SubstitutionPolicies enum

Represents the substitution policies available for cache management.

These policies determine how items in a cache are replaced when the cache reaches its capacity and a new item needs to be added. Each policy has its own strategy for selecting which item to remove from the cache.

The policies are:

  • fifo: First In, First Out. Entries are removed in the same order they were added, akin to a queue.
  • random: A random entry is selected for removal. This policy does not necessarily consider the use or order of entries.
  • lru: Least Recently Used. The entry that has not been accessed for the longest time is removed first. This policy prioritizes keeping entries that are accessed more frequently and is commonly used in caching systems to improve hit rates.
  • mru: Most Recently Used. The entry that was most recently accessed is removed first. This policy assumes that the most recently used entries are less likely to be accessed again soon compared to entries that have not been accessed for a while.
Inheritance
Available extensions

Values

fifo → const SubstitutionPolicies

First In, First Out (FIFO) policy.

Entries are removed in the same order they were added, akin to a queue. This means that the oldest entry (the first one that was added and has not yet been removed) is the first to be removed when making space for a new entry.

random → const SubstitutionPolicies

Random replacement policy.

A random entry is selected for removal without considering the order of entries or how frequently they have been accessed. This policy is the simplest in terms of implementation and computational overhead but may not always provide the best performance in terms of cache hit rate.

lru → const SubstitutionPolicies

Least Recently Used (LRU) policy.

The entry that has not been accessed for the longest time is removed first. This policy helps to ensure that frequently accessed entries remain in the cache while less frequently used entries are evicted, thus potentially improving cache performance by prioritizing entries that are more likely to be accessed again soon.

mru → const SubstitutionPolicies

Most Recently Used (MRU) policy.

The entry that was most recently accessed is removed first. This policy assumes that the most recently used entries are less likely to be accessed again soon compared to entries that have not been accessed for a while. It can be useful in certain scenarios where the most recent accesses are deemed to be less important than older ones.

Properties

hashCode → int
The hash code for this object.
no setterinherited
index → int
A numeric identifier for the enumerated value.
no setterinherited
name → String

Available on Enum, provided by the EnumName extension

The name of the enum value.
no setter
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited

Constants

values → const List<SubstitutionPolicies>
A constant List of the values in this enum, in order of their declaration.