Package org.opencms.flex

Class CmsFlexCacheEntry

java.lang.Object
org.opencms.flex.CmsFlexCacheEntry
All Implemented Interfaces:
I_CmsLruCacheObject, I_CmsMemoryMonitorable
public class CmsFlexCacheEntry extends 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:

  • Field Details

  • Constructor Details

    • 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 Details

    • 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(String resource, Map<String,String[]> parameters, Map<String,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(Map<String,List<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

    • addToLruCache

      public void addToLruCache()
      Description copied from interface: I_CmsLruCacheObject
      Invoked after an object was added to the cache.

      Specified by:
      addToLruCache in interface I_CmsLruCacheObject
      See Also:

    • 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 List<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

    • getBucketSet

      public CmsFlexBucketConfiguration.BucketSet getBucketSet()
      Gets the bucket set for this flex cache entry (may be null).

      Returns:
      the bucket set for this flex 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

    • getLruCacheCosts

      public int getLruCacheCosts()
      Description copied from interface: I_CmsLruCacheObject
      Returns the cache costs of this object, as for example it's byte size.

      Specified by:
      getLruCacheCosts in interface I_CmsLruCacheObject
      Returns:
      the cache costs of this object
      See Also:

    • getMemorySize

      public int getMemorySize()
      Description copied from interface: I_CmsMemoryMonitorable
      Returns the memory size of the object.

      Specified by:
      getMemorySize in interface I_CmsMemoryMonitorable
      Returns:
      the memory size of the object
      See Also:

    • getNextLruObject

      public I_CmsLruCacheObject getNextLruObject()
      Description copied from interface: I_CmsLruCacheObject
      Returns the next object in the double linked list of all cached objects.

      Specified by:
      getNextLruObject in interface I_CmsLruCacheObject
      Returns:
      the next object in the double linked list of all cached objects
      See Also:

    • getPreviousLruObject

      public I_CmsLruCacheObject getPreviousLruObject()
      Description copied from interface: I_CmsLruCacheObject
      Returns the previous object in the double linked list of all cached objects.

      Specified by:
      getPreviousLruObject in interface I_CmsLruCacheObject
      Returns:
      the previous object in the double linked list of all cached objects
      See Also:

    • getValue

      public Object getValue()
      Description copied from interface: I_CmsLruCacheObject
      Returns the Object value.

      Specified by:
      getValue in interface I_CmsLruCacheObject
      Returns:
      the Object value
      See Also:

    • limitDateExpires

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

    • removeFromLruCache

      public void removeFromLruCache()
      Description copied from interface: I_CmsLruCacheObject
      Invoked after the object was removed to the cache.

      Specified by:
      removeFromLruCache in interface I_CmsLruCacheObject
      See Also:

    • service

      public void service(CmsFlexRequest req, CmsFlexResponse res) throws CmsFlexCacheException, javax.servlet.ServletException, 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()
      IOException - might be thrown from call to RequestDispatcher.include() or from Response.sendRedirect()

    • setBucketSet

      public void setBucketSet(CmsFlexBucketConfiguration.BucketSet bucketSet)
      Sets the bucket set for this flex cache entry.

      Parameters:
      bucketSet - the bucket set to set

    • 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

    • setNextLruObject

      public void setNextLruObject(I_CmsLruCacheObject theNextEntry)
      Description copied from interface: I_CmsLruCacheObject
      Set the next object in the double linked list of all cached objects.

      Specified by:
      setNextLruObject in interface I_CmsLruCacheObject
      Parameters:
      theNextEntry - the next object
      See Also:

    • setPreviousLruObject

      public void setPreviousLruObject(I_CmsLruCacheObject thePreviousEntry)
      Description copied from interface: I_CmsLruCacheObject
      Set the previous object in the double linked list of all cached objects.

      Specified by:
      setPreviousLruObject in interface I_CmsLruCacheObject
      Parameters:
      thePreviousEntry - the previous object
      See Also:

    • setRedirect

      public void setRedirect(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(String theVariationKey, Map<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 String toString()
      Overrides:
      toString in class Object
      Returns:
      a basic String representation of this CmsFlexCache entry
      See Also: