/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at
 * trunk/opends/resource/legal-notices/OpenDS.LICENSE
 * or https://OpenDS.dev.java.net/OpenDS.LICENSE.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at
 * trunk/opends/resource/legal-notices/OpenDS.LICENSE.  If applicable,
 * add the following below this CDDL HEADER, with the fields enclosed
 * by brackets "[]" replaced with your own identifying information:
 *      Portions Copyright [yyyy] [name of copyright owner]
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 * CDDL HEADER END
 *
 *
 *      Copyright 2008 Sun Microsystems, Inc.
 */
package org.opends.server.admin.std.server;



import java.util.SortedSet;
import org.opends.server.admin.server.ConfigurationAddListener;
import org.opends.server.admin.server.ConfigurationChangeListener;
import org.opends.server.admin.server.ConfigurationDeleteListener;
import org.opends.server.admin.std.meta.BackendCfgDefn.WritabilityMode;
import org.opends.server.config.ConfigException;



/**
 * A server-side interface for querying Local DB Backend settings.
 * <p>
 * The Local DB Backend uses the Berkeley DB Java Edition to store
 * user-provided data in a local repository.
 */
public interface LocalDBBackendCfg extends BackendCfg {

  /**
   * Gets the configuration class associated with this Local DB Backend.
   *
   * @return Returns the configuration class associated with this Local DB Backend.
   */
  Class<? extends LocalDBBackendCfg> configurationClass();



  /**
   * Register to be notified when this Local DB Backend is changed.
   *
   * @param listener
   *          The Local DB Backend configuration change listener.
   */
  void addLocalDBChangeListener(ConfigurationChangeListener<LocalDBBackendCfg> listener);



  /**
   * Deregister an existing Local DB Backend configuration change listener.
   *
   * @param listener
   *          The Local DB Backend configuration change listener.
   */
  void removeLocalDBChangeListener(ConfigurationChangeListener<LocalDBBackendCfg> listener);



  /**
   * Gets the "compact-encoding" property.
   * <p>
   * Indicates whether the backend should use a compact form when
   * encoding entries by compressing the attribute descriptions and
   * object class sets.
   * <p>
   * Note that this property applies only to the entries themselves
   * and does not impact the index data.
   *
   * @return Returns the value of the "compact-encoding" property.
   */
  boolean isCompactEncoding();



  /**
   * Gets the "db-cache-percent" property.
   * <p>
   * Specifies the percentage of JVM memory to allocate to the
   * database cache.
   * <p>
   * Specifies the percentage of memory available to the JVM that
   * should be used for caching database contents. Note that this is
   * only used if the value of the db-cache-size property is set to "0
   * MB". Otherwise, the value of that property is used instead to
   * control the cache size configuration.
   *
   * @return Returns the value of the "db-cache-percent" property.
   */
  int getDBCachePercent();



  /**
   * Gets the "db-cache-size" property.
   * <p>
   * The amount of JVM memory to allocate to the database cache.
   * <p>
   * Specifies the amount of memory that should be used for caching
   * database contents. A value of "0 MB" indicates that the
   * db-cache-percent property should be used instead to specify the
   * cache size.
   *
   * @return Returns the value of the "db-cache-size" property.
   */
  long getDBCacheSize();



  /**
   * Gets the "db-checkpointer-bytes-interval" property.
   * <p>
   * Specifies the maximum number of bytes that may be written to the
   * database before it is forced to perform a checkpoint.
   * <p>
   * This can be used to bound the recovery time that may be required
   * if the database environment is opened without having been properly
   * closed. If this property is set to a non-zero value, the
   * checkpointer wakeup interval is not used. To use time-based
   * checkpointing, set this property to zero.
   *
   * @return Returns the value of the "db-checkpointer-bytes-interval" property.
   */
  long getDBCheckpointerBytesInterval();



  /**
   * Gets the "db-checkpointer-wakeup-interval" property.
   * <p>
   * Specifies the maximum length of time that may pass between
   * checkpoints.
   * <p>
   * Note that this is only used if the value of the checkpointer
   * bytes interval is zero.
   *
   * @return Returns the value of the "db-checkpointer-wakeup-interval" property.
   */
  long getDBCheckpointerWakeupInterval();



  /**
   * Gets the "db-cleaner-min-utilization" property.
   * <p>
   * Specifies the minimum percentage of "live" data that the database
   * cleaner attempts to keep in database log files.
   * <p>
   * If the amount of live data in any database log file drops below
   * this percentage, then the cleaner moves the remaining live data in
   * that file to the end of the database and deletes the original file
   * in order to keep the database relatively compact.
   *
   * @return Returns the value of the "db-cleaner-min-utilization" property.
   */
  int getDBCleanerMinUtilization();



  /**
   * Gets the "db-directory" property.
   * <p>
   * Specifies the path to the filesystem directory that is used to
   * hold the Berkeley DB Java Edition database files containing the
   * data for this backend.
   * <p>
   * The path may be either an absolute path or a path relative to the
   * directory containing the base of the OpenDS Directory Server
   * installation. The path may be any valid directory path in which
   * the server has appropriate permissions to read and write files and
   * has sufficient space to hold the database contents.
   *
   * @return Returns the value of the "db-directory" property.
   */
  String getDBDirectory();



  /**
   * Gets the "db-directory-permissions" property.
   * <p>
   * Specifies the permissions that should be applied to the directory
   * containing the server database files.
   * <p>
   * They should be expressed as three-digit octal values, which is
   * the traditional representation for UNIX file permissions. The
   * three digits represent the permissions that are available for the
   * directory's owner, group members, and other users (in that order),
   * and each digit is the octal representation of the read, write, and
   * execute bits. Note that this only impacts permissions on the
   * database directory and not on the files written into that
   * directory. On UNIX systems, the user's umask controls permissions
   * given to the database files.
   *
   * @return Returns the value of the "db-directory-permissions" property.
   */
  String getDBDirectoryPermissions();



  /**
   * Gets the "db-evictor-lru-only" property.
   * <p>
   * Indicates whether the database should evict existing data from
   * the cache based on an LRU policy (where the least recently used
   * information will be evicted first).
   * <p>
   * If set to "false", then the eviction keeps internal nodes of the
   * underlying Btree in the cache over leaf nodes, even if the leaf
   * nodes have been accessed more recently. This may be a better
   * configuration for databases in which only a very small portion of
   * the data is cached.
   *
   * @return Returns the value of the "db-evictor-lru-only" property.
   */
  boolean isDBEvictorLruOnly();



  /**
   * Gets the "db-evictor-nodes-per-scan" property.
   * <p>
   * Specifies the number of Btree nodes that should be evicted from
   * the cache in a single pass if it is determined that it is
   * necessary to free existing data in order to make room for new
   * information.
   * <p>
   * Changes to this property do not take effect until the backend is
   * restarted. It is recommended that you also change this property
   * when you set db-evictor-lru-only to false. This setting controls
   * the number of Btree nodes that are considered, or sampled, each
   * time a node is evicted. A setting of 100 often produces good
   * results, but this may vary from application to application. The
   * larger the nodes per scan, the more accurate the algorithm.
   * However, setting it too high is detrimental; the need to consider
   * larger numbers of nodes for each eviction may delay the completion
   * of a given database operation, which will impact the response time
   * of the application thread.
   *
   * @return Returns the value of the "db-evictor-nodes-per-scan" property.
   */
  int getDBEvictorNodesPerScan();



  /**
   * Gets the "db-log-file-max" property.
   * <p>
   * Specifies the maximum size for a database log file.
   *
   * @return Returns the value of the "db-log-file-max" property.
   */
  long getDBLogFileMax();



  /**
   * Gets the "db-logging-file-handler-on" property.
   * <p>
   * Indicates whether the database should maintain a je.info file in
   * the same directory as the database log directory.
   * <p>
   * This file contains information about the internal processing
   * performed by the underlying database.
   *
   * @return Returns the value of the "db-logging-file-handler-on" property.
   */
  boolean isDBLoggingFileHandlerOn();



  /**
   * Gets the "db-logging-level" property.
   * <p>
   * Specifies the log level that should be used by the database when
   * it is writing information into the je.info file.
   * <p>
   * The database trace logging level is (in increasing order of
   * verbosity) chosen from: OFF, SEVERE, WARNING, INFO, CONFIG, FINE,
   * FINER, FINEST, ALL.
   *
   * @return Returns the value of the "db-logging-level" property.
   */
  String getDBLoggingLevel();



  /**
   * Gets the "db-num-cleaner-threads" property.
   * <p>
   * Specifies the number of threads that the backend should maintain
   * to keep the database log files at or near the desired utilization.
   * <p>
   * In environments with high write throughput, multiple cleaner
   * threads may be required to maintain the desired utilization.
   *
   * @return Returns the value of the "db-num-cleaner-threads" property.
   */
  Integer getDBNumCleanerThreads();



  /**
   * Gets the "db-num-lock-tables" property.
   * <p>
   * Specifies the number of lock tables that are used by the
   * underlying database.
   * <p>
   * This can be particularly important to help improve scalability by
   * avoiding contention on systems with large numbers of CPUs. The
   * value of this configuration property should be set to a prime
   * number that is less than or equal to the number of worker threads
   * configured for use in the server.
   *
   * @return Returns the value of the "db-num-lock-tables" property.
   */
  Integer getDBNumLockTables();



  /**
   * Gets the "db-run-cleaner" property.
   * <p>
   * Indicates whether the database cleaner threads should be enabled.
   * <p>
   * The cleaner threads are used to periodically compact the database
   * by identifying database files with a low (that is, less than the
   * amount specified by the db-cleaner-min-utilization property)
   * percentage of live data, moving the remaining live data to the end
   * of the log and deleting that file.
   *
   * @return Returns the value of the "db-run-cleaner" property.
   */
  boolean isDBRunCleaner();



  /**
   * Gets the "db-txn-no-sync" property.
   * <p>
   * Indicates whether database writes should be primarily written to
   * an internal buffer but not immediately written to disk.
   * <p>
   * Setting the value of this configuration attribute to "true" may
   * improve write performance but could cause the most recent changes
   * to be lost if the OpenDS Directory Server or the underlying JVM
   * exits abnormally, or if an OS or hardware failure occurs (a
   * behavior similar to running with transaction durability disabled
   * in the Sun Java System Directory Server).
   *
   * @return Returns the value of the "db-txn-no-sync" property.
   */
  boolean isDBTxnNoSync();



  /**
   * Gets the "db-txn-write-no-sync" property.
   * <p>
   * Indicates whether the database should synchronously flush data as
   * it is written to disk.
   * <p>
   * If this value is set to "false", then all data written to disk is
   * synchronously flushed to persistent storage and thereby providing
   * full durability. If it is set to "true", then data may be cached
   * for a period of time by the underlying operating system before
   * actually being written to disk. This may improve performance, but
   * could cause the most recent changes to be lost in the event of an
   * underlying OS or hardware failure (but not in the case that the
   * OpenDS Directory Server or the JVM exits abnormally).
   *
   * @return Returns the value of the "db-txn-write-no-sync" property.
   */
  boolean isDBTxnWriteNoSync();



  /**
   * Gets the "entries-compressed" property.
   * <p>
   * Indicates whether the backend should attempt to compress entries
   * before storing them in the database.
   * <p>
   * Note that this property applies only to the entries themselves
   * and does not impact the index data. Further, the effectiveness of
   * the compression is based on the type of data contained in the
   * entry.
   *
   * @return Returns the value of the "entries-compressed" property.
   */
  boolean isEntriesCompressed();



  /**
   * Gets the "import-queue-size" property.
   * <p>
   * This parameter has been deprecated in OpenDS 2.1 and will be
   * removed in OpenDS 3.0. It is only being kept for migration ease
   * and is ignored in OpenDS versions after 2.0.
   *
   * @return Returns the value of the "import-queue-size" property.
   */
  int getImportQueueSize();



  /**
   * Gets the "import-thread-count" property.
   * <p>
   * This parameter has been deprecated in OpenDS 2.1 and will be
   * removed in OpenDS 3.0. It is only being kept for migration ease
   * and is ignored in OpenDS versions after 2.0.
   * <p>
   * This parameter has been deprecated in OpenDS 2.1 and will be
   * removed in OpenDS 3.0. It is only being kept for migration ease
   * and is ignored in OpenDS versions after 2.0.
   *
   * @return Returns the value of the "import-thread-count" property.
   */
  int getImportThreadCount();



  /**
   * Gets the "index-entry-limit" property.
   * <p>
   * Specifies the maximum number of entries that is allowed to match
   * a given index key before that particular index key is no longer
   * maintained.
   * <p>
   * This property is analogous to the ALL IDs threshold in the Sun
   * Java System Directory Server. Note that this is the default limit
   * for the backend, and it may be overridden on a per-attribute
   * basis.A value of 0 means there is no limit.
   *
   * @return Returns the value of the "index-entry-limit" property.
   */
  int getIndexEntryLimit();



  /**
   * Gets the "java-class" property.
   * <p>
   * Specifies the fully-qualified name of the Java class that
   * provides the backend implementation.
   *
   * @return Returns the value of the "java-class" property.
   */
  String getJavaClass();



  /**
   * Gets the "je-property" property.
   * <p>
   * Specifies the database and environment properties for the
   * Berkeley DB Java Edition database serving the data for this
   * backend.
   * <p>
   * Any Berkeley DB Java Edition property can be specified using the
   * following form: property-name=property-value. Refer to OpenDS
   * documentation for further information on related properties, their
   * implications, and range values. The definitive identification of
   * all the property parameters is available in the example.properties
   * file of Berkeley DB Java Edition distribution.
   *
   * @return Returns an unmodifiable set containing the values of the "je-property" property.
   */
  SortedSet<String> getJEProperty();



  /**
   * Gets the "preload-time-limit" property.
   * <p>
   * Specifies the length of time that the backend is allowed to spend
   * "pre-loading" data when it is initialized.
   * <p>
   * The pre-load process is used to pre-populate the database cache,
   * so that it can be more quickly available when the server is
   * processing requests. A duration of zero means there is no
   * pre-load.
   *
   * @return Returns the value of the "preload-time-limit" property.
   */
  long getPreloadTimeLimit();



  /**
   * Gets the "writability-mode" property.
   * <p>
   * Specifies the behavior that the backend should use when
   * processing write operations.
   *
   * @return Returns the value of the "writability-mode" property.
   */
  WritabilityMode getWritabilityMode();



  /**
   * Lists the Local DB Indexes.
   *
   * @return Returns an array containing the names of the
   *         Local DB Indexes.
   */
  String[] listLocalDBIndexes();



  /**
   * Gets the named Local DB Index.
   *
   * @param name
   *          The name of the Local DB Index to retrieve.
   * @return Returns the named Local DB Index.
   * @throws ConfigException
   *           If the Local DB Index could not be found or it
   *           could not be successfully decoded.
   */
  LocalDBIndexCfg getLocalDBIndex(String name) throws ConfigException;



  /**
   * Registers to be notified when new Local DB Indexes are added.
   *
   * @param listener
   *          The Local DB Index configuration add listener.
   * @throws ConfigException
   *          If the add listener could not be registered.
   */
  void addLocalDBIndexAddListener(ConfigurationAddListener<LocalDBIndexCfg> listener) throws ConfigException;



  /**
   * Deregisters an existing Local DB Index configuration add listener.
   *
   * @param listener
   *          The Local DB Index configuration add listener.
   */
  void removeLocalDBIndexAddListener(ConfigurationAddListener<LocalDBIndexCfg> listener);



  /**
   * Registers to be notified when existing Local DB Indexes are deleted.
   *
   * @param listener
   *          The Local DB Index configuration delete listener.
   * @throws ConfigException
   *          If the delete listener could not be registered.
   */
  void addLocalDBIndexDeleteListener(ConfigurationDeleteListener<LocalDBIndexCfg> listener) throws ConfigException;



  /**
   * Deregisters an existing Local DB Index configuration delete listener.
   *
   * @param listener
   *          The Local DB Index configuration delete listener.
   */
  void removeLocalDBIndexDeleteListener(ConfigurationDeleteListener<LocalDBIndexCfg> listener);



  /**
   * Lists the Local DB VLV Indexes.
   *
   * @return Returns an array containing the names of the
   *         Local DB VLV Indexes.
   */
  String[] listLocalDBVLVIndexes();



  /**
   * Gets the named Local DB VLV Index.
   *
   * @param name
   *          The name of the Local DB VLV Index to retrieve.
   * @return Returns the named Local DB VLV Index.
   * @throws ConfigException
   *           If the Local DB VLV Index could not be found or it
   *           could not be successfully decoded.
   */
  LocalDBVLVIndexCfg getLocalDBVLVIndex(String name) throws ConfigException;



  /**
   * Registers to be notified when new Local DB VLV Indexes are added.
   *
   * @param listener
   *          The Local DB VLV Index configuration add listener.
   * @throws ConfigException
   *          If the add listener could not be registered.
   */
  void addLocalDBVLVIndexAddListener(ConfigurationAddListener<LocalDBVLVIndexCfg> listener) throws ConfigException;



  /**
   * Deregisters an existing Local DB VLV Index configuration add listener.
   *
   * @param listener
   *          The Local DB VLV Index configuration add listener.
   */
  void removeLocalDBVLVIndexAddListener(ConfigurationAddListener<LocalDBVLVIndexCfg> listener);



  /**
   * Registers to be notified when existing Local DB VLV Indexes are deleted.
   *
   * @param listener
   *          The Local DB VLV Index configuration delete listener.
   * @throws ConfigException
   *          If the delete listener could not be registered.
   */
  void addLocalDBVLVIndexDeleteListener(ConfigurationDeleteListener<LocalDBVLVIndexCfg> listener) throws ConfigException;



  /**
   * Deregisters an existing Local DB VLV Index configuration delete listener.
   *
   * @param listener
   *          The Local DB VLV Index configuration delete listener.
   */
  void removeLocalDBVLVIndexDeleteListener(ConfigurationDeleteListener<LocalDBVLVIndexCfg> listener);

}
