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 |