Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
1 | <?php |
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35 | class Varnish extends HttpProxyClient implements BanCapable, PurgeCapable, RefreshCapable, TagCapable |
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36 | { |
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37 | const HTTP_METHOD_BAN = 'BAN'; |
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38 | const HTTP_METHOD_PURGE = 'PURGE'; |
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39 | const HTTP_METHOD_REFRESH = 'GET'; |
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40 | const HTTP_HEADER_HOST = 'X-Host'; |
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41 | const HTTP_HEADER_URL = 'X-Url'; |
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42 | const HTTP_HEADER_CONTENT_TYPE = 'X-Content-Type'; |
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43 | |||
44 | /** |
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45 | * Default name of the header used to invalidate content with specific tags. |
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46 | * |
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47 | * This happens to be the same as TagHeaderFormatter::DEFAULT_HEADER_NAME |
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48 | * but does not technically need to be the same. |
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49 | * |
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50 | * @var string |
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51 | */ |
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52 | const DEFAULT_HTTP_HEADER_CACHE_TAGS = 'X-Cache-Tags'; |
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53 | |||
54 | /** |
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55 | * {@inheritdoc} |
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56 | */ |
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57 | 4 | public function invalidateTags(array $tags) |
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58 | { |
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59 | 4 | $tagMode = $this->options['tag_mode']; |
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60 | 4 | $escapedTags = array_map('preg_quote', $this->escapeTags($tags)); |
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61 | |||
62 | 4 | if ($tagMode === 'purge_single') { |
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63 | $elems = 1; |
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64 | 4 | } elseif (mb_strlen(implode('|', $escapedTags)) >= $this->options['header_length']) { |
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65 | /* |
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66 | * estimate the amount of tags to invalidate by dividing the max |
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67 | * header length by the largest tag (minus 1 for the implode character) |
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68 | */ |
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69 | 1 | $tagsize = max(array_map('mb_strlen', $escapedTags)); |
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70 | 1 | $elems = floor($this->options['header_length'] / ($tagsize - 1)) ?: 1; |
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71 | 1 | } else { |
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72 | 3 | $elems = count($escapedTags); |
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73 | } |
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74 | |||
75 | 4 | foreach (array_chunk($escapedTags, $elems) as $tagchunk) { |
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76 | 4 | if ($tagMode === 'ban') { |
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77 | 4 | $tagExpression = sprintf('(%s)(,.+)?$', implode('|', $tagchunk)); |
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78 | 4 | $this->ban([$this->options['tags_header'] => $tagExpression]); |
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79 | 4 | } else { |
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80 | $this->queueRequest( |
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81 | self::HTTP_METHOD_PURGE, |
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82 | '/', |
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83 | [$this->options['tags_header'] => implode(' ', $tagchunk)], |
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84 | false |
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85 | ); |
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86 | } |
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87 | 4 | } |
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88 | |||
89 | 4 | return $this; |
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90 | } |
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91 | |||
92 | /** |
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93 | * {@inheritdoc} |
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94 | */ |
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95 | 10 | public function ban(array $headers) |
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96 | { |
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97 | 10 | $headers = array_merge( |
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98 | 10 | $this->options['default_ban_headers'], |
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99 | $headers |
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100 | 10 | ); |
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101 | |||
102 | 10 | $this->queueRequest(self::HTTP_METHOD_BAN, '/', $headers, false); |
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103 | |||
104 | 10 | return $this; |
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105 | } |
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106 | |||
107 | /** |
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108 | * {@inheritdoc} |
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109 | */ |
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110 | 4 | public function banPath($path, $contentType = null, $hosts = null) |
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111 | { |
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112 | 4 | if (is_array($hosts)) { |
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113 | 2 | if (!count($hosts)) { |
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114 | 1 | throw new InvalidArgumentException('Either supply a list of hosts or null, but not an empty array.'); |
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115 | } |
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116 | 1 | $hosts = '^('.implode('|', $hosts).')$'; |
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117 | 1 | } |
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118 | |||
119 | $headers = [ |
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120 | 3 | self::HTTP_HEADER_URL => $path, |
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121 | 3 | ]; |
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122 | |||
123 | 3 | if ($contentType) { |
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124 | 2 | $headers[self::HTTP_HEADER_CONTENT_TYPE] = $contentType; |
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125 | 2 | } |
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126 | 3 | if ($hosts) { |
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127 | 1 | $headers[self::HTTP_HEADER_HOST] = $hosts; |
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128 | 1 | } |
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129 | |||
130 | 3 | return $this->ban($headers); |
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131 | } |
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132 | |||
133 | /** |
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134 | * {@inheritdoc} |
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135 | */ |
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136 | 4 | public function purge($url, array $headers = []) |
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142 | |||
143 | /** |
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144 | * {@inheritdoc} |
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145 | */ |
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146 | 3 | View Code Duplication | public function refresh($url, array $headers = []) |
153 | |||
154 | /** |
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155 | * {@inheritdoc} |
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156 | */ |
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157 | 19 | protected function configureOptions() |
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181 | } |
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182 |
In PHP, under loose comparison (like
==
, or!=
, orswitch
conditions), values of different types might be equal.For
string
values, the empty string''
is a special case, in particular the following results might be unexpected: