MapItem{} + k := reflect.ValueOf(&item.Key).Elem() + if d.unmarshal(n.children[i], k) { + v := reflect.ValueOf(&item.Value).Elem() + if d.unmarshal(n.children[i+1], v) { + slice = append(slice, item) + } + } + } + out.Set(reflect.ValueOf(slice)) + d.mapType = mapType + return true +} + +func (d *decoder) mappingStruct(n *node, out reflect.Value) (good bool) { + sinfo, err := getStructInfo(out.Type()) + if err != nil { + panic(err) + } + name := settableValueOf("") + l := len(n.children) + + var inlineMap reflect.Value + var elemType reflect.Type + if sinfo.InlineMap != -1 { + inlineMap = out.Field(sinfo.InlineMap) + inlineMap.Set(reflect.New(inlineMap.Type()).Elem()) + elemType = inlineMap.Type().Elem() + } + + var doneFields []bool + if d.strict { + doneFields = make([]bool, len(sinfo.FieldsList)) + } + for i := 0; i < l; i += 2 { + ni := n.children[i] + if isMerge(ni) { + d.merge(n.children[i+1], out) + continue + } + if !d.unmarshal(ni, name) { + continue + } + if info, ok := sinfo.FieldsMap[name.String()]; ok { + if d.strict { + if doneFields[info.Id] { + d.terrors = append(d.terrors, fmt.Sprintf("line %d: field %s already set in type %s", ni.line+1, name.String(), out.Type())) + continue + } + doneFields[info.Id] = true + } + var field reflect.Value + if info.Inline == nil { + field = out.Field(info.Num) + } else { + field = out.FieldByIndex(info.Inline) + } + d.unmarshal(n.children[i+1], field) + } else if sinfo.InlineMap != -1 { + if inlineMap.IsNil() { + inlineMap.Set(reflect.MakeMap(inlineMap.Type())) + } + value := reflect.New(elemType).Elem() + d.unmarshal(n.children[i+1], value) + d.setMapIndex(n.children[i+1], inlineMap, name, value) + } else if d.strict { + d.terrors = append(d.terrors, fmt.Sprintf("line %d: field %s not found in type %s", ni.line+1, name.String(), out.Type())) + } + } + return true +} + +func failWantMap() { + failf("map merge requires map or sequence of maps as the value") +} + +func (d *decoder) merge(n *node, out reflect.Value) { + switch n.kind { + case mappingNode: + d.unmarshal(n, out) + case aliasNode: + an, ok := d.doc.anchors[n.value] + if ok && an.kind != mappingNode { + failWantMap() + } + d.unmarshal(n, out) + case sequenceNode: + // Step backwards as earlier nodes take precedence. + for i := len(n.children) - 1; i >= 0; i-- { + ni := n.children[i] + if ni.kind == aliasNode { + an, ok := d.doc.anchors[ni.value] + if ok && an.kind != mappingNode { + failWantMap() + } + } else if ni.kind != mappingNode { + failWantMap() + } + d.unmarshal(ni, out) + } + default: + failWantMap() + } +} + +func isMerge(n *node) bool { + return n.kind == scalarNode && n.value == "<<" && (n.implicit == true || n.tag == yaml_MERGE_TAG) +} |