forgejo-federation/modules/packages/rubygems/marshal.go
flynnnnnnnnnn e81ccc406b
Implement FSFE REUSE for golang files (#21840)
Change all license headers to comply with REUSE specification.

Fix #16132

Co-authored-by: flynnnnnnnnnn <flynnnnnnnnnn@github>
Co-authored-by: John Olheiser <john.olheiser@gmail.com>
2022-11-27 18:20:29 +00:00

310 lines
6.3 KiB
Go

// Copyright 2021 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package rubygems
import (
"bufio"
"bytes"
"errors"
"io"
"reflect"
)
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 = errors.New("Type is unsupported")
// ErrInvalidIntRange indicates an invalid number range
ErrInvalidIntRange = errors.New("Number is not in valid range")
)
// RubyUserMarshal is a Ruby object that has a marshal_load function.
type RubyUserMarshal struct {
Name string
Value interface{}
}
// RubyUserDef is a Ruby object that has a _load function.
type RubyUserDef struct {
Name string
Value interface{}
}
// RubyObject is a default Ruby object.
type RubyObject struct {
Name string
Member map[string]interface{}
}
// 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 interface{}) 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 interface{}) 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 len int
if 122 < i && i <= 0xff {
len = 1
} else if 0xff < i && i <= 0xffff {
len = 2
} else if 0xffff < i && i <= 0xffffff {
len = 3
} else if 0xffffff < i && i <= 0x3fffffff {
len = 4
} else if -0x100 <= i && i < -123 {
len = -1
} else if -0x10000 <= i && i < -0x100 {
len = -2
} else if -0x1000000 <= i && i < -0x100000 {
len = -3
} else if -0x40000000 <= i && i < -0x1000000 {
len = -4
} else {
return ErrInvalidIntRange
}
if err := e.w.WriteByte(byte(len)); err != nil {
return err
}
if len < 0 {
len = -len
}
for c := 0; c < len; 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
}
len := arr.Len()
if err := e.marshalIntInternal(int64(len)); err != nil {
return err
}
for i := 0; i < len; 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
}