AnnotationConditionProvider.java

/*
 * Copyright 2012 SFB 632.
 *
 * 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 annis.sqlgen;

import annis.model.QueryAnnotation;
import annis.model.QueryNode;
import annis.model.QueryNode.TextMatching;
import static annis.sqlgen.TableAccessStrategy.NODE_ANNOTATION_TABLE;
import static annis.sqlgen.TableAccessStrategy.NODE_TABLE;
import com.google.common.base.Objects;
import com.google.common.escape.Escaper;
import com.google.common.escape.Escapers;
import java.util.Collection;
import java.util.Set;

/**
 * Bundles behavior
 * how to add annotation constraints to the generated SQL.
 * @author Thomas Krause <krauseto@hu-berlin.de>
 */
public class AnnotationConditionProvider
{

  public static final Escaper likeEscaper = Escapers.builder()
    .addEscape('\'', "''")
    .addEscape('%', "\\%")
    .addEscape('_', "\\_")
    .addEscape('\\', "\\\\")
    .build();

  public static final Escaper regexEscaper = Escapers.builder()
    .addEscape('\'', "''")
    .build();

  /**
   * Adds annotation conditions for a single node.
   * @param conditions Condition list where the conditions should be added to
   * @param index Index for a specific annotation
   * @param annotation The annotation to add
   * @param table Table to operate on
   * @param tas {@link TableAccessStrategy} for the given node.
   */
  public void addAnnotationConditions(Collection<String> conditions,
    int index, QueryAnnotation annotation, String table,
    TableAccessStrategy tas)
  {
    TextMatching tm = annotation.getTextMatching();

    String column = annotation.getNamespace() == null
      ? "annotext" : "qannotext";

    Escaper escaper = tm != null && tm.isRegex() ? regexEscaper : likeEscaper;

    String val;
    if (tm == null)
    {
      val = "%";
    }
    else
    {
      val = escaper.escape(annotation.getValue());
    }

    String prefix;
    if (annotation.getNamespace() == null)
    {
      prefix = escaper.escape(annotation.getName()) + ":";
    }
    else
    {
      prefix = escaper.escape(annotation.getNamespace())
        + ":" + escaper.escape(annotation.getName()) + ":";
    }

    if (tm == null || tm == TextMatching.EXACT_EQUAL)
    {
      conditions.add(tas.aliasedColumn(table, column, index)
        + " LIKE '" + prefix + val + "'");
    }
    else if (tm == TextMatching.EXACT_NOT_EQUAL)
    {
      conditions.add(tas.aliasedColumn(table, column, index)
        + " LIKE '" + prefix +  "%'");
      conditions.add(tas.aliasedColumn(table, column, index)
        + " NOT LIKE '" + prefix + val + "'");
    }
    else if (tm == TextMatching.REGEXP_EQUAL)
    {
      conditions.add(tas.aliasedColumn(table, column, index)
        + " ~ '^(" + prefix + "(" + val + "))$'");
    }
    else if (tm == TextMatching.REGEXP_NOT_EQUAL)
    {
      conditions.add(tas.aliasedColumn(table, column, index)
        + " LIKE '" + prefix +  "%'");
      conditions.add(tas.aliasedColumn(table, column, index)
        + " !~ '^(" + prefix + "(" +  val + "))$'");
    }
  }

  public void addEqualValueConditions(Collection<String> conditions, QueryNode node,
    QueryNode target, TableAccessStrategy tasNode, TableAccessStrategy tasTarget,
    boolean equal)
  {
    String op = equal ? "=" : "<>";

    if (node.isToken() && target.isToken())
    {
      // join on span
      conditions.add(tasNode.aliasedColumn(NODE_TABLE, "span")
        + " " + op + " " + tasTarget.aliasedColumn(NODE_TABLE, "span"));
    }
    else if (haveSameNodeAnnotationDefinitions(
      node.getNodeAnnotations(), target.getNodeAnnotations()))
    {
      // join on node_anno_ref
      conditions.add(tasNode.aliasedColumn(NODE_ANNOTATION_TABLE, "qannotext")
        + " " + op + " " + tasTarget.aliasedColumn(NODE_ANNOTATION_TABLE, "qannotext"));
    }
    else
    {
      // most complex query, join on the actual value
      String left;
      if (node.isToken())
      {
        left = tasNode.aliasedColumn(NODE_TABLE, "span");
      }
      else
      {
        left = "(splitanno("
          + tasNode.aliasedColumn(NODE_ANNOTATION_TABLE, "qannotext") 
          +"))[3]";
      }
      String right;
      if (target.isToken())
      {
        right = tasTarget.aliasedColumn(NODE_TABLE, "span");
      }
      else
      {
        right = "(splitanno("
          + tasTarget.aliasedColumn(NODE_ANNOTATION_TABLE, "qannotext") 
          +"))[3]";
      }
      conditions.add(left + " " + op + " " + right);
    }

  }

  private boolean haveSameNodeAnnotationDefinitions(
    Set<QueryAnnotation> sourceAnnos,
    Set<QueryAnnotation> targetAnnos)
  {
    if (sourceAnnos != null && targetAnnos != null
      && sourceAnnos.size() == 1 && targetAnnos.size() == 1)
    {
      QueryAnnotation anno1 = sourceAnnos.iterator().next();
      QueryAnnotation anno2 = targetAnnos.iterator().next();

      if (Objects.equal(anno1.getNamespace(), anno2.getNamespace())
        && Objects.equal(anno1.getName(), anno2.getName()))
      {
        return true;
      }
    }

    return false;
  }

  public String getNodeAnnoNamespaceSQL(TableAccessStrategy tas)
  {
    return tas.aliasedColumn("annotation_category", "namespace");
  }

  public String getNodeAnnoNameSQL(TableAccessStrategy tas)
  {
    return tas.aliasedColumn("annotation_category", "name");
  }

}