IGNITE-6553 Standalone WAL iterator fails to handle WAL delete data records - Fixes apache#2797.

Author: dpavlov

modules/core/src/main/java/org/apache/ignite/internal/pagemem/wal/record/DataEntry.java

@@ -23,6 +23,7 @@
 import org.apache.ignite.internal.processors.cache.version.GridCacheVersion;
 import org.apache.ignite.internal.util.tostring.GridToStringInclude;
 import org.apache.ignite.internal.util.typedef.internal.S;
+import org.jetbrains.annotations.Nullable;
 
 /**
  * Represents Data Entry ({@link #key}, {@link #val value}) pair update {@link #op operation} in WAL log.
@@ -32,13 +33,13 @@ public class DataEntry {
     @GridToStringInclude
     protected int cacheId;
 
-    /** Cache object key */
+    /** Cache object key. */
     protected KeyCacheObject key;
 
-    /** Cache object value */
-    protected CacheObject val;
+    /** Cache object value. May be {@code} null for {@link GridCacheOperation#DELETE} */
+    @Nullable protected CacheObject val;
 
-    /** Entry operation performed */
+    /** Entry operation performed. */
     @GridToStringInclude
     protected GridCacheOperation op;
 
@@ -67,7 +68,7 @@ private DataEntry() {
     /**
      * @param cacheId Cache ID.
      * @param key Key.
-     * @param val Value.
+     * @param val Value or null for delete operation.
      * @param op Operation.
      * @param nearXidVer Near transaction version.
      * @param writeVer Write version.
@@ -78,7 +79,7 @@ private DataEntry() {
     public DataEntry(
         int cacheId,
         KeyCacheObject key,
-        CacheObject val,
+        @Nullable CacheObject val,
         GridCacheOperation op,
         GridCacheVersion nearXidVer,
         GridCacheVersion writeVer,

modules/core/src/main/java/org/apache/ignite/internal/pagemem/wal/record/UnwrapDataEntry.java

@@ -31,21 +31,21 @@ public class UnwrapDataEntry extends DataEntry {
     /** Cache object value context. Context is used for unwrapping objects. */
     private final CacheObjectValueContext cacheObjValCtx;
 
-    /** Keep binary. This flag disables converting of non primitive types (BinaryObjects) */
+    /** Keep binary. This flag disables converting of non primitive types (BinaryObjects). */
     private boolean keepBinary;
 
     /**
      * @param cacheId Cache ID.
      * @param key Key.
-     * @param val Value.
+     * @param val Value or null for delete operation.
      * @param op Operation.
      * @param nearXidVer Near transaction version.
      * @param writeVer Write version.
      * @param expireTime Expire time.
      * @param partId Partition ID.
      * @param partCnt Partition counter.
      * @param cacheObjValCtx cache object value context for unwrapping objects.
-     * @param keepBinary disable unwrapping for non primitive objects, Binary Objects would be returned instead
+     * @param keepBinary disable unwrapping for non primitive objects, Binary Objects would be returned instead.
      */
     public UnwrapDataEntry(
         final int cacheId,
@@ -66,39 +66,47 @@ public UnwrapDataEntry(
 
     /**
      * Unwraps key value from cache key object into primitive boxed type or source class. If client classes were used
-     * in key, call of this method requires classes to be available in classpath
+     * in key, call of this method requires classes to be available in classpath.
      *
-     * @return Key which was placed into cache. Or null if failed
+     * @return Key which was placed into cache. Or null if failed to convert.
      */
     public Object unwrappedKey() {
         try {
             if (keepBinary && key instanceof BinaryObject)
                 return key;
+
             Object unwrapped = key.value(cacheObjValCtx, false);
+
             if (unwrapped instanceof BinaryObject) {
                 if (keepBinary)
                     return unwrapped;
                 unwrapped = ((BinaryObject)unwrapped).deserialize();
             }
+
             return unwrapped;
         }
         catch (Exception e) {
             cacheObjValCtx.kernalContext().log(UnwrapDataEntry.class)
                 .error("Unable to convert key [" + key + "]", e);
+
             return null;
         }
     }
 
     /**
      * Unwraps value value from cache value object into primitive boxed type or source class. If client classes were
-     * used in key, call of this method requires classes to be available in classpath
+     * used in key, call of this method requires classes to be available in classpath.
      *
-     * @return Value which was placed into cache. Or null if failed
+     * @return Value which was placed into cache. Or null for delete operation or for failure.
      */
     public Object unwrappedValue() {
         try {
+            if (val == null)
+                return null;
+
             if (keepBinary && val instanceof BinaryObject)
                 return val;
+
             return val.value(cacheObjValCtx, false);
         }
         catch (Exception e) {

modules/core/src/main/java/org/apache/ignite/internal/processors/cache/persistence/wal/reader/StandaloneWalRecordsIterator.java

@@ -335,12 +335,17 @@ private DataEntry postProcessDataEntry(
 
         if (dataEntry instanceof LazyDataEntry) {
             final LazyDataEntry lazyDataEntry = (LazyDataEntry)dataEntry;
+
             key = processor.toKeyCacheObject(fakeCacheObjCtx,
                 lazyDataEntry.getKeyType(),
                 lazyDataEntry.getKeyBytes());
-            val = processor.toCacheObject(fakeCacheObjCtx,
-                lazyDataEntry.getValType(),
-                lazyDataEntry.getValBytes());
+
+            final byte type = lazyDataEntry.getValType();
+
+            val = type == 0 ? null :
+                processor.toCacheObject(fakeCacheObjCtx,
+                    type,
+                    lazyDataEntry.getValBytes());
         }
         else {
             key = dataEntry.key();

modules/core/src/test/java/org/apache/ignite/internal/processors/cache/persistence/db/wal/reader/IgniteWalReaderTest.java

@@ -356,6 +356,7 @@ private void putAllDummyRecords(Ignite ignite, int recordsToWrite) {
 
         cache0.putAll(values);
     }
+
     /**
      * Puts provided number of records to fill WAL under transactions
      *
@@ -912,8 +913,16 @@ private void runRemoveOperationTest(CacheAtomicityMode mode) throws Exception {
             deletesFound != null && deletesFound > 0);
     }
 
-    @NotNull private IgniteWalIteratorFactory createWalIteratorFactory(String subfolderName,
-        String workDir) throws IgniteCheckedException {
+    /**
+     * @param subfolderName Subfolder name.
+     * @param workDir Work directory.
+     * @return WAL iterator factory.
+     * @throws IgniteCheckedException If failed.
+     */
+    @NotNull private IgniteWalIteratorFactory createWalIteratorFactory(
+        String subfolderName,
+        String workDir
+    ) throws IgniteCheckedException {
         final File binaryMeta = U.resolveWorkDirectory(workDir, "binary_meta", false);
         final File binaryMetaWithConsId = new File(binaryMeta, subfolderName);
         final File marshallerMapping = U.resolveWorkDirectory(workDir, "marshaller", false);
@@ -924,7 +933,6 @@ private void runRemoveOperationTest(CacheAtomicityMode mode) throws Exception {
             marshallerMapping);
     }
 
-
     /**
      * @param values collection with numbers
      * @return sum of numbers