$hwm
$hwm :
Provides a buffer stream that can be written to to fill a buffer, and read from to remove bytes from the buffer.
This stream returns a "hwm" metadata value that tells upstream consumers what the configured high water mark of the stream is, or the maximum preferred size of the buffer.
__construct(integer $hwm = 16384)
| integer | $hwm | High water mark, representing the preferred maximum buffer size. If the size of the buffer exceeds the high water mark, then calls to write will continue to succeed but will return false to inform writers to slow down until the buffer has been drained by reading from it. |
__toString() : string
Reads all data from the stream into a string, from the beginning to end.
This method MUST attempt to seek to the beginning of the stream before reading data and read the stream until the end is reached.
Warning: This could attempt to load a large amount of data into memory.
This method MUST NOT raise an exception in order to conform with PHP's string casting operations.
seek(integer $offset, integer $whence = SEEK_SET)
Seek to a position in the stream.
| integer | $offset | Stream offset |
| integer | $whence | Specifies how the cursor position will be calculated
based on the seek offset. Valid values are identical to the built-in
PHP $whence values for |
read(integer $length) : string
Reads data from the buffer.
| integer | $length | Read up to $length bytes from the object and return them. Fewer than $length bytes may be returned if underlying stream call returns fewer bytes. |
Returns the data read from the stream, or an empty string if no bytes are available.
getMetadata(string $key = null) : array|mixed|null
Get stream metadata as an associative array or retrieve a specific key.
The keys returned are identical to the keys returned from PHP's stream_get_meta_data() function.
| string | $key | Specific metadata to retrieve. |
Returns an associative array if no key is provided. Returns a specific key value if a key is provided and the value is found, or null if the key is not found.