1package bare
2
3import (
4	"encoding/binary"
5	"fmt"
6	"io"
7	"math"
8)
9
10// A Writer for BARE primitive types.
11type Writer struct {
12	base    io.Writer
13	scratch [binary.MaxVarintLen64]byte
14}
15
16// Returns a new BARE primitive writer wrapping the given io.Writer.
17func NewWriter(base io.Writer) *Writer {
18	return &Writer{base: base}
19}
20
21func (w *Writer) WriteUint(i uint64) error {
22	n := binary.PutUvarint(w.scratch[:], i)
23	_, err := w.base.Write(w.scratch[:n])
24	return err
25}
26
27func (w *Writer) WriteU8(i uint8) error {
28	return binary.Write(w.base, binary.LittleEndian, i)
29}
30
31func (w *Writer) WriteU16(i uint16) error {
32	return binary.Write(w.base, binary.LittleEndian, i)
33}
34
35func (w *Writer) WriteU32(i uint32) error {
36	return binary.Write(w.base, binary.LittleEndian, i)
37}
38
39func (w *Writer) WriteU64(i uint64) error {
40	return binary.Write(w.base, binary.LittleEndian, i)
41}
42
43func (w *Writer) WriteInt(i int64) error {
44	var buf [binary.MaxVarintLen64]byte
45	n := binary.PutVarint(buf[:], i)
46	_, err := w.base.Write(buf[:n])
47	return err
48}
49
50func (w *Writer) WriteI8(i int8) error {
51	return binary.Write(w.base, binary.LittleEndian, i)
52}
53
54func (w *Writer) WriteI16(i int16) error {
55	return binary.Write(w.base, binary.LittleEndian, i)
56}
57
58func (w *Writer) WriteI32(i int32) error {
59	return binary.Write(w.base, binary.LittleEndian, i)
60}
61
62func (w *Writer) WriteI64(i int64) error {
63	return binary.Write(w.base, binary.LittleEndian, i)
64}
65
66func (w *Writer) WriteF32(f float32) error {
67	if math.IsNaN(float64(f)) {
68		return fmt.Errorf("NaN is not permitted in BARE floats")
69	}
70	return binary.Write(w.base, binary.LittleEndian, f)
71}
72
73func (w *Writer) WriteF64(f float64) error {
74	if math.IsNaN(f) {
75		return fmt.Errorf("NaN is not permitted in BARE floats")
76	}
77	return binary.Write(w.base, binary.LittleEndian, f)
78}
79
80func (w *Writer) WriteBool(b bool) error {
81	return binary.Write(w.base, binary.LittleEndian, b)
82}
83
84func (w *Writer) WriteString(str string) error {
85	return w.WriteData([]byte(str))
86}
87
88// Writes a fixed amount of arbitrary data, defined by the length of the slice.
89func (w *Writer) WriteDataFixed(data []byte) error {
90	var amt int = 0
91	for amt < len(data) {
92		n, err := w.base.Write(data[amt:])
93		if err != nil {
94			return err
95		}
96		amt += n
97	}
98	return nil
99}
100
101// Writes arbitrary data whose length is encoded into the message.
102func (w *Writer) WriteData(data []byte) error {
103	err := w.WriteUint(uint64(len(data)))
104	if err != nil {
105		return err
106	}
107	var amt int = 0
108	for amt < len(data) {
109		n, err := w.base.Write(data[amt:])
110		if err != nil {
111			return err
112		}
113		amt += n
114	}
115	return nil
116}
117