| // +build !appengine |
| |
| package msgp |
| |
| import ( |
| "reflect" |
| "unsafe" |
| ) |
| |
| const ( |
| // spec says int and uint are always |
| // the same size, but that int/uint |
| // size may not be machine word size |
| smallint = unsafe.Sizeof(int(0)) == 4 |
| ) |
| |
| // UnsafeString returns the byte slice as a volatile string |
| // THIS SHOULD ONLY BE USED BY THE CODE GENERATOR. |
| // THIS IS EVIL CODE. |
| // YOU HAVE BEEN WARNED. |
| func UnsafeString(b []byte) string { |
| return *(*string)(unsafe.Pointer(&reflect.StringHeader{Data: uintptr(unsafe.Pointer(&b[0])), Len: len(b)})) |
| } |
| |
| // UnsafeBytes returns the string as a byte slice |
| // THIS SHOULD ONLY BE USED BY THE CODE GENERATOR. |
| // THIS IS EVIL CODE. |
| // YOU HAVE BEEN WARNED. |
| func UnsafeBytes(s string) []byte { |
| return *(*[]byte)(unsafe.Pointer(&reflect.SliceHeader{ |
| Len: len(s), |
| Cap: len(s), |
| Data: (*(*reflect.StringHeader)(unsafe.Pointer(&s))).Data, |
| })) |
| } |
| |
| // Number can be |
| // an int64, uint64, float32, |
| // or float64 internally. |
| // It can decode itself |
| // from any of the native |
| // messagepack number types. |
| // The zero-value of Number |
| // is Int(0). Using the equality |
| // operator with Number compares |
| // both the type and the value |
| // of the number. |
| type Number struct { |
| // internally, this |
| // is just a tagged union. |
| // the raw bits of the number |
| // are stored the same way regardless. |
| bits uint64 |
| typ Type |
| } |
| |
| // AsFloat64 sets the number to |
| // a float64. |
| func (n *Number) AsFloat64(f float64) { |
| n.typ = Float64Type |
| n.bits = *(*uint64)(unsafe.Pointer(&f)) |
| } |
| |
| // AsInt sets the number to an int64. |
| func (n *Number) AsInt(i int64) { |
| |
| // we always store int(0) |
| // as {0, InvalidType} in |
| // order to preserve |
| // the behavior of the == operator |
| if i == 0 { |
| n.typ = InvalidType |
| n.bits = 0 |
| return |
| } |
| |
| n.typ = IntType |
| n.bits = uint64(i) |
| } |
| |
| // AsUint sets the number to a uint64. |
| func (n *Number) AsUint(u uint64) { |
| n.typ = UintType |
| n.bits = u |
| } |
| |
| // AsFloat32 sets the number to a float32. |
| func (n *Number) AsFloat32(f float32) { |
| n.typ = Float32Type |
| g := float64(f) |
| n.bits = *(*uint64)(unsafe.Pointer(&g)) |
| } |
| |
| // Type will return one of: |
| // Float64Type, Float32Type, UintType, or IntType. |
| func (n *Number) Type() Type { |
| if n.typ == InvalidType { |
| return IntType |
| } |
| return n.typ |
| } |
| |
| // Float casts the number of the float, |
| // and returns whether or not that was |
| // the underlying type. (This is legal |
| // for both float32 and float64 types.) |
| func (n *Number) Float() (float64, bool) { |
| return *(*float64)(unsafe.Pointer(&n.bits)), n.typ == Float64Type || n.typ == Float32Type |
| } |
| |
| // Int casts the number as an int64, and |
| // returns whether or not that was the |
| // underlying type. |
| func (n *Number) Int() (int64, bool) { |
| return int64(n.bits), n.typ == IntType || n.typ == InvalidType |
| } |
| |
| // Uint casts the number as a uint64, and returns |
| // whether or not that was the underlying type. |
| func (n *Number) Uint() (uint64, bool) { |
| return n.bits, n.typ == UintType |
| } |
| |
| // EncodeMsg implements msgp.Encodable |
| func (n *Number) EncodeMsg(w *Writer) error { |
| switch n.typ { |
| case InvalidType: |
| return w.WriteInt(0) |
| case IntType: |
| return w.WriteInt64(int64(n.bits)) |
| case UintType: |
| return w.WriteUint64(n.bits) |
| case Float64Type: |
| return w.WriteFloat64(*(*float64)(unsafe.Pointer(&n.bits))) |
| case Float32Type: |
| return w.WriteFloat32(float32(*(*float64)(unsafe.Pointer(&n.bits)))) |
| default: |
| // this should never ever happen |
| panic("(*Number).typ is invalid") |
| } |
| } |
| |
| // MarshalMsg implements msgp.Marshaler |
| func (n *Number) MarshalMsg(b []byte) ([]byte, error) { |
| switch n.typ { |
| case InvalidType: |
| return AppendInt(b, 0), nil |
| case IntType: |
| return AppendInt64(b, int64(n.bits)), nil |
| case UintType: |
| return AppendUint64(b, n.bits), nil |
| case Float64Type: |
| return AppendFloat64(b, *(*float64)(unsafe.Pointer(&n.bits))), nil |
| case Float32Type: |
| return AppendFloat32(b, float32(*(*float64)(unsafe.Pointer(&n.bits)))), nil |
| default: |
| panic("(*Number).typ is invalid") |
| } |
| } |