/**
* Increase the memory limit to the given level if it's currently too low.
* Only increases up to the maximum defined in {@link set_increase_memory_limit_max()},
* and defaults to the 'memory_limit' setting in the PHP configuration.
*
* @param A memory limit string, such as "64M". If omitted, unlimited memory will be set.
* @return Boolean TRUE indicates a successful change, FALSE a denied change.
*/
function increase_memory_limit_to($memoryLimit = -1)
{
$curLimit = ini_get('memory_limit');
// Can't go higher than infinite
if ($curLimit == -1) {
return true;
}
// Check hard maximums
$max = get_increase_memory_limit_max();
if ($max != -1 && translate_memstring($memoryLimit) > translate_memstring($max)) {
return false;
}
// Increase the memory limit if it's too low
if ($memoryLimit == -1 || translate_memstring($memoryLimit) > translate_memstring($curLimit)) {
ini_set('memory_limit', $memoryLimit);
}
return true;
}
/**
* Increase the memory limit to the given level if it's currently too low.
* @param A memory limit string, such as "64M". If omitted, unlimited memory will be set.
*/
function increase_memory_limit_to($memoryLimit = -1)
{
$curLimit = ini_get('memory_limit');
// Can't go higher than infinite
if ($curLimit == -1) {
return;
}
// Increase the memory limit if it's too low
if ($memoryLimit == -1 || translate_memstring($memoryLimit) > translate_memstring($curLimit)) {
ini_set('memory_limit', $memoryLimit);
}
}
/**
* Check if we've got enough memory available for resampling this image. This check is rough,
* so it will not catch all images that are too large - it also won't work accurately on large,
* animated GIFs as bits per pixel can't be calculated for an animated GIF with a global color
* table.
*
* @param string $filename
* @return boolean
*/
public function checkAvailableMemory($filename)
{
$limit = translate_memstring(ini_get('memory_limit'));
if ($limit < 0) {
return true;
}
// memory_limit == -1
$imageInfo = getimagesize($filename);
// bits per channel (rounded up, default to 1)
$bits = isset($imageInfo['bits']) ? ($imageInfo['bits'] + 7) / 8 : 1;
// channels (default 4 rgba)
$channels = isset($imageInfo['channels']) ? $imageInfo['channels'] : 4;
$bytesPerPixel = $bits * $channels;
// width * height * bytes per pixel
$memoryRequired = $imageInfo[0] * $imageInfo[1] * $bytesPerPixel;
return $memoryRequired + memory_get_usage() < $limit;
}