| /* |
| * 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.directory.server.xdbm.search.cursor; |
| |
| |
| import org.apache.directory.api.ldap.model.constants.Loggers; |
| import org.apache.directory.api.ldap.model.cursor.Cursor; |
| import org.apache.directory.api.ldap.model.cursor.CursorException; |
| import org.apache.directory.api.ldap.model.cursor.InvalidCursorPositionException; |
| import org.apache.directory.api.ldap.model.entry.Entry; |
| import org.apache.directory.api.ldap.model.exception.LdapException; |
| import org.apache.directory.api.ldap.model.schema.AttributeType; |
| import org.apache.directory.server.i18n.I18n; |
| import org.apache.directory.server.xdbm.AbstractIndexCursor; |
| import org.apache.directory.server.xdbm.Index; |
| import org.apache.directory.server.xdbm.IndexEntry; |
| import org.apache.directory.server.xdbm.Store; |
| import org.apache.directory.server.xdbm.search.evaluator.GreaterEqEvaluator; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| |
| /** |
| * A Cursor over entry candidates matching a GreaterEq assertion filter. This |
| * Cursor operates in two modes. The first is when an index exists for the |
| * attribute the assertion is built on. The second is when the user index for |
| * the assertion attribute does not exist. Different Cursors are used in each |
| * of these cases where the other remains null. |
| * |
| * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> |
| */ |
| public class GreaterEqCursor<V> extends AbstractIndexCursor<V> |
| { |
| /** A dedicated log for cursors */ |
| private static final Logger LOG_CURSOR = LoggerFactory.getLogger( Loggers.CURSOR_LOG.getName() ); |
| |
| /** Speedup for logs */ |
| private static final boolean IS_DEBUG = LOG_CURSOR.isDebugEnabled(); |
| |
| private static final String UNSUPPORTED_MSG = "GreaterEqCursors only support positioning by element when a user index exists on the asserted attribute."; |
| |
| /** An greater eq evaluator for candidates */ |
| private final GreaterEqEvaluator<V> greaterEqEvaluator; |
| |
| /** Cursor over attribute entry matching filter: set when index present */ |
| private final Cursor<IndexEntry<V, String>> userIdxCursor; |
| |
| /** NDN Cursor on all entries in (set when no index on user attribute) */ |
| private final Cursor<IndexEntry<String, String>> uuidIdxCursor; |
| |
| /** |
| * Used to store indexEntry from uuidCandidate so it can be saved after |
| * call to evaluate() which changes the value so it's not referring to |
| * the NDN but to the value of the attribute instead. |
| */ |
| private IndexEntry<String, String> uuidCandidate; |
| |
| |
| /** |
| * Creates a new instance of an GreaterEqCursor |
| * @param store The store |
| * @param equalityEvaluator The GreaterEqEvaluator |
| * @throws Exception If the creation failed |
| */ |
| @SuppressWarnings("unchecked") |
| public GreaterEqCursor( Store store, GreaterEqEvaluator<V> greaterEqEvaluator ) throws Exception |
| { |
| if ( IS_DEBUG ) |
| { |
| LOG_CURSOR.debug( "Creating GreaterEqCursor {}", this ); |
| } |
| |
| this.greaterEqEvaluator = greaterEqEvaluator; |
| |
| AttributeType attributeType = greaterEqEvaluator.getExpression().getAttributeType(); |
| |
| if ( store.hasIndexOn( attributeType ) ) |
| { |
| userIdxCursor = ( ( Index<V, String> ) store.getIndex( attributeType ) ).forwardCursor(); |
| uuidIdxCursor = null; |
| } |
| else |
| { |
| uuidIdxCursor = new AllEntriesCursor( store ); |
| userIdxCursor = null; |
| } |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| protected String getUnsupportedMessage() |
| { |
| return UNSUPPORTED_MSG; |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public void before( IndexEntry<V, String> element ) throws LdapException, CursorException |
| { |
| checkNotClosed( "before()" ); |
| |
| if ( userIdxCursor != null ) |
| { |
| /* |
| * First we need to check and make sure this element is within |
| * bounds as mandated by the assertion node. To do so we compare |
| * it's value with the value of the node. If it is smaller or |
| * equal to this lower bound then we simply position the |
| * userIdxCursor before the first element. Otherwise we let the |
| * underlying userIdx Cursor position the element. |
| */ |
| if ( greaterEqEvaluator.getComparator().compare( element.getKey(), |
| greaterEqEvaluator.getExpression().getValue().getValue() ) <= 0 ) |
| { |
| beforeFirst(); |
| return; |
| } |
| |
| userIdxCursor.before( element ); |
| setAvailable( false ); |
| } |
| else |
| { |
| super.before( element ); |
| } |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public void after( IndexEntry<V, String> element ) throws LdapException, CursorException |
| { |
| checkNotClosed( "after()" ); |
| |
| if ( userIdxCursor != null ) |
| { |
| int comparedValue = greaterEqEvaluator.getComparator().compare( element.getKey(), |
| greaterEqEvaluator.getExpression().getValue().getValue() ); |
| |
| /* |
| * First we need to check and make sure this element is within |
| * bounds as mandated by the assertion node. To do so we compare |
| * it's value with the value of the node. If it is equal to this |
| * lower bound then we simply position the userIdxCursor after |
| * this first node. If it is less than this value then we |
| * position the Cursor before the first entry. |
| */ |
| if ( comparedValue == 0 ) |
| { |
| userIdxCursor.after( element ); |
| setAvailable( false ); |
| |
| return; |
| } |
| |
| if ( comparedValue < 0 ) |
| { |
| beforeFirst(); |
| |
| return; |
| } |
| |
| // Element is in the valid range as specified by assertion |
| userIdxCursor.after( element ); |
| setAvailable( false ); |
| } |
| else |
| { |
| super.after( element ); |
| } |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @SuppressWarnings("unchecked") |
| public void beforeFirst() throws LdapException, CursorException |
| { |
| checkNotClosed( "beforeFirst()" ); |
| |
| if ( userIdxCursor != null ) |
| { |
| IndexEntry<V, String> advanceTo = new IndexEntry<V, String>(); |
| advanceTo.setKey( ( V ) greaterEqEvaluator.getExpression().getValue().getValue() ); |
| userIdxCursor.before( advanceTo ); |
| } |
| else |
| { |
| uuidIdxCursor.beforeFirst(); |
| uuidCandidate = null; |
| } |
| |
| setAvailable( false ); |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public void afterLast() throws LdapException, CursorException |
| { |
| checkNotClosed( "afterLast()" ); |
| |
| if ( userIdxCursor != null ) |
| { |
| userIdxCursor.afterLast(); |
| } |
| else |
| { |
| uuidIdxCursor.afterLast(); |
| uuidCandidate = null; |
| } |
| |
| setAvailable( false ); |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public boolean first() throws LdapException, CursorException |
| { |
| beforeFirst(); |
| |
| return next(); |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public boolean last() throws LdapException, CursorException |
| { |
| afterLast(); |
| |
| return previous(); |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public boolean previous() throws LdapException, CursorException |
| { |
| checkNotClosed( "previous()" ); |
| |
| if ( userIdxCursor != null ) |
| { |
| /* |
| * We have to check and make sure the previous value complies by |
| * being greater than or eq to the expression node's value |
| */ |
| while ( userIdxCursor.previous() ) |
| { |
| checkNotClosed( "previous()" ); |
| IndexEntry<?, String> candidate = userIdxCursor.get(); |
| |
| if ( greaterEqEvaluator.getComparator().compare( candidate.getKey(), |
| greaterEqEvaluator.getExpression().getValue().getValue() ) >= 0 ) |
| { |
| return setAvailable( true ); |
| } |
| } |
| |
| return setAvailable( false ); |
| } |
| |
| while ( uuidIdxCursor.previous() ) |
| { |
| checkNotClosed( "previous()" ); |
| uuidCandidate = uuidIdxCursor.get(); |
| |
| if ( greaterEqEvaluator.evaluate( uuidCandidate ) ) |
| { |
| return setAvailable( true ); |
| } |
| } |
| |
| return setAvailable( false ); |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public boolean next() throws LdapException, CursorException |
| { |
| checkNotClosed( "next()" ); |
| |
| if ( userIdxCursor != null ) |
| { |
| /* |
| * No need to do the same check that is done in previous() since |
| * values are increasing with calls to next(). |
| */ |
| return setAvailable( userIdxCursor.next() ); |
| } |
| |
| while ( uuidIdxCursor.next() ) |
| { |
| checkNotClosed( "next()" ); |
| uuidCandidate = uuidIdxCursor.get(); |
| |
| if ( greaterEqEvaluator.evaluate( uuidCandidate ) ) |
| { |
| return setAvailable( true ); |
| } |
| } |
| |
| return setAvailable( false ); |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public IndexEntry<V, String> get() throws CursorException |
| { |
| checkNotClosed( "get()" ); |
| |
| if ( userIdxCursor != null ) |
| { |
| if ( available() ) |
| { |
| return userIdxCursor.get(); |
| } |
| |
| throw new InvalidCursorPositionException( I18n.err( I18n.ERR_708 ) ); |
| } |
| |
| if ( available() ) |
| { |
| return ( IndexEntry<V, String> ) uuidCandidate; |
| } |
| |
| throw new InvalidCursorPositionException( I18n.err( I18n.ERR_708 ) ); |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public void close() |
| { |
| if ( IS_DEBUG ) |
| { |
| LOG_CURSOR.debug( "Closing GreaterEqCursor {}", this ); |
| } |
| |
| super.close(); |
| |
| if ( userIdxCursor != null ) |
| { |
| userIdxCursor.close(); |
| } |
| else |
| { |
| uuidIdxCursor.close(); |
| uuidCandidate = null; |
| } |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public void close( Exception cause ) |
| { |
| if ( IS_DEBUG ) |
| { |
| LOG_CURSOR.debug( "Closing GreaterEqCursor {}", this ); |
| } |
| |
| super.close( cause ); |
| |
| if ( userIdxCursor != null ) |
| { |
| userIdxCursor.close( cause ); |
| } |
| else |
| { |
| uuidIdxCursor.close( cause ); |
| uuidCandidate = null; |
| } |
| } |
| |
| |
| /** |
| * @see Object#toString() |
| */ |
| public String toString( String tabs ) |
| { |
| StringBuilder sb = new StringBuilder(); |
| |
| sb.append( tabs ).append( "GreaterEqCursor (" ); |
| |
| if ( available() ) |
| { |
| sb.append( "available)" ); |
| } |
| else |
| { |
| sb.append( "absent)" ); |
| } |
| |
| sb.append( "#candidate<" ).append( uuidCandidate ).append( ">:\n" ); |
| |
| sb.append( tabs + " >>" ).append( greaterEqEvaluator ).append( '\n' ); |
| |
| if ( userIdxCursor != null ) |
| { |
| sb.append( tabs + " <user>\n" ); |
| sb.append( userIdxCursor.toString( tabs + " " ) ); |
| } |
| |
| if ( uuidIdxCursor != null ) |
| { |
| sb.append( tabs + " <uuid>\n" ); |
| sb.append( uuidIdxCursor.toString( tabs + " " ) ); |
| } |
| |
| return sb.toString(); |
| } |
| |
| |
| /** |
| * @see Object#toString() |
| */ |
| public String toString() |
| { |
| return toString( "" ); |
| } |
| } |