Package jline.lang.nodes

Class Cache

  • All Implemented Interfaces:
    java.io.Serializable , jline.lang.Copyable 
    public class Cache
extends StatefulNode implements Serializable

    A cache node that implements cache replacement policies and class switching based on cache hits and misses.

    The Cache node models a caching system where incoming jobs request items from a finite cache. When a requested item is found in the cache (hit), the job may be routed to one class; when the item is not found (miss), it may be routed to a different class. This enables modeling of cache-aware queueing networks where performance depends on cache hit rates.

    Key features:

    • Multi-level cache support with configurable capacity per level
    • Various replacement strategies (LRU, FIFO, RANDOM, etc.)
    • Popularity-based item access patterns (e.g., Zipf distribution)
    • Class switching based on hit/miss outcomes
    • Optional graph-based cache structures
    Since:

    1.0

    • Constructor Detail

      • Cache

        Cache(Network model, String name, int nitems, int itemLevelCap, ReplacementStrategy replPolicy)
        Creates a single-level cache with the specified item capacity and replacement policy.
        Parameters:
        model - The network model this cache belongs to
        name - The name of the cache node
        nitems - The total number of items that can be requested from this cache
        itemLevelCap - The capacity of the cache (number of items it can hold)
        replPolicy - The replacement strategy to use when the cache is full

      • Cache

        Cache(Network model, String name, int nitems, int itemLevelCap, ReplacementStrategy replPolicy, Array<Matrix> graph)
        Creates a single-level cache with the specified item capacity, replacement policy, and graph structure.
        Parameters:
        model - The network model this cache belongs to
        name - The name of the cache node
        nitems - The total number of items that can be requested from this cache
        itemLevelCap - The capacity of the cache (number of items it can hold)
        replPolicy - The replacement strategy to use when the cache is full
        graph - Optional graph structure defining cache organization

      • Cache

        Cache(Network model, String name, int nitems, Matrix itemLevelCap, ReplacementStrategy replPolicy)
        Creates a multi-level cache with different capacities per level and a replacement policy.
        Parameters:
        model - The network model this cache belongs to
        name - The name of the cache node
        nitems - The total number of items that can be requested from this cache
        itemLevelCap - A matrix specifying the capacity of each cache level
        replPolicy - The replacement strategy to use when the cache is full

      • Cache

        Cache(Network model, String name, int nitems, Matrix itemLevelCap, ReplacementStrategy replPolicy, Array<Matrix> graph)
        Creates a multi-level cache with different capacities per level, replacement policy, and graph structure.
        Parameters:
        model - The network model this cache belongs to
        name - The name of the cache node
        nitems - The total number of items that can be requested from this cache
        itemLevelCap - A matrix specifying the capacity of each cache level
        replPolicy - The replacement strategy to use when the cache is full
        graph - Optional graph structure defining cache organization

    • Method Detail

      • getItems

         ItemSet getItems()

        Gets the set of items that can be stored in this cache.

        Returns:

        The ItemSet object managing the cache items

      • getItemLevelCap

         Matrix getItemLevelCap()

        Gets the capacity configuration for each cache level.

        Returns:

        A matrix where each element specifies the item capacity of a cache level

      • getGraph

         Array<Matrix> getGraph()

        Gets the graph structure defining the cache organization.

        Returns:

        Array of matrices representing the cache graph structure, or null if not defined

      • getCacheServer

         CacheClassSwitcher getCacheServer()

        Gets the internal cache server that handles class switching logic.

        Returns:

        The CacheClassSwitcher instance managing hit/miss class transitions

      • getAccessProb

         Matrix getAccessProb(int i, int j)

        Gets the access probability matrix for a specific cache level and job class.

        Parameters:
        i - The cache level index
        j - The job class index
        Returns:

        The access probability matrix for the specified indices

      • getHitClass

         Matrix getHitClass()

        For an incoming job of class r, HITCLASS[r] is the new class of that job after a hit

        Returns:

        - the matrix of hit classes

      • getHitRatio

         Matrix getHitRatio()

        Gets the actual hit probability/ratio for each job class.

        This returns the observed hit rates from simulation or analysis, not the theoretical expected values.

        Returns:

        A matrix containing the hit ratio for each job class

      • getMissClass

         Matrix getMissClass()

        For an incoming job of class r, MISSCLASS[r] is the new class of that job after a miss

        Returns:

        - the matrix of miss classes

      • getMissRatio

         Matrix getMissRatio()

        Gets the actual miss probability/ratio for each job class.

        This returns the observed miss rates from simulation or analysis, not the theoretical expected values.

        Returns:

        A matrix containing the miss ratio for each job class

      • getNumberOfItems

         int getNumberOfItems()

        Gets the total number of items that can be requested from this cache.

        Returns:

        The number of distinct items in the item set

      • getSections

         List<Section> getSections()

        Gets the internal sections of this cache node.

        Returns the three main sections: input buffer, cache server, and output dispatcher.

        Returns:

        A list containing the input, server, and output sections

      • getnLevels

         int getnLevels()

        Gets the number of cache levels.

        Returns:

        The number of levels in this multi-level cache

      • popularityGet

         Distribution popularityGet(int i)

        Gets the popularity distribution for a linear index.

        Converts a linear index to 2D coordinates and retrieves the distribution.

        Parameters:
        i - The linear index
        Returns:

        The popularity distribution at the specified index

      • popularityGet

         Distribution popularityGet(int i, int j)

        Gets the popularity distribution for a specific item class and job class.

        Parameters:
        i - The item class index
        j - The job class index
        Returns:

        The popularity distribution, or null if not set

      • popularityLength

         int popularityLength()

        Gets the maximum dimension of the popularity matrix.

        Returns:

        The maximum of rows and columns in the popularity matrix

      • popularitySet

         void popularitySet(int i, Distribution o)

        Sets the popularity distribution for a linear index.

        Converts a linear index to 2D coordinates and sets the distribution.

        Parameters:
        i - The linear index
        o - The popularity distribution to set

      • popularitySet

         void popularitySet(int i, int j, Distribution o)

        Sets the popularity distribution for a specific item class and job class.

        Automatically expands the popularity matrix dimensions if necessary.

        Parameters:
        i - The item class index
        j - The job class index
        o - The popularity distribution to set

      • reset

         void reset()

        Resets the internal data structures when the network model is reset.

        Clears the actual hit and miss probability matrices to prepare for a new simulation or analysis run.

      • setAccessProb

         void setAccessProb(Array<Array<Matrix>> R)

        Sets the access probability matrices for all cache levels and job classes.

        Parameters:
        R - A 2D array of matrices containing access probabilities

      • setHitClass

         void setHitClass(JobClass jobinclass, JobClass joboutclass)

        Sets the output class for jobs that experience a cache hit.

        When a job of class jobinclass hits in the cache, it will be transformed to class joboutclass.

        Parameters:
        jobinclass - The incoming job class
        joboutclass - The job class after a cache hit

      • setMissClass

         void setMissClass(JobClass jobinclass, JobClass joboutclass)

        Sets the output class for jobs that experience a cache miss.

        When a job of class jobinclass misses in the cache, it will be transformed to class joboutclass.

        Parameters:
        jobinclass - The incoming job class
        joboutclass - The job class after a cache miss

      • setProbRouting

         void setProbRouting(JobClass jobClass, Node destination, double probability)

        Sets probabilistic routing for a job class to a destination node.

        Parameters:
        jobClass - The job class to configure routing for
        destination - The destination node
        probability - The routing probability

      • setRead

         void setRead(JobClass jobClass, Distribution distribution)

        Sets the read policy for a job class using a popularity distribution.

        The distribution determines which items are requested by jobs of this class. Common distributions include Zipf for modeling popularity skew.

        Parameters:
        jobClass - The job class to configure
        distribution - The discrete popularity distribution over items

      • setReadItemEntry

         void setReadItemEntry(JobClass jobClass, Distribution popularity, int cardinality)

        Sets the read policy for a job class with explicit item cardinality.

        Similar to setRead but allows specifying the number of items explicitly, useful when the distribution needs to be configured with a specific cardinality.

        Parameters:
        jobClass - The job class to configure
        popularity - The discrete popularity distribution
        cardinality - The number of items in the distribution support

      • setResultHitProb

         void setResultHitProb(Matrix actualHitProb)

        Sets the actual hit probabilities from simulation or analysis results.

        Parameters:
        actualHitProb - Matrix containing the observed hit probabilities

      • setResultMissProb

         void setResultMissProb(Matrix actualMissProb)

        Sets the actual miss probabilities from simulation or analysis results.

        Parameters:
        actualMissProb - Matrix containing the observed miss probabilities

      • setScheduling

         void setScheduling(int jobClass, SchedStrategy strategy)

        Sets the scheduling strategy for a job class.

        Note: Currently this method has no implementation as caches use FCFS scheduling.

        Parameters:
        jobClass - The job class index
        strategy - The scheduling strategy (unused)