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 array<string, array<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 can be a null false or a scalar type value |
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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 mixed $stream stream type resource |
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125 | */ |
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126 | 66 | public function __construct($stream) |
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127 | { |
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128 | 66 | if (!is_resource($stream)) { |
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129 | 3 | throw new TypeError(sprintf('Argument passed must be a stream resource, %s given', gettype($stream))); |
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130 | } |
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131 | |||
132 | 63 | if ('stream' !== ($type = get_resource_type($stream))) { |
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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 | 60 | $this->is_seekable = stream_get_meta_data($stream)['seekable']; |
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137 | 60 | $this->stream = $stream; |
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138 | 60 | } |
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139 | |||
140 | /** |
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141 | * {@inheritdoc} |
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142 | */ |
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143 | 60 | public function __destruct() |
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144 | { |
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145 | $walker = static function ($filter): bool { |
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146 | 12 | return @stream_filter_remove($filter); |
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147 | 60 | }; |
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148 | |||
149 | 60 | array_walk_recursive($this->filters, $walker); |
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150 | |||
151 | 60 | if ($this->should_close_stream && is_resource($this->stream)) { |
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152 | 42 | fclose($this->stream); |
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153 | } |
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154 | |||
155 | 60 | unset($this->stream); |
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156 | 60 | } |
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157 | |||
158 | /** |
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159 | * {@inheritdoc} |
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160 | */ |
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161 | 3 | public function __clone() |
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162 | { |
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163 | 3 | throw new Exception(sprintf('An object of class %s cannot be cloned', static::class)); |
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164 | } |
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165 | |||
166 | /** |
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167 | * {@inheritdoc} |
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168 | */ |
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169 | 3 | public function __debugInfo(): array |
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170 | { |
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171 | 3 | return stream_get_meta_data($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 | 21 | public static function createFromPath(string $path, string $open_mode = 'r', $context = null): self |
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187 | { |
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188 | 21 | $args = [$path, $open_mode]; |
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189 | 21 | if (null !== $context) { |
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190 | 3 | $args[] = false; |
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191 | 3 | $args[] = $context; |
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192 | } |
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193 | |||
194 | 21 | $resource = @fopen(...$args); |
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195 | 21 | if (!is_resource($resource)) { |
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196 | 6 | throw new Exception(sprintf('`%s`: failed to open stream: No such file or directory', $path)); |
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197 | } |
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198 | |||
199 | 15 | $instance = new self($resource); |
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200 | 15 | $instance->should_close_stream = true; |
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201 | |||
202 | 15 | return $instance; |
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203 | } |
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204 | |||
205 | /** |
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206 | * Return a new instance from a string. |
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207 | */ |
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208 | 30 | public static function createFromString(string $content = ''): self |
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209 | { |
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210 | /** @var resource $resource */ |
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211 | 30 | $resource = fopen('php://temp', 'r+'); |
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212 | 30 | fwrite($resource, $content); |
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213 | |||
214 | 30 | $instance = new self($resource); |
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215 | 30 | $instance->should_close_stream = true; |
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216 | |||
217 | 30 | return $instance; |
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218 | } |
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219 | |||
220 | /** |
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221 | * Return the URI of the underlying stream. |
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222 | */ |
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223 | 12 | public function getPathname(): string |
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224 | { |
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225 | 12 | return stream_get_meta_data($this->stream)['uri']; |
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226 | } |
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227 | |||
228 | /** |
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229 | * append a filter. |
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230 | * |
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231 | * @see http://php.net/manual/en/function.stream-filter-append.php |
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232 | * |
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233 | * @param null|mixed $params |
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234 | * @throws Exception if the filter can not be appended |
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235 | */ |
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236 | 18 | public function appendFilter(string $filtername, int $read_write, $params = null): void |
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237 | { |
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238 | 18 | $res = @stream_filter_append($this->stream, $filtername, $read_write, $params); |
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239 | 18 | if (!is_resource($res)) { |
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240 | 6 | throw new InvalidArgument(sprintf('unable to locate filter `%s`', $filtername)); |
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241 | } |
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242 | |||
243 | 12 | $this->filters[$filtername][] = $res; |
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244 | 12 | } |
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245 | |||
246 | /** |
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247 | * Set CSV control. |
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248 | * |
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249 | * @see http://php.net/manual/en/SplFileObject.setcsvcontrol.php |
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250 | */ |
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251 | 39 | public function setCsvControl(string $delimiter = ',', string $enclosure = '"', string $escape = '\\'): void |
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255 | |||
256 | /** |
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257 | * Filter Csv control characters. |
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258 | * |
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259 | * @throws Exception If the Csv control character is not one character only. |
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260 | */ |
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261 | 60 | protected function filterControl(string $delimiter, string $enclosure, string $escape, string $caller): array |
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262 | { |
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263 | 60 | if (1 !== strlen($delimiter)) { |
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264 | 6 | throw new InvalidArgument(sprintf('%s() expects delimiter to be a single character', $caller)); |
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265 | } |
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266 | |||
267 | 57 | if (1 !== strlen($enclosure)) { |
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268 | 3 | throw new InvalidArgument(sprintf('%s() expects enclosure to be a single character', $caller)); |
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269 | } |
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270 | |||
271 | 54 | if (1 === strlen($escape) || ('' === $escape && 70400 <= PHP_VERSION_ID)) { |
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272 | 49 | return [$delimiter, $enclosure, $escape]; |
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273 | } |
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274 | |||
275 | 5 | throw new InvalidArgument(sprintf('%s() expects escape to be a single character', $caller)); |
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276 | } |
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277 | |||
278 | /** |
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279 | * Set CSV control. |
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280 | * |
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281 | * @see http://php.net/manual/en/SplFileObject.getcsvcontrol.php |
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282 | * |
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283 | * @return string[] |
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284 | */ |
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285 | 61 | public function getCsvControl(): array |
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286 | { |
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287 | 61 | return [$this->delimiter, $this->enclosure, $this->escape]; |
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288 | } |
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289 | |||
290 | /** |
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291 | * Set CSV stream flags. |
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292 | * |
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293 | * @see http://php.net/manual/en/SplFileObject.setflags.php |
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294 | */ |
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295 | 48 | public function setFlags(int $flags): void |
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296 | { |
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297 | 48 | $this->flags = $flags; |
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298 | 48 | } |
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299 | |||
300 | /** |
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301 | * Write a field array as a CSV line. |
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302 | * |
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303 | * @see http://php.net/manual/en/SplFileObject.fputcsv.php |
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304 | * |
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305 | * @return int|false |
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306 | */ |
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307 | 21 | public function fputcsv(array $fields, string $delimiter = ',', string $enclosure = '"', string $escape = '\\') |
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308 | { |
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309 | 21 | $controls = $this->filterControl($delimiter, $enclosure, $escape, __METHOD__); |
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310 | |||
311 | 12 | return fputcsv($this->stream, $fields, ...$controls); |
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312 | } |
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313 | |||
314 | /** |
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315 | * Get line number. |
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316 | * |
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317 | * @see http://php.net/manual/en/SplFileObject.key.php |
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318 | * |
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319 | * @return int |
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320 | */ |
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321 | 36 | public function key() |
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322 | { |
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323 | 36 | return $this->offset; |
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324 | } |
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325 | |||
326 | /** |
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327 | * Read next line. |
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328 | * |
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329 | * @see http://php.net/manual/en/SplFileObject.next.php |
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330 | */ |
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331 | 30 | public function next(): void |
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332 | { |
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333 | 30 | $this->value = false; |
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334 | 30 | $this->offset++; |
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335 | 30 | } |
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336 | |||
337 | /** |
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338 | * Rewind the file to the first line. |
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339 | * |
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340 | * @see http://php.net/manual/en/SplFileObject.rewind.php |
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341 | * |
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342 | * @throws Exception if the stream resource is not seekable |
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343 | */ |
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344 | 51 | public function rewind(): void |
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345 | { |
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346 | 51 | if (!$this->is_seekable) { |
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347 | 3 | throw new Exception('stream does not support seeking'); |
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348 | } |
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349 | |||
350 | 48 | rewind($this->stream); |
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351 | 48 | $this->offset = 0; |
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352 | 48 | $this->value = false; |
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353 | 48 | if (0 !== ($this->flags & SplFileObject::READ_AHEAD)) { |
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354 | 33 | $this->current(); |
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355 | } |
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356 | 48 | } |
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357 | |||
358 | /** |
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359 | * Not at EOF. |
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360 | * |
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361 | * @see http://php.net/manual/en/SplFileObject.valid.php |
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362 | * |
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363 | * @return bool |
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364 | */ |
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365 | 45 | public function valid() |
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366 | { |
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367 | 45 | if (0 !== ($this->flags & SplFileObject::READ_AHEAD)) { |
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368 | 33 | return $this->current() !== false; |
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369 | } |
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370 | |||
371 | 12 | return !feof($this->stream); |
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372 | } |
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373 | |||
374 | /** |
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375 | * Retrieves the current line of the file. |
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376 | * |
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377 | * @see http://php.net/manual/en/SplFileObject.current.php |
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378 | * |
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379 | * @return mixed The value of the current element. |
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380 | */ |
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381 | 36 | public function current() |
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391 | |||
392 | /** |
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393 | * Retrieves the current line as a CSV Record. |
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394 | * |
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395 | * @return array|false|null |
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396 | */ |
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397 | 36 | protected function getCurrentRecord() |
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405 | |||
406 | /** |
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407 | * Seek to specified line. |
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408 | * |
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409 | * @see http://php.net/manual/en/SplFileObject.seek.php |
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410 | * |
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411 | * @param int $position |
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412 | * @throws Exception if the position is negative |
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413 | */ |
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414 | 12 | public function seek($position): void |
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415 | { |
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416 | 12 | if ($position < 0) { |
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417 | 3 | throw new Exception(sprintf('%s() can\'t seek stream to negative line %d', __METHOD__, $position)); |
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418 | } |
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419 | |||
420 | 9 | $this->rewind(); |
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421 | 6 | while ($this->key() !== $position && $this->valid()) { |
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422 | 3 | $this->current(); |
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423 | 3 | $this->next(); |
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424 | } |
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425 | |||
426 | 6 | if (0 !== $position) { |
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427 | 3 | $this->offset--; |
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428 | } |
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429 | |||
430 | 6 | $this->current(); |
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431 | 6 | } |
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432 | |||
433 | /** |
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434 | * Output all remaining data on a file pointer. |
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435 | * |
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436 | * @see http://php.net/manual/en/SplFileObject.fpatssthru.php |
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437 | * |
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438 | * @return int|false |
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439 | */ |
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440 | 3 | public function fpassthru() |
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444 | |||
445 | /** |
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446 | * Read from file. |
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447 | * |
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448 | * @see http://php.net/manual/en/SplFileObject.fread.php |
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449 | * |
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450 | * @param int $length The number of bytes to read |
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451 | * |
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452 | * @return string|false |
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453 | */ |
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454 | 48 | public function fread(int $length) |
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458 | |||
459 | /** |
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460 | * Gets a line from file. |
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461 | * |
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462 | * @see http://php.net/manual/en/SplFileObject.fgets.php |
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463 | * |
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464 | * @return string|false |
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465 | */ |
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466 | 6 | public function fgets() |
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470 | |||
471 | /** |
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472 | * Seek to a position. |
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473 | * |
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474 | * @see http://php.net/manual/en/SplFileObject.fseek.php |
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475 | * |
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476 | * @throws Exception if the stream resource is not seekable |
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477 | */ |
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478 | 18 | public function fseek(int $offset, int $whence = SEEK_SET): int |
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479 | { |
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480 | 18 | if (!$this->is_seekable) { |
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481 | 3 | throw new Exception('stream does not support seeking'); |
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482 | } |
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483 | |||
486 | |||
487 | /** |
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488 | * Write to stream. |
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489 | * |
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490 | * @see http://php.net/manual/en/SplFileObject.fwrite.php |
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491 | * |
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492 | * @return int|false |
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493 | */ |
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494 | 3 | public function fwrite(string $str, int $length = null) |
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503 | |||
504 | /** |
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505 | * Flushes the output to a file. |
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506 | * |
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507 | * @see http://php.net/manual/en/SplFileObject.fwrite.php |
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508 | */ |
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509 | 3 | public function fflush(): bool |
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513 | } |
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514 |