Package org.opencms.flex

Class CmsFlexCacheEntry

  • All Implemented Interfaces:
    I_CmsLruCacheObject, I_CmsMemoryMonitorable
    public class CmsFlexCacheEntry
extends java.lang.Object
implements I_CmsLruCacheObject, I_CmsMemoryMonitorable
    Contains the contents of a cached resource.

    It is basically a list of pre-generated output, include() calls to other resources (with request parameters) and http headers that this resource requires to be set.

    A CmsFlexCacheEntry might also describe a redirect-call, but in this case nothing else will be cached.

    The pre-generated output is saved in byte[] arrays. The include() calls are saved as Strings of the included resource name, the parameters for the calls are saved in a HashMap. The headers are saved in a HashMap. In case of a redirect, the redirect target is cached in a String.

    The CmsFlexCacheEntry can also have an expire date value, which indicates the time that his entry will become invalid and should thus be cleared from the cache.

    Since:
    6.0.0
    See Also:
    I_CmsLruCacheObject

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static int INITIAL_CAPACITY_LISTS
      Initial size for lists.

    • Constructor Summary

      Constructors 
      Constructor Description
      CmsFlexCacheEntry()
      Constructor for class CmsFlexCacheEntry.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void add​(byte[] bytes)
      Adds an array of bytes to this cache entry, this will usually be the result of some kind of output - stream.
      void add​(java.lang.String resource, java.util.Map<java.lang.String,​java.lang.String[]> parameters, java.util.Map<java.lang.String,​java.lang.Object> attrs)
      Add an include - call target resource to this cache entry.
      void addHeaders​(java.util.Map<java.lang.String,​java.util.List<java.lang.String>> headers)
      Add a map of headers to this cache entry, which are usually collected in the class CmsFlexResponse first.
      void addToLruCache()
      Invoked after an object was added to the cache.
      void complete()
      Completes this cache entry.
      java.util.List<java.lang.Object> elements()
      Returns the list of data entries of this cache entry.
      CmsFlexBucketConfiguration.BucketSet getBucketSet()
      Gets the bucket set for this flex cache entry (may be null).
      long getDateExpires()
      Returns the expiration date of this cache entry, this is set to the time when the entry becomes invalid.
      long getDateLastModified()
      Returns the "last modified" date for this Flex cache entry.
      int getLruCacheCosts()
      Returns the cache costs of this object, as for example it's byte size.
      int getMemorySize()
      Returns the memory size of the object.
      I_CmsLruCacheObject getNextLruObject()
      Returns the next object in the double linked list of all cached objects.
      I_CmsLruCacheObject getPreviousLruObject()
      Returns the previous object in the double linked list of all cached objects.
      java.lang.Object getValue()
      Returns the Object value.
      void limitDateExpires​(long limit)
      Ensures that the expiration date is at most 'limit'.
      void removeFromLruCache()
      Invoked after the object was removed to the cache.
      void service​(CmsFlexRequest req, CmsFlexResponse res)
      Processing method for this cached entry.
      void setBucketSet​(CmsFlexBucketConfiguration.BucketSet bucketSet)
      Sets the bucket set for this flex cache entry.
      void setDateExpires​(long dateExpires)
      Sets the expiration date of this Flex cache entry exactly to the given time.
      void setDateExpiresToNextTimeout​(long timeout)
      Sets an expiration date for this cache entry to the next timeout, which indicates the time this entry becomes invalid.
      void setDateLastModified​(long dateLastModified)
      Sets the "last modified" date for this Flex cache entry with the given value.
      void setDateLastModifiedToPreviousTimeout​(long timeout)
      Sets the "last modified" date for this Flex cache entry by using the last passed timeout value.
      void setNextLruObject​(I_CmsLruCacheObject theNextEntry)
      Set the next object in the double linked list of all cached objects.
      void setPreviousLruObject​(I_CmsLruCacheObject thePreviousEntry)
      Set the previous object in the double linked list of all cached objects.
      void setRedirect​(java.lang.String target, boolean permanent)
      Set a redirect target for this cache entry.
      void setVariationData​(java.lang.String theVariationKey, java.util.Map<java.lang.String,​I_CmsLruCacheObject> theVariationMap)
      Stores a backward reference to the map and key where this cache entry is stored.
      java.lang.String toString()  

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

    • Constructor Detail

      • CmsFlexCacheEntry

        public CmsFlexCacheEntry()
        Constructor for class CmsFlexCacheEntry.

        The way to use this class is to first use this empty constructor and later add data with the various add methods.

    • Method Detail

      • add

        public void add​(byte[] bytes)
        Adds an array of bytes to this cache entry, this will usually be the result of some kind of output - stream.

        Parameters:
        bytes - the output to save in the cache

      • add

        public void add​(java.lang.String resource,
                java.util.Map<java.lang.String,​java.lang.String[]> parameters,
                java.util.Map<java.lang.String,​java.lang.Object> attrs)
        Add an include - call target resource to this cache entry.

        Parameters:
        resource - a name of a resource in the OpenCms VFS
        parameters - a map of parameters specific to this include call
        attrs - a map of request attributes specific to this include call

      • addHeaders

        public void addHeaders​(java.util.Map<java.lang.String,​java.util.List<java.lang.String>> headers)
        Add a map of headers to this cache entry, which are usually collected in the class CmsFlexResponse first.

        Parameters:
        headers - the map of headers to add to the entry

      • complete

        public void complete()
        Completes this cache entry.

        A completed cache entry is made "unmodifiable", so that no further data can be added and existing data can not be changed.

        This is to prevent the (unlikely) case that some user-written class tries to make changes to a cache entry.

      • elements

        public java.util.List<java.lang.Object> elements()
        Returns the list of data entries of this cache entry.

        Data entries are byte arrays representing some kind of output or Strings representing include calls to other resources.

        Returns:
        the list of data elements of this cache entry

      • getDateExpires

        public long getDateExpires()
        Returns the expiration date of this cache entry, this is set to the time when the entry becomes invalid.

        Returns:
        the expiration date value for this resource

      • getDateLastModified

        public long getDateLastModified()
        Returns the "last modified" date for this Flex cache entry.

        Returns:
        the "last modified" date for this Flex cache entry

      • limitDateExpires

        public void limitDateExpires​(long limit)
        Ensures that the expiration date is at most 'limit'.
        Parameters:
        limit - the maximum allowed expiration date

      • service

        public void service​(CmsFlexRequest req,
                    CmsFlexResponse res)
             throws CmsFlexCacheException,
                    javax.servlet.ServletException,
                    java.io.IOException
        Processing method for this cached entry.

        If this method is called, it delivers the contents of the cached entry to the given request / response. This includes calls to all included resources.

        Parameters:
        req - the request from the client
        res - the server response
        Throws:
        CmsFlexCacheException - is thrown when problems writing to the response output-stream occur
        javax.servlet.ServletException - might be thrown from call to RequestDispatcher.include()
        java.io.IOException - might be thrown from call to RequestDispatcher.include() or from Response.sendRedirect()

      • setDateExpires

        public void setDateExpires​(long dateExpires)
        Sets the expiration date of this Flex cache entry exactly to the given time.

        Parameters:
        dateExpires - the time to expire this cache entry

      • setDateExpiresToNextTimeout

        public void setDateExpiresToNextTimeout​(long timeout)
        Sets an expiration date for this cache entry to the next timeout, which indicates the time this entry becomes invalid.

        The timeout parameter represents the minute - interval in which the cache entry is to be cleared. The interval always starts at 0.00h. A value of 60 would indicate that this entry will reach it's expiration date at the beginning of the next full hour, a timeout of 20 would indicate that the entry is invalidated at x.00, x.20 and x.40 of every hour etc.

        Parameters:
        timeout - the timeout value to be set

      • setDateLastModified

        public void setDateLastModified​(long dateLastModified)
        Sets the "last modified" date for this Flex cache entry with the given value.

        Parameters:
        dateLastModified - the value to set for the "last modified" date

      • setDateLastModifiedToPreviousTimeout

        public void setDateLastModifiedToPreviousTimeout​(long timeout)
        Sets the "last modified" date for this Flex cache entry by using the last passed timeout value.

        If a cache entry uses the timeout feature, it becomes invalid every time the timeout interval passes. Thus the "last modified" date is the time the last timeout passed.

        Parameters:
        timeout - the timeout value to use to calculate the date last modified

      • setRedirect

        public void setRedirect​(java.lang.String target,
                        boolean permanent)
        Set a redirect target for this cache entry.

        Important: When a redirect target is set, all saved data is thrown away, and new data will not be saved in the cache entry. This is so since with a redirect nothing will be displayed in the browser anyway, so there is no point in saving the data.

        Parameters:
        target - The redirect target (must be a valid URL).
        permanent - true if this is a permanent redirect

      • setVariationData

        public void setVariationData​(java.lang.String theVariationKey,
                             java.util.Map<java.lang.String,​I_CmsLruCacheObject> theVariationMap)
        Stores a backward reference to the map and key where this cache entry is stored.

        This is required for the FlexCache.

        Parameters:
        theVariationKey - the variation key
        theVariationMap - the variation map

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object
        Returns:
        a basic String representation of this CmsFlexCache entry
        See Also:
        Object.toString()