Package chemaxon.jchem.db.cache

Enum CacheManager

  • All Implemented Interfaces:
    chemaxon.jchem.db.cache.CacheManagerMBean, Serializable, Comparable<CacheManager>
    @PublicAPI
public enum CacheManager
extends Enum<CacheManager>
implements chemaxon.jchem.db.cache.CacheManagerMBean
    Singleton for managing cache-related functions. Object available as CacheManager.INSTANCE.
    Since:
    6.0

    • Enum Constant Detail

    • Method Detail

      • values

        public static CacheManager[] values()
        Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows: 
        for (CacheManager c : CacheManager.values())
    System.out.println(c);
        Returns:
        an array containing the constants of this enum type, in the order they are declared

      • valueOf

        public static CacheManager valueOf​(String name)
        Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
        Parameters:
        name - the name of the enum constant to be returned.
        Returns:
        the enum constant with the specified name
        Throws:
        IllegalArgumentException - if this enum type has no constant with the specified name
        NullPointerException - if the argument is null

      • setPinCacheDefaultValue

        public void setPinCacheDefaultValue​(boolean pinCacheDefaultValue)
        Sets the default pin behavior of loading cache. It relates to both automatically and manually loaded caches.
        Parameters:
        pinCacheDefaultValue - set the new default value
        Since:
        6.0
        See Also:
        loadCache(ConnectionHandler,String,boolean)

      • getPinCacheDefaultValue

        public boolean getPinCacheDefaultValue()
        Gets the default pin behavior of loading cache.
        Returns:
        the default behavior of pinning cache when loading cache
        Since:
        6.0
        See Also:
        loadCache(ConnectionHandler,String,boolean)

      • loadCache

        public void loadCache​(ConnectionHandler connectionHandler,
                      String tableName,
                      boolean haltOnError,
                      boolean pinCache)
               throws Exception
        Loads or updates cache directly into memory without making a (first) search in the table.
        Parameters:
        connectionHandler - ConnectionHandler with live connection
        tableName - the name of the structure table to load into the cache
        haltOnError - if true, stops on any errors during loading; tries to recover otherwise
        pinCache - if set to true, the cache is pinned into memory and won't be released when physical memory is deemed insufficient to hold an additional structure table cached. Otherwise it is thrown out in that case.
        Throws:
        Exception - depending on the haltOnError setting, it may throw an exception
        Since:
        6.0

      • loadCache

        public void loadCache​(ConnectionHandler connectionHandler,
                      String tableName,
                      boolean haltOnError)
               throws Exception
        Loads or updates cache directly into memory without making a (first) search in the table.
        Parameters:
        connectionHandler - ConnectionHandler with live connection
        tableName - the name of the structure table to load into the cache
        haltOnError - if true, stops on any errors during loading; tries to recover otherwise
        Throws:
        Exception - depending on the haltOnError setting, it may throw an exception
        Since:
        6.0

      • loadCache

        public void loadCache​(ConnectionHandler connectionHandler,
                      String tableName,
                      String indexedTable,
                      String indexedColumn,
                      boolean haltOnError,
                      boolean pinCache)
               throws Exception
        For internal use only.
        Parameters:
        connectionHandler - ConnectionHandler with live connection
        tableName - the name of the structure table to load into the cache
        indexedTable - the name of the table
        indexedColumn - the name of the indexed column
        haltOnError - if true, stops on any errors during loading; tries to recover otherwise.
        pinCache - if true, the cache is pinned
        Throws:
        Exception - whatever

      • pinCache

        public void pinCache​(ConnectionHandler connectionHandler,
                     String tableName)
              throws Exception,
                     IllegalArgumentException
        Pins cache into memory. The cache is pinned into memory and won't be released when physical memory is deemed insufficient to hold an additional structure table cached.
        Parameters:
        connectionHandler - ConnectionHandler with live connection
        tableName - the name of the structure table to be pinned into the cache
        Throws:
        Exception - depending on the haltOnError setting, it may throw an exception
        IllegalArgumentException - if no cache is loaded into memory for the structure table
        Since:
        6.0

      • unpinCache

        public void unpinCache​(ConnectionHandler connectionHandler,
                       String tableName)
                throws Exception,
                       IllegalArgumentException
        Unpins cache from memory without making a (first) search in the table. The cache is pinned into memory and won't be released when physical memory is deemed insufficient to hold an additional structure table cached.
        Parameters:
        connectionHandler - ConnectionHandler with live connection
        tableName - the name of the structure table to be pinned into the cache
        Throws:
        Exception - depending on the haltOnError setting, it may throw an exception
        IllegalArgumentException - if no cache is loaded into memory for the structure table
        Since:
        6.0

      • findCache

        public chemaxon.jchem.db.cache.JChemCache findCache​(ConnectionHandler ch,
                                                    String tableName,
                                                    boolean cartridgeMode)
                                             throws chemaxon.jchem.base.storage.PersistenceException
        For internal use only.
        Parameters:
        ch - the connection to use
        tableName - the name of the table
        cartridgeMode - true if cartridge
        Returns:
        a cache responsible for the table
        Throws:
        chemaxon.jchem.base.storage.PersistenceException - if some error occurs

      • getCacheRemovalMethod

        public chemaxon.jchem.db.cache.CacheRemovalMethod getCacheRemovalMethod()
        For internal use only.
        Returns:
        the current cacheRemovalMethod

      • setCacheRemovalMethod

        public void setCacheRemovalMethod​(chemaxon.jchem.db.cache.CacheRemovalMethod cacheRemovalMethod)
        For internal use only.
        Parameters:
        cacheRemovalMethod - the removalmethod to use

      • unloadCache

        public void unloadCache​(ConnectionHandler connectionHandler,
                        String tableName,
                        boolean cartridgeMode,
                        boolean haltOnError)
                 throws chemaxon.jchem.base.storage.PersistenceException
        For internal use only.
        Parameters:
        connectionHandler - connection handler to use
        tableName - the name of the table
        cartridgeMode - true if used from cartridge
        haltOnError - haltonerror state
        Throws:
        chemaxon.jchem.base.storage.PersistenceException - if it encounter some problem

      • unloadCache

        public void unloadCache​(ConnectionHandler connectionHandler,
                        String tableName)
                 throws Exception,
                        IllegalArgumentException
        Unloads cache from the memory. This can be useful when the server is low on memory and an unused table is loaded into memory.
        Parameters:
        connectionHandler - ConnectionHandler with live connection
        tableName - the name of the structure table to unload from cache
        Throws:
        Exception - if some error is encountered.
        IllegalArgumentException - if no cache is loaded into memory for the structure table
        Since:
        6.0

      • isCacheLoaded

        public boolean isCacheLoaded​(ConnectionHandler connectionHandler,
                             String tableName)
                      throws Exception
        Returns whether the cache is loaded. If the cache load has been started, but it isn't finished yet, the function returns false. Be aware that when changes are made in the table, the cache needs to be updated. So despite this function returning true, the next search may be slower than usual.
        Parameters:
        connectionHandler - ConnectionHandler with live connection
        tableName - the name of the structure table to look for
        Returns:
        true if cache is loaded
        Throws:
        Exception - if some error is encountered.
        Since:
        6.0

      • isCacheLoadStarted

        public boolean isCacheLoadStarted​(ConnectionHandler connectionHandler,
                                  String tableName)
                           throws Exception
        Returns whether the cache is loaded or cache load has been started.
        Parameters:
        connectionHandler - ConnectionHandler with live connection
        tableName - the name of the structure table to look for
        Returns:
        true if cache is loaded or the cache load has been started
        Throws:
        Exception - if some error is encountered.
        Since:
        6.0

      • setMaxCacheSize

        public void setMaxCacheSize​(int maxCacheSizeMB)
        Sets the desired cache memory allocation policy.
        NOTE: the current cache size won't change automatically, only during next cache load or update event. If set to -1 (auto-detect) or minFreeMem is not set to 0, the program tries to determine the maximum amount of memory available for allocation by calling the garbage collector and determining the available memory.
        NOTE: Under Java Runtime Environment 1.3.1 or older the available memory size cannot be determined. In this case JChem allocates cache for tables until it detects OutOfMemoryError during loading.
        Parameters:
        maxCacheSizeMB - the maximum amount of memory the cache allowed to utilize in megabytes. Set -1 for auto-detection (default): maxCacheSize = available_memory - minFreeMem
        Since:
        6.1
        See Also:
        setMinNonCachedMemory(int)

      • setMinNonCachedMemory

        public void setMinNonCachedMemory​(int minNonCachedMemoryMB)
        Sets the desired cache memory allocation policy.
        NOTE: the current cache size won't change automatically, only during next cache load or update event. If not set to 0 or maxCacheSize is set to -1 (auto-detect), the program tries to determine the maximum amount of memory available for allocation by calling the garbage collector and determining the available memory.
        NOTE: Under Java Runtime Environment 1.3.1 or older the available memory size cannot be determined. In this case JChem allocates cache for tables until it detects OutOfMemoryError during loading.
        Parameters:
        minNonCachedMemoryMB - the minimum amount of memory that should be left free for future non-cache allocations in megabytes.
        Set to 0 if not specified.
        Set to -1 for auto-detection (default):
        • 10 % of all available space for future allocations
        • Not smaller, than 250 MB
        • Nor bigger, than 1000 MB
        Since:
        6.1
        See Also:
        setMaxCacheSize(int)

      • getCachedTables

        public Hashtable<String,​Long> getCachedTables()
        Gets the names and sizes of tables currently in the cache.
        Returns:
        the names and allocated memory size in bytes as key - value (String - Long) pairs.
        Since:
        6.1

      • clearCache

        public void clearCache()
        Clears the cache that stores fingerprints and structures.
        Since:
        6.1

      • setCacheExpirationTime

        public void setCacheExpirationTime​(double hours)
        Sets the expiration time for the structure cache. At the start of each search all tables are purged from cache that were searched before the specified time period. Naturally the currently searched tables are never purged.
        Parameters:
        hours - the time in hours. The default value is 0. Set to 0 for no expiration.
        Since:
        6.1
        See Also:
        setMaxCacheSize(int), setMinNonCachedMemory(int)