/*
 *
 * MariaDB Client for Java
 *
 * Copyright (c) 2012-2014 Monty Program Ab.
 * Copyright (c) 2015-2020 MariaDB Corporation Ab.
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library 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 Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along
 * with this library; if not, write to Monty Program Ab info@montyprogram.com.
 *
 * This particular MariaDB Client for Java file is work
 * derived from a Drizzle-JDBC. Drizzle-JDBC file which is covered by subject to
 * the following copyright and notice provisions:
 *
 * Copyright (c) 2009-2011, Marcus Eriksson
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * Redistributions of source code must retain the above copyright notice, this list
 * of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice, this
 * list of conditions and the following disclaimer in the documentation and/or
 * other materials provided with the distribution.
 *
 * Neither the name of the driver nor the names of its contributors may not be
 * used to endorse or promote products derived from this software without specific
 * prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS  AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 */

package org.mariadb.jdbc.internal.io.output;

import java.io.*;
import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import org.mariadb.jdbc.internal.io.LruTraceCache;
import org.mariadb.jdbc.internal.util.exceptions.MaxAllowedPacketException;

public abstract class AbstractPacketOutputStream extends FilterOutputStream
    implements PacketOutputStream {

  private static final byte QUOTE = (byte) '\'';
  private static final byte DBL_QUOTE = (byte) '"';
  private static final byte ZERO_BYTE = (byte) '\0';
  private static final byte BACKSLASH = (byte) '\\';

  private static final int SMALL_BUFFER_SIZE = 8192;
  private static final int MEDIUM_BUFFER_SIZE = 128 * 1024;
  private static final int LARGE_BUFFER_SIZE = 1024 * 1024;
  protected final int maxQuerySizeToLog;
  protected byte[] buf;
  protected int pos;
  protected int maxAllowedPacket = Integer.MAX_VALUE;
  protected long cmdLength;
  protected boolean permitTrace;
  protected int seqNo = 0;
  protected String serverThreadLog = "";
  protected LruTraceCache traceCache = null;
  private int mark = -1;
  private boolean bufferContainDataAfterMark = false;
  protected long threadId;

  /**
   * Common feature to write data into socket, creating MariaDB Packet.
   *
   * @param out socket outputStream
   * @param maxQuerySizeToLog maximum query size to log
   * @param threadId thread id
   */
  public AbstractPacketOutputStream(OutputStream out, int maxQuerySizeToLog, long threadId) {
    super(out);
    buf = new byte[SMALL_BUFFER_SIZE];
    this.maxQuerySizeToLog = maxQuerySizeToLog;
    cmdLength = 0;
    this.threadId = threadId;
  }

  public abstract int getMaxPacketLength();

  public abstract void startPacket(int seqNo);

  protected abstract void flushBuffer(boolean commandEnd) throws IOException;

  /**
   * Buffer growing use 4 size only to avoid creating/copying that are expensive operations.
   * possible size
   *
   * <ol>
   *   <li>SMALL_BUFFER_SIZE = 8k (default)
   *   <li>MEDIUM_BUFFER_SIZE = 128k
   *   <li>LARGE_BUFFER_SIZE = 1M
   *   <li>getMaxPacketLength = 16M (+ 4 is using no compression)
   * </ol>
   *
   * @param len length to add
   */
  private void growBuffer(int len) throws IOException {
    int bufferLength = buf.length;
    int newCapacity;
    if (bufferLength == SMALL_BUFFER_SIZE) {
      if (len + pos < MEDIUM_BUFFER_SIZE) {
        newCapacity = MEDIUM_BUFFER_SIZE;
      } else if (len + pos < LARGE_BUFFER_SIZE) {
        newCapacity = LARGE_BUFFER_SIZE;
      } else {
        newCapacity = getMaxPacketLength();
      }
    } else if (bufferLength == MEDIUM_BUFFER_SIZE) {
      if (len + pos < LARGE_BUFFER_SIZE) {
        newCapacity = LARGE_BUFFER_SIZE;
      } else {
        newCapacity = getMaxPacketLength();
      }
    } else if (bufferContainDataAfterMark) {
      // want to add some information to buffer without having the command Header
      // must grow buffer until having all the query
      newCapacity = Math.max(len + pos, getMaxPacketLength());
    } else {
      newCapacity = getMaxPacketLength();
    }

    if (mark != -1 && len + pos > newCapacity) {
      // buffer is > 16M with mark.
      // flush until mark, reset pos at beginning
      flushBufferStopAtMark();

      if (len + pos <= bufferLength) {
        return;
      }

      // need to keep all data, buffer can grow more than maxPacketLength
      // grow buffer if needed
      if (len + pos > newCapacity) {
        newCapacity = len + pos;
      }
    }

    byte[] newBuf = new byte[newCapacity];
    System.arraycopy(buf, 0, newBuf, 0, pos);
    buf = newBuf;
  }

  /**
   * Send empty packet.
   *
   * @param seqNo packet sequence
   * @throws IOException if socket error occur.
   */
  public void writeEmptyPacket(int seqNo) throws IOException {
    startPacket(seqNo);
    writeEmptyPacket();
    out.flush();
    cmdLength = 0;
  }

  public abstract void writeEmptyPacket() throws IOException;

  /**
   * Send packet to socket.
   *
   * @throws IOException if socket error occur.
   */
  public void flush() throws IOException {
    flushBuffer(true);
    out.flush();

    // if buffer is big, and last query doesn't use at least half of it, resize buffer to default
    // value
    if (buf.length > SMALL_BUFFER_SIZE && cmdLength * 2 < buf.length) {
      buf = new byte[SMALL_BUFFER_SIZE];
    }

    if (cmdLength >= maxAllowedPacket) {
      throw new MaxAllowedPacketException(
          "query size (" + cmdLength + ") is >= to max_allowed_packet (" + maxAllowedPacket + ")",
          true);
    }
  }

  public boolean checkRemainingSize(int len) {
    return getMaxPacketLength() - pos > len;
  }

  /**
   * Count query size. If query size is greater than max_allowed_packet and nothing has been already
   * send, throw an exception to avoid having the connection closed.
   *
   * @param length additional length to query size
   * @throws MaxAllowedPacketException if query has not to be send.
   */
  public void checkMaxAllowedLength(int length) throws MaxAllowedPacketException {
    if (cmdLength + length >= maxAllowedPacket && cmdLength == 0) {
      // launch exception only if no packet has been send.
      throw new MaxAllowedPacketException(
          "query size ("
              + (cmdLength + length)
              + ") is >= to max_allowed_packet ("
              + maxAllowedPacket
              + ")",
          false);
    }
  }

  public boolean exceedMaxLength() {
    return cmdLength + (pos - initialPacketPos()) >= maxAllowedPacket;
  }

  public OutputStream getOutputStream() {
    return out;
  }

  /**
   * Write short value into buffer. flush buffer if too small.
   *
   * @param value short value
   * @throws IOException if socket error occur
   */
  public void writeShort(short value) throws IOException {
    if (2 > buf.length - pos) {
      // not enough space remaining
      byte[] arr = new byte[2];
      arr[0] = (byte) value;
      arr[1] = (byte) (value >> 8);
      write(arr, 0, 2);
      return;
    }

    buf[pos] = (byte) value;
    buf[pos + 1] = (byte) (value >> 8);
    pos += 2;
  }

  /**
   * Write int value into buffer. flush buffer if too small.
   *
   * @param value int value
   * @throws IOException if socket error occur
   */
  public void writeInt(int value) throws IOException {
    if (4 > buf.length - pos) {
      // not enough space remaining
      byte[] arr = new byte[4];
      arr[0] = (byte) value;
      arr[1] = (byte) (value >> 8);
      arr[2] = (byte) (value >> 16);
      arr[3] = (byte) (value >> 24);
      write(arr, 0, 4);
      return;
    }

    buf[pos] = (byte) value;
    buf[pos + 1] = (byte) (value >> 8);
    buf[pos + 2] = (byte) (value >> 16);
    buf[pos + 3] = (byte) (value >> 24);
    pos += 4;
  }

  /**
   * Write long value into buffer. flush buffer if too small.
   *
   * @param value long value
   * @throws IOException if socket error occur
   */
  public void writeLong(long value) throws IOException {
    if (8 > buf.length - pos) {
      // not enough space remaining
      byte[] arr = new byte[8];
      arr[0] = (byte) value;
      arr[1] = (byte) (value >> 8);
      arr[2] = (byte) (value >> 16);
      arr[3] = (byte) (value >> 24);
      arr[4] = (byte) (value >> 32);
      arr[5] = (byte) (value >> 40);
      arr[6] = (byte) (value >> 48);
      arr[7] = (byte) (value >> 56);
      write(arr, 0, 8);
      return;
    }

    buf[pos] = (byte) value;
    buf[pos + 1] = (byte) (value >> 8);
    buf[pos + 2] = (byte) (value >> 16);
    buf[pos + 3] = (byte) (value >> 24);
    buf[pos + 4] = (byte) (value >> 32);
    buf[pos + 5] = (byte) (value >> 40);
    buf[pos + 6] = (byte) (value >> 48);
    buf[pos + 7] = (byte) (value >> 56);
    pos += 8;
  }

  /**
   * Write byte value, len times into buffer. flush buffer if too small.
   *
   * @param value byte value
   * @param len number of time to write value.
   * @throws IOException if socket error occur.
   */
  public void writeBytes(byte value, int len) throws IOException {
    if (len > buf.length - pos) {
      // not enough space remaining
      byte[] arr = new byte[len];
      Arrays.fill(arr, value);
      write(arr, 0, len);
      return;
    }

    for (int i = pos; i < pos + len; i++) {
      buf[i] = value;
    }
    pos += len;
  }

  /**
   * Write field length into buffer, flush socket if needed.
   *
   * @param length field length
   * @throws IOException if socket error occur.
   */
  public void writeFieldLength(long length) throws IOException {
    if (length < 251) {

      write((byte) length);
      return;
    }

    if (length < 65536) {

      if (3 > buf.length - pos) {
        // not enough space remaining
        byte[] arr = new byte[3];
        arr[0] = (byte) 0xfc;
        arr[1] = (byte) length;
        arr[2] = (byte) (length >>> 8);
        write(arr, 0, 3);
        return;
      }

      buf[pos] = (byte) 0xfc;
      buf[pos + 1] = (byte) length;
      buf[pos + 2] = (byte) (length >>> 8);
      pos += 3;
      return;
    }

    if (length < 16777216) {

      if (4 > buf.length - pos) {
        // not enough space remaining
        byte[] arr = new byte[4];
        arr[0] = (byte) 0xfd;
        arr[1] = (byte) length;
        arr[2] = (byte) (length >>> 8);
        arr[3] = (byte) (length >>> 16);
        write(arr, 0, 4);
        return;
      }

      buf[pos] = (byte) 0xfd;
      buf[pos + 1] = (byte) length;
      buf[pos + 2] = (byte) (length >>> 8);
      buf[pos + 3] = (byte) (length >>> 16);
      pos += 4;
      return;
    }

    if (9 > buf.length - pos) {
      // not enough space remaining
      byte[] arr = new byte[9];
      arr[0] = (byte) 0xfe;
      arr[1] = (byte) length;
      arr[2] = (byte) (length >>> 8);
      arr[3] = (byte) (length >>> 16);
      arr[4] = (byte) (length >>> 24);
      arr[5] = (byte) (length >>> 32);
      arr[6] = (byte) (length >>> 40);
      arr[7] = (byte) (length >>> 48);
      arr[8] = (byte) (length >>> 56);
      write(arr, 0, 9);
      return;
    }

    buf[pos] = (byte) 0xfe;
    buf[pos + 1] = (byte) length;
    buf[pos + 2] = (byte) (length >>> 8);
    buf[pos + 3] = (byte) (length >>> 16);
    buf[pos + 4] = (byte) (length >>> 24);
    buf[pos + 5] = (byte) (length >>> 32);
    buf[pos + 6] = (byte) (length >>> 40);
    buf[pos + 7] = (byte) (length >>> 48);
    buf[pos + 8] = (byte) (length >>> 56);
    pos += 9;
  }

  /**
   * Write byte into buffer, flush buffer to socket if needed.
   *
   * @param value byte to send
   * @throws IOException if socket error occur.
   */
  public void write(int value) throws IOException {
    if (pos >= buf.length) {
      if (pos >= getMaxPacketLength() && !bufferContainDataAfterMark) {
        // buffer is more than a Packet, must flushBuffer()
        flushBuffer(false);
      } else {
        growBuffer(1);
      }
    }
    buf[pos++] = (byte) value;
  }

  public void write(byte[] arr) throws IOException {
    write(arr, 0, arr.length);
  }

  /**
   * Write byte array to buffer. If buffer is full, flush socket.
   *
   * @param arr byte array
   * @param off offset
   * @param len byte length to write
   * @throws IOException if socket error occur
   */
  public void write(byte[] arr, int off, int len) throws IOException {
    if (len > buf.length - pos) {
      if (buf.length != getMaxPacketLength()) {
        growBuffer(len);
      }

      // max buffer size
      if (len > buf.length - pos) {

        if (mark != -1) {
          growBuffer(len);
          if (mark != -1) {
            flushBufferStopAtMark();
          }

        } else {
          // not enough space in buffer, will stream :
          // fill buffer and flush until all data are snd
          int remainingLen = len;
          do {
            int lenToFillBuffer = Math.min(getMaxPacketLength() - pos, remainingLen);
            System.arraycopy(arr, off, buf, pos, lenToFillBuffer);
            remainingLen -= lenToFillBuffer;
            off += lenToFillBuffer;
            pos += lenToFillBuffer;
            if (remainingLen > 0) {
              flushBuffer(false);
            } else {
              break;
            }
          } while (true);
          return;
        }
      }
    }

    System.arraycopy(arr, off, buf, pos, len);
    pos += len;
  }

  public void write(String str) throws IOException {
    write(str, false, false);
  }

  /**
   * Write string to socket.
   *
   * @param str string
   * @param escape must be escape
   * @param noBackslashEscapes escape method
   * @throws IOException if socket error occur
   */
  public void write(String str, boolean escape, boolean noBackslashEscapes) throws IOException {

    int charsLength = str.length();

    // not enough space remaining
    if (charsLength * 3 + 2 >= buf.length - pos) {
      byte[] arr = str.getBytes(StandardCharsets.UTF_8);
      if (escape) {
        write(QUOTE);
        writeBytesEscaped(arr, arr.length, noBackslashEscapes);
        write(QUOTE);
      } else {
        write(arr, 0, arr.length);
      }
      return;
    }

    // create UTF-8 byte array
    // since java char are internally using UTF-16 using surrogate's pattern, 4 bytes unicode
    // characters will
    // represent 2 characters : example "\uD83C\uDFA4" = 🎤 unicode 8 "no microphones"
    // so max size is 3 * charLength
    // (escape characters are 1 byte encoded, so length might only be 2 when escape)
    // + 2 for the quotes for text protocol
    int charsOffset = 0;
    char currChar;

    // quick loop if only ASCII chars for faster escape
    if (escape) {
      buf[pos++] = QUOTE;
      if (noBackslashEscapes) {
        for (;
            charsOffset < charsLength && (currChar = str.charAt(charsOffset)) < 0x80;
            charsOffset++) {
          if (currChar == QUOTE) {
            buf[pos++] = QUOTE;
          }
          buf[pos++] = (byte) currChar;
        }
      } else {
        for (;
            charsOffset < charsLength && (currChar = str.charAt(charsOffset)) < 0x80;
            charsOffset++) {
          if (currChar == BACKSLASH
              || currChar == QUOTE
              || currChar == 0
              || currChar == DBL_QUOTE) {
            buf[pos++] = BACKSLASH;
          }
          buf[pos++] = (byte) currChar;
        }
      }
    } else {
      for (;
          charsOffset < charsLength && (currChar = str.charAt(charsOffset)) < 0x80;
          charsOffset++) {
        buf[pos++] = (byte) currChar;
      }
    }

    // if quick loop not finished
    while (charsOffset < charsLength) {
      currChar = str.charAt(charsOffset++);
      if (currChar < 0x80) {
        if (escape) {
          if (noBackslashEscapes) {
            if (currChar == QUOTE) {
              buf[pos++] = QUOTE;
            }
          } else if (currChar == BACKSLASH
              || currChar == QUOTE
              || currChar == ZERO_BYTE
              || currChar == DBL_QUOTE) {
            buf[pos++] = BACKSLASH;
          }
        }
        buf[pos++] = (byte) currChar;
      } else if (currChar < 0x800) {
        buf[pos++] = (byte) (0xc0 | (currChar >> 6));
        buf[pos++] = (byte) (0x80 | (currChar & 0x3f));
      } else if (currChar >= 0xD800 && currChar < 0xE000) {
        // reserved for surrogate - see https://en.wikipedia.org/wiki/UTF-16
        if (currChar < 0xDC00) {
          // is high surrogate
          if (charsOffset + 1 > charsLength) {
            buf[pos++] = (byte) 0x63;
          } else {
            char nextChar = str.charAt(charsOffset);
            if (nextChar >= 0xDC00 && nextChar < 0xE000) {
              // is low surrogate
              int surrogatePairs =
                  ((currChar << 10) + nextChar) + (0x010000 - (0xD800 << 10) - 0xDC00);
              buf[pos++] = (byte) (0xf0 | ((surrogatePairs >> 18)));
              buf[pos++] = (byte) (0x80 | ((surrogatePairs >> 12) & 0x3f));
              buf[pos++] = (byte) (0x80 | ((surrogatePairs >> 6) & 0x3f));
              buf[pos++] = (byte) (0x80 | (surrogatePairs & 0x3f));
              charsOffset++;
            } else {
              // must have low surrogate
              buf[pos++] = (byte) 0x3f;
            }
          }
        } else {
          // low surrogate without high surrogate before
          buf[pos++] = (byte) 0x3f;
        }
      } else {
        buf[pos++] = (byte) (0xe0 | ((currChar >> 12)));
        buf[pos++] = (byte) (0x80 | ((currChar >> 6) & 0x3f));
        buf[pos++] = (byte) (0x80 | (currChar & 0x3f));
      }
    }
    if (escape) {
      buf[pos++] = QUOTE;
    }
  }

  /**
   * Write stream into socket.
   *
   * @param is inputStream
   * @param escape must be escape
   * @param noBackslashEscapes escape method
   * @throws IOException if socket error occur
   */
  public void write(InputStream is, boolean escape, boolean noBackslashEscapes) throws IOException {
    byte[] array = new byte[4096];
    int len;
    if (escape) {
      while ((len = is.read(array)) > 0) {
        writeBytesEscaped(array, len, noBackslashEscapes);
      }
    } else {
      while ((len = is.read(array)) > 0) {
        write(array, 0, len);
      }
    }
  }

  /**
   * Write stream into socket.
   *
   * @param is inputStream
   * @param length write length
   * @param escape must be escape
   * @param noBackslashEscapes escape method
   * @throws IOException if socket error occur
   */
  public void write(InputStream is, long length, boolean escape, boolean noBackslashEscapes)
      throws IOException {
    byte[] array = new byte[4096];
    int len;
    while (length > 0 && (len = is.read(array, 0, Math.min(4096, (int) length))) > 0) {
      if (escape) {
        writeBytesEscaped(array, len, noBackslashEscapes);
      } else {
        write(array, 0, len);
      }
      length -= len;
    }
  }

  /**
   * Write reader into socket.
   *
   * @param reader reader
   * @param escape must be escape
   * @param noBackslashEscapes escape method
   * @throws IOException if socket error occur
   */
  public void write(Reader reader, boolean escape, boolean noBackslashEscapes) throws IOException {
    char[] buffer = new char[4096];
    int len;
    while ((len = reader.read(buffer)) >= 0) {
      byte[] data = new String(buffer, 0, len).getBytes(StandardCharsets.UTF_8);
      if (escape) {
        writeBytesEscaped(data, data.length, noBackslashEscapes);
      } else {
        write(data);
      }
    }
  }

  /**
   * Write reader into socket.
   *
   * @param reader reader
   * @param length write length
   * @param escape must be escape
   * @param noBackslashEscapes escape method
   * @throws IOException if socket error occur
   */
  public void write(Reader reader, long length, boolean escape, boolean noBackslashEscapes)
      throws IOException {
    char[] buffer = new char[4096];
    int len;
    while (length > 0 && (len = reader.read(buffer, 0, Math.min((int) length, 4096))) >= 0) {
      byte[] data = new String(buffer, 0, len).getBytes(StandardCharsets.UTF_8);
      if (escape) {
        writeBytesEscaped(data, data.length, noBackslashEscapes);
      } else {
        write(data);
      }
      length -= len;
    }
  }

  /**
   * Write escape bytes to socket.
   *
   * @param bytes bytes
   * @param len len to write
   * @param noBackslashEscapes escape method
   * @throws IOException if socket error occur
   */
  public void writeBytesEscaped(byte[] bytes, int len, boolean noBackslashEscapes)
      throws IOException {
    if (len * 2 > buf.length - pos) {

      // makes buffer bigger (up to 16M)
      if (buf.length != getMaxPacketLength()) {
        growBuffer(len * 2);
      }

      // data may be bigger than buffer.
      // must flush buffer when full (and reset position to 0)
      if (len * 2 > buf.length - pos) {

        if (mark != -1) {
          growBuffer(len * 2);
          if (mark != -1) {
            flushBufferStopAtMark();
          }

        } else {

          // not enough space in buffer, will fill buffer
          if (noBackslashEscapes) {
            for (int i = 0; i < len; i++) {
              if (QUOTE == bytes[i]) {
                buf[pos++] = QUOTE;
                if (buf.length <= pos) {
                  flushBuffer(false);
                }
              }
              buf[pos++] = bytes[i];
              if (buf.length <= pos) {
                flushBuffer(false);
              }
            }
          } else {
            for (int i = 0; i < len; i++) {
              if (bytes[i] == QUOTE
                  || bytes[i] == BACKSLASH
                  || bytes[i] == DBL_QUOTE
                  || bytes[i] == ZERO_BYTE) {
                buf[pos++] = '\\';
                if (buf.length <= pos) {
                  flushBuffer(false);
                }
              }
              buf[pos++] = bytes[i];
              if (buf.length <= pos) {
                flushBuffer(false);
              }
            }
          }
          return;
        }
      }
    }

    // sure to have enough place filling buffer directly
    if (noBackslashEscapes) {
      for (int i = 0; i < len; i++) {
        if (QUOTE == bytes[i]) {
          buf[pos++] = QUOTE;
        }
        buf[pos++] = bytes[i];
      }
    } else {
      for (int i = 0; i < len; i++) {
        if (bytes[i] == QUOTE
            || bytes[i] == BACKSLASH
            || bytes[i] == '"'
            || bytes[i] == ZERO_BYTE) {
          buf[pos++] = BACKSLASH; // add escape slash
        }
        buf[pos++] = bytes[i];
      }
    }
  }

  public int getMaxAllowedPacket() {
    return maxAllowedPacket;
  }

  public abstract void setMaxAllowedPacket(int maxAllowedPacket);

  public void permitTrace(boolean permitTrace) {
    this.permitTrace = permitTrace;
  }

  /**
   * Set server thread id.
   *
   * @param serverThreadId current server thread id.
   * @param isMaster is server master
   */
  public void setServerThreadId(long serverThreadId, Boolean isMaster) {
    this.serverThreadLog =
        "conn=" + serverThreadId + ((isMaster != null) ? "(" + (isMaster ? "M" : "S") + ")" : "");
  }

  public void setTraceCache(LruTraceCache traceCache) {
    this.traceCache = traceCache;
  }

  @Override
  public void mark() {
    mark = pos;
  }

  @Override
  public boolean isMarked() {
    return mark != -1;
  }

  /**
   * Flush to last mark.
   *
   * @throws IOException if flush fail.
   */
  @Override
  public void flushBufferStopAtMark() throws IOException {
    final int end = pos;
    pos = mark;
    flushBuffer(true);
    out.flush();
    startPacket(0);

    System.arraycopy(buf, mark, buf, pos, end - mark);
    pos += end - mark;
    mark = -1;
    bufferContainDataAfterMark = true;
  }

  public boolean bufferIsDataAfterMark() {
    return bufferContainDataAfterMark;
  }

  /**
   * Reset mark flag and send bytes after mark flag.
   *
   * @return bytes after mark flag
   */
  public byte[] resetMark() {
    mark = -1;

    if (bufferContainDataAfterMark) {
      byte[] data = Arrays.copyOfRange(buf, initialPacketPos(), pos);
      startPacket(0);
      bufferContainDataAfterMark = false;
      return data;
    }
    return null;
  }
}
