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.a;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertFalse;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  import java.io.BufferedOutputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.util.zip.InflaterOutputStream;
  
  import org.junit.jupiter.api.AfterEach;
  import org.junit.jupiter.api.Test;
  
  import com.mysql.cj.protocol.MessageSender;
  
  public class CompressedPacketSenderTest extends PacketSenderTestBase {
      private ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
      private MessageSender<NativePacketPayload> sender = new CompressedPacketSender(new BufferedOutputStream(this.outputStream));
  
      /**
       * Test utility to transform a buffer containing compressed packets into a sequence of payloads.
       */
      static class CompressedPackets {
          byte[] packetData;
          private ByteArrayOutputStream decompressedStream;
  
          byte[] payload;
          int compressedPayloadLen;
          int compressedSequenceId;
          int uncompressedPayloadLen;
          int offset = 0; // offset after all currently read data
  
          public CompressedPackets(byte[] packetData) {
              this.packetData = packetData;
              this.decompressedStream = new ByteArrayOutputStream();
          }
  
          public boolean nextPayload() throws IOException {
              if (this.offset == this.packetData.length) {
                  return false;
              }
              // read compressed packet header
              this.compressedPayloadLen = NativeUtils.decodeMysqlThreeByteInteger(this.packetData, this.offset);
              this.compressedSequenceId = this.packetData[this.offset + 3];
              this.uncompressedPayloadLen = NativeUtils.decodeMysqlThreeByteInteger(this.packetData, this.offset + 4);
              this.offset += CompressedPacketSender.COMP_HEADER_LENGTH;
              if (this.uncompressedPayloadLen == 0) {
                  // uncompressed packet
                  this.payload = java.util.Arrays.copyOfRange(this.packetData, this.offset, this.offset + this.compressedPayloadLen);
              } else {
                  // uncompress payload
                  InflaterOutputStream inflater = new InflaterOutputStream(this.decompressedStream);
                  inflater.write(this.packetData, this.offset, this.compressedPayloadLen);
                  inflater.finish();
                  inflater.flush();
                  this.payload = this.decompressedStream.toByteArray();
                  this.decompressedStream.reset();
              }
              this.offset += this.compressedPayloadLen;
              return true;
          }
      }
  
      @AfterEach
      public void cleanupByteArrayOutputStream() {
          this.outputStream.reset();
      }
  
      @Test
      public void basicCompressedPacketTest() throws IOException {
          final int packetLen = 3000; // needs to be big enough to compress
  
          byte[] packet = new byte[packetLen];
          fillPacketSequentially(packet);
  
          final byte packetSequence = 22;
          this.sender.send(packet, packetLen, packetSequence);
  
          // check encoded packet
          CompressedPackets packets = new CompressedPackets(this.outputStream.toByteArray());
  
          final int compressedPacketLen = 316; // expected value generated from this test case - compression is deterministic
          assertEquals(compressedPacketLen, packets.packetData.length);
          assertEquals(compressedPacketLen - CompressedPacketSender.COMP_HEADER_LENGTH, NativeUtils.decodeMysqlThreeByteInteger(packets.packetData));
          assertEquals(packetSequence, packets.packetData[3]); // compressed sequence is independent
          assertEquals(packetLen + NativeConstants.HEADER_LENGTH, NativeUtils.decodeMysqlThreeByteInteger(packets.packetData, 4));
  
          // decompress payload and check
          assertTrue(packets.nextPayload());
          assertEquals(packetLen, NativeUtils.decodeMysqlThreeByteInteger(packets.payload));
          assertEquals(packetSequence, packets.payload[3]);
          checkSequentiallyFilledPacket(packets.payload, 4, packetLen);
          assertFalse(packets.nextPayload());
      }
  
      /**
       * Test the situation where a single packet is split into two and the second part doesn't exceed the capacity of the second compressed packet.
       * 
       * @throws IOException
       */
      @Test
      public void basicTwoPartSplitPacketTest() throws IOException {
          final int packetLen = NativeConstants.MAX_PACKET_SIZE + 20000;
          byte[] packet = new byte[packetLen];
          // mark key positions in packet to check split packet
          packet[0] = 41;
          packet[NativeConstants.MAX_PACKET_SIZE - 1] = 42;
          packet[NativeConstants.MAX_PACKET_SIZE] = 43;
          packet[packetLen - 1] = 44;
  
          final byte packetSequence = 45;
          this.sender.send(packet, packetLen, packetSequence);
  
          // check encoded packet
          CompressedPackets packets = new CompressedPackets(this.outputStream.toByteArray());
  
          // first packet
          assertTrue(packets.nextPayload());
          assertEquals(packetSequence, packets.compressedSequenceId);
          assertEquals(NativeConstants.MAX_PACKET_SIZE, packets.uncompressedPayloadLen);
          assertEquals(packets.uncompressedPayloadLen, packets.payload.length);
          assertEquals(41, packets.payload[NativeConstants.HEADER_LENGTH]);
          int firstPacketRawPacketLen = NativeUtils.decodeMysqlThreeByteInteger(packets.payload);
          assertEquals(NativeConstants.MAX_PACKET_SIZE, firstPacketRawPacketLen);
          int firstPacketUncompressedPayloadLen = packets.uncompressedPayloadLen;
  
          // second packet
          assertTrue(packets.nextPayload());
          assertEquals(packetSequence + 1, packets.compressedSequenceId);
          assertEquals(packetLen - firstPacketUncompressedPayloadLen + (2 * NativeConstants.HEADER_LENGTH), packets.uncompressedPayloadLen);
          assertEquals(packets.uncompressedPayloadLen, packets.payload.length);
          assertEquals(43, packets.payload[NativeConstants.HEADER_LENGTH + NativeConstants.HEADER_LENGTH]);
          assertEquals(42, packets.payload[NativeConstants.HEADER_LENGTH - 1]);
          assertEquals(44, packets.payload[packets.uncompressedPayloadLen - 1]);
          int secondPacketUncompressedPayloadLen = packets.uncompressedPayloadLen;
  
          assertEquals(packetLen, firstPacketUncompressedPayloadLen + secondPacketUncompressedPayloadLen - (2 * NativeConstants.HEADER_LENGTH));
  
          // done
          assertFalse(packets.nextPayload());
      }
  
      /**
       * Test the situation where a single packet is split into two and the second part exceeds the capacity of the second compressed packet requiring a third
       * compressed packet.
       * 
       * @throws IOException
       */
      @Test
      public void twoPacketToThreeCompressedPacketNoBoundary() throws IOException {
          final int packetLen = (NativeConstants.MAX_PACKET_SIZE * 2) - 1;
  
          byte[] packet = new byte[packetLen];
  
          this.sender.send(packet, packetLen, (byte) 0);
  
          // check encoded packet
          CompressedPackets packets = new CompressedPackets(this.outputStream.toByteArray());
  
          assertTrue(packets.nextPayload());
  
          assertTrue(packets.nextPayload());
  
          // last packet is uncompressed
          // payload is 7 bytes: 4 (from first packet) + 3 (from second packet) bytes
          assertEquals(7, NativeUtils.decodeMysqlThreeByteInteger(packets.packetData, packets.offset));
          assertEquals(2, packets.packetData[packets.offset + 3]); // sequence
          assertEquals(0, NativeUtils.decodeMysqlThreeByteInteger(packets.packetData, packets.offset + 4)); // uncompressed
  
          assertEquals(CompressedPacketSender.COMP_HEADER_LENGTH + 7, packets.packetData.length - packets.offset);
      }
  
      /**
       * This tests that the splitting of MySQL packets includes an additional empty packet to signal the end of the multi-packet sequence.
       * 
       * @throws IOException
       */
      @Test
      public void twoPacketToThreeWithEmptyUncompressedPacket() throws IOException {
          // it takes three mysql packets to represent a large packet that spans the exact capacity of two packets
          final int packetLen = NativeConstants.MAX_PACKET_SIZE * 2;
  
          byte[] packet = new byte[packetLen];
          // seed data to check packets after splitting & compression
          packet[packetLen - 4] = 22;
          packet[packetLen - 3] = 23;
          packet[packetLen - 2] = 24;
          packet[packetLen - 1] = 25;
  
          this.sender.send(packet, packetLen, (byte) 0);
  
          // check encoded packet
          CompressedPackets packets = new CompressedPackets(this.outputStream.toByteArray());
  
          assertTrue(packets.nextPayload());
          assertTrue(packets.nextPayload());
          assertTrue(packets.nextPayload());
  
          // third packet includes remaining 8 bytes of data and the blank header for the third mysql packet
  
          // last packet is uncompressed
          // payload is: 4 (bumped from first packet) + 4 (bumped from second packet) bytes + empty header (4)
          assertEquals(12, packets.compressedPayloadLen);
          assertEquals(0, packets.uncompressedPayloadLen); // uncompressed indicator
          // last four bytes of original packet should be second four bytes here
          assertEquals(22, packets.payload[4]);
          assertEquals(23, packets.payload[5]);
          assertEquals(24, packets.payload[6]);
          assertEquals(25, packets.payload[7]);
  
          // third MySQL packet is an empty header
          assertEquals(2, packets.payload[11]); // sequence
          assertEquals(0, NativeUtils.decodeMysqlThreeByteInteger(packets.payload, 8)); // payload len
      }
  
      @Test
      public void smallPacketsArentCompressed() throws IOException {
          final int packetLen = CompressedPacketSender.MIN_COMPRESS_LEN - 1; // needs to be big enough to compress
  
          byte[] packet = new byte[packetLen];
          fillPacketSequentially(packet);
  
          final byte packetSequence = 33;
          this.sender.send(packet, packetLen, packetSequence);
  
          // check encoded packet
          byte[] sentPacket = this.outputStream.toByteArray();
  
          assertEquals(packetLen + NativeConstants.HEADER_LENGTH + CompressedPacketSender.COMP_HEADER_LENGTH, sentPacket.length);
          // header field for compressed payload length should equal uncompressed len + header
          assertEquals(packetLen + NativeConstants.HEADER_LENGTH, NativeUtils.decodeMysqlThreeByteInteger(sentPacket));
          assertEquals(packetSequence, sentPacket[3]);
          // header field for uncompressed payload length should be 0
          assertEquals(0, NativeUtils.decodeMysqlThreeByteInteger(sentPacket, 4));
  
          assertEquals(packetLen, NativeUtils.decodeMysqlThreeByteInteger(sentPacket, CompressedPacketSender.COMP_HEADER_LENGTH));
          assertEquals(packetSequence, sentPacket[CompressedPacketSender.COMP_HEADER_LENGTH + 3]);
          checkSequentiallyFilledPacket(sentPacket, CompressedPacketSender.COMP_HEADER_LENGTH + NativeConstants.HEADER_LENGTH, packetLen);
      }
  
      @Test
      public void incompressiblePacketsArentCompressed() throws IOException {
          final int packetLen = CompressedPacketSender.MIN_COMPRESS_LEN * 2; // needs to be big enough to compress
  
          byte[] packet = new byte[packetLen];
          // this sequential data is not easily compressible by the DEFLATE algorithm
          fillPacketSequentially(packet);
  
          final byte packetSequence = 33;
          this.sender.send(packet, packetLen, packetSequence);
  
          // check encoded packet
          byte[] sentPacket = this.outputStream.toByteArray();
  
          assertEquals(packetLen + NativeConstants.HEADER_LENGTH + CompressedPacketSender.COMP_HEADER_LENGTH, sentPacket.length);
          // header field for compressed payload length should equal uncompressed len + header
          assertEquals(packetLen + NativeConstants.HEADER_LENGTH, NativeUtils.decodeMysqlThreeByteInteger(sentPacket));
          assertEquals(packetSequence, sentPacket[3]);
          // header field for uncompressed payload length should be 0
          assertEquals(0, NativeUtils.decodeMysqlThreeByteInteger(sentPacket, 4));
  
          assertEquals(packetLen, NativeUtils.decodeMysqlThreeByteInteger(sentPacket, CompressedPacketSender.COMP_HEADER_LENGTH));
          assertEquals(packetSequence, sentPacket[CompressedPacketSender.COMP_HEADER_LENGTH + 3]);
          checkSequentiallyFilledPacket(sentPacket, CompressedPacketSender.COMP_HEADER_LENGTH + NativeConstants.HEADER_LENGTH, packetLen);
      }
  }
  