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 |