skip iterator

dhfs-parent/objects/src/main/java/com/usatiuk/dhfs/objects/CloseableKvIterator.java

@@ -7,4 +7,6 @@ import java.util.Iterator;
 
 public interface CloseableKvIterator<K extends Comparable<K>, V> extends Iterator<Pair<K, V>>, AutoCloseableNoThrow {
     K peekNextKey();
+
+    void skip();
 }

dhfs-parent/objects/src/main/java/com/usatiuk/dhfs/objects/InconsistentKvIteratorWrapper.java

@@ -30,6 +30,7 @@ public class InconsistentKvIteratorWrapper<K extends Comparable<K>, V> implement
     }
 
     private void refresh() {
+        Log.tracev("Refreshing iterator: {0}", _backing);
         _backing.close();
         if (_peekedKey != null) {
             _backing = _iteratorSupplier.apply(Pair.of(IteratorStart.GE, _peekedKey));
@@ -69,6 +70,25 @@ public class InconsistentKvIteratorWrapper<K extends Comparable<K>, V> implement
         }
     }
 
+    @Override
+    public void skip() {
+        while (true) {
+            try {
+                _lastReturnedKey = _backing.peekNextKey();
+                _backing.skip();
+                _peekedNext = false;
+                _peekedKey = null;
+                return;
+            } catch (NoSuchElementException ignored) {
+                assert !_peekedNext;
+                throw ignored;
+            } catch (StaleIteratorException ignored) {
+                refresh();
+                continue;
+            }
+        }
+    }
+
     @Override
     public void close() {
         _backing.close();

dhfs-parent/objects/src/main/java/com/usatiuk/dhfs/objects/InconsistentSelfRefreshingKvIterator.java

@@ -91,6 +91,20 @@ public class InconsistentSelfRefreshingKvIterator<K extends Comparable<K>, V> im
         }
     }
 
+    @Override
+    public void skip() {
+        _lock.lock();
+        try {
+            maybeRefresh();
+            _lastReturnedKey = _backing.peekNextKey();
+            _backing.skip();
+            _peekedNext = false;
+            _peekedKey = null;
+        } finally {
+            _lock.unlock();
+        }
+    }
+
     @Override
     public void close() {
         _backing.close();

dhfs-parent/objects/src/main/java/com/usatiuk/dhfs/objects/InvalidatableKvIterator.java

@@ -37,6 +37,17 @@ public class InvalidatableKvIterator<K extends Comparable<K>, V> implements Clos
         }
     }
 
+    @Override
+    public void skip() {
+        _lock.lock();
+        try {
+            checkVersion();
+            _backing.skip();
+        } finally {
+            _lock.unlock();
+        }
+    }
+
     @Override
     public void close() {
         _backing.close();

dhfs-parent/objects/src/main/java/com/usatiuk/dhfs/objects/MappingKvIterator.java

@@ -18,6 +18,11 @@ public class MappingKvIterator<K extends Comparable<K>, V, V_T> implements Close
         return _backing.peekNextKey();
     }
 
+    @Override
+    public void skip() {
+        _backing.skip();
+    }
+
     @Override
     public void close() {
         _backing.close();

dhfs-parent/objects/src/main/java/com/usatiuk/dhfs/objects/MergingKvIterator.java

@@ -49,7 +49,7 @@ public class MergingKvIterator<K extends Comparable<K>, V> implements CloseableK
             _sortedIterators.put(key, iterator);
             advanceIterator(them);
         } else {
-            iterator.next();
+            iterator.skip();
             advanceIterator(iterator);
         }
     }
@@ -61,6 +61,17 @@ public class MergingKvIterator<K extends Comparable<K>, V> implements CloseableK
         return _sortedIterators.firstKey();
     }
 
+    @Override
+    public void skip() {
+        var cur = _sortedIterators.pollFirstEntry();
+        if (cur == null) {
+            throw new NoSuchElementException();
+        }
+        cur.getValue().skip();
+        advanceIterator(cur.getValue());
+        Log.tracev("{0} Skip: {1}, next: {2}", _name, cur, _sortedIterators);
+    }
+
     @Override
     public void close() {
         for (CloseableKvIterator<K, V> iterator : _iterators.keySet()) {
@@ -81,7 +92,7 @@ public class MergingKvIterator<K extends Comparable<K>, V> implements CloseableK
         }
         var curVal = cur.getValue().next();
         advanceIterator(cur.getValue());
-        Log.tracev("{0} Read: {1}, next: {2}", _name, curVal, _sortedIterators);
+        Log.tracev("{0} Read from {1}: {2}, next: {3}", _name, cur.getValue(), curVal, _sortedIterators);
         return curVal;
     }
 

dhfs-parent/objects/src/main/java/com/usatiuk/dhfs/objects/NavigableMapKvIterator.java

@@ -40,6 +40,15 @@ public class NavigableMapKvIterator<K extends Comparable<K>, V> implements Close
         return _next.getKey();
     }
 
+    @Override
+    public void skip() {
+        if (_next == null) {
+            throw new NoSuchElementException();
+        }
+        _next = null;
+        fillNext();
+    }
+
     @Override
     public void close() {
     }

dhfs-parent/objects/src/main/java/com/usatiuk/dhfs/objects/PredicateKvIterator.java

@@ -33,6 +33,14 @@ public class PredicateKvIterator<K extends Comparable<K>, V, V_T> implements Clo
         return _next.getKey();
     }
 
+    @Override
+    public void skip() {
+        if (_next == null)
+            throw new NoSuchElementException();
+        _next = null;
+        fillNext();
+    }
+
     @Override
     public void close() {
         _backing.close();

dhfs-parent/objects/src/main/java/com/usatiuk/dhfs/objects/SelfRefreshingKvIterator.java

@@ -91,6 +91,14 @@ public class SelfRefreshingKvIterator<K extends Comparable<K>, V> implements Clo
         return _next.getKey();
     }
 
+    @Override
+    public void skip() {
+        if (_next == null) {
+            throw new NoSuchElementException();
+        }
+        prepareNext();
+    }
+
     @Override
     public void close() {
         _backing.close();

dhfs-parent/objects/src/main/java/com/usatiuk/dhfs/objects/SnapshotManager.java

@@ -280,6 +280,14 @@ public class SnapshotManager {
                 return _next.getKey();
             }
 
+            @Override
+            public void skip() {
+                if (_next == null)
+                    throw new NoSuchElementException();
+                _next = null;
+                fillNext();
+            }
+
             @Override
             public void close() {
                 _backing.close();
@@ -321,6 +329,11 @@ public class SnapshotManager {
                 return _backing.peekNextKey();
             }
 
+            @Override
+            public void skip() {
+                _backing.skip();
+            }
+
             @Override
             public void close() {
                 _backing.close();

dhfs-parent/objects/src/main/java/com/usatiuk/dhfs/objects/TombstoneMergingKvIterator.java

@@ -41,6 +41,11 @@ public class TombstoneMergingKvIterator<K extends Comparable<K>, V> implements C
         return _backing.peekNextKey();
     }
 
+    @Override
+    public void skip() {
+        _backing.skip();
+    }
+
     @Override
     public void close() {
         _backing.close();

dhfs-parent/objects/src/main/java/com/usatiuk/dhfs/objects/persistence/CachingObjectPersistentStore.java

@@ -155,6 +155,11 @@ public class CachingObjectPersistentStore {
             return _delegate.peekNextKey();
         }
 
+        @Override
+        public void skip() {
+            _delegate.skip();
+        }
+
         @Override
         public void close() {
             _delegate.close();
@@ -179,6 +184,7 @@ public class CachingObjectPersistentStore {
     // Warning: it has a nasty side effect of global caching, so in this case don't even call next on it,
     // if some objects are still in writeback
     public CloseableKvIterator<JObjectKey, JDataVersionedWrapper> getIterator(IteratorStart start, JObjectKey key) {
+        Log.tracev("Getting cache iterator: {0}, {1}", start, key);
         _cacheVersionLock.readLock().lock();
         try {
             return new InconsistentSelfRefreshingKvIterator<>(

dhfs-parent/objects/src/main/java/com/usatiuk/dhfs/objects/persistence/LmdbObjectPersistentStore.java

@@ -171,6 +171,11 @@ public class LmdbObjectPersistentStore implements ObjectPersistentStore {
             return ret;
         }
 
+        @Override
+        public void skip() {
+            _hasNext = _cursor.next();
+        }
+
         @Override
         public JObjectKey peekNextKey() {
             if (!_hasNext) {

dhfs-parent/objects/src/main/java/com/usatiuk/dhfs/objects/persistence/SerializingObjectPersistentStore.java

@@ -43,6 +43,11 @@ public class SerializingObjectPersistentStore {
             return _delegate.peekNextKey();
         }
 
+        @Override
+        public void skip() {
+            _delegate.skip();
+        }
+
         @Override
         public void close() {
             _delegate.close();

dhfs-parent/objects/src/main/java/com/usatiuk/dhfs/objects/transaction/ReadTrackingObjectSourceFactory.java

@@ -83,6 +83,11 @@ public class ReadTrackingObjectSourceFactory {
                 return _backing.peekNextKey();
             }
 
+            @Override
+            public void skip() {
+                _backing.skip();
+            }
+
             @Override
             public void close() {
                 _backing.close();

dhfs-parent/objects/src/test/java/com/usatiuk/dhfs/objects/MergingKvIteratorTest.java

@@ -33,6 +33,15 @@ public class MergingKvIteratorTest {
             return _next.getKey();
         }
 
+        @Override
+        public void skip() {
+            if (_next == null) {
+                throw new NoSuchElementException();
+            }
+            _next = null;
+            fillNext();
+        }
+
         @Override
         public void close() {
         }