Fixed shyiko#258 - checksum detection fails when custom FORMAT_DESCRIPTION event data deserializer is set

Author: Stanley Shyiko

src/main/java/com/github/shyiko/mysql/binlog/event/FormatDescriptionEventData.java

@@ -15,6 +15,8 @@
  */
 package com.github.shyiko.mysql.binlog.event;
 
+import com.github.shyiko.mysql.binlog.event.deserialization.ChecksumType;
+
 /**
  * @author <a href="mailto:stanley.shyiko@gmail.com">Stanley Shyiko</a>
  */
@@ -24,6 +26,7 @@ public class FormatDescriptionEventData implements EventData {
     private String serverVersion;
     private int headerLength;
     private int dataLength;
+    private ChecksumType checksumType = ChecksumType.NONE;
 
     public int getBinlogVersion() {
         return binlogVersion;
@@ -57,6 +60,14 @@ public int getDataLength() {
         return dataLength;
     }
 
+    public ChecksumType getChecksumType() {
+        return checksumType;
+    }
+
+    public void setChecksumType(ChecksumType checksumType) {
+        this.checksumType = checksumType;
+    }
+
     @Override
     public String toString() {
         final StringBuilder sb = new StringBuilder();
@@ -65,6 +76,7 @@ public String toString() {
         sb.append(", serverVersion='").append(serverVersion).append('\'');
         sb.append(", headerLength=").append(headerLength);
         sb.append(", dataLength=").append(dataLength);
+        sb.append(", checksumType=").append(checksumType);
         sb.append('}');
         return sb.toString();
     }

src/main/java/com/github/shyiko/mysql/binlog/event/deserialization/EventDeserializer.java

@@ -253,12 +253,7 @@ private EventData deserializeFormatDescriptionEventData(ByteArrayInputStream inp
                 } else {
                     formatDescriptionEvent = (FormatDescriptionEventData) eventData;
                 }
-                int checksumBlockLength = eventBodyLength - formatDescriptionEvent.getDataLength();
-                if (checksumBlockLength > 0) {
-                    inputStream.skip(inputStream.available() - checksumBlockLength);
-                    int checksumType = inputStream.read();
-                    checksumLength = ChecksumType.byOrdinal(checksumType).getLength();
-                }
+                checksumLength = formatDescriptionEvent.getChecksumType().getLength();
             } finally {
                 inputStream.skipToTheEndOfTheBlock();
             }

src/main/java/com/github/shyiko/mysql/binlog/event/deserialization/FormatDescriptionEventDataDeserializer.java

@@ -29,13 +29,19 @@ public class FormatDescriptionEventDataDeserializer implements EventDataDeserial
 
     @Override
     public FormatDescriptionEventData deserialize(ByteArrayInputStream inputStream) throws IOException {
+        int eventBodyLength = inputStream.available();
         FormatDescriptionEventData eventData = new FormatDescriptionEventData();
         eventData.setBinlogVersion(inputStream.readInteger(2));
         eventData.setServerVersion(inputStream.readString(50).trim());
         inputStream.skip(4); // redundant, present in a header
         eventData.setHeaderLength(inputStream.readInteger(1));
         inputStream.skip(EventType.FORMAT_DESCRIPTION.ordinal() - 1);
         eventData.setDataLength(inputStream.readInteger(1));
+        int checksumBlockLength = eventBodyLength - eventData.getDataLength();
+        if (checksumBlockLength > 0) {
+            inputStream.skip(inputStream.available() - checksumBlockLength);
+            eventData.setChecksumType(ChecksumType.byOrdinal(inputStream.read()));
+        }
         return eventData;
     }
 }

src/test/java/com/github/shyiko/mysql/binlog/BinaryLogFileReaderIntegrationTest.java

@@ -61,6 +61,15 @@ public void testChecksumCRC32() throws Exception {
         readAll(reader, 303);
     }
 
+    @Test
+    public void testChecksumCRC32WithCustomEventDataDeserializer() throws Exception {
+        EventDeserializer eventDeserializer = new EventDeserializer();
+        eventDeserializer.setEventDataDeserializer(EventType.FORMAT_DESCRIPTION, new NullEventDataDeserializer());
+        BinaryLogFileReader reader = new BinaryLogFileReader(
+                new FileInputStream("src/test/resources/mysql-bin.checksum-crc32"), eventDeserializer);
+        readAll(reader, 303);
+    }
+
     private void readAll(BinaryLogFileReader reader, int expect) throws IOException {
         try {
             int numberOfEvents = 0;