krz/vox-populi

  1<?php
  2
  3namespace Psr\Http\Message;
  4
  5/**
  6 * Describes a data stream.
  7 *
  8 * Typically, an instance will wrap a PHP stream; this interface provides
  9 * a wrapper around the most common operations, including serialization of
 10 * the entire stream to a string.
 11 */
 12interface StreamInterface
 13{
 14    /**
 15     * Reads all data from the stream into a string, from the beginning to end.
 16     *
 17     * This method MUST attempt to seek to the beginning of the stream before
 18     * reading data and read the stream until the end is reached.
 19     *
 20     * Warning: This could attempt to load a large amount of data into memory.
 21     *
 22     * This method MUST NOT raise an exception in order to conform with PHP's
 23     * string casting operations.
 24     *
 25     * @see http://php.net/manual/en/language.oop5.magic.php#object.tostring
 26     * @return string
 27     */
 28    public function __toString();
 29
 30    /**
 31     * Closes the stream and any underlying resources.
 32     *
 33     * @return void
 34     */
 35    public function close();
 36
 37    /**
 38     * Separates any underlying resources from the stream.
 39     *
 40     * After the stream has been detached, the stream is in an unusable state.
 41     *
 42     * @return resource|null Underlying PHP stream, if any
 43     */
 44    public function detach();
 45
 46    /**
 47     * Get the size of the stream if known.
 48     *
 49     * @return int|null Returns the size in bytes if known, or null if unknown.
 50     */
 51    public function getSize();
 52
 53    /**
 54     * Returns the current position of the file read/write pointer
 55     *
 56     * @return int Position of the file pointer
 57     * @throws \RuntimeException on error.
 58     */
 59    public function tell();
 60
 61    /**
 62     * Returns true if the stream is at the end of the stream.
 63     *
 64     * @return bool
 65     */
 66    public function eof();
 67
 68    /**
 69     * Returns whether or not the stream is seekable.
 70     *
 71     * @return bool
 72     */
 73    public function isSeekable();
 74
 75    /**
 76     * Seek to a position in the stream.
 77     *
 78     * @link http://www.php.net/manual/en/function.fseek.php
 79     * @param int $offset Stream offset
 80     * @param int $whence Specifies how the cursor position will be calculated
 81     *     based on the seek offset. Valid values are identical to the built-in
 82     *     PHP $whence values for `fseek()`.  SEEK_SET: Set position equal to
 83     *     offset bytes SEEK_CUR: Set position to current location plus offset
 84     *     SEEK_END: Set position to end-of-stream plus offset.
 85     * @throws \RuntimeException on failure.
 86     */
 87    public function seek($offset, $whence = SEEK_SET);
 88
 89    /**
 90     * Seek to the beginning of the stream.
 91     *
 92     * If the stream is not seekable, this method will raise an exception;
 93     * otherwise, it will perform a seek(0).
 94     *
 95     * @see seek()
 96     * @link http://www.php.net/manual/en/function.fseek.php
 97     * @throws \RuntimeException on failure.
 98     */
 99    public function rewind();
100
101    /**
102     * Returns whether or not the stream is writable.
103     *
104     * @return bool
105     */
106    public function isWritable();
107
108    /**
109     * Write data to the stream.
110     *
111     * @param string $string The string that is to be written.
112     * @return int Returns the number of bytes written to the stream.
113     * @throws \RuntimeException on failure.
114     */
115    public function write($string);
116
117    /**
118     * Returns whether or not the stream is readable.
119     *
120     * @return bool
121     */
122    public function isReadable();
123
124    /**
125     * Read data from the stream.
126     *
127     * @param int $length Read up to $length bytes from the object and return
128     *     them. Fewer than $length bytes may be returned if underlying stream
129     *     call returns fewer bytes.
130     * @return string Returns the data read from the stream, or an empty string
131     *     if no bytes are available.
132     * @throws \RuntimeException if an error occurs.
133     */
134    public function read($length);
135
136    /**
137     * Returns the remaining contents in a string
138     *
139     * @return string
140     * @throws \RuntimeException if unable to read or an error occurs while
141     *     reading.
142     */
143    public function getContents();
144
145    /**
146     * Get stream metadata as an associative array or retrieve a specific key.
147     *
148     * The keys returned are identical to the keys returned from PHP's
149     * stream_get_meta_data() function.
150     *
151     * @link http://php.net/manual/en/function.stream-get-meta-data.php
152     * @param string $key Specific metadata to retrieve.
153     * @return array|mixed|null Returns an associative array if no key is
154     *     provided. Returns a specific key value if a key is provided and the
155     *     value is found, or null if the key is not found.
156     */
157    public function getMetadata($key = null);
158}