CatalogDeltaLog.java

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// Copyright 2012 Cloudera Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package com.cloudera.impala.catalog;

import java.util.Map;
import java.util.SortedMap;
import java.util.TreeMap;

import com.cloudera.impala.thrift.TCatalogObject;
import com.cloudera.impala.thrift.TTable;
import com.google.common.base.Preconditions;

public class CatalogDeltaLog {
  // Map of the catalog version an object was removed from the catalog
  // to the catalog object, ordered by catalog version.
  private SortedMap<Long, TCatalogObject> removedCatalogObjects_ =
      new TreeMap<Long, TCatalogObject>();

  public synchronized void addRemovedObject(TCatalogObject catalogObject) {
    Preconditions.checkNotNull(catalogObject);
    removedCatalogObjects_.put(catalogObject.getCatalog_version(), catalogObject);
  }

  public synchronized void garbageCollect(long currentCatalogVersion) {
    // Nothing will be garbage collected so avoid creating a new object.
    if (!removedCatalogObjects_.isEmpty() &&
        removedCatalogObjects_.firstKey() < currentCatalogVersion) {
      removedCatalogObjects_ = new TreeMap<Long, TCatalogObject>(
          removedCatalogObjects_.tailMap(currentCatalogVersion));
    }
  }

  public synchronized boolean wasObjectRemovedAfter(TCatalogObject catalogObject) {
    Preconditions.checkNotNull(catalogObject);
    if (removedCatalogObjects_.isEmpty()) return false;

    // Get all the items that were removed after the catalog version of this object.
    SortedMap<Long, TCatalogObject> candidateObjects =
        removedCatalogObjects_.tailMap(catalogObject.getCatalog_version());
    for (Map.Entry<Long, TCatalogObject> entry: candidateObjects.entrySet()) {
      if (objectNamesMatch(catalogObject, entry.getValue())) return true;
    }
    return false;
  }

  private boolean objectNamesMatch(TCatalogObject first, TCatalogObject second) {
    if (first.getType() != second.getType()) return false;
    switch (first.getType()) {
      case DATABASE:
        return first.getDb().getDb_name().equalsIgnoreCase(second.getDb().getDb_name());
      case TABLE:
      case VIEW:
        TTable firstTbl = first.getTable();
        return firstTbl.getDb_name().equalsIgnoreCase(second.getTable().getDb_name()) &&
            firstTbl.getTbl_name().equalsIgnoreCase(second.getTable().getTbl_name());
      case FUNCTION:
        return first.getFn().getSignature().equals(second.getFn().getSignature()) &&
            first.getFn().getName().equals(second.getFn().getName());
      case ROLE:
        return first.getRole().getRole_name().equalsIgnoreCase(
            second.getRole().getRole_name());
      case PRIVILEGE:
        return first.getPrivilege().getPrivilege_name().equalsIgnoreCase(
            second.getPrivilege().getPrivilege_name()) &&
            first.getPrivilege().getRole_id() == second.getPrivilege().getRole_id();
      default: return false;
    }
  }
}