summaryrefslogtreecommitdiff
path: root/libgo/go/net/parse.go
blob: e1d0130c9ac7ebb925a4c78d374da84edcb337c4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Simple file i/o and string manipulation, to avoid
// depending on strconv and bufio and strings.

package net

import (
	"io"
	"os"
)

type file struct {
	file  *os.File
	data  []byte
	atEOF bool
}

func (f *file) close() { f.file.Close() }

func (f *file) getLineFromData() (s string, ok bool) {
	data := f.data
	i := 0
	for i = 0; i < len(data); i++ {
		if data[i] == '\n' {
			s = string(data[0:i])
			ok = true
			// move data
			i++
			n := len(data) - i
			copy(data[0:], data[i:])
			f.data = data[0:n]
			return
		}
	}
	if f.atEOF && len(f.data) > 0 {
		// EOF, return all we have
		s = string(data)
		f.data = f.data[0:0]
		ok = true
	}
	return
}

func (f *file) readLine() (s string, ok bool) {
	if s, ok = f.getLineFromData(); ok {
		return
	}
	if len(f.data) < cap(f.data) {
		ln := len(f.data)
		n, err := io.ReadFull(f.file, f.data[ln:cap(f.data)])
		if n >= 0 {
			f.data = f.data[0 : ln+n]
		}
		if err == io.EOF || err == io.ErrUnexpectedEOF {
			f.atEOF = true
		}
	}
	s, ok = f.getLineFromData()
	return
}

func open(name string) (*file, error) {
	fd, err := os.Open(name)
	if err != nil {
		return nil, err
	}
	return &file{fd, make([]byte, 0, os.Getpagesize()), false}, nil
}

func byteIndex(s string, c byte) int {
	for i := 0; i < len(s); i++ {
		if s[i] == c {
			return i
		}
	}
	return -1
}

// Count occurrences in s of any bytes in t.
func countAnyByte(s string, t string) int {
	n := 0
	for i := 0; i < len(s); i++ {
		if byteIndex(t, s[i]) >= 0 {
			n++
		}
	}
	return n
}

// Split s at any bytes in t.
func splitAtBytes(s string, t string) []string {
	a := make([]string, 1+countAnyByte(s, t))
	n := 0
	last := 0
	for i := 0; i < len(s); i++ {
		if byteIndex(t, s[i]) >= 0 {
			if last < i {
				a[n] = string(s[last:i])
				n++
			}
			last = i + 1
		}
	}
	if last < len(s) {
		a[n] = string(s[last:])
		n++
	}
	return a[0:n]
}

func getFields(s string) []string { return splitAtBytes(s, " \r\t\n") }

// Bigger than we need, not too big to worry about overflow
const big = 0xFFFFFF

// Decimal to integer starting at &s[i0].
// Returns number, new offset, success.
func dtoi(s string, i0 int) (n int, i int, ok bool) {
	n = 0
	for i = i0; i < len(s) && '0' <= s[i] && s[i] <= '9'; i++ {
		n = n*10 + int(s[i]-'0')
		if n >= big {
			return 0, i, false
		}
	}
	if i == i0 {
		return 0, i, false
	}
	return n, i, true
}

// Hexadecimal to integer starting at &s[i0].
// Returns number, new offset, success.
func xtoi(s string, i0 int) (n int, i int, ok bool) {
	n = 0
	for i = i0; i < len(s); i++ {
		if '0' <= s[i] && s[i] <= '9' {
			n *= 16
			n += int(s[i] - '0')
		} else if 'a' <= s[i] && s[i] <= 'f' {
			n *= 16
			n += int(s[i]-'a') + 10
		} else if 'A' <= s[i] && s[i] <= 'F' {
			n *= 16
			n += int(s[i]-'A') + 10
		} else {
			break
		}
		if n >= big {
			return 0, i, false
		}
	}
	if i == i0 {
		return 0, i, false
	}
	return n, i, true
}

// xtoi2 converts the next two hex digits of s into a byte.
// If s is longer than 2 bytes then the third byte must be e.
// If the first two bytes of s are not hex digits or the third byte
// does not match e, false is returned.
func xtoi2(s string, e byte) (byte, bool) {
	if len(s) > 2 && s[2] != e {
		return 0, false
	}
	n, ei, ok := xtoi(s[:2], 0)
	return byte(n), ok && ei == 2
}

// Integer to decimal.
func itoa(i int) string {
	var buf [30]byte
	n := len(buf)
	neg := false
	if i < 0 {
		i = -i
		neg = true
	}
	ui := uint(i)
	for ui > 0 || n == len(buf) {
		n--
		buf[n] = byte('0' + ui%10)
		ui /= 10
	}
	if neg {
		n--
		buf[n] = '-'
	}
	return string(buf[n:])
}

// Convert i to decimal string.
func itod(i uint) string {
	if i == 0 {
		return "0"
	}

	// Assemble decimal in reverse order.
	var b [32]byte
	bp := len(b)
	for ; i > 0; i /= 10 {
		bp--
		b[bp] = byte(i%10) + '0'
	}

	return string(b[bp:])
}

// Convert i to a hexadecimal string. Leading zeros are not printed.
func appendHex(dst []byte, i uint32) []byte {
	if i == 0 {
		return append(dst, '0')
	}
	for j := 7; j >= 0; j-- {
		v := i >> uint(j*4)
		if v > 0 {
			dst = append(dst, hexDigit[v&0xf])
		}
	}
	return dst
}

// Number of occurrences of b in s.
func count(s string, b byte) int {
	n := 0
	for i := 0; i < len(s); i++ {
		if s[i] == b {
			n++
		}
	}
	return n
}

// Index of rightmost occurrence of b in s.
func last(s string, b byte) int {
	i := len(s)
	for i--; i >= 0; i-- {
		if s[i] == b {
			break
		}
	}
	return i
}