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.protocol.a;
  
  import com.mysql.cj.Messages;
  import com.mysql.cj.MysqlType;
  import com.mysql.cj.conf.PropertyKey;
  import com.mysql.cj.exceptions.ExceptionFactory;
  import com.mysql.cj.protocol.ColumnDefinition;
  import com.mysql.cj.protocol.ProtocolEntityFactory;
  import com.mysql.cj.protocol.Resultset;
  import com.mysql.cj.protocol.Resultset.Concurrency;
  import com.mysql.cj.protocol.ResultsetRow;
  import com.mysql.cj.protocol.a.NativeConstants.StringLengthDataType;
  import com.mysql.cj.protocol.a.NativeConstants.StringSelfDataType;
  import com.mysql.cj.protocol.a.result.BinaryBufferRow;
  import com.mysql.cj.protocol.a.result.ByteArrayRow;
  import com.mysql.cj.result.Field;
  
  /**
   * Handle binary-encoded data for server-side PreparedStatements
   *
   */
  public class BinaryRowFactory extends AbstractRowFactory implements ProtocolEntityFactory<ResultsetRow, NativePacketPayload> {
  
      public BinaryRowFactory(NativeProtocol protocol, ColumnDefinition columnDefinition, Resultset.Concurrency resultSetConcurrency,
              boolean canReuseRowPacketForBufferRow) {
          this.columnDefinition = columnDefinition;
          this.resultSetConcurrency = resultSetConcurrency;
          this.canReuseRowPacketForBufferRow = canReuseRowPacketForBufferRow;
          this.useBufferRowSizeThreshold = protocol.getPropertySet().getMemorySizeProperty(PropertyKey.largeRowSizeThreshold);
          this.exceptionInterceptor = protocol.getExceptionInterceptor();
          this.valueDecoder = new MysqlBinaryValueDecoder();
      }
  
      @Override
      public ResultsetRow createFromMessage(NativePacketPayload rowPacket) {
  
          // use a buffer row for reusable packets (streaming results), blobs and long strings
          // or if we're over the threshold
          boolean useBufferRow = this.canReuseRowPacketForBufferRow || this.columnDefinition.hasLargeFields()
                  || rowPacket.getPayloadLength() >= this.useBufferRowSizeThreshold.getValue();
  
          // bump past ProtocolBinary::ResultsetRow packet header
          rowPacket.setPosition(rowPacket.getPosition() + 1);
  
          if (this.resultSetConcurrency == Concurrency.UPDATABLE || !useBufferRow) {
              return unpackBinaryResultSetRow(this.columnDefinition.getFields(), rowPacket);
          }
  
          return new BinaryBufferRow(rowPacket, this.columnDefinition, this.exceptionInterceptor, this.valueDecoder);
      }
  
      @Override
      public boolean canReuseRowPacketForBufferRow() {
          return this.canReuseRowPacketForBufferRow;
      }
  
      /**
       * Un-packs binary-encoded result set data for one row
       * 
       * @param fields
       *            {@link Field}s array
       * @param binaryData
       *            data
       * 
       * @return byte[][]
       */
      private final ResultsetRow unpackBinaryResultSetRow(Field[] fields, NativePacketPayload binaryData) {
          int numFields = fields.length;
  
          byte[][] unpackedRowBytes = new byte[numFields][];
  
          //
          // Unpack the null bitmask, first
          //
  
          int nullCount = (numFields + 9) / 8;
          int nullMaskPos = binaryData.getPosition();
          binaryData.setPosition(nullMaskPos + nullCount);
          int bit = 4; // first two bits are reserved for future use
  
          byte[] buf = binaryData.getByteBuffer();
          for (int i = 0; i < numFields; i++) {
              if ((buf[nullMaskPos] & bit) != 0) {
                  unpackedRowBytes[i] = null;
              } else {
                  extractNativeEncodedColumn(binaryData, fields, i, unpackedRowBytes);
              }
  
              if (((bit <<= 1) & 255) == 0) {
                  bit = 1; /* To next byte */
  
                  nullMaskPos++;
              }
          }
  
          return new ByteArrayRow(unpackedRowBytes, this.exceptionInterceptor, new MysqlBinaryValueDecoder());
      }
  
      /**
       * Copy the raw result bytes from the
       * 
       * @param binaryData
       *            packet to the
       * @param fields
       *            {@link Field}s array
       * @param columnIndex
       *            column index
       * @param unpackedRowData
       *            byte array.
       */
      private final void extractNativeEncodedColumn(NativePacketPayload binaryData, Field[] fields, int columnIndex, byte[][] unpackedRowData) {
          int type = fields[columnIndex].getMysqlTypeId();
  
          int len = NativeUtils.getBinaryEncodedLength(type);
  
          if (type == MysqlType.FIELD_TYPE_NULL) {
              // Do nothing
          } else if (len == 0) {
              unpackedRowData[columnIndex] = binaryData.readBytes(StringSelfDataType.STRING_LENENC);
          } else if (len > 0) {
              unpackedRowData[columnIndex] = binaryData.readBytes(StringLengthDataType.STRING_FIXED, len);
          } else {
              throw ExceptionFactory.createException(Messages.getString("MysqlIO.97", new Object[] { type, columnIndex, fields.length }));
          }
      }
  }
  