Invalidating Inconsistencies

[XedinUnknown]

In a few places on the page about invalidation, it says that the invalidation method is set by passing additional values to "Item->get", such as:

Defining which method to use done by passing an Invalidation constant to the Item->get() class when it retrieves it's value

There's also a mistake there, calling a method a class. In other instances, the method doesn't have parentheses at the end, such as here:

When this method is used Item->get takes one additional argument

In the examples no additional values are passed to that method. Instead, a method not mentioned before is invoked, such as:

$userInfo->setInvalidationMethod(Stash\Invalidation::OLD);

I still cannot understand how to control invalidation because of this. Also, you may want to replace things like "Item->get" with ItemInterface#get(), e.g. including proper inline code and displaying it as such.

[alexbowers]

We just ran across this issue at work.

I will have an attempt at rewriting some documentation soon.

Any help would be appreciated.

Feedback / thoughts @tedivm @XedinUnknown .

Thanks.

[alexbowers]

The issue we ran across was how to actually change invalidation methods.

The documentation is completely wrong in this regard.

<?php
    $item = $pool->getItem('Test');

// Get the data from the cache using the "Invalidation::OLD" technique for
// dealing with stampedes
$userInfo = $item->get();
$userInfo->setInvalidationMethod(Stash\Invalidation::OLD);

// Check to see if the cache missed, which could mean that it either didn't
// exist or was stale. If another process is regenerating this value and
// there is a stored value available then this function will return a hit.
if(!$item->isHit())
{
    // Mark this instance as the one regenerating the cache. Because our
    // protection method is Invalidation::OLD other Stash instances will
    // use the old value and count it as a hit.
    $item->lock();

    // Run the relatively expensive code.
    $userInfo = loadUserInfoFromDatabase($id);

    // Store the expensive code so the next time it doesn't miss. The store
    // function marks the stampede as over for now, so other Stash items
    // will begin working as normal.
    $pool->save($item->set($userInfo));

}

$userInfo is the variable containing the array (or whatever), that Redis has stored. It is not necessarily an object, and it is certainly not an object that is usable as a Stash instance.

I think this is supposed to be $item.