Add-on:Common plugin cache

Common plugin cache

See this add-on on the kodi.tv showcase Author: TheCollective Type: Services Repo: Kodi.tv repo v21 Kodi.tv repo v20 Summary: Common caching api for xbmc plugins.

Add-ons

Common plugin cache

Installing

This add-on is installed from the Add-on browser located in Kodi as follows:

1. Settings
2. Add-ons
3. Install from repository
4. Services
5. Common plugin cache
6. Install

Developers

This service works as an independant storage server to XBMC's implementation.

It provides proper thread safe locking and storage management.

Testing/Status

Integration and unittests are run continously by Jenkins

http://tc.tobiasussing.dk/jenkins/view/Cache%20Service/

Setup

To use the cacheing service add the following to your py file.

 try:
   import StorageServer
 except:
   import storageserverdummy as StorageServer
 cache = StorageServer.StorageServer()
 cache.table_name = "PluginName" # Name of your plugin.

You can now access the caching service through the "cache" variable.

Remember to include a fallback storageserverdummy.py file.

Debugging

To enable debugging set the following values in default.py

dbg = True # Default

Or you can change it after import with.

common.dbg = True # Default

Whenever you debug your own code you should also debug in the cache. Otherwise you should remember to DISABLE it.

cacheFunction(self, funct = False, *args)

Caching function results for one hour.

The function being cached must return a tupple ( function_return, status), a status of 200 means the result is ok and should be cached. Any other value and the function result will be returned, but not cached.

returns a tupple of the results from the function called.

 def pi_count(self):
     def arccot(x, unity):
         sum = xpower = unity // x
         n = 3
         sign = -1
         while 1:
               xpower = xpower // (x*x)
               term = xpower // n
               if not term:
                       break
               sum += sign * term
               sign = -sign
               n += 2
         return sum
  
     digits = 40
     unity = 10**(digits + 10)
     pi = 4 * (4*arccot(5, unity) - arccot(239, unity))
     return (pi // 10**10, 200)
 
 cache.table_name = "PluginName" # Name of your plugni.
 result = cache.cacheFunction(pi_count) # This will call the pi_count function, save the result in the cache, and return the result.
 time.sleep(300)
 result = cache.cacheFunction(pi_count) # This will return the cached result
 time.sleep(3600)
 result = cache.cacheFunction(pi_count) # This will again call pi_count since the result is now considered stale.

lock(self, str)

Try to aquire a lock

Returns bool

 cache.table_name = "PluginName"
 locked = cache.lock("lock_me") # Returns True
 if locked:
   print "Got lock"

 new_lock = cache.lock("lock_me") # Returns False
 if not new_lock:
   print "Couldn't aquire second lock.

unlock(self, str)

Unlock

Returns bool

 cache.table_name = "PluginName"
 lock = cache.lock("lock_me") # Returns True

 unlocked = cache.unlock("lock_me") # Returns True
 if unlocked:
   print "Discarded lock"

 new_unlocked = cache.unlock("lock_me") # Returns False
 if not new_unlocked:
   print "Couldn't discard lock."

set(self, str, object )

Store a value

Returns nothing

 cache.table_name = "PluginName"
 cache.set("some_string", "string")
 cache.set("some_int", 1234)
 cache.set("some_dict", { "our": { "dictionary": [] } } )

setMulti(self, str, dict)

Store multiple values

Returns nothing

 cache.table_name = "PluginName"

 save_data = { "some_string": "string", "some_int": 1234, "some_dict": { "our": { "dictionary": [] } } }
 cache.setMulti("pre-", save_data)

get(self, str)

Get a value

Returns stored data.

 cache.table_name = "PluginName"
 cache.set("some_string", "string")
 cache.set("some_int", 1234)
 cache.set("some_dict", { "our": { "dictionary": [] } } )

 some_string = cache.get("some_string")
 print some_string # Prints "string"

 some_int = cache.get("some_int")
 print some_int # prints 1234

 some_dict = cache.get("some_dict")
 print repr(some_dict) # prints '{ "our": { "dictionary": [] } }'

getMulti(self, str, list)

Get multiple values

Retuns list of stored data elements.

 cache.table_name = "PluginName"

 save_data = { "some_string": "string", "some_int": 1234, "some_dict": { "our": { "dictionary": [] } } }
 cache.setMulti("pre-", save_data)

 get_list = [ "some_string", "some_int", "some_dict" ]
 result = cache.getMulti("pre-", get_list)
 print result[0] # Prints "string"
 print result[1] # Prints 1234
 print repr(result[2]) # Prints '{ "our": { "dictionary": [] } }'