public function get_maxima_available()
{
if ('unix' != stack_connection_helper::get_platform()) {
return stack_string('healthunabletolistavail');
}
$this->command = 'maxima --list-avail';
$rawresult = $this->call_maxima('');
return $rawresult;
}
public function test_compute_miss_formed_command()
{
$connection = stack_connection_helper::make();
// This will induce a timeout on the CAS because we don't have a well formed CAS statement.
$strin = 'cab:block([],print("[TimeStamp= [ 0 ];';
$return = $connection->compute($strin);
$expected = array();
$this->assertEquals($return, $expected);
}
protected function guess_maxima_command($path)
{
if ('default' == stack_connection_helper::get_maximaversion()) {
throw new stack_exception("stack_cas_connection: maxima cannot be set to default on Windows platform. " . "Please choose an explicit version via the administration settings page.");
}
$cmd = $path . '/maxima.bat';
if (!is_readable($cmd)) {
throw new stack_exception("stack_cas_connection: maxima launch script {$cmd} does not exist.");
}
return $cmd;
}
public function compute($command)
{
$context = "Platform: " . stack_connection_helper::get_platform() . "\n";
$context .= "Maxima shell command: " . $this->command . "\n";
$context .= "Maxima initial command: " . $this->initcommand . "\n";
$context .= "Maxima timeout: " . $this->timeout;
$this->debug->log('Context used', $context);
$this->debug->log('Maxima command', $command);
$rawresult = $this->call_maxima($command);
$this->debug->log('CAS result', $rawresult);
$unpackedresult = $this->unpack_raw_result($rawresult);
$this->debug->log('Unpacked result as', print_r($unpackedresult, true));
if (!stack_connection_helper::check_stackmaxima_version($unpackedresult)) {
stack_connection_helper::warn_about_version_mismatch($this->debug);
}
return $unpackedresult;
}
protected function guess_maxima_command($path)
{
global $CFG;
if (stack_connection_helper::get_platform() == 'unix-optimised') {
// We are trying to use a Lisp snapshot of Maxima with all the
// STACK libraries loaded.
$lispimage = $CFG->dataroot . '/stack/maxima-optimised';
if (is_readable($lispimage)) {
return $lispimage;
}
}
if (is_readable('/Applications/Maxima.app/Contents/Resources/maxima.sh')) {
// This is the path on Macs, if Maxima has been installed following
// the instructions on Sourceforge.
return '/Applications/Maxima.app/Contents/Resources/maxima.sh';
}
// Default guess on Linux.
return 'maxima';
}
public function compute($command)
{
$cached = $this->get_cached_result($command);
if ($cached->result) {
$this->debug->log('Maxima command', $command);
$this->debug->log('Unpacked result found in the DB cache', print_r($cached->result, true));
if (!stack_connection_helper::check_stackmaxima_version($cached->result)) {
stack_connection_helper::warn_about_version_mismatch($this->debug);
// We could consider automatically purging the cache here.
}
return $cached->result;
}
$this->debug->log('Maxima command not found in the cache. Using the raw connection.');
$result = $this->rawconnection->compute($command);
// Only add to the cache if we didn't timeout!
if (!stack_connection_helper::did_cas_timeout($result)) {
$this->add_to_cache($command, $result, $cached->key);
}
return $result;
}
// If we have a linux machine, and we are testing the raw connection then we should
// attempt to automatically create an optimized maxima image on the system.
if ($config->platform === 'unix' and $genuinecascall) {
echo $OUTPUT->heading(stack_string('healthautomaxopt'), 3);
echo html_writer::tag('p', stack_string('healthautomaxoptintro'));
list($message, $debug, $result) = stack_connection_helper::stackmaxima_auto_maxima_optimise($genuinedebug);
$summary[] = array($result, $message);
echo html_writer::tag('p', $message);
echo output_debug(stack_string('debuginfo'), $debug);
}
// Test the version of the STACK libraries that Maxima is using.
// When Maxima is being run pre-compiled (maxima-optimise) or on a server,
// it is possible for the version of the Maxima libraries to get out of synch
// with the qtype_stack code.
echo $OUTPUT->heading(stack_string('healthchecksstackmaximaversion'), 3);
list($message, $details, $result) = stack_connection_helper::stackmaxima_version_healthcheck();
$summary[] = array($result, stack_string($message, $details));
echo html_writer::tag('p', stack_string($message, $details));
// Test plots.
output_cas_text(stack_string('healthcheckplots'), stack_string('healthcheckplotsintro'), get_string('healthchecksampleplots', 'qtype_stack'));
// State of the cache.
echo $OUTPUT->heading(stack_string('settingcasresultscache'), 3);
$message = stack_string('healthcheckcache_' . $config->casresultscache);
$summary[] = array(null, $message);
echo html_writer::tag('p', $message);
if ('db' == $config->casresultscache) {
echo html_writer::tag('p', stack_string('healthcheckcachestatus', stack_cas_connection_db_cache::entries_count($DB)));
echo $OUTPUT->single_button(new moodle_url($PAGE->url, array('clearcache' => 1, 'sesskey' => sesskey())), stack_string('clearthecache'));
}
echo '<hr />';
$tab = '';
public function instantiate()
{
if (null === $this->valid) {
$this->validate();
}
if (!$this->valid) {
return false;
}
// Lazy instantiation - only do this once...
// Empty session. Nothing to do.
if ($this->instantiated || null === $this->session) {
return true;
}
$connection = stack_connection_helper::make();
$results = $connection->compute($this->construct_maxima_command());
$this->debuginfo = $connection->get_debuginfo();
// Now put the information back into the correct slots.
$session = $this->session;
$newsession = array();
$newerrors = '';
$allfail = true;
$i = 0;
// We loop over each entry in the session, not over the result.
// This way we can add an error for missing values.
foreach ($session as $cs) {
$gotvalue = false;
if ('' == $cs->get_key()) {
$key = 'dumvar' . $i;
} else {
$key = $cs->get_key();
}
if (array_key_exists($i, $results)) {
$allfail = false;
// We at least got one result back from the CAS!
$result = $results["{$i}"];
// GOCHA! Results have string represenations of numbers, not int....
if ('' != $result['error'] and false === strstr($result['error'], 'clipped')) {
$cs->add_errors($result['error']);
$cs->decode_maxima_errors($result['error']);
$newerrors .= stack_maxima_format_casstring($cs->get_raw_casstring());
$newerrors .= ' ' . stack_string("stackCas_CASErrorCaused") . ' ' . $result['error'] . ' ';
}
if (array_key_exists('value', $result)) {
$val = str_replace('QMCHAR', '?', $result['value']);
$cs->set_value($val);
$gotvalue = true;
} else {
$cs->add_errors(stack_string("stackCas_failedReturnOne"));
}
if (array_key_exists('display', $result)) {
// Need to add this in here also because strings may contain question mark characters.
$disp = str_replace('QMCHAR', '?', $result['display']);
$cs->set_display($disp);
}
if (array_key_exists('valid', $result)) {
$cs->set_valid($result['valid']);
}
if (array_key_exists('answernote', $result)) {
$cs->set_answernote($result['answernote']);
}
if (array_key_exists('feedback', $result)) {
$cs->set_feedback($result['feedback']);
}
} else {
if (!$gotvalue) {
$errstr = stack_string("stackCas_failedReturn") . ' ' . stack_maxima_format_casstring($cs->get_raw_casstring());
$cs->add_errors($errstr);
$cs->set_answernote('CASFailedReturn');
$newerrors .= $errstr;
}
}
$newsession[] = $cs;
$i++;
}
$this->session = $newsession;
if ('' != $newerrors) {
$this->errors .= '<span class="error">' . stack_string('stackCas_CASError') . '</span>' . $newerrors;
}
if ($allfail) {
$this->errors = '<span class="error">' . stack_string('stackCas_allFailed') . '</span>';
}
$this->instantiated = true;
}
/**
* Initialises the database connection for the 'otherdb' cache type.
* @return moodle_database the DB connection to use.
*/
protected static function get_other_db()
{
if (!is_null(self::$otherdb)) {
return self::$otherdb;
}
$dboptions = array();
if (!empty(self::$config->cascachedbsocket)) {
$dboptions['dbsocket'] = true;
}
self::$otherdb = moodle_database::get_driver_instance(self::$config->cascachedbtype, self::$config->cascachedblibrary);
self::$otherdb->connect(self::$config->cascachedbhost, self::$config->cascachedbuser, self::$config->cascachedbpass, self::$config->cascachedbname, self::$config->cascachedbprefix, $dboptions);
return self::$otherdb;
}
protected function call_maxima($command)
{
global $CFG;
$err = '';
$starttime = microtime(true);
$request = curl_init($this->command);
$postdata = 'input=' . urlencode($command) . '&timeout=' . $this->timeout * 1000 . '&ploturlbase=!ploturl!' . '&version=' . stack_connection_helper::get_required_stackmaxima_version();
curl_setopt($request, CURLOPT_POST, true);
curl_setopt($request, CURLOPT_POSTFIELDS, $postdata);
curl_setopt($request, CURLOPT_RETURNTRANSFER, true);
curl_setopt($request, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
if (!empty($this->serveruserpass)) {
curl_setopt($request, CURLOPT_USERPWD, $this->serveruserpass);
}
$ret = curl_exec($request);
$timedout = false;
// The servlet will return 416 if the evaluation hits the timelimit.
if (curl_getinfo($request, CURLINFO_HTTP_CODE) != '200') {
if (curl_getinfo($request, CURLINFO_HTTP_CODE) != '416') {
throw new Exception('stack_cas_connection: MaximaPool error: ' . curl_getinfo($request, CURLINFO_HTTP_CODE));
} else {
$timedout = true;
}
}
// Did we get files?
if (strpos(curl_getinfo($request, CURLINFO_CONTENT_TYPE), "text/plain") === false) {
// We have to save the zip file on local disk before opening...
// how come there is no core library solution to this!?
// create temp file, save zip there.
$ziptemp = $CFG->dataroot . "/stack/tmp/";
$ziptemp = tempnam($ziptemp, "zip");
$fp = fopen($ziptemp, "w");
fwrite($fp, $ret);
fclose($fp);
$zip = zip_open($ziptemp);
$entry = zip_read($zip);
// Read the entrys of the archive.
while ($entry !== false) {
// This one contains the output from maxima.
if (zip_entry_name($entry) == 'OUTPUT') {
zip_entry_open($zip, $entry);
$ret = zip_entry_read($entry, zip_entry_filesize($entry));
zip_entry_close($entry);
} else {
$filename = $CFG->dataroot . "/stack/plots/" . zip_entry_name($entry);
zip_entry_open($zip, $entry);
$fp = fopen($filename, 'w');
$buffy = zip_entry_read($entry, 2048);
while ($buffy != '') {
fwrite($fp, $buffy);
$buffy = zip_entry_read($entry, 2048);
}
fclose($fp);
zip_entry_close($entry);
}
$entry = zip_read($zip);
}
zip_close($zip);
// Clean up.
unlink($ziptemp);
}
curl_close($request);
$now = microtime(true);
$this->debug->log('Timings', "Start: {$starttime}, End: {$now}, Taken = " . ($now - $starttime));
// Add sufficient closing ]'s to allow something to be un-parsed from the CAS.
// WARNING: the string 'The CAS timed out' is used by the cache to serach for a timout occurance.
if ($timedout) {
$ret .= ' The CAS timed out. ] ] ] ]';
}
return $ret;
}
