-
Notifications
You must be signed in to change notification settings - Fork 0
/
redcon_append.go
314 lines (297 loc) · 8.24 KB
/
redcon_append.go
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
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
package redis
import (
"strconv"
"strings"
)
// Kind is the kind of command
type Kind int
const (
// Redis is returned for Redis protocol commands
Redis Kind = iota
// Tile38 is returnd for Tile38 native protocol commands
Tile38
// Telnet is returnd for plain telnet commands
Telnet
)
var errInvalidMessage = &errProtocol{"invalid message"}
// ReadNextCommand reads the next command from the provided packet. It's
// possible that the packet contains multiple commands, or zero commands
// when the packet is incomplete.
// 'argsbuf' is an optional reusable buffer and it can be nil.
// 'complete' indicates that a command was read. false means no more commands.
// 'args' are the output arguments for the command.
// 'kind' is the type of command that was read.
// 'leftover' is any remaining unused bytes which belong to the next command.
// 'err' is returned when a protocol error was encountered.
func ReadNextCommand(packet []byte, argsbuf [][]byte) (
complete bool, args [][]byte, kind Kind, leftover []byte, err error,
) {
args = argsbuf[:0]
if len(packet) > 0 {
if packet[0] != '*' {
if packet[0] == '$' {
return readTile38Command(packet, args)
}
return readTelnetCommand(packet, args)
}
// standard redis command
for s, i := 1, 1; i < len(packet); i++ {
if packet[i] == '\n' {
if packet[i-1] != '\r' {
return false, args[:0], Redis, packet, errInvalidMultiBulkLength
}
count, ok := parseInt(packet[s : i-1])
if !ok || count < 0 {
return false, args[:0], Redis, packet, errInvalidMultiBulkLength
}
i++
if count == 0 {
return true, args[:0], Redis, packet[i:], nil
}
nextArg:
for j := 0; j < count; j++ {
if i == len(packet) {
break
}
if packet[i] != '$' {
return false, args[:0], Redis, packet,
&errProtocol{"expected '$', got '" +
string(packet[i]) + "'"}
}
for s := i + 1; i < len(packet); i++ {
if packet[i] == '\n' {
if packet[i-1] != '\r' {
return false, args[:0], Redis, packet, errInvalidBulkLength
}
n, ok := parseInt(packet[s : i-1])
if !ok || count <= 0 {
return false, args[:0], Redis, packet, errInvalidBulkLength
}
i++
if len(packet)-i >= n+2 {
if packet[i+n] != '\r' || packet[i+n+1] != '\n' {
return false, args[:0], Redis, packet, errInvalidBulkLength
}
args = append(args, packet[i:i+n])
i += n + 2
if j == count-1 {
// done reading
return true, args, Redis, packet[i:], nil
}
continue nextArg
}
break
}
}
break
}
break
}
}
}
return false, args[:0], Redis, packet, nil
}
func readTile38Command(packet []byte, argsbuf [][]byte) (
complete bool, args [][]byte, kind Kind, leftover []byte, err error,
) {
for i := 1; i < len(packet); i++ {
if packet[i] == ' ' {
n, ok := parseInt(packet[1:i])
if !ok || n < 0 {
return false, args[:0], Tile38, packet, errInvalidMessage
}
i++
if len(packet) >= i+n+2 {
if packet[i+n] != '\r' || packet[i+n+1] != '\n' {
return false, args[:0], Tile38, packet, errInvalidMessage
}
line := packet[i : i+n]
reading:
for len(line) != 0 {
if line[0] == '{' {
// The native protocol cannot understand json boundaries so it assumes that
// a json element must be at the end of the line.
args = append(args, line)
break
}
if line[0] == '"' && line[len(line)-1] == '"' {
if len(args) > 0 &&
strings.ToLower(string(args[0])) == "set" &&
strings.ToLower(string(args[len(args)-1])) == "string" {
// Setting a string value that is contained inside double quotes.
// This is only because of the boundary issues of the native protocol.
args = append(args, line[1:len(line)-1])
break
}
}
i := 0
for ; i < len(line); i++ {
if line[i] == ' ' {
value := line[:i]
if len(value) > 0 {
args = append(args, value)
}
line = line[i+1:]
continue reading
}
}
args = append(args, line)
break
}
return true, args, Tile38, packet[i+n+2:], nil
}
break
}
}
return false, args[:0], Tile38, packet, nil
}
func readTelnetCommand(packet []byte, argsbuf [][]byte) (
complete bool, args [][]byte, kind Kind, leftover []byte, err error,
) {
// just a plain text command
for i := 0; i < len(packet); i++ {
if packet[i] == '\n' {
var line []byte
if i > 0 && packet[i-1] == '\r' {
line = packet[:i-1]
} else {
line = packet[:i]
}
var quote bool
var quotech byte
var escape bool
outer:
for {
nline := make([]byte, 0, len(line))
for i := 0; i < len(line); i++ {
c := line[i]
if !quote {
if c == ' ' {
if len(nline) > 0 {
args = append(args, nline)
}
line = line[i+1:]
continue outer
}
if c == '"' || c == '\'' {
if i != 0 {
return false, args[:0], Telnet, packet, errUnbalancedQuotes
}
quotech = c
quote = true
line = line[i+1:]
continue outer
}
} else {
if escape {
escape = false
switch c {
case 'n':
c = '\n'
case 'r':
c = '\r'
case 't':
c = '\t'
}
} else if c == quotech {
quote = false
quotech = 0
args = append(args, nline)
line = line[i+1:]
if len(line) > 0 && line[0] != ' ' {
return false, args[:0], Telnet, packet, errUnbalancedQuotes
}
continue outer
} else if c == '\\' {
escape = true
continue
}
}
nline = append(nline, c)
}
if quote {
return false, args[:0], Telnet, packet, errUnbalancedQuotes
}
if len(line) > 0 {
args = append(args, line)
}
break
}
return true, args, Telnet, packet[i+1:], nil
}
}
return false, args[:0], Telnet, packet, nil
}
// appendPrefix will append a "$3\r\n" style redis prefix for a message.
func appendPrefix(b []byte, c byte, n int64) []byte {
if n >= 0 && n <= 9 {
return append(b, c, byte('0'+n), '\r', '\n')
}
b = append(b, c)
b = strconv.AppendInt(b, n, 10)
return append(b, '\r', '\n')
}
// AppendUint appends a Redis protocol uint64 to the input bytes.
func AppendUint(b []byte, n uint64) []byte {
b = append(b, ':')
b = strconv.AppendUint(b, n, 10)
return append(b, '\r', '\n')
}
// AppendInt appends a Redis protocol int64 to the input bytes.
func AppendInt(b []byte, n int64) []byte {
return appendPrefix(b, ':', n)
}
// AppendArray appends a Redis protocol array to the input bytes.
func AppendArray(b []byte, n int) []byte {
return appendPrefix(b, '*', int64(n))
}
// AppendBulk appends a Redis protocol bulk byte slice to the input bytes.
func AppendBulk(b []byte, bulk []byte) []byte {
b = appendPrefix(b, '$', int64(len(bulk)))
b = append(b, bulk...)
return append(b, '\r', '\n')
}
// AppendBulkString appends a Redis protocol bulk string to the input bytes.
func AppendBulkString(b []byte, bulk string) []byte {
b = appendPrefix(b, '$', int64(len(bulk)))
b = append(b, bulk...)
return append(b, '\r', '\n')
}
// AppendString appends a Redis protocol string to the input bytes.
func AppendString(b []byte, s string) []byte {
b = append(b, '+')
b = append(b, stripNewlines(s)...)
return append(b, '\r', '\n')
}
// AppendError appends a Redis protocol error to the input bytes.
func AppendError(b []byte, s string) []byte {
b = append(b, '-')
b = append(b, stripNewlines(s)...)
return append(b, '\r', '\n')
}
// AppendOK appends a Redis protocol OK to the input bytes.
func AppendOK(b []byte) []byte {
return append(b, '+', 'O', 'K', '\r', '\n')
}
func stripNewlines(s string) string {
for i := 0; i < len(s); i++ {
if s[i] == '\r' || s[i] == '\n' {
s = strings.Replace(s, "\r", " ", -1)
s = strings.Replace(s, "\n", " ", -1)
break
}
}
return s
}
// AppendTile38 appends a Tile38 message to the input bytes.
func AppendTile38(b []byte, data []byte) []byte {
b = append(b, '$')
b = strconv.AppendInt(b, int64(len(data)), 10)
b = append(b, ' ')
b = append(b, data...)
return append(b, '\r', '\n')
}
// AppendNull appends a Redis protocol null to the input bytes.
func AppendNull(b []byte) []byte {
return append(b, '$', '-', '1', '\r', '\n')
}