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
|
# Author:: Lamont Granquist (<lamont@chef.io>)
# Copyright:: Copyright (c) Chef Software Inc.
# License:: Apache License, Version 2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# Some portions of this file are derived from material in the diff-lcs
# project licensed under the terms of the MIT license, provided below.
#
# Copyright:: Copyright 2004-2016, Austin Ziegler
# License:: MIT
#
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation files
# (the "Software"), to deal in the Software without restriction,
# including without limitation the rights to use, copy, modify, merge,
# publish, distribute, sublicense, and/or sell copies of the Software,
# and to permit persons to whom the Software is furnished to do so,
# subject the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of this Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OF OR IN
# CONNECTION WITH THE SOFTWARE OR THE USE OF OTHER DEALINGS IN THE
# SOFTWARE.
require "diff/lcs"
require "diff/lcs/hunk"
class Chef
class Util
class Diff
# @todo: to_a, to_s, to_json, inspect defs, accessors for @diff and @error
# @todo: move coercion to UTF-8 into to_json
def for_output
# formatted output to a terminal uses arrays of strings and returns error strings
@diff.nil? ? [ @error ] : @diff
end
def for_reporting
# caller needs to ensure that new files aren't posted to resource reporting
return nil if @diff.nil?
@diff.join("\\n")
end
def use_tempfile_if_missing(file)
tempfile = nil
unless File.exist?(file)
Chef::Log.trace("File #{file} does not exist to diff against, using empty tempfile")
tempfile = Tempfile.new("chef-diff")
file = tempfile.path
end
yield file
unless tempfile.nil?
tempfile.close
tempfile.unlink
end
end
def diff(old_file, new_file)
use_tempfile_if_missing(old_file) do |old_file|
use_tempfile_if_missing(new_file) do |new_file|
@error = do_diff(old_file, new_file)
end
end
end
# produces a unified-output-format diff with 3 lines of context
# ChefFS uses udiff() directly
def udiff(old_file, new_file)
diff_str = ""
file_length_difference = 0
old_data = IO.readlines(old_file).map(&:chomp)
new_data = IO.readlines(new_file).map(&:chomp)
diff_data = ::Diff::LCS.diff(old_data, new_data)
return diff_str if old_data.empty? && new_data.empty?
return "No differences encountered\n" if diff_data.empty?
# write diff header (standard unified format)
ft = File.stat(old_file).mtime.localtime.strftime("%Y-%m-%d %H:%M:%S.%N %z")
diff_str << "--- #{old_file}\t#{ft}\n"
ft = File.stat(new_file).mtime.localtime.strftime("%Y-%m-%d %H:%M:%S.%N %z")
diff_str << "+++ #{new_file}\t#{ft}\n"
# loop over diff hunks. if a hunk overlaps with the last hunk,
# join them. otherwise, print out the old one.
old_hunk = hunk = nil
diff_data.each do |piece|
hunk = ::Diff::LCS::Hunk.new(old_data, new_data, piece, 3, file_length_difference)
file_length_difference = hunk.file_length_difference
next unless old_hunk
next if hunk.merge(old_hunk)
diff_str << old_hunk.diff(:unified) << "\n"
ensure
old_hunk = hunk
end
diff_str << old_hunk.diff(:unified) << "\n"
diff_str
end
private
def do_diff(old_file, new_file)
if Chef::Config[:diff_disabled]
return "(diff output suppressed by config)"
end
diff_filesize_threshold = Chef::Config[:diff_filesize_threshold]
diff_output_threshold = Chef::Config[:diff_output_threshold]
if ::File.size(old_file) > diff_filesize_threshold || ::File.size(new_file) > diff_filesize_threshold
return "(file sizes exceed #{diff_filesize_threshold} bytes, diff output suppressed)"
end
# macOS(BSD?) diff will *sometimes* happily spit out nasty binary diffs
return "(current file is binary, diff output suppressed)" if is_binary?(old_file)
return "(new content is binary, diff output suppressed)" if is_binary?(new_file)
begin
Chef::Log.trace("Running: diff -u #{old_file} #{new_file}")
diff_str = udiff(old_file, new_file)
rescue Exception => e
# Should *not* receive this, but in some circumstances it seems that
# an exception can be thrown even using shell_out instead of shell_out!
return "Could not determine diff. Error: #{e.message}"
end
if !diff_str.empty? && diff_str != "No differences encountered\n"
if diff_str.length > diff_output_threshold
"(long diff of over #{diff_output_threshold} characters, diff output suppressed)"
else
diff_str = encode_diff_for_json(diff_str)
@diff = diff_str.split("\n")
"(diff available)"
end
else
"(no diff)"
end
end
def is_binary?(path)
File.open(path) do |file|
# XXX: this slurps into RAM, but we should have already checked our diff has a reasonable size
buff = file.read
buff = "" if buff.nil?
begin
return buff !~ /\A[\s[:print:]]*\z/m
rescue ArgumentError => e
return true if /invalid byte sequence/.match?(e.message)
raise
end
end
end
def encode_diff_for_json(diff_str)
diff_str.encode!("UTF-8", invalid: :replace, undef: :replace, replace: "?")
end
end
end
end
|
