lcache wildcard prefix clear removes all cache entries for the bin

[fabianx-ai]

diff --git a/sites/all/modules/contrib/lcache/lcache.cache.inc b/sites/all/modules/contrib/lcache/lcache.cache.inc
index c789454..daa1976 100644
--- a/sites/all/modules/contrib/lcache/lcache.cache.inc
+++ b/sites/all/modules/contrib/lcache/lcache.cache.inc
@@ -63,8 +63,8 @@ class LCache implements DrupalCacheInterface {
     $this->integrated = new \LCache\Integrated($l1, $l2, 100);
   }
 
-  protected function getAddress($cid=NULL) {
-    return new \LCache\Address($this->bin, $cid);
+  protected function getAddress($cid=NULL, $wildcard = FALSE) {
+    return new \LCache\Address($this->bin, $cid, $wildcard);
   }
 
   /**
@@ -125,7 +125,7 @@ class LCache implements DrupalCacheInterface {
       $this->integrated->collectGarbage();
     }
     else {
-      if ($wildcard) {
+      if ($wildcard && $cid == '*') {
         $address = $this->getAddress();
         $this->integrated->delete($address);
       }
@@ -136,7 +136,7 @@ class LCache implements DrupalCacheInterface {
         }
       }
       else {
-        $address = $this->getAddress($cid);
+        $address = $this->getAddress($cid, $wildcard);
         $this->integrated->delete($address);
       }
     }
diff --git a/sites/all/modules/contrib/lcache/vendor/lcache/lcache/src/Address.php b/sites/all/modules/contrib/lcache/vendor/lcache/lcache/src/Address.php
index efe5d94..dbb9680 100644
--- a/sites/all/modules/contrib/lcache/vendor/lcache/lcache/src/Address.php
+++ b/sites/all/modules/contrib/lcache/vendor/lcache/lcache/src/Address.php
@@ -12,18 +12,22 @@ final class Address implements \Serializable
     protected $bin;
     /** @var string|null */
     protected $key;
+    /** @var bool */
+    protected $wildcard = false;
 
     /**
      * Address constructor.
      *
      * @param string|null $bin
      * @param string|null $key
+     * @param bool $woldcard
      */
-    public function __construct($bin = null, $key = null)
+    public function __construct($bin = null, $key = null, $wildcard = false)
     {
         assert(!is_null($bin) || is_null($key));
         $this->bin = $bin;
         $this->key = $key;
+        $this->wildcard = $wildcard;
     }
 
     /**
@@ -50,7 +54,7 @@ final class Address implements \Serializable
      */
     public function isEntireBin()
     {
-        return is_null($this->key);
+        return is_null($this->key) || $this->wildcard;
     }
 
     /**

[davidstrauss]

I don't believe that will work correctly because a prefix wildcard clear isn't possible with LCache, so it escalates to a bin clear.

[fabianx-ai]

@davidstrauss That is not correct, it would work fine with above patch.

The bin clear is implemented as a prefix clear internally, so this should work fine.

Edited:

My original patch that comment was for was:

-      if ($wildcard) {
+      if ($wildcard && $cid == '*') {

and that indeed did not work.

[fabianx-ai]

I updated the patch.

[fabianx-ai]

@davidstrauss Besides that full bin cache clears are a little problematic with Drupal out of the box:

e.g. cache_bootstrap variable write would nuke your registry and module_implements, too.

'cache' cache_clear_all (e.g. entity_info_cache_clear) would nuke system_cache_tables and theme registry ...

etc.

[fabianx-ai]

@davidstrauss And its perfectly fine for APCu to not have the prefix clear, but do a bin clear.

[fabianx-ai]

Hm, it seems that should work fine for APCu as well as that does use an iterator over the items.

I am not seeing how a bin clear is different from a prefix clear given how its implemented.

Do I miss something?

[fabianx-ai]

Btw. Great work on lcache. Used it on an emergency black-friday project today and solved the problems with redis overload nicely. :)

Besides the too much caches are cleared issue right now ...

[fabianx-ai]

Okay, I see the StaticL2 cache makes an assumption on the bin.

I need to fix Address::isMatch as well, so that it works correctly for the StaticL2. The rest looked good to me as they all use suffix '%' matching.

[fabianx-ai]

And overall a 'bin' is as far as I can see an arbitrary concept in lcache. In the end its just the prefix of an address.

So logically there should be no difference from a:

'cache_fabian' bin vs. a 'cache:fabian' bin

if looking at it from the standpoint of an address.

[fabianx-ai]

Indeed that might be another way to fix this easier.

Just use the prefix as a 'bin', which lcache does not know anyway.

[fabianx-ai]

Ah that won't work due to the bin prefix string.

[davidstrauss]

I would prefer to make the wildcard -> full bin conversion occur only in the Drupal module/include layer. It looks like the vendor directory got committed here, which is not correct. (I didn't set up the D7 GitHub repo but will fix it.) I would, instead, update the .inc file's factory for LCache\Address to set a wildcard to have a null $key.

[fabianx-ai]

Yeah, need the wildcard support in Address class; just tested.

[fabianx-ai]

@davidstrauss Any chance you can chat quickly on IRC / freenode.net?

[fabianx-ai]

@davidstrauss The repo is fine, I am working on an emergency project, so committed vendor dir as a quick way to activate it.