large_image.cache_util package

Submodules

large_image.cache_util.base module

class large_image.cache_util.base.BaseCache(*args, getsizeof=None, **kwargs)[source]

Bases: Cache

Base interface to cachetools.Cache for use with large-image.

clear() None.  Remove all items from D.[source]
property curritems
property currsize

The current size of the cache.

static getCache() Tuple[BaseCache, allocate_lock][source]
logError(err, func, msg)[source]

Log errors, but throttle them so as not to spam the logs.

Parameters
  • err – error to log.

  • func – function to use for logging. This is something like logprint.exception or logger.error.

  • msg – the message to log.

property maxsize

The maximum size of the cache.

large_image.cache_util.cache module

class large_image.cache_util.cache.LruCacheMetaclass(name, bases, namespace, **kwargs)[source]

Bases: type

classCaches = {}
namedCaches = {}
large_image.cache_util.cache.getTileCache()[source]

Get the preferred tile cache and lock.

Returns

tileCache and tileLock.

large_image.cache_util.cache.isTileCacheSetup()[source]

Return True if the tile cache has been created.

Returns

True if _tileCache is not None.

large_image.cache_util.cache.methodcache(key=None)[source]

Decorator to wrap a function with a memoizing callable that saves results in self.cache. This is largely taken from cachetools, but uses a cache from self.cache rather than a passed value. If self.cache_lock is present and not none, a lock is used.

Parameters

key – if a function, use that for the key, otherwise use self.wrapKey.

large_image.cache_util.cache.strhash(*args, **kwargs)[source]

Generate a string hash value for an arbitrary set of args and kwargs. This relies on the repr of each element.

Parameters
  • args – arbitrary tuple of args.

  • kwargs – arbitrary dictionary of kwargs.

Returns

hashed string of the arguments.

large_image.cache_util.cachefactory module

class large_image.cache_util.cachefactory.CacheFactory[source]

Bases: object

getCache(numItems=None, cacheName=None, inProcess=False)[source]
getCacheSize(numItems, cacheName=None)[source]
logged = False
large_image.cache_util.cachefactory.getFirstAvailableCache()[source]
large_image.cache_util.cachefactory.loadCaches(entryPointName='large_image.cache', sourceDict={})[source]

Load all caches from entrypoints and add them to the availableCaches dictionary.

Parameters
  • entryPointName – the name of the entry points to load.

  • sourceDict – a dictionary to populate with the loaded caches.

large_image.cache_util.cachefactory.pickAvailableCache(sizeEach, portion=8, maxItems=None, cacheName=None)[source]

Given an estimated size of an item, return how many of those items would fit in a fixed portion of the available virtual memory.

Parameters
  • sizeEach – the expected size of an item that could be cached.

  • portion – the inverse fraction of the memory which can be used.

  • maxItems – if specified, the number of items is never more than this value.

  • cacheName – if specified, the portion can be affected by the configuration.

Returns

the number of items that should be cached. Always at least two, unless maxItems is less.

large_image.cache_util.memcache module

class large_image.cache_util.memcache.MemCache(url='127.0.0.1', username=None, password=None, getsizeof=None, mustBeAvailable=False)[source]

Bases: BaseCache

Use memcached as the backing cache.

clear() None.  Remove all items from D.[source]
property curritems
property currsize

The current size of the cache.

static getCache() Tuple[MemCache, allocate_lock][source]
property maxsize

The maximum size of the cache.

Module contents

class large_image.cache_util.CacheFactory[source]

Bases: object

getCache(numItems=None, cacheName=None, inProcess=False)[source]
getCacheSize(numItems, cacheName=None)[source]
logged = False
class large_image.cache_util.LruCacheMetaclass(name, bases, namespace, **kwargs)[source]

Bases: type

classCaches = {}
namedCaches = {}
class large_image.cache_util.MemCache(url='127.0.0.1', username=None, password=None, getsizeof=None, mustBeAvailable=False)[source]

Bases: BaseCache

Use memcached as the backing cache.

clear() None.  Remove all items from D.[source]
property curritems
property currsize

The current size of the cache.

static getCache() Tuple[MemCache, allocate_lock][source]
property maxsize

The maximum size of the cache.

large_image.cache_util.getTileCache()[source]

Get the preferred tile cache and lock.

Returns

tileCache and tileLock.

large_image.cache_util.isTileCacheSetup()[source]

Return True if the tile cache has been created.

Returns

True if _tileCache is not None.

large_image.cache_util.methodcache(key=None)[source]

Decorator to wrap a function with a memoizing callable that saves results in self.cache. This is largely taken from cachetools, but uses a cache from self.cache rather than a passed value. If self.cache_lock is present and not none, a lock is used.

Parameters

key – if a function, use that for the key, otherwise use self.wrapKey.

large_image.cache_util.pickAvailableCache(sizeEach, portion=8, maxItems=None, cacheName=None)[source]

Given an estimated size of an item, return how many of those items would fit in a fixed portion of the available virtual memory.

Parameters
  • sizeEach – the expected size of an item that could be cached.

  • portion – the inverse fraction of the memory which can be used.

  • maxItems – if specified, the number of items is never more than this value.

  • cacheName – if specified, the portion can be affected by the configuration.

Returns

the number of items that should be cached. Always at least two, unless maxItems is less.

large_image.cache_util.strhash(*args, **kwargs)[source]

Generate a string hash value for an arbitrary set of args and kwargs. This relies on the repr of each element.

Parameters
  • args – arbitrary tuple of args.

  • kwargs – arbitrary dictionary of kwargs.

Returns

hashed string of the arguments.