PriorityCache

Stores a maximum number of items keeping only items with the highest priority.

class PriorityCache : ICacheInfo (

T

) {

import ocean.core.Verify;;

struct CacheItem;

uint n_lookups;

uint n_misses;

this(size_t max_items);

T* get(hash_t key, bool track_misses);

T* getOrCreate(hash_t key, ulong priority, bool existed, bool tracK_get_miss);

T* getUpdateOrCreate(hash_t key, ulong priority, bool existed, bool tracK_get_miss);

T* updatePriority(hash_t key, ulong new_priority, bool tracK_get_miss);

T* getPriority(hash_t key, ulong priority);

bool exists(hash_t key);

bool remove(hash_t key);

T* getHighestPriorityItem(hash_t key, ulong priority);

T* getLowestPriorityItem(hash_t key, ulong priority);

alias ForeachDg = int delegate(ref hash_t key, ref T item, ref ulong priority);

int opApply(ForeachDg dg);

int opApplyReverse(ForeachDg dg);

void clear();

size_t length();

size_t max_length();

uint num_lookups();

uint num_misses();

void resetStats();

void itemDropped(hash_t key, T value);

bool whenNewAndLeastPriority(ulong new_item_lowest_priority, ulong current_lowest_priority);

}

Constructors

this this(size_t max_items): Constructor.

Members

Aliases

ForeachDg alias ForeachDg = int delegate(ref hash_t key, ref T item, ref ulong priority): The signature for the delegate to be used in a foreach loop:

Functions

clear void clear(): Removes all items from the cache.
exists bool exists(hash_t key): Checks whether an item exists in the cache.
get T* get(hash_t key, bool track_misses): Obtains the item that corresponds a key. Returns null if the key doesn't exist.
getHighestPriorityItem T* getHighestPriorityItem(hash_t key, ulong priority): Returns the item with highest priority.
getLowestPriorityItem T* getLowestPriorityItem(hash_t key, ulong priority): Returns the item with lowest priority.
getOrCreate T* getOrCreate(hash_t key, ulong priority, bool existed, bool tracK_get_miss): Get an item with a given key if it already existed or creates a new item with the given priority if it didn't exist.
getPriority T* getPriority(hash_t key, ulong priority): Retrieves an item's priority if it exists.
getUpdateOrCreate T* getUpdateOrCreate(hash_t key, ulong priority, bool existed, bool tracK_get_miss): Updates the priority of an item if it already existed or creates a new item with the given priority if it didn't exist.
itemDropped void itemDropped(hash_t key, T value): A notifier which is fired and an item is removed from the cache.
length size_t length()
max_length size_t max_length()
num_lookups uint num_lookups()
num_misses uint num_misses()
opApply int opApply(ForeachDg dg): A foreach-iterator for iterating over the items in the tree.
opApplyReverse int opApplyReverse(ForeachDg dg): A foreach-iterator for iterating over the items in the tree.
remove bool remove(hash_t key): Removes an item from the cache.
resetStats void resetStats(): Resets the statistics counter values.
updatePriority T* updatePriority(hash_t key, ulong new_priority, bool tracK_get_miss): Updates an existing item's priority.
whenNewAndLeastPriority bool whenNewAndLeastPriority(ulong new_item_lowest_priority, ulong current_lowest_priority): Called by attemptCreateNode() when the cache is full and the new item to be added has a lower priority than the already existing lowest priority item. The method decides which of the two items should be stored.

Structs

CacheItem struct CacheItem: A wrapper around the stored item

Variables

n_lookups uint n_lookups;
n_misses uint n_misses;: Counters for the cache lookups and misses.

Inherited Members

From ICacheInfo

max_length size_t max_length()
length size_t length()
num_lookups uint num_lookups()
num_misses uint num_misses()
resetStats void resetStats(): Resets the statistics counter values.

Meta

Source

See Implementation

ocean util container cache PriorityCache classes

PriorityCache