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:
Complex classes like Snapshot often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use Snapshot, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 19 | class Snapshot |
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| 20 | { |
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| 21 | /** |
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| 22 | * @var Blacklist |
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| 23 | */ |
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| 24 | private $blacklist; |
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| 25 | |||
| 26 | /** |
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| 27 | * @var array |
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| 28 | */ |
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| 29 | private $globalVariables = array(); |
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| 30 | |||
| 31 | /** |
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| 32 | * @var array |
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| 33 | */ |
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| 34 | private $superGlobalArrays = array(); |
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| 35 | |||
| 36 | /** |
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| 37 | * @var array |
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| 38 | */ |
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| 39 | private $superGlobalVariables = array(); |
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| 40 | |||
| 41 | /** |
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| 42 | * @var array |
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| 43 | */ |
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| 44 | private $staticAttributes = array(); |
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| 45 | |||
| 46 | /** |
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| 47 | * @var array |
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| 48 | */ |
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| 49 | private $iniSettings = array(); |
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| 50 | |||
| 51 | /** |
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| 52 | * @var array |
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| 53 | */ |
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| 54 | private $includedFiles = array(); |
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| 55 | |||
| 56 | /** |
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| 57 | * @var array |
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| 58 | */ |
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| 59 | private $constants = array(); |
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| 60 | |||
| 61 | /** |
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| 62 | * @var array |
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| 63 | */ |
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| 64 | private $functions = array(); |
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| 65 | |||
| 66 | /** |
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| 67 | * @var array |
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| 68 | */ |
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| 69 | private $interfaces = array(); |
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| 70 | |||
| 71 | /** |
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| 72 | * @var array |
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| 73 | */ |
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| 74 | private $classes = array(); |
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| 75 | |||
| 76 | /** |
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| 77 | * @var array |
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| 78 | */ |
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| 79 | private $traits = array(); |
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| 80 | |||
| 81 | /** |
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| 82 | * Creates a snapshot of the current global state. |
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| 83 | * |
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| 84 | * @param Blacklist $blacklist |
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| 85 | * @param bool $includeGlobalVariables |
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| 86 | * @param bool $includeStaticAttributes |
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| 87 | * @param bool $includeConstants |
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| 88 | * @param bool $includeFunctions |
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| 89 | * @param bool $includeClasses |
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| 90 | * @param bool $includeInterfaces |
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| 91 | * @param bool $includeTraits |
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| 92 | * @param bool $includeIniSettings |
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| 93 | * @param bool $includeIncludedFiles |
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| 94 | */ |
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| 95 | public function __construct(Blacklist $blacklist = null, $includeGlobalVariables = true, $includeStaticAttributes = true, $includeConstants = true, $includeFunctions = true, $includeClasses = true, $includeInterfaces = true, $includeTraits = true, $includeIniSettings = true, $includeIncludedFiles = true) |
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| 96 | { |
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| 97 | if ($blacklist === null) { |
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| 98 | $blacklist = new Blacklist; |
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| 99 | } |
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| 100 | |||
| 101 | $this->blacklist = $blacklist; |
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| 102 | |||
| 103 | if ($includeConstants) { |
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| 104 | $this->snapshotConstants(); |
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| 105 | } |
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| 106 | |||
| 107 | if ($includeFunctions) { |
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| 108 | $this->snapshotFunctions(); |
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| 109 | } |
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| 110 | |||
| 111 | if ($includeClasses || $includeStaticAttributes) { |
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| 112 | $this->snapshotClasses(); |
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| 113 | } |
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| 114 | |||
| 115 | if ($includeInterfaces) { |
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| 116 | $this->snapshotInterfaces(); |
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| 117 | } |
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| 118 | |||
| 119 | if ($includeGlobalVariables) { |
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| 120 | $this->setupSuperGlobalArrays(); |
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| 121 | $this->snapshotGlobals(); |
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| 122 | } |
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| 123 | |||
| 124 | if ($includeStaticAttributes) { |
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| 125 | $this->snapshotStaticAttributes(); |
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| 126 | } |
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| 127 | |||
| 128 | if ($includeIniSettings) { |
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| 129 | $this->iniSettings = ini_get_all(null, false); |
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| 130 | } |
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| 131 | |||
| 132 | if ($includeIncludedFiles) { |
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| 133 | $this->includedFiles = get_included_files(); |
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| 134 | } |
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| 135 | |||
| 136 | if (function_exists('get_declared_traits')) { |
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| 137 | $this->traits = get_declared_traits(); |
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| 138 | } |
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| 139 | } |
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| 140 | |||
| 141 | /** |
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| 142 | * @return Blacklist |
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| 143 | */ |
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| 144 | public function blacklist() |
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| 145 | { |
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| 146 | return $this->blacklist; |
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| 147 | } |
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| 148 | |||
| 149 | /** |
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| 150 | * @return array |
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| 151 | */ |
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| 152 | public function globalVariables() |
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| 153 | { |
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| 154 | return $this->globalVariables; |
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| 155 | } |
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| 156 | |||
| 157 | /** |
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| 158 | * @return array |
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| 159 | */ |
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| 160 | public function superGlobalVariables() |
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| 161 | { |
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| 162 | return $this->superGlobalVariables; |
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| 163 | } |
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| 164 | |||
| 165 | /** |
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| 166 | * Returns a list of all super-global variable arrays. |
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| 167 | * |
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| 168 | * @return array |
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| 169 | */ |
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| 170 | public function superGlobalArrays() |
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| 171 | { |
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| 172 | return $this->superGlobalArrays; |
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| 173 | } |
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| 174 | |||
| 175 | /** |
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| 176 | * @return array |
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| 177 | */ |
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| 178 | public function staticAttributes() |
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| 179 | { |
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| 180 | return $this->staticAttributes; |
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| 181 | } |
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| 182 | |||
| 183 | /** |
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| 184 | * @return array |
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| 185 | */ |
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| 186 | public function iniSettings() |
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| 187 | { |
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| 188 | return $this->iniSettings; |
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| 189 | } |
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| 190 | |||
| 191 | /** |
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| 192 | * @return array |
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| 193 | */ |
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| 194 | public function includedFiles() |
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| 195 | { |
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| 196 | return $this->includedFiles; |
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| 197 | } |
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| 198 | |||
| 199 | /** |
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| 200 | * @return array |
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| 201 | */ |
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| 202 | public function constants() |
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| 203 | { |
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| 204 | return $this->constants; |
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| 205 | } |
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| 206 | |||
| 207 | /** |
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| 208 | * @return array |
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| 209 | */ |
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| 210 | public function functions() |
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| 211 | { |
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| 212 | return $this->functions; |
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| 213 | } |
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| 214 | |||
| 215 | /** |
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| 216 | * @return array |
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| 217 | */ |
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| 218 | public function interfaces() |
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| 219 | { |
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| 220 | return $this->interfaces; |
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| 221 | } |
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| 222 | |||
| 223 | /** |
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| 224 | * @return array |
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| 225 | */ |
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| 226 | public function classes() |
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| 227 | { |
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| 228 | return $this->classes; |
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| 229 | } |
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| 230 | |||
| 231 | /** |
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| 232 | * @return array |
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| 233 | */ |
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| 234 | public function traits() |
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| 235 | { |
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| 236 | return $this->traits; |
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| 237 | } |
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| 238 | |||
| 239 | /** |
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| 240 | * Creates a snapshot user-defined constants. |
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| 241 | */ |
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| 242 | private function snapshotConstants() |
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| 243 | { |
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| 244 | $constants = get_defined_constants(true); |
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| 245 | |||
| 246 | if (isset($constants['user'])) { |
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| 247 | $this->constants = $constants['user']; |
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| 248 | } |
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| 249 | } |
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| 250 | |||
| 251 | /** |
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| 252 | * Creates a snapshot user-defined functions. |
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| 253 | */ |
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| 254 | private function snapshotFunctions() |
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| 255 | { |
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| 256 | $functions = get_defined_functions(); |
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| 257 | |||
| 258 | $this->functions = $functions['user']; |
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| 259 | } |
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| 260 | |||
| 261 | /** |
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| 262 | * Creates a snapshot user-defined classes. |
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| 263 | */ |
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| 264 | private function snapshotClasses() |
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| 265 | { |
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| 266 | foreach (array_reverse(get_declared_classes()) as $className) { |
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| 267 | $class = new ReflectionClass($className); |
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| 268 | |||
| 269 | if (!$class->isUserDefined()) { |
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| 270 | break; |
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| 271 | } |
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| 272 | |||
| 273 | $this->classes[] = $className; |
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| 274 | } |
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| 275 | |||
| 276 | $this->classes = array_reverse($this->classes); |
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| 277 | } |
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| 278 | |||
| 279 | /** |
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| 280 | * Creates a snapshot user-defined interfaces. |
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| 281 | */ |
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| 282 | private function snapshotInterfaces() |
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| 283 | { |
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| 284 | foreach (array_reverse(get_declared_interfaces()) as $interfaceName) { |
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| 285 | $class = new ReflectionClass($interfaceName); |
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| 286 | |||
| 287 | if (!$class->isUserDefined()) { |
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| 288 | break; |
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| 289 | } |
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| 290 | |||
| 291 | $this->interfaces[] = $interfaceName; |
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| 292 | } |
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| 293 | |||
| 294 | $this->interfaces = array_reverse($this->interfaces); |
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| 295 | } |
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| 296 | |||
| 297 | /** |
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| 298 | * Creates a snapshot of all global and super-global variables. |
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| 299 | */ |
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| 300 | private function snapshotGlobals() |
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| 301 | { |
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| 302 | $superGlobalArrays = $this->superGlobalArrays(); |
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| 303 | |||
| 304 | foreach ($superGlobalArrays as $superGlobalArray) { |
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| 305 | $this->snapshotSuperGlobalArray($superGlobalArray); |
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| 306 | } |
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| 307 | |||
| 308 | foreach (array_keys($GLOBALS) as $key) { |
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| 309 | if ($key != 'GLOBALS' && |
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| 310 | !in_array($key, $superGlobalArrays) && |
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| 311 | $this->canBeSerialized($GLOBALS[$key]) && |
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| 312 | !$this->blacklist->isGlobalVariableBlacklisted($key)) { |
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| 313 | $this->globalVariables[$key] = unserialize(serialize($GLOBALS[$key])); |
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| 314 | } |
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| 315 | } |
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| 316 | } |
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| 317 | |||
| 318 | /** |
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| 319 | * Creates a snapshot a super-global variable array. |
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| 320 | * |
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| 321 | * @param $superGlobalArray |
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| 322 | */ |
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| 323 | private function snapshotSuperGlobalArray($superGlobalArray) |
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| 324 | { |
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| 325 | $this->superGlobalVariables[$superGlobalArray] = array(); |
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| 326 | |||
| 327 | if (isset($GLOBALS[$superGlobalArray]) && is_array($GLOBALS[$superGlobalArray])) { |
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| 328 | foreach ($GLOBALS[$superGlobalArray] as $key => $value) { |
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| 329 | $this->superGlobalVariables[$superGlobalArray][$key] = unserialize(serialize($value)); |
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| 330 | } |
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| 331 | } |
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| 332 | } |
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| 333 | |||
| 334 | /** |
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| 335 | * Creates a snapshot of all static attributes in user-defined classes. |
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| 336 | */ |
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| 337 | private function snapshotStaticAttributes() |
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| 338 | { |
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| 339 | foreach ($this->classes as $className) { |
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| 340 | $class = new ReflectionClass($className); |
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| 341 | $snapshot = array(); |
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| 342 | |||
| 343 | foreach ($class->getProperties() as $attribute) { |
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| 344 | if ($attribute->isStatic()) { |
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| 345 | $name = $attribute->getName(); |
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| 346 | |||
| 347 | if ($this->blacklist->isStaticAttributeBlacklisted($className, $name)) { |
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| 348 | continue; |
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| 349 | } |
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| 350 | |||
| 351 | $attribute->setAccessible(true); |
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| 352 | $value = $attribute->getValue(); |
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| 353 | |||
| 354 | if ($this->canBeSerialized($value)) { |
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| 355 | $snapshot[$name] = unserialize(serialize($value)); |
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| 356 | } |
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| 357 | } |
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| 358 | } |
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| 359 | |||
| 360 | if (!empty($snapshot)) { |
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| 361 | $this->staticAttributes[$className] = $snapshot; |
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| 362 | } |
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| 363 | } |
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| 364 | } |
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| 365 | |||
| 366 | /** |
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| 367 | * Returns a list of all super-global variable arrays. |
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| 368 | * |
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| 369 | * @return array |
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| 370 | */ |
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| 371 | private function setupSuperGlobalArrays() |
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| 372 | { |
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| 373 | $this->superGlobalArrays = array( |
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| 374 | '_ENV', |
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| 375 | '_POST', |
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| 376 | '_GET', |
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| 377 | '_COOKIE', |
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| 378 | '_SERVER', |
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| 379 | '_FILES', |
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| 380 | '_REQUEST' |
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| 381 | ); |
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| 382 | |||
| 383 | if (ini_get('register_long_arrays') == '1') { |
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| 384 | $this->superGlobalArrays = array_merge( |
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| 385 | $this->superGlobalArrays, |
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| 386 | array( |
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| 387 | 'HTTP_ENV_VARS', |
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| 388 | 'HTTP_POST_VARS', |
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| 389 | 'HTTP_GET_VARS', |
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| 390 | 'HTTP_COOKIE_VARS', |
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| 391 | 'HTTP_SERVER_VARS', |
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| 392 | 'HTTP_POST_FILES' |
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| 393 | ) |
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| 394 | ); |
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| 395 | } |
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| 396 | } |
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| 397 | |||
| 398 | /** |
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| 399 | * @param mixed $variable |
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| 400 | * @return bool |
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| 401 | * @todo Implement this properly |
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| 402 | */ |
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| 403 | private function canBeSerialized($variable) |
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| 404 | { |
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| 405 | if (!is_object($variable)) { |
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| 406 | return !is_resource($variable); |
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| 407 | } |
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| 408 | |||
| 409 | if ($variable instanceof \stdClass) { |
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| 410 | return true; |
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| 411 | } |
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| 412 | |||
| 413 | $class = new ReflectionClass($variable); |
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| 414 | |||
| 415 | do { |
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| 416 | if ($class->isInternal()) { |
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| 417 | return $variable instanceof Serializable; |
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| 418 | } |
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| 419 | } while ($class = $class->getParentClass()); |
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| 420 | |||
| 421 | return true; |
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| 422 | } |
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| 423 | } |
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| 424 |