Complex classes like Stream 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 Stream, and based on these observations, apply Extract Interface, too.
1 | <?php |
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49 | class Stream implements SeekableIterator |
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50 | { |
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51 | /** |
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52 | * Attached filters. |
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53 | * |
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54 | * @var resource[] |
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55 | */ |
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56 | protected $filters = []; |
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57 | |||
58 | /** |
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59 | * stream resource. |
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60 | * |
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61 | * @var resource |
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62 | */ |
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63 | protected $stream; |
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64 | |||
65 | /** |
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66 | * Tell whether the stream should be closed on object destruction. |
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67 | * |
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68 | * @var bool |
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69 | */ |
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70 | protected $should_close_stream = false; |
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71 | |||
72 | /** |
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73 | * Current iterator value. |
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74 | * |
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75 | * @var mixed |
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76 | */ |
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77 | protected $value; |
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78 | |||
79 | /** |
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80 | * Current iterator key. |
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81 | * |
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82 | * @var int |
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83 | */ |
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84 | protected $offset; |
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85 | |||
86 | /** |
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87 | * Flags for the Document. |
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88 | * |
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89 | * @var int |
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90 | */ |
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91 | protected $flags = 0; |
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92 | |||
93 | /** |
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94 | * the field delimiter (one character only). |
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95 | * |
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96 | * @var string |
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97 | */ |
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98 | protected $delimiter = ','; |
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99 | |||
100 | /** |
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101 | * the field enclosure character (one character only). |
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102 | * |
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103 | * @var string |
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104 | */ |
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105 | protected $enclosure = '"'; |
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106 | |||
107 | /** |
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108 | * the field escape character (one character only). |
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109 | * |
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110 | * @var string |
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111 | */ |
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112 | protected $escape = '\\'; |
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113 | |||
114 | /** |
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115 | * Tell whether the current stream is seekable;. |
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116 | * |
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117 | * @var bool |
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118 | */ |
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119 | protected $is_seekable = false; |
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120 | |||
121 | /** |
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122 | * New instance. |
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123 | * |
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124 | * @param resource $resource stream type resource |
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125 | */ |
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126 | 48 | public function __construct($resource) |
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127 | { |
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128 | 48 | if (!is_resource($resource)) { |
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129 | 3 | throw new TypeError(sprintf('Argument passed must be a stream resource, %s given', gettype($resource))); |
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130 | } |
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131 | |||
132 | 45 | if ('stream' !== ($type = get_resource_type($resource))) { |
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133 | 3 | throw new TypeError(sprintf('Argument passed must be a stream resource, %s resource given', $type)); |
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134 | } |
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135 | |||
136 | 42 | $this->is_seekable = stream_get_meta_data($resource)['seekable']; |
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137 | 42 | $this->stream = $resource; |
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138 | 42 | } |
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139 | |||
140 | /** |
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141 | * {@inheritdoc} |
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142 | */ |
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143 | public function __destruct() |
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144 | { |
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145 | 42 | $walker = static function ($filter): bool { |
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146 | 12 | return @stream_filter_remove($filter); |
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147 | 42 | }; |
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148 | |||
149 | 42 | array_walk_recursive($this->filters, $walker); |
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150 | |||
151 | 42 | if ($this->should_close_stream && is_resource($this->stream)) { |
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152 | 27 | fclose($this->stream); |
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153 | } |
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154 | |||
155 | 42 | unset($this->stream); |
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156 | 42 | } |
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157 | |||
158 | /** |
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159 | * {@inheritdoc} |
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160 | */ |
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161 | 3 | public function __clone() |
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162 | { |
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163 | 3 | throw new Exception(sprintf('An object of class %s cannot be cloned', static::class)); |
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164 | } |
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165 | |||
166 | /** |
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167 | * {@inheritdoc} |
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168 | */ |
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169 | 3 | public function __debugInfo() |
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170 | { |
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171 | 3 | return stream_get_meta_data($this->stream) + [ |
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172 | 3 | 'delimiter' => $this->delimiter, |
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173 | 3 | 'enclosure' => $this->enclosure, |
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174 | 3 | 'escape' => $this->escape, |
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175 | 3 | 'stream_filters' => array_keys($this->filters), |
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176 | ]; |
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177 | } |
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178 | |||
179 | /** |
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180 | * Return a new instance from a file path. |
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181 | * |
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182 | * @param resource|null $context |
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183 | * |
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184 | * @throws Exception if the stream resource can not be created |
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185 | * |
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186 | * @return static |
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187 | */ |
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188 | 21 | public static function createFromPath(string $path, string $open_mode = 'r', $context = null) |
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189 | { |
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190 | 21 | $args = [$path, $open_mode]; |
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191 | 21 | if (null !== $context) { |
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192 | 3 | $args[] = false; |
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193 | 3 | $args[] = $context; |
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194 | } |
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195 | |||
196 | 21 | if (!$resource = @fopen(...$args)) { |
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197 | 6 | throw new Exception(sprintf('`%s`: failed to open stream: No such file or directory', $path)); |
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198 | } |
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199 | |||
200 | 15 | $instance = new static($resource); |
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201 | 15 | $instance->should_close_stream = true; |
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202 | |||
203 | 15 | return $instance; |
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204 | } |
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205 | |||
206 | /** |
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207 | * Return a new instance from a string. |
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208 | * |
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209 | * @return static |
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210 | */ |
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211 | 15 | public static function createFromString(string $content) |
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212 | { |
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213 | 15 | $resource = fopen('php://temp', 'r+'); |
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214 | 15 | fwrite($resource, $content); |
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215 | |||
216 | 15 | $instance = new static($resource); |
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217 | 15 | $instance->should_close_stream = true; |
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218 | |||
219 | 15 | return $instance; |
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220 | } |
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221 | |||
222 | /** |
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223 | * Return the URI of the underlying stream. |
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224 | */ |
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225 | 12 | public function getPathname(): string |
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226 | { |
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227 | 12 | return stream_get_meta_data($this->stream)['uri']; |
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228 | } |
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229 | |||
230 | /** |
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231 | * append a filter. |
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232 | * |
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233 | * @see http://php.net/manual/en/function.stream-filter-append.php |
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234 | * |
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235 | * @param null|mixed $params |
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236 | * @throws Exception if the filter can not be appended |
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237 | */ |
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238 | 18 | public function appendFilter(string $filtername, int $read_write, $params = null) |
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239 | { |
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240 | 18 | $res = @stream_filter_append($this->stream, $filtername, $read_write, $params); |
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241 | 18 | if (is_resource($res)) { |
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242 | 12 | $this->filters[$filtername][] = $res; |
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243 | 12 | return; |
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244 | } |
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245 | |||
246 | 6 | throw new Exception(sprintf('unable to locate filter `%s`', $filtername)); |
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247 | } |
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248 | |||
249 | /** |
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250 | * Set CSV control. |
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251 | * |
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252 | * @see http://php.net/manual/en/splfileobject.setcsvcontrol.php |
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253 | */ |
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254 | 21 | public function setCsvControl(string $delimiter = ',', string $enclosure = '"', string $escape = '\\') |
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255 | { |
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256 | 21 | list($this->delimiter, $this->enclosure, $this->escape) = $this->filterControl($delimiter, $enclosure, $escape, __METHOD__); |
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257 | 21 | } |
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258 | |||
259 | /** |
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260 | * Filter Csv control characters. |
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261 | * |
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262 | * @throws Exception If the Csv control character is not one character only. |
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263 | */ |
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264 | 42 | protected function filterControl(string $delimiter, string $enclosure, string $escape, string $caller): array |
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265 | { |
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266 | 42 | $controls = ['delimiter' => $delimiter, 'enclosure' => $enclosure, 'escape' => $escape]; |
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267 | 42 | foreach ($controls as $type => $control) { |
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268 | 42 | if (1 !== strlen($control)) { |
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269 | 42 | throw new Exception(sprintf('%s() expects %s to be a single character', $caller, $type)); |
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270 | } |
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271 | } |
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272 | |||
273 | 33 | return array_values($controls); |
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274 | } |
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275 | |||
276 | /** |
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277 | * Set CSV control. |
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278 | * |
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279 | * @see http://php.net/manual/en/splfileobject.getcsvcontrol.php |
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280 | * |
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281 | * @return string[] |
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282 | */ |
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283 | 45 | public function getCsvControl() |
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284 | { |
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285 | 45 | return [$this->delimiter, $this->enclosure, $this->escape]; |
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286 | } |
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287 | |||
288 | /** |
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289 | * Set CSV stream flags. |
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290 | * |
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291 | * @see http://php.net/manual/en/splfileobject.setflags.php |
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292 | */ |
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293 | 33 | public function setFlags(int $flags) |
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294 | { |
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295 | 33 | $this->flags = $flags; |
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296 | 33 | } |
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297 | |||
298 | /** |
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299 | * Write a field array as a CSV line. |
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300 | * |
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301 | * @see http://php.net/manual/en/splfileobject.fputcsv.php |
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302 | * |
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303 | * @return int|bool |
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304 | */ |
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305 | 21 | public function fputcsv(array $fields, string $delimiter = ',', string $enclosure = '"', string $escape = '\\') |
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306 | { |
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307 | 21 | $controls = $this->filterControl($delimiter, $enclosure, $escape, __METHOD__); |
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308 | |||
309 | 12 | return fputcsv($this->stream, $fields, ...$controls); |
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310 | } |
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311 | |||
312 | /** |
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313 | * Get line number. |
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314 | * |
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315 | * @see http://php.net/manual/en/splfileobject.key.php |
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316 | * |
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317 | * @return int |
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318 | */ |
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319 | 18 | public function key() |
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320 | { |
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321 | 18 | return $this->offset; |
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322 | } |
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323 | |||
324 | /** |
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325 | * Read next line. |
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326 | * |
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327 | * @see http://php.net/manual/en/splfileobject.next.php |
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328 | */ |
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329 | 18 | public function next() |
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330 | { |
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331 | 18 | $this->value = false; |
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332 | 18 | $this->offset++; |
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333 | 18 | } |
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334 | |||
335 | /** |
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336 | * Rewind the file to the first line. |
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337 | * |
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338 | * @see http://php.net/manual/en/splfileobject.rewind.php |
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339 | * |
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340 | * @throws Exception if the stream resource is not seekable |
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341 | */ |
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342 | 36 | public function rewind() |
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343 | { |
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344 | 36 | if (!$this->is_seekable) { |
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345 | 3 | throw new Exception('stream does not support seeking'); |
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346 | } |
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347 | |||
348 | 33 | rewind($this->stream); |
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349 | 33 | $this->offset = 0; |
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350 | 33 | $this->value = false; |
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351 | 33 | if ($this->flags & SplFileObject::READ_AHEAD) { |
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352 | 18 | $this->current(); |
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353 | } |
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354 | 33 | } |
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355 | |||
356 | /** |
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357 | * Not at EOF. |
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358 | * |
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359 | * @see http://php.net/manual/en/splfileobject.valid.php |
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360 | * |
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361 | * @return bool |
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362 | */ |
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363 | 30 | public function valid() |
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364 | { |
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365 | 30 | if ($this->flags & SplFileObject::READ_AHEAD) { |
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366 | 18 | return $this->current() !== false; |
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367 | } |
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368 | |||
369 | 12 | return !feof($this->stream); |
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370 | } |
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371 | |||
372 | /** |
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373 | * Retrieves the current line of the file. |
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374 | * |
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375 | * @see http://php.net/manual/en/splfileobject.current.php |
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376 | */ |
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377 | 21 | public function current() |
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387 | |||
388 | /** |
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389 | * Retrieves the current line as a CSV Record. |
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390 | * |
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391 | * @return array|bool |
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392 | */ |
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393 | 21 | protected function getCurrentRecord() |
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401 | |||
402 | /** |
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403 | * Seek to specified line. |
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404 | * |
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405 | * @see http://php.net/manual/en/splfileobject.seek.php |
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406 | * |
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407 | * @param int $position |
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408 | * @throws Exception if the position is negative |
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409 | */ |
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410 | 9 | public function seek($position) |
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425 | |||
426 | /** |
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427 | * Output all remaining data on a file pointer. |
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428 | * |
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429 | * @see http://php.net/manual/en/splfileobject.fpatssthru.php |
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430 | * |
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431 | * @return int |
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432 | */ |
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433 | 3 | public function fpassthru() |
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437 | |||
438 | /** |
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439 | * Read from file. |
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440 | * |
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441 | * @see http://php.net/manual/en/splfileobject.fread.php |
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442 | * |
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443 | * @param int $length The number of bytes to read |
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444 | * |
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445 | * @return string|false |
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446 | */ |
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447 | 33 | public function fread($length) |
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451 | |||
452 | /** |
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453 | * Gets a line from file. |
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454 | * |
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455 | * @see http://php.net/manual/en/splfileobject.fgets.php |
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456 | * |
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457 | * @return string|false |
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458 | */ |
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459 | 6 | public function fgets() |
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460 | { |
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461 | 6 | return fgets($this->stream); |
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462 | } |
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463 | |||
464 | /** |
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465 | * Seek to a position. |
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466 | * |
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467 | * @see http://php.net/manual/en/splfileobject.fseek.php |
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468 | * |
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469 | * @throws Exception if the stream resource is not seekable |
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470 | * |
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471 | * @return int |
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472 | */ |
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473 | 18 | public function fseek(int $offset, int $whence = SEEK_SET) |
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481 | |||
482 | /** |
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483 | * Write to stream. |
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484 | * |
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485 | * @see http://php.net/manual/en/splfileobject.fwrite.php |
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486 | * |
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487 | * @return int|bool |
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488 | */ |
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489 | 3 | public function fwrite(string $str, int $length = null) |
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498 | |||
499 | /** |
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500 | * Flushes the output to a file. |
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501 | * |
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502 | * @see http://php.net/manual/en/splfileobject.fwrite.php |
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503 | * |
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504 | * @return bool |
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505 | */ |
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506 | 3 | public function fflush() |
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510 | } |
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511 |