WIP: More work toward entity cache, very broken at this point.

pom.xml

@@ -5,7 +5,7 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>net.helenus</groupId>
     <artifactId>helenus-core</artifactId>
-    <version>2.0.26-SNAPSHOT</version>
+    <version>2.0.27-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>helenus</name>

src/main/java/net/helenus/core/UnitOfWork.java

@@ -1,8 +1,10 @@
 package net.helenus.core;
 
+import com.datastax.driver.core.ResultSet;
 import com.diffplug.common.base.Errors;
 import com.google.common.collect.TreeTraverser;
 import net.helenus.core.operation.AbstractCache;
+import net.helenus.core.operation.CacheKey;
 import net.helenus.core.operation.UnitOfWorkCache;
 import net.helenus.support.HelenusException;
 
@@ -16,6 +18,7 @@ public final class UnitOfWork implements AutoCloseable {
   private final HelenusSession session;
   private final UnitOfWork parent;
   private List<CommitThunk> postCommit = new ArrayList<CommitThunk>();
+  private final Map<CacheKey, ResultSet> cache = new HashMap<>();
   private boolean aborted = false;
   private boolean committed = false;
 
@@ -56,6 +59,10 @@ public final class UnitOfWork implements AutoCloseable {
     }
   }
 
+  public UnitOfWork getEnclosingUnitOfWork() { return parent; }
+
+  public Map<CacheKey, ResultSet> getCache() { return cache; }
+
   private Iterator<UnitOfWork> getChildNodes() {
     return nested.iterator();
   }
@@ -85,6 +92,8 @@ public final class UnitOfWork implements AutoCloseable {
       committed = true;
       aborted = false;
 
+      // TODO(gburd): union this cache with parent's (if there is a parent) or with the session cache for all cacheable entities we currently hold
+
       nested.forEach((uow) -> Errors.rethrow().wrap(uow::commit));
 
       // Apply all post-commit functions for

src/main/java/net/helenus/core/operation/AbstractCache.java

@@ -15,7 +15,7 @@ import java.util.concurrent.TimeUnit;
 
 public abstract class AbstractCache<K, V> {
   final Logger logger = LoggerFactory.getLogger(getClass());
-  protected Cache<K, V> cache;
+  public Cache<K, V> cache;
 
   public AbstractCache() {
     RemovalListener<K, V> listener =
@@ -38,8 +38,11 @@ public abstract class AbstractCache<K, V> {
                       .build();
   }
 
-  protected abstract ResultSet apply(
-      Statement statement, OperationsDelegate delegate, ResultSetFuture resultSetFuture)
-      throws InterruptedException, ExecutionException;
-
+    V get(K key) {
+        return cache.getIfPresent(key);
+    }
+
+    void put(K key, V value) {
+        cache.put(key, value);
+    }
 }

src/main/java/net/helenus/core/operation/AbstractFilterOptionalOperation.java

@@ -15,15 +15,19 @@
  */
 package net.helenus.core.operation;
 
+import java.util.LinkedHashMap;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Map;
+
 import net.helenus.core.*;
+import net.helenus.mapping.HelenusProperty;
 
 public abstract class AbstractFilterOptionalOperation<
         E, O extends AbstractFilterOptionalOperation<E, O>>
     extends AbstractOptionalOperation<E, O> {
 
-  protected List<Filter<?>> filters = null;
+  protected Map<HelenusProperty, Filter<?>> filters = null;
   protected List<Filter<?>> ifFilters = null;
 
   public AbstractFilterOptionalOperation(AbstractSessionOperations sessionOperations) {
@@ -95,9 +99,9 @@ public abstract class AbstractFilterOptionalOperation<
 
   private void addFilter(Filter<?> filter) {
     if (filters == null) {
-      filters = new LinkedList<Filter<?>>();
+      filters = new LinkedHashMap<HelenusProperty, Filter<?>>();
     }
-    filters.add(filter);
+    filters.put(filter.getNode().getProperty(), filter);
   }
 
   private void addIfFilter(Filter<?> filter) {

src/main/java/net/helenus/core/operation/AbstractFilterStreamOperation.java

@@ -15,15 +15,19 @@
  */
 package net.helenus.core.operation;
 
+import java.util.LinkedHashMap;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Map;
+
 import net.helenus.core.*;
+import net.helenus.mapping.HelenusProperty;
 
 public abstract class AbstractFilterStreamOperation<
         E, O extends AbstractFilterStreamOperation<E, O>>
     extends AbstractStreamOperation<E, O> {
 
-  protected List<Filter<?>> filters = null;
+  protected Map<HelenusProperty, Filter<?>> filters = null;
   protected List<Filter<?>> ifFilters = null;
 
   public AbstractFilterStreamOperation(AbstractSessionOperations sessionOperations) {
@@ -95,9 +99,9 @@ public abstract class AbstractFilterStreamOperation<
 
   private void addFilter(Filter<?> filter) {
     if (filters == null) {
-      filters = new LinkedList<Filter<?>>();
+      filters = new LinkedHashMap<HelenusProperty, Filter<?>>();
     }
-    filters.add(filter);
+    filters.put(filter.getNode().getProperty(), filter);
   }
 
   private void addIfFilter(Filter<?> filter) {

src/main/java/net/helenus/core/operation/AbstractOperation.java

@@ -25,7 +25,7 @@ public abstract class AbstractOperation<E, O extends AbstractOperation<E, O>>
 
   public abstract E transform(ResultSet resultSet);
 
-  protected AbstractCache getCache() {
+  public AbstractCache getCache() {
     return null;
   }
 
@@ -46,21 +46,19 @@ public abstract class AbstractOperation<E, O extends AbstractOperation<E, O>>
   }
 
   public E sync() {
-    return Executioner.INSTANCE.<E>sync(
-            sessionOps, null, options(buildStatement()), getCache(), traceContext, this, showValues);
+    return Executioner.INSTANCE.<E>sync(sessionOps, null, traceContext, this, showValues);
   }
   public E sync(UnitOfWork uow) {
-    return Executioner.INSTANCE.<E>sync(
-            sessionOps, uow, options(buildStatement()), getCache(), traceContext, this, showValues);
+    return Executioner.INSTANCE.<E>sync(sessionOps, uow, traceContext, this, showValues);
   }
 
   public CompletableFuture<E> async() {
-    return Executioner.INSTANCE.<E>async(
-            sessionOps, null, options(buildStatement()), getCache(), traceContext, this, showValues);
+    AbstractCache cache = getCache();
+    boolean cacheResult = cache != null;
+    return Executioner.INSTANCE.<E>async(sessionOps, null, traceContext, this, showValues);
   }
 
   public CompletableFuture<E> async(UnitOfWork uow) {
-    return Executioner.INSTANCE.<E>async(
-            sessionOps, uow, options(buildStatement()), getCache(), traceContext, this, showValues);
+    return Executioner.INSTANCE.<E>async(sessionOps, uow, traceContext, this, showValues);
   }
 }

src/main/java/net/helenus/core/operation/AbstractOptionalOperation.java

@@ -28,13 +28,22 @@ import net.helenus.core.UnitOfWork;
 public abstract class AbstractOptionalOperation<E, O extends AbstractOptionalOperation<E, O>>
     extends AbstractStatementOperation<E, O> implements OperationsDelegate<Optional<E>> {
 
+  private Function<Optional<E>, E> extractor = new Function<Optional<E>, E>() {
+
+    @Override
+    public E apply(Optional<E> e) {
+      return e.orElse(null);
+    }
+  };
+
+
   public AbstractOptionalOperation(AbstractSessionOperations sessionOperations) {
     super(sessionOperations);
   }
 
   public abstract Optional<E> transform(ResultSet resultSet);
 
-  protected AbstractCache getCache() { return null; }
+  public AbstractCache getCache() { return null; }
 
   public CacheKey getCacheKey() {
     return null;
@@ -57,23 +66,19 @@ public abstract class AbstractOptionalOperation<E, O extends AbstractOptionalOpe
   }
 
   public Optional<E> sync() {
-    return Executioner.INSTANCE.<Optional<E>>sync(
-            sessionOps, null, options(buildStatement()), getCache(), traceContext, this, showValues);
+    return Executioner.INSTANCE.<Optional<E>>sync(sessionOps, null, extractor, traceContext, this, showValues);
   }
 
   public Optional<E> sync(UnitOfWork uow) {
-      return Executioner.INSTANCE.<Optional<E>>sync(
-              sessionOps, uow, options(buildStatement()), getCache(), traceContext, this, showValues);
+      return Executioner.INSTANCE.<Optional<E>>sync(sessionOps, uow, extractor, traceContext, this, showValues);
   }
 
   public CompletableFuture<Optional<E>> async() {
-    return Executioner.INSTANCE.<Optional<E>>async(
-            sessionOps, null, options(buildStatement()), getCache(), traceContext, this, showValues);
+    return Executioner.INSTANCE.<Optional<E>>async(sessionOps, null, extractor, traceContext, this, showValues);
   }
 
   public CompletableFuture<Optional<E>> async(UnitOfWork uow) {
-      return Executioner.INSTANCE.<Optional<E>>async(
-              sessionOps, uow, options(buildStatement()), getCache(), traceContext, this, showValues);
+      return Executioner.INSTANCE.<Optional<E>>async(sessionOps, uow, extractor, traceContext, this, showValues);
   }
 
 }

src/main/java/net/helenus/core/operation/AbstractStatementOperation.java

@@ -38,7 +38,7 @@ public abstract class AbstractStatementOperation<E, O extends AbstractStatementO
 
   protected final AbstractSessionOperations sessionOps;
 
-  public abstract Statement buildStatement();
+  public abstract Statement buildStatement(boolean cached);
 
   protected boolean showValues = true;
   protected TraceContext traceContext;
@@ -181,7 +181,7 @@ public abstract class AbstractStatementOperation<E, O extends AbstractStatementO
     return (O) this;
   }
 
-  protected Statement options(Statement statement) {
+  public Statement options(Statement statement) {
 
     if (defaultTimestamp != null) {
       statement.setDefaultTimestamp(defaultTimestamp[0]);
@@ -224,11 +224,11 @@ public abstract class AbstractStatementOperation<E, O extends AbstractStatementO
   }
 
   public Statement statement() {
-    return buildStatement();
+    return buildStatement(false);
   }
 
   public String cql() {
-    Statement statement = buildStatement();
+    Statement statement = buildStatement(false);
     if (statement == null) return "";
     if (statement instanceof BuiltStatement) {
       BuiltStatement buildStatement = (BuiltStatement) statement;
@@ -240,7 +240,7 @@ public abstract class AbstractStatementOperation<E, O extends AbstractStatementO
 
   public PreparedStatement prepareStatement() {
 
-    Statement statement = buildStatement();
+    Statement statement = buildStatement(true);
 
     if (statement instanceof RegularStatement) {
 
@@ -254,7 +254,7 @@ public abstract class AbstractStatementOperation<E, O extends AbstractStatementO
 
   public ListenableFuture<PreparedStatement> prepareStatementAsync() {
 
-    Statement statement = buildStatement();
+    Statement statement = buildStatement(true);
 
     if (statement instanceof RegularStatement) {
 

src/main/java/net/helenus/core/operation/AbstractStreamOperation.java

@@ -34,7 +34,7 @@ public abstract class AbstractStreamOperation<E, O extends AbstractStreamOperati
 
   public abstract Stream<E> transform(ResultSet resultSet);
 
-  protected AbstractCache getCache() {
+  public AbstractCache getCache() {
     return null;
   }
 
@@ -59,22 +59,18 @@ public abstract class AbstractStreamOperation<E, O extends AbstractStreamOperati
   }
 
   public Stream<E> sync() {
-    return Executioner.INSTANCE.<Stream<E>>sync(
-            sessionOps, null, options(buildStatement()), getCache(), traceContext, this, showValues);
+    return Executioner.INSTANCE.<Stream<E>>sync(sessionOps, null, traceContext, this, showValues);
   }
 
   public Stream<E> sync(UnitOfWork uow) {
-    return Executioner.INSTANCE.<Stream<E>>sync(
-            sessionOps, uow, options(buildStatement()), getCache(), traceContext, this, showValues);
+    return Executioner.INSTANCE.<Stream<E>>sync(sessionOps, uow, traceContext, this, showValues);
   }
 
   public CompletableFuture<Stream<E>> async() {
-    return Executioner.INSTANCE.<Stream<E>>async(
-            sessionOps, null, options(buildStatement()), getCache(), traceContext, this, showValues);
+    return Executioner.INSTANCE.<Stream<E>>async(sessionOps, null, traceContext, this, showValues);
   }
 
   public CompletableFuture<Stream<E>> async(UnitOfWork uow) {
-    return Executioner.INSTANCE.<Stream<E>>async(
-            sessionOps, uow, options(buildStatement()), getCache(), traceContext, this, showValues);
+    return Executioner.INSTANCE.<Stream<E>>async(sessionOps, uow, traceContext, this, showValues);
   }
 }

src/main/java/net/helenus/core/operation/BoundOperation.java

@@ -36,7 +36,7 @@ public final class BoundOperation<E> extends AbstractOperation<E, BoundOperation
   }
 
   @Override
-  public Statement buildStatement() {
+  public Statement buildStatement(boolean cached) {
     return boundStatement;
   }
 }

src/main/java/net/helenus/core/operation/BoundOptionalOperation.java

@@ -39,7 +39,7 @@ public final class BoundOptionalOperation<E>
   }
 
   @Override
-  protected AbstractCache getCache() {
+  public AbstractCache getCache() {
     return delegate.getCache();
   }
 
@@ -49,7 +49,7 @@ public final class BoundOptionalOperation<E>
   }
 
   @Override
-  public Statement buildStatement() {
+  public Statement buildStatement(boolean cached) {
     return boundStatement;
   }
 }

src/main/java/net/helenus/core/operation/BoundStreamOperation.java

@@ -36,7 +36,7 @@ public final class BoundStreamOperation<E>
   }
 
   @Override
-  protected AbstractCache getCache() {
+  public AbstractCache getCache() {
     return delegate.getCache();
   }
 
@@ -51,7 +51,7 @@ public final class BoundStreamOperation<E>
   }
 
   @Override
-  public Statement buildStatement() {
+  public Statement buildStatement(boolean cached) {
     return boundStatement;
   }
 }

src/main/java/net/helenus/core/operation/CacheKey.java

@@ -1,20 +1,19 @@
 package net.helenus.core.operation;
 
 import com.datastax.driver.core.Statement;
+import net.helenus.mapping.HelenusEntity;
 
 import java.io.Serializable;
 
 public class CacheKey implements Serializable {
 
   private String key;
-
-  static String of(Statement statement) {
-    return "use " + statement.getKeyspace() + "; " + statement.toString();
-  }
+  private HelenusEntity entity;
 
   CacheKey() {}
 
-  CacheKey(String key) {
+  CacheKey(HelenusEntity entity, String key) {
+    this.entity = entity;
     this.key = key;
   }
 
@@ -23,7 +22,7 @@ public class CacheKey implements Serializable {
   }
 
   public String toString() {
-    return key;
+    return entity.getName() + "." + key;
   }
 
   @Override

src/main/java/net/helenus/core/operation/CountOperation.java

@@ -40,7 +40,7 @@ public final class CountOperation extends AbstractFilterOperation<Long, CountOpe
   }
 
   @Override
-  public BuiltStatement buildStatement() {
+  public BuiltStatement buildStatement(boolean cached) {
 
     if (filters != null && !filters.isEmpty()) {
       filters.forEach(f -> addPropertyNode(f.getNode()));

src/main/java/net/helenus/core/operation/DeleteOperation.java

@@ -46,7 +46,7 @@ public final class DeleteOperation extends AbstractFilterOperation<ResultSet, De
   }
 
   @Override
-  public BuiltStatement buildStatement() {
+  public BuiltStatement buildStatement(boolean cached) {
 
     if (filters != null && !filters.isEmpty()) {
       filters.forEach(f -> addPropertyNode(f.getNode()));

src/main/java/net/helenus/core/operation/Executioner.java

@@ -6,79 +6,93 @@ import brave.propagation.TraceContext;
 import com.datastax.driver.core.ResultSet;
 import com.datastax.driver.core.ResultSetFuture;
 import com.datastax.driver.core.Statement;
+
+import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
+import java.util.function.Function;
+
 import net.helenus.core.AbstractSessionOperations;
 import net.helenus.core.UnitOfWork;
 
+
 public enum Executioner {
   INSTANCE;
 
-  <E> E sync(
-      AbstractSessionOperations session,
-      UnitOfWork uow,
-      Statement statement,
-      AbstractCache cache,
-      TraceContext traceContext,
-      OperationsDelegate<E> delegate,
-      boolean showValues) {
-    ResultSetFuture futureResultSet = session.executeAsync(statement, showValues);
-    return this.<E>execute(
-        futureResultSet, session, uow, statement, cache, traceContext, delegate, showValues);
+  <E> E sync(AbstractSessionOperations session, UnitOfWork uow, Function<E, ?> extractor,
+             TraceContext traceContext, OperationsDelegate<E> delegate, boolean showValues) {
+    return this.<E>execute(session, uow, traceContext, delegate, showValues);
   }
 
-  public <E> CompletableFuture<E> async(
-      AbstractSessionOperations session,
-      UnitOfWork uow,
-      Statement statement,
-      AbstractCache cache,
-      TraceContext traceContext,
-      OperationsDelegate<E> delegate,
-      boolean showValues) {
-
-    ResultSetFuture futureResultSet = session.executeAsync(statement, showValues);
-    return CompletableFuture.<E>supplyAsync(
-        () ->
-            execute(
-                futureResultSet, session, uow, statement, cache, traceContext, delegate, showValues));
+  public <E> CompletableFuture<E> async(AbstractSessionOperations session, UnitOfWork uow, TraceContext traceContext,
+      OperationsDelegate<E> delegate, boolean showValues) {
+    return CompletableFuture.<E>supplyAsync(() -> execute(session, uow, traceContext, delegate, showValues));
   }
 
-  public <E> E execute(
-      ResultSetFuture futureResultSet,
-      AbstractSessionOperations session,
-      UnitOfWork uow,
-      Statement statement,
-      AbstractCache cache,
-      TraceContext traceContext,
-      OperationsDelegate<E> delegate,
-      boolean showValues) {
+  public <E> E execute(AbstractSessionOperations session, UnitOfWork uow, TraceContext traceContext,
+                       OperationsDelegate<E> delegate, boolean showValues) {
 
+    // Start recording in a Zipkin sub-span our execution time to perform this operation.
     Tracer tracer = session.getZipkinTracer();
     Span span = null;
     if (tracer != null && traceContext != null) {
       span = tracer.newChild(traceContext);
     }
 
-    if (uow != null) {
-      cache = uow.getCacheEnclosing(cache);
-    }
-
     try {
       if (span != null) {
         span.name("cassandra");
         span.start();
       }
 
-      ResultSet resultSet;
-      if (cache != null) {
-        resultSet = cache.apply(statement, delegate, futureResultSet);
+      // Determine if we are caching and if so where to put the results.
+      AbstractCache<CacheKey, Object> cache = null;
+      boolean prepareStatementForCaching = false;
+      if (uow != null ) {
+        prepareStatementForCaching = true;
+        cache = uow.getCacheEnclosing(delegate.getCache());
       } else {
-        resultSet = futureResultSet.get();
+        cache = delegate.getCache();
+        prepareStatementForCaching = cache != null;
       }
 
-      E result = delegate.transform(resultSet);
+      // TODO: first, ask the delegate for the cacheKey
+      // if this is a SELECT query:
+      //  if not in cache build the statement, execute the future, cache the result, transform the result then cache the transformations
+      // if INSERT/UPSERT/UPDATE
+      // if DELETE
+      // if COUNT
+      CacheKey key = (cache == null) ? null : delegate.getCacheKey();
+      E result = null;
+
+      if (key != null && cache != null) {
+        // Right now we only support Optional<Entity> fetch via complete primary key.
+        Object value = cache.get(key);
+        if (value != null) {
+          result = (E) Optional.of(value);
+          // if log statements: log cache hit for entity, primary key
+          // metrics.cacheHit +1
+        } else {
+          // if log statements: log cache miss for entity, primary key
+          // metrics.cacheMiss +1
+        }
+      }
+
+      ResultSet resultSet = null;
+      if (result == null) {
+        Statement statement = delegate.options(delegate.buildStatement(prepareStatementForCaching));
+        // if log statements... log it here.
+        ResultSetFuture futureResultSet = session.executeAsync(statement, showValues);
+        resultSet = futureResultSet.get();
+      }
+      result = delegate.transform(resultSet);
+
+      if (cache != null) {
+        updateCache.apply(result, cache);
+      }
+
+      return (E) result;
 
-      return result;
     } catch (InterruptedException | ExecutionException e) {
       throw new RuntimeException(e);
     } finally {
@@ -87,4 +101,5 @@ public enum Executioner {
       }
     }
   }
+
 }

src/main/java/net/helenus/core/operation/InsertOperation.java

@@ -120,7 +120,7 @@ public final class InsertOperation<T> extends AbstractOperation<T, InsertOperati
   }
 
   @Override
-  public BuiltStatement buildStatement() {
+  public BuiltStatement buildStatement(boolean cached) {
 
     values.forEach(t -> addPropertyNode(t._1));
 

src/main/java/net/helenus/core/operation/OperationsDelegate.java

@@ -1,9 +1,18 @@
 package net.helenus.core.operation;
 
 import com.datastax.driver.core.ResultSet;
+import com.datastax.driver.core.Statement;
+
+
+interface OperationsDelegate<E> {
+
+  Statement buildStatement(boolean cached);
+
+  Statement options(Statement statement);
 
-public interface OperationsDelegate<E> {
   E transform(ResultSet resultSet);
 
+  AbstractCache getCache();
+
   CacheKey getCacheKey();
 }

src/main/java/net/helenus/core/operation/PreparedStreamOperation.java

@@ -44,7 +44,7 @@ public final class PreparedStreamOperation<E> {
       key = key.replaceFirst(Pattern.quote("?"), param.toString());
     }
 
-    return new BoundStreamOperation<E>(boundStatement, new CacheKey(key), operation);
+    return new BoundStreamOperation<E>(boundStatement, operation.getCacheKey(), operation);
   }
 
   @Override

src/main/java/net/helenus/core/operation/SelectFirstOperation.java

@@ -38,8 +38,18 @@ public final class SelectFirstOperation<E>
   }
 
   @Override
-  public BuiltStatement buildStatement() {
-    return src.buildStatement();
+  public AbstractCache getCache() {
+    return src.getCache();
+  }
+
+  @Override
+  public CacheKey getCacheKey() {
+    return src.getCacheKey();
+  }
+
+  @Override
+  public BuiltStatement buildStatement(boolean cached) {
+    return src.buildStatement(cached);
   }
 
   @Override

src/main/java/net/helenus/core/operation/SelectFirstTransformingOperation.java

@@ -36,8 +36,8 @@ public final class SelectFirstTransformingOperation<R, E>
   }
 
   @Override
-  public BuiltStatement buildStatement() {
-    return src.buildStatement();
+  public BuiltStatement buildStatement(boolean cached) {
+    return src.buildStatement(cached);
   }
 
   @Override

src/main/java/net/helenus/core/operation/SelectOperation.java

@@ -27,6 +27,9 @@ import java.util.*;
 import java.util.function.Function;
 import java.util.stream.Stream;
 import java.util.stream.StreamSupport;
+
+import com.google.common.base.Joiner;
+import com.google.common.collect.Iterables;
 import net.helenus.core.*;
 import net.helenus.core.reflect.HelenusPropertyNode;
 import net.helenus.mapping.HelenusEntity;
@@ -166,13 +169,6 @@ public final class SelectOperation<E> extends AbstractFilterStreamOperation<E, S
     return this;
   }
 
-  protected AbstractCache getCache() {
-    if (!ignoreSessionCache) {
-      return sessionOps.getSessionCache();
-    }
-    return null;
-  }
-
   public SelectOperation<E> ignoreCache() {
     ignoreSessionCache = true;
     return this;
@@ -189,17 +185,53 @@ public final class SelectOperation<E> extends AbstractFilterStreamOperation<E, S
   }
 
   @Override
-  public BuiltStatement buildStatement() {
+  public AbstractCache getCache() {// TODO, not really public API...
+    if (!ignoreSessionCache) {
+      return sessionOps.getSessionCache();
+    }
+    return null;
+  }
+
+  @Override
+  public CacheKey getCacheKey() {
+
+    List<String>keys = new ArrayList<>(filters.size());
+    HelenusEntity entity = props.get(0).getEntity();
+
+    for (HelenusPropertyNode prop : props) {
+      switch(prop.getProperty().getColumnType()) {
+        case PARTITION_KEY:
+        case CLUSTERING_COLUMN:
+
+          Filter filter = filters.get(prop.getProperty());
+          if (filter != null) {
+            keys.add(filter.toString());
+          } else {
+            // we're missing a part of the primary key, so we can't create a proper cache key
+            return null;
+          }
+          break;
+        default:
+          // We've past the primary key components in this ordered list, so we're done building
+          // the cache key.
+          if (keys.size() > 0) {
+            return new CacheKey(entity, Joiner.on(",").join(keys));
+          }
+          return null;
+      }
+    }
+    return null;
+  }
+
+  @Override
+  public BuiltStatement buildStatement(boolean cached) {
 
     HelenusEntity entity = null;
     Selection selection = QueryBuilder.select();
 
-    // iff in txn or cacheable add ttl and timestamp to result set for each col selected
-    // construct set of primary keys (partition and col)
-    // construct cache key
-
     for (HelenusPropertyNode prop : props) {
-      selection = selection.column(prop.getColumnName());
+      String columnName = prop.getColumnName();
+      selection = selection.column(columnName);
 
       if (prop.getProperty().caseSensitiveIndex()) {
         allowFiltering = true;
@@ -214,6 +246,25 @@ public final class SelectOperation<E> extends AbstractFilterStreamOperation<E, S
                         + " or "
                         + prop.getEntity().getMappingInterface());
       }
+
+      if (cached) {
+        switch(prop.getProperty().getColumnType()) {
+          case PARTITION_KEY:
+          case CLUSTERING_COLUMN:
+            break;
+          default:
+            if (entity.equals(prop.getEntity())) {
+              if (prop.getNext().isPresent()) {
+                columnName = Iterables.getLast(prop).getColumnName().toCql(true);
+              }
+              if (!prop.getProperty().getDataType().isCollectionType()) {
+                selection.writeTime(columnName);
+                selection.ttl(columnName);
+              }
+            }
+            break;
+        }
+      }
     }
 
     if (entity == null) {
@@ -234,7 +285,7 @@ public final class SelectOperation<E> extends AbstractFilterStreamOperation<E, S
 
       Where where = select.where();
 
-      for (Filter<?> filter : filters) {
+      for (Filter<?> filter : filters.values()) {
         where.and(filter.getClause(sessionOps.getValuePreparer()));
       }
     }

src/main/java/net/helenus/core/operation/SelectTransformingOperation.java

@@ -36,12 +36,12 @@ public final class SelectTransformingOperation<R, E>
   }
 
   @Override
-  public BuiltStatement buildStatement() {
-    return src.buildStatement();
+  public BuiltStatement buildStatement(boolean cached) {
+    return src.buildStatement(cached);
   }
 
   @Override
-  protected AbstractCache getCache() {
+  public AbstractCache getCache() {
     return src.getCache();
   }
 

src/main/java/net/helenus/core/operation/SessionCache.java

@@ -6,31 +6,20 @@ import com.datastax.driver.core.Statement;
 import com.google.common.cache.Cache;
 import java.util.concurrent.ExecutionException;
 
-public class SessionCache extends AbstractCache<String, ResultSet> {
+public class SessionCache extends AbstractCache<CacheKey, ResultSet> {
 
-  protected ResultSet apply(
-      Statement statement, OperationsDelegate delegate, ResultSetFuture resultSetFuture)
+  protected ResultSet apply(CacheKey key, OperationsDelegate delegate)
       throws InterruptedException, ExecutionException {
-    final CacheKey key = delegate.getCacheKey();
-    final String cacheKey = (key == null) ? CacheKey.of(statement) : key.toString();
+
+
     ResultSet resultSet = null;
-    if (cacheKey == null) {
-      resultSet = resultSetFuture.get();
-    } else {
-      resultSet = cache.getIfPresent(cacheKey);
-      if (resultSet == null) {
-        resultSet = resultSetFuture.get();
+    resultSet = cache.getIfPresent(key);
+
     if (resultSet != null) {
-          cache.put(cacheKey, resultSet);
-        }
-      }
+      cache.put(key, resultSet);
     }
+
     return resultSet;
   }
 
-  public ResultSet get(Statement statement, OperationsDelegate delegate) {
-    final CacheKey key = delegate.getCacheKey();
-    final String cacheKey = (key == null) ? CacheKey.of(statement) : key.toString();
-    return cache.getIfPresent(cacheKey);
-  }
 }

src/main/java/net/helenus/core/operation/UnitOfWorkCache.java

@@ -1,19 +1,13 @@
 package net.helenus.core.operation;
 
-import com.datastax.driver.core.ResultSet;
-import com.datastax.driver.core.ResultSetFuture;
-import com.datastax.driver.core.Statement;
+import java.util.Optional;
+
 import net.helenus.core.UnitOfWork;
 
-import java.util.HashMap;
-import java.util.Map;
-import java.util.concurrent.ExecutionException;
-
-public class UnitOfWorkCache extends AbstractCache<String, ResultSet> {
+public class UnitOfWorkCache extends AbstractCache<CacheKey, Object> {
 
     private final UnitOfWork uow;
-    private final Map<String, ResultSet> cache = new HashMap<String, ResultSet>();
-    private AbstractCache sessionCache;
+    private AbstractCache<CacheKey, Object> sessionCache;
 
     public UnitOfWorkCache(UnitOfWork uow, AbstractCache sessionCache) {
         super();
@@ -22,32 +16,22 @@ public class UnitOfWorkCache extends AbstractCache<String, ResultSet> {
     }
 
     @Override
-    protected ResultSet apply(Statement statement, OperationsDelegate delegate, ResultSetFuture resultSetFuture)
-            throws InterruptedException, ExecutionException {
-        return resultSetFuture.get();
-        /*
-        final CacheKey key = delegate.getCacheKey();
-        final String cacheKey = (key == null) ? CacheKey.of(statement) : key.toString();
-        ResultSet resultSet = null;
-        if (cacheKey == null) {
-            if (sessionCache != null) {
-                ResultSet rs = sessionCache.apply(statement, delegate, resultSetFuture);
-                if (rs != null) {
-                    return rs;
+    Object get(CacheKey key) {
+        Object result = null;
+        UnitOfWork parent = null;
+        do {
+            result = uow.getCache().get(key);
+            parent = uow.getEnclosingUnitOfWork();
+        } while(result == null && parent != null);
+        if (result == null) {
+            result = sessionCache.get(key);
         }
+        return result;
     }
-        } else {
-            resultSet = cache.get(cacheKey);
-            if (resultSet != null) {
-                return resultSet;
-            }
-        }
-        resultSet = resultSetFuture.get();
-        if (resultSet != null) {
-            cache.put(cacheKey, resultSet);
-        }
-        return resultSet;
-        */
+
+    @Override
+    void put(CacheKey key, Object result) {
+        cache.put(key, result);
     }
 
 }

src/main/java/net/helenus/core/operation/UpdateOperation.java

@@ -507,7 +507,7 @@ public final class UpdateOperation<E> extends AbstractFilterOperation<E, UpdateO
   }
 
   @Override
-  public BuiltStatement buildStatement() {
+  public BuiltStatement buildStatement(boolean cached) {
 
     if (entity == null) {
       throw new HelenusMappingException("empty update operation");

src/main/java/net/helenus/mapping/javatype/AbstractCollectionJavaType.java

@@ -0,0 +1,7 @@
+package net.helenus.mapping.javatype;
+
+public abstract class AbstractCollectionJavaType extends AbstractJavaType {
+
+    public static boolean isCollectionType() { return true; }
+
+}

src/main/java/net/helenus/mapping/javatype/AbstractJavaType.java

@@ -33,6 +33,8 @@ import net.helenus.support.HelenusMappingException;
 
 public abstract class AbstractJavaType {
 
+  public static boolean isCollectionType() { return false; }
+
   public abstract Class<?> getJavaClass();
 
   public boolean isApplicable(Class<?> javaClass) {

src/main/java/net/helenus/mapping/javatype/ListJavaType.java

@@ -35,7 +35,7 @@ import net.helenus.mapping.type.UDTListDataType;
 import net.helenus.support.Either;
 import net.helenus.support.HelenusMappingException;
 
-public final class ListJavaType extends AbstractJavaType {
+public final class ListJavaType extends AbstractCollectionJavaType {
 
   @Override
   public Class<?> getJavaClass() {

src/main/java/net/helenus/mapping/javatype/MapJavaType.java

@@ -18,6 +18,7 @@ package net.helenus.mapping.javatype;
 import com.datastax.driver.core.*;
 import java.lang.reflect.Method;
 import java.lang.reflect.Type;
+import java.util.AbstractCollection;
 import java.util.Map;
 import java.util.Optional;
 import java.util.function.Function;
@@ -31,7 +32,7 @@ import net.helenus.mapping.type.*;
 import net.helenus.support.Either;
 import net.helenus.support.HelenusMappingException;
 
-public final class MapJavaType extends AbstractJavaType {
+public final class MapJavaType extends AbstractCollectionJavaType {
 
   @Override
   public Class<?> getJavaClass() {

src/main/java/net/helenus/mapping/javatype/SetJavaType.java

@@ -35,7 +35,7 @@ import net.helenus.mapping.type.UDTSetDataType;
 import net.helenus.support.Either;
 import net.helenus.support.HelenusMappingException;
 
-public final class SetJavaType extends AbstractJavaType {
+public final class SetJavaType extends AbstractCollectionJavaType {
 
   @Override
   public Class<?> getJavaClass() {

src/main/java/net/helenus/mapping/type/AbstractCollectionDataType.java

@@ -0,0 +1,13 @@
+package net.helenus.mapping.type;
+
+import net.helenus.mapping.ColumnType;
+
+public abstract class AbstractCollectionDataType extends AbstractDataType {
+
+    public AbstractCollectionDataType(ColumnType columnType) {
+        super(columnType);
+    }
+
+    public boolean isCollectionType() { return true; }
+
+}

src/main/java/net/helenus/mapping/type/AbstractDataType.java

@@ -54,4 +54,7 @@ public abstract class AbstractDataType {
     throw new HelenusMappingException(
         "wrong column type " + columnType + " for UserDefinedType in columnName " + columnName);
   }
+
+  public boolean isCollectionType() { return false; }
+
 }

src/main/java/net/helenus/mapping/type/DTDataType.java

@@ -34,6 +34,7 @@ public final class DTDataType extends AbstractDataType {
   private final DataType dataType;
   private final Class<?> javaClass;
   private final Class<?>[] typeArguments;
+  private final boolean isCollectionType;
 
   public DTDataType(ColumnType columnType, DataType dataType) {
     this(
@@ -53,6 +54,7 @@ public final class DTDataType extends AbstractDataType {
     this.dataType = dataType;
     this.javaClass = javaClass;
     this.typeArguments = typeArguments;
+    this.isCollectionType = dataType.isCollection();
   }
 
   public static DTDataType list(
@@ -193,6 +195,10 @@ public final class DTDataType extends AbstractDataType {
     return null;
   }
 
+  public boolean isCollectionType() {
+    return isCollectionType;
+  }
+
   @Override
   public String toString() {
     return dataType.toString();

src/main/java/net/helenus/mapping/type/UDTKeyMapDataType.java

@@ -18,12 +18,14 @@ package net.helenus.mapping.type;
 import com.datastax.driver.core.DataType;
 import com.datastax.driver.core.UserType;
 import com.datastax.driver.core.schemabuilder.*;
+
+import java.util.AbstractCollection;
 import java.util.List;
 import net.helenus.mapping.ColumnType;
 import net.helenus.mapping.IdentityName;
 import net.helenus.support.HelenusMappingException;
 
-public final class UDTKeyMapDataType extends AbstractDataType {
+public final class UDTKeyMapDataType extends AbstractCollectionDataType {
 
   private final IdentityName keyType;
   private final Class<?> udtKeyClass;

src/main/java/net/helenus/mapping/type/UDTListDataType.java

@@ -23,7 +23,7 @@ import net.helenus.mapping.ColumnType;
 import net.helenus.mapping.IdentityName;
 import net.helenus.support.HelenusMappingException;
 
-public final class UDTListDataType extends AbstractDataType {
+public final class UDTListDataType extends AbstractCollectionDataType {
 
   private final IdentityName udtName;
   private final Class<?> udtClass;

src/main/java/net/helenus/mapping/type/UDTMapDataType.java

@@ -23,7 +23,7 @@ import net.helenus.mapping.ColumnType;
 import net.helenus.mapping.IdentityName;
 import net.helenus.support.HelenusMappingException;
 
-public final class UDTMapDataType extends AbstractDataType {
+public final class UDTMapDataType extends AbstractCollectionDataType {
 
   private final IdentityName keyType;
   private final Class<?> udtKeyClass;

src/main/java/net/helenus/mapping/type/UDTSetDataType.java

@@ -23,7 +23,7 @@ import net.helenus.mapping.ColumnType;
 import net.helenus.mapping.IdentityName;
 import net.helenus.support.HelenusMappingException;
 
-public final class UDTSetDataType extends AbstractDataType {
+public final class UDTSetDataType extends AbstractCollectionDataType {
 
   private final IdentityName udtName;
   private final Class<?> udtClass;

src/main/java/net/helenus/mapping/type/UDTValueMapDataType.java

@@ -23,7 +23,7 @@ import net.helenus.mapping.ColumnType;
 import net.helenus.mapping.IdentityName;
 import net.helenus.support.HelenusMappingException;
 
-public final class UDTValueMapDataType extends AbstractDataType {
+public final class UDTValueMapDataType extends AbstractCollectionDataType {
 
   private final DataType keyType;
   private final IdentityName valueType;

src/test/java/net/helenus/test/integration/core/simple/SimpleUserTest.java

@@ -17,9 +17,11 @@ package net.helenus.test.integration.core.simple;
 
 import static net.helenus.core.Query.eq;
 
+import com.datastax.driver.core.ResultSet;
 import net.helenus.core.Helenus;
 import net.helenus.core.HelenusSession;
 import net.helenus.core.Operator;
+import net.helenus.core.operation.UpdateOperation;
 import net.helenus.core.reflect.Drafted;
 import net.helenus.mapping.HelenusEntity;
 import net.helenus.support.Fun;
@@ -248,6 +250,25 @@ public class SimpleUserTest extends AbstractEmbeddedCassandraTest {
     Assert.assertEquals(0L, cnt);
   }
 
+  public void testZipkin() throws Exception {
+    session
+            .update()
+            .set(user::name, null)
+            .set(user::age, null)
+            .set(user::type, null)
+            .where(user::id, eq(100L))
+            .zipkinContext(null)
+            .sync();
+
+
+    UpdateOperation<ResultSet> update = session.update();
+    update
+            .set(user::name, null)
+            .zipkinContext(null)
+            .sync();
+
+  }
+
   private void assertUsers(User expected, User actual) {
     Assert.assertEquals(expected.id(), actual.id());
     Assert.assertEquals(expected.name(), actual.name());

src/test/java/net/helenus/test/integration/core/unitofwork/UnitOfWorkTest.java

@@ -62,14 +62,13 @@ public class UnitOfWorkTest extends AbstractEmbeddedCassandraTest {
 
     @Test
     public void testSelectAfterInsertProperlyCachesEntity() throws Exception {
-        /*
         Widget w1, w2, w3, w4;
         UUID key = UUIDs.timeBased();
 
         try (UnitOfWork uow = session.begin()) {
 
             // This should cache the inserted Widget.
-            w1 = session.<Widget>upsert(widget)
+            w1 = session.<Widget>insert(widget)
                     .value(widget::id, key)
                     .value(widget::name, RandomString.make(20))
                     .sync(uow);
@@ -106,7 +105,6 @@ public class UnitOfWorkTest extends AbstractEmbeddedCassandraTest {
 
         Assert.assertNotEquals(w1, w4);
         Assert.assertTrue(w1.equals(w4));
-        */
     }
 
 }