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Diffstat (limited to '')
| -rw-r--r-- | modules/packages/rubygems/marshal.go | 311 |
1 files changed, 311 insertions, 0 deletions
diff --git a/modules/packages/rubygems/marshal.go b/modules/packages/rubygems/marshal.go new file mode 100644 index 0000000..4e6a5fc --- /dev/null +++ b/modules/packages/rubygems/marshal.go @@ -0,0 +1,311 @@ +// Copyright 2021 The Gitea Authors. All rights reserved. +// SPDX-License-Identifier: MIT + +package rubygems + +import ( + "bufio" + "bytes" + "io" + "reflect" + + "code.gitea.io/gitea/modules/util" +) + +const ( + majorVersion = 4 + minorVersion = 8 + + typeNil = '0' + typeTrue = 'T' + typeFalse = 'F' + typeFixnum = 'i' + typeString = '"' + typeSymbol = ':' + typeSymbolLink = ';' + typeArray = '[' + typeIVar = 'I' + typeUserMarshal = 'U' + typeUserDef = 'u' + typeObject = 'o' +) + +var ( + // ErrUnsupportedType indicates an unsupported type + ErrUnsupportedType = util.NewInvalidArgumentErrorf("type is unsupported") + // ErrInvalidIntRange indicates an invalid number range + ErrInvalidIntRange = util.NewInvalidArgumentErrorf("number is not in valid range") +) + +// RubyUserMarshal is a Ruby object that has a marshal_load function. +type RubyUserMarshal struct { + Name string + Value any +} + +// RubyUserDef is a Ruby object that has a _load function. +type RubyUserDef struct { + Name string + Value any +} + +// RubyObject is a default Ruby object. +type RubyObject struct { + Name string + Member map[string]any +} + +// MarshalEncoder mimics Rubys Marshal class. +// Note: Only supports types used by the RubyGems package registry. +type MarshalEncoder struct { + w *bufio.Writer + symbols map[string]int +} + +// NewMarshalEncoder creates a new MarshalEncoder +func NewMarshalEncoder(w io.Writer) *MarshalEncoder { + return &MarshalEncoder{ + w: bufio.NewWriter(w), + symbols: map[string]int{}, + } +} + +// Encode encodes the given type +func (e *MarshalEncoder) Encode(v any) error { + if _, err := e.w.Write([]byte{majorVersion, minorVersion}); err != nil { + return err + } + + if err := e.marshal(v); err != nil { + return err + } + + return e.w.Flush() +} + +func (e *MarshalEncoder) marshal(v any) error { + if v == nil { + return e.marshalNil() + } + + val := reflect.ValueOf(v) + typ := reflect.TypeOf(v) + + if typ.Kind() == reflect.Ptr { + val = val.Elem() + typ = typ.Elem() + } + + switch typ.Kind() { + case reflect.Bool: + return e.marshalBool(val.Bool()) + case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32: + return e.marshalInt(val.Int()) + case reflect.String: + return e.marshalString(val.String()) + case reflect.Slice, reflect.Array: + return e.marshalArray(val) + } + + switch typ.Name() { + case "RubyUserMarshal": + return e.marshalUserMarshal(val.Interface().(RubyUserMarshal)) + case "RubyUserDef": + return e.marshalUserDef(val.Interface().(RubyUserDef)) + case "RubyObject": + return e.marshalObject(val.Interface().(RubyObject)) + } + + return ErrUnsupportedType +} + +func (e *MarshalEncoder) marshalNil() error { + return e.w.WriteByte(typeNil) +} + +func (e *MarshalEncoder) marshalBool(b bool) error { + if b { + return e.w.WriteByte(typeTrue) + } + return e.w.WriteByte(typeFalse) +} + +func (e *MarshalEncoder) marshalInt(i int64) error { + if err := e.w.WriteByte(typeFixnum); err != nil { + return err + } + + return e.marshalIntInternal(i) +} + +func (e *MarshalEncoder) marshalIntInternal(i int64) error { + if i == 0 { + return e.w.WriteByte(0) + } else if 0 < i && i < 123 { + return e.w.WriteByte(byte(i + 5)) + } else if -124 < i && i <= -1 { + return e.w.WriteByte(byte(i - 5)) + } + + var length int + if 122 < i && i <= 0xff { + length = 1 + } else if 0xff < i && i <= 0xffff { + length = 2 + } else if 0xffff < i && i <= 0xffffff { + length = 3 + } else if 0xffffff < i && i <= 0x3fffffff { + length = 4 + } else if -0x100 <= i && i < -123 { + length = -1 + } else if -0x10000 <= i && i < -0x100 { + length = -2 + } else if -0x1000000 <= i && i < -0x100000 { + length = -3 + } else if -0x40000000 <= i && i < -0x1000000 { + length = -4 + } else { + return ErrInvalidIntRange + } + + if err := e.w.WriteByte(byte(length)); err != nil { + return err + } + if length < 0 { + length = -length + } + + for c := 0; c < length; c++ { + if err := e.w.WriteByte(byte(i >> uint(8*c) & 0xff)); err != nil { + return err + } + } + + return nil +} + +func (e *MarshalEncoder) marshalString(str string) error { + if err := e.w.WriteByte(typeIVar); err != nil { + return err + } + + if err := e.marshalRawString(str); err != nil { + return err + } + + if err := e.marshalIntInternal(1); err != nil { + return err + } + + if err := e.marshalSymbol("E"); err != nil { + return err + } + + return e.marshalBool(true) +} + +func (e *MarshalEncoder) marshalRawString(str string) error { + if err := e.w.WriteByte(typeString); err != nil { + return err + } + + if err := e.marshalIntInternal(int64(len(str))); err != nil { + return err + } + + _, err := e.w.WriteString(str) + return err +} + +func (e *MarshalEncoder) marshalSymbol(str string) error { + if index, ok := e.symbols[str]; ok { + if err := e.w.WriteByte(typeSymbolLink); err != nil { + return err + } + return e.marshalIntInternal(int64(index)) + } + + e.symbols[str] = len(e.symbols) + + if err := e.w.WriteByte(typeSymbol); err != nil { + return err + } + + if err := e.marshalIntInternal(int64(len(str))); err != nil { + return err + } + + _, err := e.w.WriteString(str) + return err +} + +func (e *MarshalEncoder) marshalArray(arr reflect.Value) error { + if err := e.w.WriteByte(typeArray); err != nil { + return err + } + + length := arr.Len() + + if err := e.marshalIntInternal(int64(length)); err != nil { + return err + } + + for i := 0; i < length; i++ { + if err := e.marshal(arr.Index(i).Interface()); err != nil { + return err + } + } + return nil +} + +func (e *MarshalEncoder) marshalUserMarshal(userMarshal RubyUserMarshal) error { + if err := e.w.WriteByte(typeUserMarshal); err != nil { + return err + } + + if err := e.marshalSymbol(userMarshal.Name); err != nil { + return err + } + + return e.marshal(userMarshal.Value) +} + +func (e *MarshalEncoder) marshalUserDef(userDef RubyUserDef) error { + var buf bytes.Buffer + if err := NewMarshalEncoder(&buf).Encode(userDef.Value); err != nil { + return err + } + + if err := e.w.WriteByte(typeUserDef); err != nil { + return err + } + if err := e.marshalSymbol(userDef.Name); err != nil { + return err + } + if err := e.marshalIntInternal(int64(buf.Len())); err != nil { + return err + } + _, err := e.w.Write(buf.Bytes()) + return err +} + +func (e *MarshalEncoder) marshalObject(obj RubyObject) error { + if err := e.w.WriteByte(typeObject); err != nil { + return err + } + if err := e.marshalSymbol(obj.Name); err != nil { + return err + } + if err := e.marshalIntInternal(int64(len(obj.Member))); err != nil { + return err + } + for k, v := range obj.Member { + if err := e.marshalSymbol(k); err != nil { + return err + } + if err := e.marshal(v); err != nil { + return err + } + } + return nil +} |