NearCache

lru_cmp(x, y)

Least recently used comparison.

Parameters:

• x – (DataRecord), first record to be compared.
• y – (DataRecord), second record to be compared.

Returns:

(int), -1 if first record is older, 0 if records have same last access time, 1 if second record is older.

lfu_cmp(x, y)

Least frequently used comparison.

Parameters:

• x – (DataRecord), first record to be compared.
• y – (DataRecord), second record to be compared.

Returns:

(int), positive if first record is accessed more than second, 0 in equality, otherwise negative.

random_cmp(x, y)

Random comparison.

Parameters:

• x – (DataRecord), first record to be compared.
• y – (DataRecord), second record to be compared.

Returns:

(int), 0.

class DataRecord(key, value, create_time=None, ttl_seconds=None)

Bases: object

An expirable and evictable data object which represents a cache entry.

is_expired(max_idle_seconds)

Determines whether this record is expired or not.

Parameters:max_idle_seconds – (long), the maximum idle time of record, maximum time after the last access time. Returns:(bool), true is this record is not expired.

class NearCache(serialization_service, in_memory_format, time_to_live_seconds, max_idle_seconds, invalidate_on_change, eviction_policy, eviction_max_size, eviction_sampling_count=None, eviction_sampling_pool_size=None)

Bases: dict

NearCache is a local cache used by MapFeatNearCache.

logger = <logging.Logger object>

get_statistics()

Returns the statistics of the NearCache. :return: (Number, Number), evicted entry count and expired entry count.