public function crawl($url)
{
- $res = $this->fetch($url);
+ $res = $this->fetch($url);
+ if ($res === false) {
+ return;
+ }
+
$linkInfos = $this->extractLinks($res);
if ($this->showLinksOnly) {
$this->showLinks($linkInfos);
protected function fetch($url)
{
+ $existingDoc = $this->es->get($url);
+
$req = new HttpRequest($url);
$req->setHeader(
'accept',
implode(',', array_keys(static::$supportedIndexTypes))
);
+ if ($existingDoc) {
+ $nMoDate = strtotime($existingDoc->modate);
+ $req->setHeader('If-Modified-Since: ' . date('r', $nMoDate));
+ }
+
$res = $req->send();
- if ($res->getStatus() !== 200) {
+ if ($res->getStatus() === 304) {
+ //not modified since last time, so don't crawl again
+ return false;
+ } else if ($res->getStatus() !== 200) {
throw new \Exception(
"Response code is not 200 but "
. $res->getStatus() . ", stopping"