content: /*
   * Copyright (c) 2016, 2020, Oracle and/or its affiliates.
   *
   * This program is free software; you can redistribute it and/or modify it under
   * the terms of the GNU General Public License, version 2.0, as published by the
   * Free Software Foundation.
   *
   * This program is also distributed with certain software (including but not
   * limited to OpenSSL) that is licensed under separate terms, as designated in a
   * particular file or component or in included license documentation. The
   * authors of MySQL hereby grant you an additional permission to link the
   * program and your derivative works with the separately licensed software that
   * they have included with MySQL.
   *
   * Without limiting anything contained in the foregoing, this file, which is
   * part of MySQL Connector/J, is also subject to the Universal FOSS Exception,
   * version 1.0, a copy of which can be found at
   * http://oss.oracle.com/licenses/universal-foss-exception.
   *
   * This program is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
   * FOR A PARTICULAR PURPOSE. See the GNU General Public License, version 2.0,
   * for more details.
   *
   * You should have received a copy of the GNU General Public License along with
   * this program; if not, write to the Free Software Foundation, Inc.,
   * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
   */
  
  package com.mysql.cj.result;
  
  import java.util.HashMap;
  import java.util.Map;
  import java.util.TreeMap;
  
  import com.mysql.cj.protocol.ColumnDefinition;
  
  /**
   * Protocol::ColumnDefinition41 object
   *
   */
  public class DefaultColumnDefinition implements ColumnDefinition {
  
      protected Field[] fields;
  
      /** Map column names (and all of their permutations) to column indices */
      private Map<String, Integer> columnLabelToIndex = null;
  
      /**
       * The above map is a case-insensitive tree-map, it can be slow, this caches lookups into that map, because the other alternative is to create new
       * object instances for every call to findColumn()....
       */
      private Map<String, Integer> columnToIndexCache = new HashMap<>();
  
      /** Map of fully-specified column names to column indices */
      private Map<String, Integer> fullColumnNameToIndex = null;
  
      /** Map column names (and all of their permutations) to column indices */
      private Map<String, Integer> columnNameToIndex = null;
  
      private boolean builtIndexMapping = false;
  
      public DefaultColumnDefinition() {
      }
  
      public DefaultColumnDefinition(Field[] fields) {
          this.fields = fields;
      }
  
      public Field[] getFields() {
          return this.fields;
      }
  
      public void setFields(Field[] fields) {
          this.fields = fields;
      }
  
      @Override
  
      /**
       * Builds a hash between column names and their indices for fast retrieval.
       */
      public void buildIndexMapping() {
          int numFields = this.fields.length;
          this.columnLabelToIndex = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
          this.fullColumnNameToIndex = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
          this.columnNameToIndex = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
  
          // We do this in reverse order, so that the 'first' column with a given name ends up as the final mapping in the hashtable...
          //
          // Quoting the JDBC Spec:
          //
          // "Column names used as input to getter methods are case insensitive. When a getter method is called with a column name and several columns have the
          // same name, the value of the first matching column will be returned. "
          //
          for (int i = numFields - 1; i >= 0; i--) {
              Integer index = Integer.valueOf(i);
              String columnName = this.fields[i].getOriginalName();
              String columnLabel = this.fields[i].getName();
              String fullColumnName = this.fields[i].getFullName();
  
              if (columnLabel != null) {
                  this.columnLabelToIndex.put(columnLabel, index);
              }
  
              if (fullColumnName != null) {
                  this.fullColumnNameToIndex.put(fullColumnName, index);
              }
  
              if (columnName != null) {
                  this.columnNameToIndex.put(columnName, index);
              }
          }
  
          // set the flag to prevent rebuilding...
          this.builtIndexMapping = true;
      }
  
      public boolean hasBuiltIndexMapping() {
          return this.builtIndexMapping;
      }
  
      public Map<String, Integer> getColumnLabelToIndex() {
          return this.columnLabelToIndex;
      }
  
      public void setColumnLabelToIndex(Map<String, Integer> columnLabelToIndex) {
          this.columnLabelToIndex = columnLabelToIndex;
      }
  
      public Map<String, Integer> getFullColumnNameToIndex() {
          return this.fullColumnNameToIndex;
      }
  
      public void setFullColumnNameToIndex(Map<String, Integer> fullColNameToIndex) {
          this.fullColumnNameToIndex = fullColNameToIndex;
      }
  
      public Map<String, Integer> getColumnNameToIndex() {
          return this.columnNameToIndex;
      }
  
      public void setColumnNameToIndex(Map<String, Integer> colNameToIndex) {
          this.columnNameToIndex = colNameToIndex;
      }
  
      public Map<String, Integer> getColumnToIndexCache() {
          return this.columnToIndexCache;
      }
  
      public void setColumnToIndexCache(Map<String, Integer> columnToIndexCache) {
          this.columnToIndexCache = columnToIndexCache;
      }
  
      public void initializeFrom(ColumnDefinition columnDefinition) {
          this.fields = columnDefinition.getFields();
          this.columnLabelToIndex = columnDefinition.getColumnNameToIndex();
          this.fullColumnNameToIndex = columnDefinition.getFullColumnNameToIndex();
          this.builtIndexMapping = true;
      }
  
      public void exportTo(ColumnDefinition columnDefinition) {
          columnDefinition.setFields(this.fields);
          columnDefinition.setColumnNameToIndex(this.columnLabelToIndex);
          columnDefinition.setFullColumnNameToIndex(this.fullColumnNameToIndex);
      }
  
      public int findColumn(String columnName, boolean useColumnNamesInFindColumn, int indexBase) {
  
          Integer index;
  
          if (!hasBuiltIndexMapping()) {
              buildIndexMapping();
          }
  
          index = this.columnToIndexCache.get(columnName);
  
          if (index != null) {
              return index.intValue() + indexBase;
          }
  
          index = this.columnLabelToIndex.get(columnName);
  
          if (index == null && useColumnNamesInFindColumn) {
              index = this.columnNameToIndex.get(columnName);
          }
  
          if (index == null) {
              index = this.fullColumnNameToIndex.get(columnName);
          }
  
          if (index != null) {
              this.columnToIndexCache.put(columnName, index);
  
              return index.intValue() + indexBase;
          }
  
          // Try this inefficient way, now
  
          for (int i = 0; i < this.fields.length; i++) {
              if (this.fields[i].getName().equalsIgnoreCase(columnName)) {
                  return i + indexBase;
              } else if (this.fields[i].getFullName().equalsIgnoreCase(columnName)) {
                  return i + indexBase;
              }
          }
  
          return -1;
      }
  
      /**
       * Check if fields with type BLOB, MEDIUMBLOB, LONGBLOB, TEXT, MEDIUMTEXT or LONGTEXT
       * exist in this ColumnDefinition.
       * This check is used for making a decision about whether we want to force a
       * buffer row (better for rows with large fields).
       * 
       * @return true if this ColumnDefinition has large fields
       */
      public boolean hasLargeFields() {
          if (this.fields != null) {
              for (int i = 0; i < this.fields.length; i++) {
                  switch (this.fields[i].getMysqlType()) {
                      case BLOB:
                      case MEDIUMBLOB:
                      case LONGBLOB:
                      case TEXT:
                      case MEDIUMTEXT:
                      case LONGTEXT:
                      case JSON:
                          return true;
                      default:
                          break;
                  }
              }
          }
          return false;
      }
  
  }
  