CMemcache doesn't allow me to delete cache id

Archives Yii 1.0.x Discussions
1

i need to manually unset/invalidate a fragment cache (i use $this->beginCache('left-menu', array('duration'=>86400)) to create the cache) with a specific id in some actions so i use:

$return = Yii::app()->cache->delete('MyKeyString');

…but the cache is not invalidate infact the delete() method always return false…why?

2

The cache key used by output cache is more complicated than the id you provide in beginCache()…

3

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The cache key used by output cache is more complicated than the id you provide in beginCache()...
sorry i didn't understand this....what do you mean?
4

I mean beginCache('left-menu') does not use 'left-menu' as the underlying cache key. It combines other information to implement cache variation.

5

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I mean beginCache('left-menu') does not use 'left-menu' as the underlying cache key. It combines other information to implement cache variation.
ok so how what is the right use? The manual says that we can set the key as a string and that we can delete/invalidate the cache passing that key string to the delete method....so how can i invalidate my cache?
6

You would have to have a way generate the key that Yii is generating when it sets the cache key.

I know for setting the item it's a combination of a prefix which is usually blank and then using md5 to generate the key that is stored. I discovered this when i was trying to view a item i cached as a test using telnet to connect to the daemon.

7

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You would have to have a way generate the key that Yii is generating when it sets the cache key.

I know for setting the item it's a combination of a prefix which is usually blank and then using md5 to generate the key that is stored. I discovered this when i was trying to view a item i cached as a test using telnet to connect to the daemon.

sorry i still don't understand. What is the purpose of the delete method if i cannot use it?
8

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I mean beginCache('left-menu') does not use 'left-menu' as the underlying cache key. It combines other information to implement cache variation.
so can you explain us how to clear/invalidate a cache setted with CController::beginCache() method knowing that i passed to that method a string as a cache key?
9

This is currently not possible. The reason is that: given your id, the actual key to the cache is calculated as func(id, other factors). The factors include GET parameters, session parameters, etc. As you can, a single ID may correspond to multiple cache entries.

We may considering adding a support to delete cache items based on partial match of cache keys. Could you please create a ticket for this? Thanks.

10

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This is currently not possible. The reason is that: given your id, the actual key to the cache is calculated as func(id, other factors). The factors include GET parameters, session parameters, etc. As you can, a single ID may correspond to multiple cache entries.

We may considering adding a support to delete cache items based on partial match of cache keys. Could you please create a ticket for this? Thanks.

mmm…so right now how can i delete a particular cache created with beginCache? Only setting a expire time or dependency check?
11

can you also explain me the purpose (and when we can use it) of the delete() method if i cannot use it to invalidate the cache?

12

The delete operation is used to delete a data item that you store directly via Yii::app()->cache->set() or add(). COutputCache is different because there may not be a one-to-one mapping between ID and the underlying cache key.

13

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The delete operation is used to delete a data item that you store directly via Yii::app()->cache->set() or add(). COutputCache is different because there may not be a one-to-one mapping between ID and the underlying cache key.
ok understand. So how i invalidate/delete a fragment cache? Only with expire time or dependecy check?
14

Yes, that's the only option right now.

15

You could try recaching the fragment and specify 1 for it's ttl.

That way after 1 sec it would expire.

Perhaps the fragment cache could be modified to return the encode key as stored in the cache

16

i tried:



 if($this->beginCache('myId', array('duration' => 3600) {





    // content to cache


    $this->endCache();





}

But with the help of the logs i see that the application doesn't cache 'cause everytime it executes the code in the if statement

17

Did you enable 'cache' component?

18

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Did you enable 'cache' component?
yes i got: 


 'cache'=>array(


                            'class'=>'system.caching.CMemCache',


                            'servers'=>array(array('host'=>'localhost', 'port'=>11211, 'weight'=>60)),


                 ),

in my config

19

I see no reason why this wouldn't work unless your memcache has problem. Try with a CDbCache?

20

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I see no reason why this wouldn't work unless your memcache has problem. Try with a CDbCache?
sorry you are right i didn't have the memcached daemon started :)