fix cache and generate short cache key

[ilaoniu]

Fix cache

The $cacheItem can only be null or boolean value, so $cacheItem->get() method call will throw an exception and be caught by the outer try catch code block, the cache will not work normally.

Shorter cache key

When use database as cache driver, the cache key is too long(500 chars), with md5 it can be limited to 50 chars.

Cache TTL

When use Redis or Memcached as cache driver, the cache can automatically expire, otherwise the memory usage will continue to increase.

[serbanghita]

The $cacheItem can only be null or boolean value

$cacheItem can only be CacheItem|null because $cacheKey is always a base64 string.
I don't understand what do you mean.

so $cacheItem->get() method call will throw an exception and be caught by the outer try catch code block, the cache will not work normally.

Indeed get() and set() can throw Unhandled \Psr\SimpleCache\InvalidArgumentException.
I think I need to handle and ignore the exception IF hypothetically the cache key is invalid.

When use database as cache driver, the cache key is too long(500 chars), with md5 it can be limited to 50 chars.

this is a good point, I guess I made it base64 because I wanted the debug aspect of it. I'd make this configurable, def I'd not go for md5 because of the collisions, but a sha1

When use Redis or Memcached as cache driver, the cache can automatically expire, otherwise the memory usage will continue to increase.

Agree on the cache TTL, good catch!

[serbanghita]

What I can do is:

1. add TTL config
2. make the encoding of the cache key configurable (so I can keep backwards compat)
3. address Unhandled \Psr\SimpleCache\InvalidArgumentException. I guess nobody wants their detection script to break because of faulty cache

I'll fork your PR and make these changes

[serbanghita]

@ilaoniu tests are failing

[ilaoniu]

Oh, you are right. There is no problem with calling $cacheItem->get().

[serbanghita]

@ilaoniu thank you!
I've merged it

I've added tests and made the config option cacheKeyFn, by default it's base64