content: /*
   * Copyright (c) 2015, 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.x;
  
  import java.io.IOException;
  import java.math.BigDecimal;
  import java.math.BigInteger;
  import java.nio.ByteBuffer;
  import java.nio.CharBuffer;
  
  import com.google.protobuf.CodedInputStream;
  import com.mysql.cj.exceptions.AssertionFailedException;
  import com.mysql.cj.exceptions.DataReadException;
  import com.mysql.cj.protocol.InternalDate;
  import com.mysql.cj.protocol.InternalTime;
  import com.mysql.cj.protocol.InternalTimestamp;
  import com.mysql.cj.protocol.ValueDecoder;
  import com.mysql.cj.result.Field;
  import com.mysql.cj.result.ValueFactory;
  
  public class XProtocolDecoder implements ValueDecoder {
  
      public static XProtocolDecoder instance = new XProtocolDecoder();
  
      @Override
      public <T> T decodeDate(byte[] bytes, int offset, int length, ValueFactory<T> vf) {
          return decodeTimestamp(bytes, offset, length, 0, vf);
      }
  
      @Override
      public <T> T decodeTime(byte[] bytes, int offset, int length, int scale, ValueFactory<T> vf) {
          try {
              CodedInputStream inputStream = CodedInputStream.newInstance(bytes, offset, length);
              boolean negative = inputStream.readRawByte() > 0;
              int hours = 0;
              int minutes = 0;
              int seconds = 0;
  
              int nanos = 0;
  
              if (!inputStream.isAtEnd()) {
                  hours = (int) inputStream.readInt64();
                  if (!inputStream.isAtEnd()) {
                      minutes = (int) inputStream.readInt64();
                      if (!inputStream.isAtEnd()) {
                          seconds = (int) inputStream.readInt64();
                          if (!inputStream.isAtEnd()) {
                              nanos = 1000 * (int) inputStream.readInt64();
                          }
                      }
                  }
              }
  
              return vf.createFromTime(new InternalTime(negative ? -1 * hours : hours, minutes, seconds, nanos, scale));
          } catch (IOException e) {
              throw new DataReadException(e);
          }
      }
  
      @Override
      public <T> T decodeTimestamp(byte[] bytes, int offset, int length, int scale, ValueFactory<T> vf) {
          try {
              CodedInputStream inputStream = CodedInputStream.newInstance(bytes, offset, length);
              int year = (int) inputStream.readUInt64();
              int month = (int) inputStream.readUInt64();
              int day = (int) inputStream.readUInt64();
  
              // do we have a time too?
              if (inputStream.getBytesUntilLimit() > 0) {
                  int hours = 0;
                  int minutes = 0;
                  int seconds = 0;
  
                  int nanos = 0;
  
                  if (!inputStream.isAtEnd()) {
                      hours = (int) inputStream.readInt64();
                      if (!inputStream.isAtEnd()) {
                          minutes = (int) inputStream.readInt64();
                          if (!inputStream.isAtEnd()) {
                              seconds = (int) inputStream.readInt64();
                              if (!inputStream.isAtEnd()) {
                                  nanos = 1000 * (int) inputStream.readInt64();
                              }
                          }
                      }
                  }
  
                  return vf.createFromTimestamp(new InternalTimestamp(year, month, day, hours, minutes, seconds, nanos, scale));
              }
              return vf.createFromDate(new InternalDate(year, month, day));
          } catch (IOException e) {
              throw new DataReadException(e);
          }
      }
  
      @Override
      public <T> T decodeDatetime(byte[] bytes, int offset, int length, int scale, ValueFactory<T> vf) {
          try {
              CodedInputStream inputStream = CodedInputStream.newInstance(bytes, offset, length);
              int year = (int) inputStream.readUInt64();
              int month = (int) inputStream.readUInt64();
              int day = (int) inputStream.readUInt64();
  
              // do we have a time too?
              if (inputStream.getBytesUntilLimit() > 0) {
                  int hours = 0;
                  int minutes = 0;
                  int seconds = 0;
  
                  int nanos = 0;
  
                  if (!inputStream.isAtEnd()) {
                      hours = (int) inputStream.readInt64();
                      if (!inputStream.isAtEnd()) {
                          minutes = (int) inputStream.readInt64();
                          if (!inputStream.isAtEnd()) {
                              seconds = (int) inputStream.readInt64();
                              if (!inputStream.isAtEnd()) {
                                  nanos = 1000 * (int) inputStream.readInt64();
                              }
                          }
                      }
                  }
  
                  return vf.createFromDatetime(new InternalTimestamp(year, month, day, hours, minutes, seconds, nanos, scale));
              }
              return vf.createFromDate(new InternalDate(year, month, day));
          } catch (IOException e) {
              throw new DataReadException(e);
          }
      }
  
      @Override
      public <T> T decodeInt1(byte[] bytes, int offset, int length, ValueFactory<T> vf) {
          // TODO Auto-generated method stub
          return null;
      }
  
      @Override
      public <T> T decodeUInt1(byte[] bytes, int offset, int length, ValueFactory<T> vf) {
          // TODO Auto-generated method stub
          return null;
      }
  
      @Override
      public <T> T decodeInt2(byte[] bytes, int offset, int length, ValueFactory<T> vf) {
          // TODO Auto-generated method stub
          return null;
      }
  
      @Override
      public <T> T decodeUInt2(byte[] bytes, int offset, int length, ValueFactory<T> vf) {
          // TODO Auto-generated method stub
          return null;
      }
  
      @Override
      public <T> T decodeInt4(byte[] bytes, int offset, int length, ValueFactory<T> vf) {
          // TODO Auto-generated method stub
          return null;
      }
  
      @Override
      public <T> T decodeUInt4(byte[] bytes, int offset, int length, ValueFactory<T> vf) {
          // TODO Auto-generated method stub
          return null;
      }
  
      @Override
      public <T> T decodeInt8(byte[] bytes, int offset, int length, ValueFactory<T> vf) {
          try {
              return vf.createFromLong(CodedInputStream.newInstance(bytes, offset, length).readSInt64());
          } catch (IOException e) {
              throw new DataReadException(e);
          }
      }
  
      @Override
      public <T> T decodeUInt8(byte[] bytes, int offset, int length, ValueFactory<T> vf) {
          try {
              // protobuf stores an unsigned 64bit int into a java long with the highest bit as the sign, we re-interpret it using ByteBuffer (with a prepended
              // 0-byte to avoid negative)
              BigInteger v = new BigInteger(
                      ByteBuffer.allocate(9).put((byte) 0).putLong(CodedInputStream.newInstance(bytes, offset, length).readUInt64()).array());
              return vf.createFromBigInteger(v);
          } catch (IOException e) {
              throw new DataReadException(e);
          }
      }
  
      @Override
      public <T> T decodeFloat(byte[] bytes, int offset, int length, ValueFactory<T> vf) {
          try {
              return vf.createFromDouble(CodedInputStream.newInstance(bytes, offset, length).readFloat());
          } catch (IOException e) {
              throw new DataReadException(e);
          }
      }
  
      @Override
      public <T> T decodeDouble(byte[] bytes, int offset, int length, ValueFactory<T> vf) {
          try {
              return vf.createFromDouble(CodedInputStream.newInstance(bytes, offset, length).readDouble());
          } catch (IOException e) {
              throw new DataReadException(e);
          }
      }
  
      @Override
      public <T> T decodeDecimal(byte[] bytes, int offset, int length, ValueFactory<T> vf) {
          try {
              CodedInputStream inputStream = CodedInputStream.newInstance(bytes, offset, length);
              // packed BCD format (c.f. wikipedia)
              // TODO: optimization possibilities include using int/long if the digits is < X and scale = 0
              byte scale = inputStream.readRawByte();
              // we allocate an extra char for the sign
              CharBuffer unscaledString = CharBuffer.allocate(2 * inputStream.getBytesUntilLimit());
              unscaledString.position(1);
              byte sign = 0;
              // read until we encounter the sign bit
              while (true) {
                  int b = 0xFF & inputStream.readRawByte();
                  if ((b >> 4) > 9) {
                      sign = (byte) (b >> 4);
                      break;
                  }
                  unscaledString.append((char) ((b >> 4) + '0'));
                  if ((b & 0x0f) > 9) {
                      sign = (byte) (b & 0x0f);
                      break;
                  }
                  unscaledString.append((char) ((b & 0x0f) + '0'));
              }
              if (inputStream.getBytesUntilLimit() > 0) {
                  throw AssertionFailedException
                          .shouldNotHappen("Did not read all bytes while decoding decimal. Bytes left: " + inputStream.getBytesUntilLimit());
              }
              switch (sign) {
                  case 0xa:
                  case 0xc:
                  case 0xe:
                  case 0xf:
                      unscaledString.put(0, '+');
                      break;
                  case 0xb:
                  case 0xd:
                      unscaledString.put(0, '-');
                      break;
              }
              // may have filled the CharBuffer or one remaining. need to remove it before toString()
              int characters = unscaledString.position();
              unscaledString.clear(); // reset position
              BigInteger unscaled = new BigInteger(unscaledString.subSequence(0, characters).toString());
              return vf.createFromBigDecimal(new BigDecimal(unscaled, scale));
          } catch (IOException e) {
              throw new DataReadException(e);
          }
      }
  
      @Override
      public <T> T decodeByteArray(byte[] bytes, int offset, int length, Field f, ValueFactory<T> vf) {
          try {
              CodedInputStream inputStream = CodedInputStream.newInstance(bytes, offset, length);
              // c.f. Streaming_command_delegate::get_string()
              int size = inputStream.getBytesUntilLimit();
              size--; // for null terminator
              return vf.createFromBytes(inputStream.readRawBytes(size), 0, size, f);
          } catch (IOException e) {
              throw new DataReadException(e);
          }
      }
  
      @Override
      public <T> T decodeBit(byte[] bytes, int offset, int length, ValueFactory<T> vf) {
          try {
              // protobuf stores an unsigned 64bit int into a java long with the highest bit as the sign, we re-interpret it using ByteBuffer (with a prepended
              // 0-byte to avoid negative)
              byte[] buf = ByteBuffer.allocate(Long.BYTES + 1).put((byte) 0).putLong(CodedInputStream.newInstance(bytes, offset, length).readUInt64()).array();
              return vf.createFromBit(buf, 0, Long.BYTES + 1);
          } catch (IOException e) {
              throw new DataReadException(e);
          }
      }
  
      @Override
      public <T> T decodeSet(byte[] bytes, int offset, int length, Field f, ValueFactory<T> vf) {
          try {
              CodedInputStream inputStream = CodedInputStream.newInstance(bytes, offset, length);
              StringBuilder vals = new StringBuilder();
              while (inputStream.getBytesUntilLimit() > 0) {
                  if (vals.length() > 0) {
                      vals.append(",");
                  }
                  long valLen = inputStream.readUInt64();
                  // TODO: charset
                  vals.append(new String(inputStream.readRawBytes((int) valLen)));
              }
              // TODO: charset mess here
              byte[] buf = vals.toString().getBytes();
              return vf.createFromBytes(buf, 0, buf.length, f);
          } catch (IOException e) {
              throw new DataReadException(e);
          }
      }
  
      @Override
      public <T> T decodeYear(byte[] bytes, int offset, int length, ValueFactory<T> vf) {
          // TODO Auto-generated method stub
          return null;
      }
  }
  