org.apache.hadoop.fs.permission.ScopedAclEntries Maven / Gradle / Ivy
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.hadoop.fs.permission;
import java.util.Collections;
import java.util.List;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.fs.permission.AclEntry;
import org.apache.hadoop.fs.permission.AclEntryScope;
/**
* Groups a list of ACL entries into separate lists for access entries vs.
* default entries.
*/
@InterfaceAudience.LimitedPrivate({"HDFS", "MapReduce"})
@InterfaceStability.Unstable
public final class ScopedAclEntries {
private static final int PIVOT_NOT_FOUND = -1;
private final List accessEntries;
private final List defaultEntries;
/**
* Creates a new ScopedAclEntries from the given list. It is assumed that the
* list is already sorted such that all access entries precede all default
* entries.
*
* @param aclEntries List<AclEntry> to separate
*/
public ScopedAclEntries(List aclEntries) {
int pivot = calculatePivotOnDefaultEntries(aclEntries);
if (pivot != PIVOT_NOT_FOUND) {
accessEntries = pivot != 0 ? aclEntries.subList(0, pivot) :
Collections.emptyList();
defaultEntries = aclEntries.subList(pivot, aclEntries.size());
} else {
accessEntries = aclEntries;
defaultEntries = Collections.emptyList();
}
}
/**
* Returns access entries.
*
* @return List<AclEntry> containing just access entries, or an empty
* list if there are no access entries
*/
public List getAccessEntries() {
return accessEntries;
}
/**
* Returns default entries.
*
* @return List<AclEntry> containing just default entries, or an empty
* list if there are no default entries
*/
public List getDefaultEntries() {
return defaultEntries;
}
/**
* Returns the pivot point in the list between the access entries and the
* default entries. This is the index of the first element in the list that
* is a default entry.
*
* @param aclBuilder ArrayList containing entries to build
* @return int pivot point, or -1 if list contains no default entries
*/
private static int calculatePivotOnDefaultEntries(List aclBuilder) {
for (int i = 0; i < aclBuilder.size(); ++i) {
if (aclBuilder.get(i).getScope() == AclEntryScope.DEFAULT) {
return i;
}
}
return PIVOT_NOT_FOUND;
}
}