Package org.apache.openjpa.jdbc.kernel

Class PreparedQueryCacheImpl

java.lang.Object
org.apache.openjpa.jdbc.kernel.PreparedQueryCacheImpl
All Implemented Interfaces:
PreparedQueryCache, Configurable
public class PreparedQueryCacheImpl extends Object implements PreparedQueryCache
An implementation of the cache of prepared queries.
Since:
2.0.0
Author:
Pinaki Poddar

  • Constructor Details

    • PreparedQueryCacheImpl

      public PreparedQueryCacheImpl()

  • Method Details

    • register

      public Boolean register(String id, Query query, FetchConfiguration hints)
      Description copied from interface: PreparedQueryCache
      Register the given query for caching against the given key if it has not already been cached. If the query can not be cached, then mark it as such to avoid computing for the same key again.
      Specified by:
      register in interface PreparedQueryCache
      Returns:
      TRUE the query is registered in the cache by this call null if the query is already registered in the cache FALSE if can not be registered in the cache, either because it is known not to be cacheable from a previous attempt or a hint is given to ignore the cached version.

    • getMapView

      public Map<String,String> getMapView()
      Description copied from interface: PreparedQueryCache
      Get a map view of the cached queries indexed by identifier.
      Specified by:
      getMapView in interface PreparedQueryCache

    • cache

      public boolean cache(PreparedQuery q)
      Cache the given query keyed by its identifier. Does not cache if the identifier matches any exclusion pattern or has been marked as non-cachable. Also register the identifier as not cachable against the matched exclusion pattern.
      Specified by:
      cache in interface PreparedQueryCache
      Returns:
      true if the given query is cached. false if it can not be cached due to exclusion.
      See Also:

    • initialize

      public PreparedQuery initialize(String key, Object result)
      Description copied from interface: PreparedQueryCache
      Initialize the cached Prepared Query registered with the given key earlier by the given execution result. If it is not possible to initialize the Prepared Query from the given execution result, then the corresponding key will be marked as invalid for caching.
      Specified by:
      initialize in interface PreparedQueryCache
      Parameters:
      key - the key used during registration
      result - an opaque instance carrying the execution result of the original query.
      Returns:
      the initialized Prepared Query. If it is not possible to initialize the cached, possibly hollow Prepared Query from the given result, return null.

    • invalidate

      public boolean invalidate(String id)
      Description copied from interface: PreparedQueryCache
      Remove the PreparedQuery with the given identifier from this cache.
      Specified by:
      invalidate in interface PreparedQueryCache

    • get

      public PreparedQuery get(String id)
      Description copied from interface: PreparedQueryCache
      Get the PreparedQuery with the given identifier if it exists. null otherwise.
      Specified by:
      get in interface PreparedQueryCache

    • isCachable

      public Boolean isCachable(String id)
      Description copied from interface: PreparedQueryCache
      Affirms if a PreparedQuery can be cached against the given key.
      Specified by:
      isCachable in interface PreparedQueryCache
      Returns:
      Boolean.FALSE if the given key is explicitly marked before as not be cached or matches any of the exclusion patterns. Boolean.TRUE if the given key currently exists in the cache. Otherwise, return null implying this receiver can not determine whether this key can be cached on not.

    • markUncachable

      public PreparedQuery markUncachable(String id, PreparedQueryCache.Exclusion exclusion)
      Description copied from interface: PreparedQueryCache
      Marks the given key as not amenable to caching. Explicit marking helps to avoid repeated computational cost of determining whether a query can be cached or not.
      Specified by:
      markUncachable in interface PreparedQueryCache
      Parameters:
      id - is the key to be excluded
      exclusion - directs whether exclusion is irreversible or not.
      Returns:
      The value for the given key if it had been cached before. null otherwise.

    • isExcluded

      public PreparedQueryCache.Exclusion isExcluded(String id)
      Description copied from interface: PreparedQueryCache
      Returns the exclusion status of if the given query key.
      Specified by:
      isExcluded in interface PreparedQueryCache
      Returns:
      null implies that the key is not excluded.

    • setExcludes

      public void setExcludes(String excludes)
      Description copied from interface: PreparedQueryCache
      Sets one or more exclusion regular expression patterns separated by semicolon. Any existing cache entry whose key matches any of the given pattern will be marked non-cachable in a reversible manner.
      Specified by:
      setExcludes in interface PreparedQueryCache

    • getExcludes

      public List<PreparedQueryCache.Exclusion> getExcludes()
      Description copied from interface: PreparedQueryCache
      Gets the exclusion patterns.
      Specified by:
      getExcludes in interface PreparedQueryCache

    • addExclusionPattern

      public void addExclusionPattern(String pattern)
      Adds a pattern for exclusion. Any query cached currently whose identifier matches the given pattern will be marked invalidated as a side-effect.
      Specified by:
      addExclusionPattern in interface PreparedQueryCache

    • removeExclusionPattern

      public void removeExclusionPattern(String pattern)
      Removes a pattern for exclusion. Any query identifier marked as not cachable due to the given pattern will now be removed from the list of uncachables as a side-effect.
      Specified by:
      removeExclusionPattern in interface PreparedQueryCache
      See Also:

    • getStatistics

      public QueryStatistics<String> getStatistics()
      Description copied from interface: PreparedQueryCache
      Gets the simple statistics for executed queries. If the statistics gathering is disabled, an empty statistics is returned.
      Specified by:
      getStatistics in interface PreparedQueryCache

    • lock

      protected void lock(boolean readOnly)
      Note: Care needs to be taken so that a read lock is never held while requesting a write lock. This will result in a deadlock.
      Parameters:
      readOnly - - If true, a read lock will be acquired. Else a write lock will be acquired.

    • unlock

      protected void unlock(boolean readOnly)
      Parameters:
      readOnly - - If true, the read lock will be released. Else a write lock will be released.

    • clear

      public void clear()
      Description copied from interface: PreparedQueryCache
      Clears all cached queries.
      Specified by:
      clear in interface PreparedQueryCache

    • setEnableStatistics

      public void setEnableStatistics(boolean enable)
      Description copied from interface: PreparedQueryCache
      Enable/disable gathering of statistics.
      Specified by:
      setEnableStatistics in interface PreparedQueryCache

    • getEnableStatistics

      public boolean getEnableStatistics()
      Description copied from interface: PreparedQueryCache
      Affirm if statistics is gathered.
      Specified by:
      getEnableStatistics in interface PreparedQueryCache

    • setMaxCacheSize

      public void setMaxCacheSize(int size)

    • getCacheSize

      public int getCacheSize()

    • setConfiguration

      public void setConfiguration(Configuration conf)
      Description copied from interface: Configurable
      Invoked prior to setting bean properties.
      Specified by:
      setConfiguration in interface Configurable

    • startConfiguration

      public void startConfiguration()
      Description copied from interface: Configurable
      Invoked before bean property configuration is begun on this object.
      Specified by:
      startConfiguration in interface Configurable

    • endConfiguration

      public void endConfiguration()
      Description copied from interface: Configurable
      Invoked upon completion of bean property configuration for this object.
      Specified by:
      endConfiguration in interface Configurable