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
|
#++
# Copyright (C) 2004 Mauricio Julio Fernndez Pradier
# See LICENSE.txt for additional licensing information.
#--
##
# Allows writing of tar files
class Gem::Package::TarWriter
class FileOverflow < StandardError; end
##
# IO wrapper that allows writing a limited amount of data
class BoundedStream
##
# Maximum number of bytes that can be written
attr_reader :limit
##
# Number of bytes written
attr_reader :written
##
# Wraps +io+ and allows up to +limit+ bytes to be written
def initialize(io, limit)
@io = io
@limit = limit
@written = 0
end
##
# Writes +data+ onto the IO, raising a FileOverflow exception if the
# number of bytes will be more than #limit
def write(data)
if data.size + @written > @limit
raise FileOverflow, "You tried to feed more data than fits in the file."
end
@io.write data
@written += data.size
data.size
end
end
##
# IO wrapper that provides only #write
class RestrictedStream
##
# Creates a new RestrictedStream wrapping +io+
def initialize(io)
@io = io
end
##
# Writes +data+ onto the IO
def write(data)
@io.write data
end
end
##
# Creates a new TarWriter, yielding it if a block is given
def self.new(io)
writer = super
return writer unless block_given?
begin
yield writer
ensure
writer.close
end
nil
end
##
# Creates a new TarWriter that will write to +io+
def initialize(io)
@io = io
@closed = false
end
##
# Adds file +name+ with permissions +mode+, and yields an IO for writing the
# file to
def add_file(name, mode) # :yields: io
check_closed
raise Gem::Package::NonSeekableIO unless @io.respond_to? :pos=
name, prefix = split_name name
init_pos = @io.pos
@io.write "\0" * 512 # placeholder for the header
yield RestrictedStream.new(@io) if block_given?
size = @io.pos - init_pos - 512
remainder = (512 - (size % 512)) % 512
@io.write "\0" * remainder
final_pos = @io.pos
@io.pos = init_pos
header = Gem::Package::TarHeader.new :name => name, :mode => mode,
:size => size, :prefix => prefix
@io.write header
@io.pos = final_pos
self
end
##
# Add file +name+ with permissions +mode+ +size+ bytes long. Yields an IO
# to write the file to.
def add_file_simple(name, mode, size) # :yields: io
check_closed
name, prefix = split_name name
header = Gem::Package::TarHeader.new(:name => name, :mode => mode,
:size => size, :prefix => prefix).to_s
@io.write header
os = BoundedStream.new @io, size
yield os if block_given?
min_padding = size - os.written
@io.write("\0" * min_padding)
remainder = (512 - (size % 512)) % 512
@io.write("\0" * remainder)
self
end
##
# Raises IOError if the TarWriter is closed
def check_closed
raise IOError, "closed #{self.class}" if closed?
end
##
# Closes the TarWriter
def close
check_closed
@io.write "\0" * 1024
flush
@closed = true
end
##
# Is the TarWriter closed?
def closed?
@closed
end
##
# Flushes the TarWriter's IO
def flush
check_closed
@io.flush if @io.respond_to? :flush
end
##
# Creates a new directory in the tar file +name+ with +mode+
def mkdir(name, mode)
check_closed
name, prefix = split_name(name)
header = Gem::Package::TarHeader.new :name => name, :mode => mode,
:typeflag => "5", :size => 0,
:prefix => prefix
@io.write header
self
end
##
# Splits +name+ into a name and prefix that can fit in the TarHeader
def split_name(name) # :nodoc:
raise Gem::Package::TooLongFileName if name.size > 256
if name.size <= 100 then
prefix = ""
else
parts = name.split(/\//)
newname = parts.pop
nxt = ""
loop do
nxt = parts.pop
break if newname.size + 1 + nxt.size > 100
newname = nxt + "/" + newname
end
prefix = (parts + [nxt]).join "/"
name = newname
if name.size > 100 or prefix.size > 155 then
raise Gem::Package::TooLongFileName
end
end
return name, prefix
end
end
|
