gtsocial-umbx

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buffer.go (2341B)

      1 package bytes
      2 
      3 import (
      4 	"unicode/utf8"
      5 )
      6 
      7 // Buffer is a very simple buffer implementation that allows
      8 // access to and reslicing of the underlying byte slice.
      9 type Buffer struct {
     10 	B []byte
     11 }
     12 
     13 func NewBuffer(b []byte) Buffer {
     14 	return Buffer{
     15 		B: b,
     16 	}
     17 }
     18 
     19 func (b *Buffer) Write(p []byte) (int, error) {
     20 	b.Grow(len(p))
     21 	return copy(b.B[b.Len()-len(p):], p), nil
     22 }
     23 
     24 func (b *Buffer) WriteString(s string) (int, error) {
     25 	b.Grow(len(s))
     26 	return copy(b.B[b.Len()-len(s):], s), nil
     27 }
     28 
     29 func (b *Buffer) WriteByte(c byte) error {
     30 	l := b.Len()
     31 	b.Grow(1)
     32 	b.B[l] = c
     33 	return nil
     34 }
     35 
     36 func (b *Buffer) WriteRune(r rune) (int, error) {
     37 	if r < utf8.RuneSelf {
     38 		b.WriteByte(byte(r))
     39 		return 1, nil
     40 	}
     41 
     42 	l := b.Len()
     43 	b.Grow(utf8.UTFMax)
     44 	n := utf8.EncodeRune(b.B[l:b.Len()], r)
     45 	b.B = b.B[:l+n]
     46 
     47 	return n, nil
     48 }
     49 
     50 func (b *Buffer) WriteAt(p []byte, start int64) (int, error) {
     51 	b.Grow(len(p) - int(int64(b.Len())-start))
     52 	return copy(b.B[start:], p), nil
     53 }
     54 
     55 func (b *Buffer) WriteStringAt(s string, start int64) (int, error) {
     56 	b.Grow(len(s) - int(int64(b.Len())-start))
     57 	return copy(b.B[start:], s), nil
     58 }
     59 
     60 func (b *Buffer) Truncate(size int) {
     61 	b.B = b.B[:b.Len()-size]
     62 }
     63 
     64 func (b *Buffer) ShiftByte(index int) {
     65 	copy(b.B[index:], b.B[index+1:])
     66 }
     67 
     68 func (b *Buffer) Shift(start int64, size int) {
     69 	copy(b.B[start:], b.B[start+int64(size):])
     70 }
     71 
     72 func (b *Buffer) DeleteByte(index int) {
     73 	b.ShiftByte(index)
     74 	b.Truncate(1)
     75 }
     76 
     77 func (b *Buffer) Delete(start int64, size int) {
     78 	b.Shift(start, size)
     79 	b.Truncate(size)
     80 }
     81 
     82 func (b *Buffer) InsertByte(index int64, c byte) {
     83 	l := b.Len()
     84 	b.Grow(1)
     85 	copy(b.B[index+1:], b.B[index:l])
     86 	b.B[index] = c
     87 }
     88 
     89 func (b *Buffer) Insert(index int64, p []byte) {
     90 	l := b.Len()
     91 	b.Grow(len(p))
     92 	copy(b.B[index+int64(len(p)):], b.B[index:l])
     93 	copy(b.B[index:], p)
     94 }
     95 
     96 func (b *Buffer) Bytes() []byte {
     97 	return b.B
     98 }
     99 
    100 func (b *Buffer) String() string {
    101 	return string(b.B)
    102 }
    103 
    104 func (b *Buffer) StringPtr() string {
    105 	return BytesToString(b.B)
    106 }
    107 
    108 func (b *Buffer) Cap() int {
    109 	return cap(b.B)
    110 }
    111 
    112 func (b *Buffer) Len() int {
    113 	return len(b.B)
    114 }
    115 
    116 func (b *Buffer) Reset() {
    117 	b.B = b.B[:0]
    118 }
    119 
    120 func (b *Buffer) Grow(size int) {
    121 	b.Guarantee(size)
    122 	b.B = b.B[:b.Len()+size]
    123 }
    124 
    125 func (b *Buffer) Guarantee(size int) {
    126 	if size > b.Cap()-b.Len() {
    127 		nb := make([]byte, 2*b.Cap()+size)
    128 		copy(nb, b.B)
    129 		b.B = nb[:b.Len()]
    130 	}
    131 }