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// to you under the Apache License, Version 2.0 (the
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//   http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.impala.catalog;

import java.util.List;
import java.util.Set;

import org.apache.impala.analysis.TableName;
import org.apache.impala.authorization.AuthorizationPolicy;
import org.apache.impala.common.InternalException;
import org.apache.impala.thrift.TCatalogObject;
import org.apache.impala.thrift.TGetPartitionStatsResponse;
import org.apache.impala.thrift.TPartitionKeyValue;
import org.apache.impala.thrift.TUniqueId;
import org.apache.impala.util.PatternMatcher;

/**
 * Interface between the front-end (analysis and planning) classes and the Catalog.
 */
public interface FeCatalog {
  /** @see Catalog#getDbs(PatternMatcher) */
  List<? extends FeDb> getDbs(PatternMatcher matcher);

  /** @see Catalog#getTableNames(String, PatternMatcher) */
  List<String> getTableNames(String dbName, PatternMatcher matcher)
      throws DatabaseNotFoundException;

  /** @see Catalog#getTable(String, String) */
  FeTable getTable(String dbName, String tableName)
      throws DatabaseNotFoundException;

  /** @see Catalog#getTableNoThrow(String, String) */
  FeTable getTableNoThrow(String dbName, String tableName);

  /** @see Catalog#getTableIfCached(String, String) */
  FeTable getTableIfCached(String dbName, String tableName)
      throws DatabaseNotFoundException;

  /** @see Catalog#getTableIfCachedNoThrow(String, String) */
  FeTable getTableIfCachedNoThrow(String dbName, String tableName);

  /** @see Catalog#getTCatalogObject(TCatalogObject) */
  TCatalogObject getTCatalogObject(TCatalogObject objectDesc)
      throws CatalogException;

  /** @see Catalog#getDb(String) */
  FeDb getDb(String db);

  /** @see Catalog#getHdfsPartition(String, String, List) */
  FeFsPartition getHdfsPartition(String db, String tbl,
      List<TPartitionKeyValue> partitionSpec) throws CatalogException;

  /** @see Catalog#getDataSources(PatternMatcher) */
  List<? extends FeDataSource> getDataSources(PatternMatcher createHivePatternMatcher);

  /** @see Catalog#getDataSource(String) */
  public FeDataSource getDataSource(String dataSourceName);

  /** @see Catalog#getFunction(Function, Function.CompareMode) */
  // TODO(todd): introduce FeFunction
  public Function getFunction(Function desc, Function.CompareMode mode);

  // TODO(todd): introduce FeFsCachePool
  /** @see Catalog#getHdfsCachePool(String) */
  public HdfsCachePool getHdfsCachePool(String poolName);

  /**
   * Issues a load request to the catalogd for the given tables.
   */
  void prioritizeLoad(Set<TableName> tableNames) throws InternalException;

  /**
   * Fetches partition statistics for a table. The table is loaded if needed. If the table
   * does not exist or cannot be loaded, an exception is thrown.
   */
  TGetPartitionStatsResponse getPartitionStats(TableName table) throws InternalException;

  /**
   * Causes the calling thread to wait until a catalog update notification has been sent
   * or the given timeout has been reached. A timeout value of 0 indicates an indefinite
   * wait. Does not protect against spurious wakeups, so this should be called in a loop.
   */
  void waitForCatalogUpdate(long timeoutMs);

  /**
   * @return the ID of the catalog service from which this catalog most recently
   * loaded.
   */
  TUniqueId getCatalogServiceId();

  AuthorizationPolicy getAuthPolicy();
  String getDefaultKuduMasterHosts();


  /**
   * Returns true if the catalog is ready to accept requests (has
   * received and processed a valid catalog topic update from the StateStore),
   * false otherwise.
   */
  boolean isReady();

  /**
   * Force the catalog into a particular readiness state.
   * Used only by tests.
   */
  void setIsReady(boolean isReady);

}