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
|
require 'remcached/pack_array'
module Memcached
class Packet
##
# Initialize with fields
def initialize(contents={})
@contents = contents
(self.class.fields +
self.class.extras).each do |name,fmt,default|
self[name] ||= default if default
end
end
##
# Get field
def [](field)
@contents[field]
end
##
# Set field
def []=(field, value)
@contents[field] = value
end
##
# Define a field for subclasses
def self.field(name, packed, default=nil)
instance_eval do
@fields ||= []
@fields << [name, packed, default]
end
end
##
# Fields of parent and this class
def self.fields
parent_class = ancestors[1]
parent_fields = parent_class.respond_to?(:fields) ? parent_class.fields : []
class_fields = instance_eval { @fields || [] }
parent_fields + class_fields
end
##
# Define an extra for subclasses
def self.extra(name, packed, default=nil)
instance_eval do
@extras ||= []
@extras << [name, packed, default]
end
end
##
# Extras of this class
def self.extras
parent_class = ancestors[1]
parent_extras = parent_class.respond_to?(:extras) ? parent_class.extras : []
class_extras = instance_eval { @extras || [] }
parent_extras + class_extras
end
##
# Build a packet by parsing header fields
def self.parse_header(buf)
pack_fmt = fields.collect { |name,fmt,default| fmt }.join
values = PackArray.unpack(buf, pack_fmt)
contents = {}
fields.each do |name,fmt,default|
contents[name] = values.shift
end
new contents
end
##
# Parse body of packet when the +:total_body_length+ field is
# known by header. Pass it at least +total_body_length+ bytes.
#
# return:: [String] remaining bytes
def parse_body(buf)
if self[:total_body_length] < 1
buf, rest = "", buf
else
buf, rest = buf[0..(self[:total_body_length] - 1)], buf[self[:total_body_length]..-1]
end
if self[:extras_length] > 0
self[:extras] = parse_extras(buf[0..(self[:extras_length]-1)])
else
self[:extras] = parse_extras("")
end
if self[:key_length] > 0
self[:key] = buf[self[:extras_length]..(self[:extras_length]+self[:key_length]-1)]
else
self[:key] = ""
end
self[:value] = buf[(self[:extras_length]+self[:key_length])..-1]
rest
end
##
# Serialize for wire
def to_s
extras_s = extras_to_s
key_s = self[:key].to_s
value_s = self[:value].to_s
self[:extras_length] = extras_s.length
self[:key_length] = key_s.length
self[:total_body_length] = extras_s.length + key_s.length + value_s.length
header_to_s + extras_s + key_s + value_s
end
protected
def parse_extras(buf)
pack_fmt = self.class.extras.collect { |name,fmt,default| fmt }.join
values = PackArray.unpack(buf, pack_fmt)
self.class.extras.each do |name,fmt,default|
@self[name] = values.shift || default
end
end
def header_to_s
pack_fmt = ''
values = []
self.class.fields.each do |name,fmt,default|
values << self[name]
pack_fmt += fmt
end
PackArray.pack(values, pack_fmt)
end
def extras_to_s
values = []
pack_fmt = ''
self.class.extras.each do |name,fmt,default|
values << self[name] || default
pack_fmt += fmt
end
PackArray.pack(values, pack_fmt)
end
end
##
# Request header:
#
# Byte/ 0 | 1 | 2 | 3 |
# / | | | |
# |0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
# +---------------+---------------+---------------+---------------+
# 0| Magic | Opcode | Key length |
# +---------------+---------------+---------------+---------------+
# 4| Extras length | Data type | Reserved |
# +---------------+---------------+---------------+---------------+
# 8| Total body length |
# +---------------+---------------+---------------+---------------+
# 12| Opaque |
# +---------------+---------------+---------------+---------------+
# 16| CAS |
# | |
# +---------------+---------------+---------------+---------------+
# Total 24 bytes
class Request < Packet
field :magic, 'C', 0x80
field :opcode, 'C', 0
field :key_length, 'n'
field :extras_length, 'C'
field :data_type, 'C', 0
field :reserved, 'n', 0
field :total_body_length, 'N'
field :opaque, 'N', 0
field :cas, 'Q', 0
def self.parse_header(buf)
me = super
me[:magic] == 0x80 ? me : nil
end
class Get < Request
def initialize(contents)
super({:opcode=>Commands::GET}.merge(contents))
end
class Quiet < Get
def initialize(contents)
super({:opcode=>Commands::GETQ}.merge(contents))
end
end
end
class Add < Request
extra :flags, 'N', 0
extra :expiration, 'N', 0
def initialize(contents)
super({:opcode=>Commands::ADD}.merge(contents))
end
class Quiet < Add
def initialize(contents)
super({:opcode=>Commands::ADDQ}.merge(contents))
end
end
end
class Set < Request
extra :flags, 'N', 0
extra :expiration, 'N', 0
def initialize(contents)
super({:opcode=>Commands::SET}.merge(contents))
end
class Quiet < Set
def initialize(contents)
super({:opcode=>Commands::SETQ}.merge(contents))
end
end
end
class Delete < Request
def initialize(contents)
super({:opcode=>Commands::DELETE}.merge(contents))
end
class Quiet < Delete
def initialize(contents)
super({:opcode=>Commands::DELETEQ}.merge(contents))
end
end
end
class Stats < Request
def initialize(contents)
super({:opcode=>Commands::STAT}.merge(contents))
end
end
class NoOp < Request
def initialize
super(:opcode=>Commands::NOOP)
end
end
end
##
# Response header:
#
# Byte/ 0 | 1 | 2 | 3 |
# / | | | |
# |0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
# +---------------+---------------+---------------+---------------+
# 0| Magic | Opcode | Key Length |
# +---------------+---------------+---------------+---------------+
# 4| Extras length | Data type | Status |
# +---------------+---------------+---------------+---------------+
# 8| Total body length |
# +---------------+---------------+---------------+---------------+
# 12| Opaque |
# +---------------+---------------+---------------+---------------+
# 16| CAS |
# | |
# +---------------+---------------+---------------+---------------+
# Total 24 bytes
class Response < Packet
field :magic, 'C', 0x81
field :opcode, 'C', 0
field :key_length, 'n'
field :extras_length, 'C'
field :data_type, 'C', 0
field :status, 'n', Errors::NO_ERROR
field :total_body_length, 'N'
field :opaque, 'N', 0
field :cas, 'Q', 0
def self.parse_header(buf)
me = super
me[:magic] == 0x81 ? me : nil
end
end
end
|
