/**
* This function implements the reading mechanism for a shared memory
* segment following a specific layout.
* @param $index position that should be read regarding the layout.
* if $index is left -1 then the upcoming parameters will
* be used to perform a search otherwise they are used to
* perform checks on the elment addressed.
* @param $skey string key for the element's $kpos'th node
* @param $kpos $skey position regarding the segment layout
* @param $val value of the last serialized element stored
* if it is a string the type of the objects will be compared
* otherwise the obejects will be compared
* @return trimmed string for the whole contents of the segment if
* $index is -1, if $index is >= 0 and valid the complete
* element at this position, otherwise an empty string
*/
public function read($index = -1, $skey = "", $kpos = -1, $val = null, $full = true)
{
$rs = "";
$this->log(__METHOD__ . ": idx=%, skey=%, kpos=%, val=%, full=%", array($index, $skey, $kpos, StringUtil::get_object_string($val), $full));
// reading the whole contents if index is not set and the upcoming
// parameters either
if (strncmp(gettype($index), "integer", 7) == 0 && $index == -1 && strncmp(gettype($skey), "string", 6) == 0 && strlen($skey) == 0 && strncmp(gettype($kpos), "integer", 7) == 0 && $kpos == -1) {
$s = shmop_read($this->element->get_shm_seg_id(), 0, $this->element->get_shm_seg_size());
if ($s) {
$rs = trim($s);
}
// searching if the index is not set but parameters 2 to 5 are
// but not with default values
} else {
if (strncmp(gettype($index), "integer", 7) == 0 && $index == -1 && strncmp(gettype($skey), "string", 6) == 0 && strlen($skey) > 0 && strncmp(gettype($kpos), "integer", 7) == 0 && $kpos > -1) {
$rs = $this->search($index, $skey, $kpos, $val, $this->get_search_type());
// reading an index is a bit more complex
} else {
if (strncmp(gettype($index), "integer", 7) == 0 && $index > -1) {
$xcontents = $this->get();
$xcli = count($xcontents) - 1;
// now lets get the requested element if it exist
// and complete its layout
if ($index <= $xcli) {
$rs = trim($xcontents[$index]) . $this->element->get_shm_seg_var_eright() . $this->element->get_shm_seg_var_delimiter();
}
}
}
}
if ($full) {
return $rs;
} else {
return unserialize(substr($rs, strrpos($rs, $this->element->get_shm_seg_var_eleft()) + 1, strlen($rs) - strlen($this->element->get_shm_seg_var_eright() . $this->element->get_shm_seg_var_delimiter()) - strrpos($rs, $this->element->get_shm_seg_var_eleft()) - 1));
}
}
/**
* Function to flat several objects for logging. Arrays will be flattened.
* For other objects there will be looked after a class method named
* __toString(). If no such method exists the object signature will be used.
* @param object $obj object to flatte for logging.
* @param boolean $debug indicates to get detailed information for $obj
* @return string flattened object, its string representation or a unique id
*/
public function flatten($obj = null, $debug = false)
{
$a = array();
// NOTE: get_class_methods invokes autoloader for a string value
if (is_object($obj) && strncmp(gettype(get_class_methods($obj)), "array", 5) == 0) {
$a = get_class_methods($obj);
}
$ret = "";
if (in_array("__toString", $a)) {
$ret = $obj->__toString();
} else {
if (strncmp(gettype($obj), "array", 5) == 0) {
$ret = StringUtil::get_object_string($obj);
} else {
if (strncmp(gettype($obj), "string", 6) == 0) {
$ret = $obj;
} else {
if (strncmp(gettype($obj), "integer", 7) == 0) {
$ret = strval($obj);
} else {
if (is_null($obj)) {
$ret = "NULL";
} else {
if (is_object($obj)) {
$ret = get_class($obj) . spl_object_hash($obj);
}
}
}
}
}
}
if ($debug === true) {
$ret = "OBJECT(" . StringUtil::get_object_string($obj) . ")=" . $ret;
}
// replace multiple whitespaces by a single one
return $ret;
}
/**
* Set the segment type. Currently supported types be SharedMemoryWriter
* are 'stor', 'fifo', 'lifo'.
* @param $seg_type segment type
*/
public function set_shm_seg_type($seg_type = "stor")
{
if (in_array($seg_type, $this->shm_seg_supported_types, true)) {
switch ($seg_type) {
case "stor":
$this->shm_seg_type = "stor";
break;
case "fifo":
$this->shm_seg_type = "fifo";
break;
case "lifo":
$this->shm_seg_type = "lifo";
break;
default:
$this->shm_seg_type = "stor";
break;
}
} else {
$this->log(__METHOD__ . ": %", array(new SegmentException(StringUtil::get_object_string($seg_type), 3)));
throw new SegmentException(StringUtil::get_object_string($seg_type), 3);
}
}
