Refactor result set and execution plan interface hierarchies

core/src/main/java/com/orientechnologies/orient/core/sql/executor/AbstractExecutionStep.java

@@ -7,34 +7,34 @@
 /**
  * @author Luigi Dell'Aquila
  */
-public abstract class AbstractExecutionStep implements OExecutionStep {
+public abstract class AbstractExecutionStep implements OExecutionStepInternal {
 
   protected final OCommandContext ctx;
-  protected Optional<OExecutionStep> prev = Optional.empty();
-  protected Optional<OExecutionStep> next = Optional.empty();
-  protected boolean timedOut = false;
+  protected Optional<OExecutionStepInternal> prev     = Optional.empty();
+  protected Optional<OExecutionStepInternal> next     = Optional.empty();
+  protected boolean                          timedOut = false;
 
   public AbstractExecutionStep(OCommandContext ctx) {
     this.ctx = ctx;
   }
 
-  @Override public void setPrevious(OExecutionStep step) {
+  @Override public void setPrevious(OExecutionStepInternal step) {
     this.prev = Optional.ofNullable(step);
   }
 
-  @Override public void setNext(OExecutionStep step) {
+  @Override public void setNext(OExecutionStepInternal step) {
     this.next = Optional.ofNullable(step);
   }
 
   public OCommandContext getContext() {
     return ctx;
   }
 
-  public Optional<OExecutionStep> getPrev() {
+  public Optional<OExecutionStepInternal> getPrev() {
     return prev;
   }
 
-  public Optional<OExecutionStep> getNext() {
+  public Optional<OExecutionStepInternal> getNext() {
     return next;
   }
 

core/src/main/java/com/orientechnologies/orient/core/sql/executor/AggregateProjectionCalculationStep.java

@@ -18,8 +18,8 @@ public class AggregateProjectionCalculationStep extends ProjectionCalculationSte
   private final OGroupBy groupBy;
 
   //the key is the GROUP BY key, the value is the (partially) aggregated value
-  private Map<List, OResult> aggregateResults = new LinkedHashMap<>();
-  private List<OResult>      finalResults     = null;
+  private Map<List, OResultInternal> aggregateResults = new LinkedHashMap<>();
+  private List<OResultInternal>      finalResults     = null;
 
   private int nextItem = 0;
 
@@ -71,7 +71,7 @@ private void executeAggregation(OCommandContext ctx, int nRecords) {
     if (!prev.isPresent()) {
       throw new OCommandExecutionException("Cannot execute an aggregation or a GROUP BY without a previous result");
     }
-    OExecutionStep prevStep = prev.get();
+    OExecutionStepInternal prevStep = prev.get();
     OTodoResultSet lastRs = prevStep.syncPull(ctx, nRecords);
     while (lastRs.hasNext()) {
       aggregate(lastRs.next(), ctx);
@@ -82,7 +82,7 @@ private void executeAggregation(OCommandContext ctx, int nRecords) {
     finalResults = new ArrayList<>();
     finalResults.addAll(aggregateResults.values());
     aggregateResults.clear();
-    for (OResult item : finalResults) {
+    for (OResultInternal item : finalResults) {
       for (String name : item.getPropertyNames()) {
         Object prevVal = item.getProperty(name);
         if (prevVal instanceof AggregationContext) {
@@ -100,9 +100,9 @@ private void aggregate(OResult next, OCommandContext ctx) {
         key.add(val);
       }
     }
-    OResult preAggr = aggregateResults.get(key);
+    OResultInternal preAggr = aggregateResults.get(key);
     if (preAggr == null) {
-      preAggr = new OResult();
+      preAggr = new OResultInternal();
       aggregateResults.put(key, preAggr);
     }
 
@@ -122,7 +122,7 @@ private void aggregate(OResult next, OCommandContext ctx) {
   }
 
   @Override public String prettyPrint(int depth, int indent) {
-    String spaces = OExecutionStep.getIndent(depth, indent);
+    String spaces = OExecutionStepInternal.getIndent(depth, indent);
     return spaces + "+ CALCULATE AGGREGATE PROJECTIONS\n" +
         spaces + "      " + projection.toString() + "" +
         (groupBy == null ? "" : (spaces + "\n      " + groupBy.toString()));

core/src/main/java/com/orientechnologies/orient/core/sql/executor/EmptyStep.java

@@ -6,7 +6,7 @@
 /**
  * Created by luigidellaquila on 08/07/16.
  */
-public class EmptyStep implements OExecutionStep {
+public class EmptyStep implements OExecutionStepInternal {
   @Override public OTodoResultSet syncPull(OCommandContext ctx, int nRecords) throws OTimeoutException {
     return new OInternalResultSet();
   }
@@ -19,11 +19,11 @@ public class EmptyStep implements OExecutionStep {
 
   }
 
-  @Override public void setPrevious(OExecutionStep step) {
+  @Override public void setPrevious(OExecutionStepInternal step) {
 
   }
 
-  @Override public void setNext(OExecutionStep step) {
+  @Override public void setNext(OExecutionStepInternal step) {
 
   }
 

core/src/main/java/com/orientechnologies/orient/core/sql/executor/FetchFromClassExecutionStep.java

@@ -142,14 +142,14 @@ private void sortClusers(int[] clusterIds) {
   }
 
   @Override public void sendTimeout() {
-    for (OExecutionStep step : subSteps) {
+    for (OExecutionStepInternal step : subSteps) {
       step.sendTimeout();
     }
     prev.ifPresent(p -> p.sendTimeout());
   }
 
   @Override public void close() {
-    for (OExecutionStep step : subSteps) {
+    for (OExecutionStepInternal step : subSteps) {
       step.close();
     }
     prev.ifPresent(p -> p.close());
@@ -161,11 +161,11 @@ private void sortClusers(int[] clusterIds) {
 
   @Override public String prettyPrint(int depth, int indent) {
     StringBuilder builder = new StringBuilder();
-    String ind = OExecutionStep.getIndent(depth, indent);
+    String ind = OExecutionStepInternal.getIndent(depth, indent);
     builder.append(ind);
     builder.append("+ FETCH FROM CLASS " + className + "\n");
     for (int i = 0; i < subSteps.length; i++) {
-      OExecutionStep step = subSteps[i];
+      OExecutionStepInternal step = subSteps[i];
       builder.append(step.prettyPrint(depth + 1, indent));
       if (i < subSteps.length - 1) {
         builder.append("\n");

core/src/main/java/com/orientechnologies/orient/core/sql/executor/FetchFromClusterExecutionStep.java

@@ -66,7 +66,7 @@ record = iterator.previous();
           record = iterator.next();
         }
         nFetched++;
-        OResult result = new OResult();
+        OResultInternal result = new OResultInternal();
         result.element = record;
         return result;
       }
@@ -103,7 +103,9 @@ record = iterator.next();
   }
 
   @Override public String prettyPrint(int depth, int indent) {
-    return OExecutionStep.getIndent(depth, indent) + "+ FETCH FROM CLUSTER " + clusterId;
+    return OExecutionStepInternal.getIndent(depth, indent) + "+ FETCH FROM CLUSTER " + clusterId + " " + (ORDER_DESC.equals(order) ?
+        "DESC" :
+        "ASC");
   }
 
   public void setOrder(Object order) {

core/src/main/java/com/orientechnologies/orient/core/sql/executor/FilterStep.java

@@ -22,7 +22,7 @@ public FilterStep(OWhereClause whereClause, OCommandContext ctx) {
     if (!prev.isPresent()) {
       throw new IllegalStateException("filter step requires a previous step");
     }
-    OExecutionStep prevStep = prev.get();
+    OExecutionStepInternal prevStep = prev.get();
 
     return new OTodoResultSet() {
       public boolean finished = false;
@@ -114,7 +114,7 @@ private void fetchNextItem() {
   }
 
   @Override public String prettyPrint(int depth, int indent) {
-    return OExecutionStep.getIndent(depth, indent) + "+ CALCULATE WHERE CONDITION : " + whereClause.toString();
+    return OExecutionStepInternal.getIndent(depth, indent) + "+ CALCULATE WHERE CONDITION : " + whereClause.toString();
   }
 
 }

core/src/main/java/com/orientechnologies/orient/core/sql/executor/LimitExecutionStep.java

@@ -45,7 +45,7 @@ public LimitExecutionStep(OLimit limit, OCommandContext ctx) {
   }
 
   @Override public String prettyPrint(int depth, int indent) {
-    return OExecutionStep.getIndent(depth, indent) + "+ LIMIT (" + limit.toString() + ")";
+    return OExecutionStepInternal.getIndent(depth, indent) + "+ LIMIT (" + limit.toString() + ")";
   }
 
 }

core/src/main/java/com/orientechnologies/orient/core/sql/executor/OExecutionPlan.java

@@ -1,13 +1,16 @@
 package com.orientechnologies.orient.core.sql.executor;
 
 import java.io.Serializable;
+import java.util.List;
 
 /**
  * Created by luigidellaquila on 06/07/16.
  */
 public interface OExecutionPlan extends Serializable{
 
+  List<OExecutionStep> getSteps();
 
-  public String prettyPrint(int indent);
+  String prettyPrint(int indent);
 
+  OResult toResult();
 }

core/src/main/java/com/orientechnologies/orient/core/sql/executor/OExecutionStep.java

@@ -1,37 +1,19 @@
 package com.orientechnologies.orient.core.sql.executor;
 
-import com.orientechnologies.common.concur.OTimeoutException;
-import com.orientechnologies.orient.core.command.OCommandContext;
+import java.util.List;
 
 /**
- * Created by luigidellaquila on 06/07/16.
+ * Created by luigidellaquila on 20/07/16.
  */
-public interface OExecutionStep extends OExecutionCallback {
+public interface OExecutionStep {
 
-  OTodoResultSet syncPull(OCommandContext ctx, int nRecords) throws OTimeoutException;
+  String getName();
 
-  void asyncPull(OCommandContext ctx, int nRecords, OExecutionCallback callback) throws OTimeoutException;
+  String getType();
 
-  void sendTimeout();
+  String getTargetNode();
 
-  void setPrevious(OExecutionStep step);
+  String getDescription();
 
-  void setNext(OExecutionStep step);
-
-  void close();
-
-  static String getIndent(int depth, int indent) {
-    StringBuilder result = new StringBuilder();
-    for (int i = 0; i < depth; i++) {
-      for (int j = 0; j < indent; j++) {
-        result.append(" ");
-      }
-    }
-    return result.toString();
-  }
-
-  default String prettyPrint(int depth, int indent) {
-    String spaces = getIndent(depth, indent);
-    return spaces + getClass().getSimpleName();
-  }
+  List<OExecutionStep> getSubSteps();
 }

core/src/main/java/com/orientechnologies/orient/core/sql/executor/OExecutionStepInternal.java

@@ -0,0 +1,60 @@
+package com.orientechnologies.orient.core.sql.executor;
+
+import com.orientechnologies.common.concur.OTimeoutException;
+import com.orientechnologies.orient.core.command.OCommandContext;
+
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Created by luigidellaquila on 06/07/16.
+ */
+public interface OExecutionStepInternal extends OExecutionStep, OExecutionCallback {
+
+  OTodoResultSet syncPull(OCommandContext ctx, int nRecords) throws OTimeoutException;
+
+  void asyncPull(OCommandContext ctx, int nRecords, OExecutionCallback callback) throws OTimeoutException;
+
+  void sendTimeout();
+
+  void setPrevious(OExecutionStepInternal step);
+
+  void setNext(OExecutionStepInternal step);
+
+  void close();
+
+  static String getIndent(int depth, int indent) {
+    StringBuilder result = new StringBuilder();
+    for (int i = 0; i < depth; i++) {
+      for (int j = 0; j < indent; j++) {
+        result.append(" ");
+      }
+    }
+    return result.toString();
+  }
+
+  default String prettyPrint(int depth, int indent) {
+    String spaces = getIndent(depth, indent);
+    return spaces + getClass().getSimpleName();
+  }
+
+  default String getName() {
+    return getClass().getSimpleName();
+  }
+
+  default String getType() {
+    return getClass().getSimpleName();
+  }
+
+  default String getDescription() {
+    return prettyPrint(0, 3);
+  }
+
+  default String getTargetNode() {
+    return "<local>";
+  }
+
+  default List<OExecutionStep> getSubSteps() {
+    return Collections.EMPTY_LIST;
+  }
+}

core/src/main/java/com/orientechnologies/orient/core/sql/executor/OInternalExecutionPlan.java

@@ -6,9 +6,15 @@
  * Created by luigidellaquila on 06/07/16.
  */
 public interface OInternalExecutionPlan extends OExecutionPlan{
-  public void close();
+  void close();
 
-  public OTodoResultSet fetchNext(int n);
+  /**
+   * if the execution can still return N elements, then the result will contain them all.
+   * If the execution contains less than N elements, then the result will contain them all, next result(s) will contain zero elements
+   * @param n
+   * @return
+   */
+  OTodoResultSet fetchNext(int n);
 
-  public void reset(OCommandContext ctx);
+  void reset(OCommandContext ctx);
 }

core/src/main/java/com/orientechnologies/orient/core/sql/executor/OInternalResultSet.java

@@ -7,7 +7,7 @@
  */
 public class OInternalResultSet implements OTodoResultSet {
   List<OResult> content = new ArrayList<>();
-  int           next    = 0;
+  int                   next    = 0;
 
   @Override public boolean hasNext() {
     return content.size() > next;

core/src/main/java/com/orientechnologies/orient/core/sql/executor/OIteratorResultSet.java

@@ -27,7 +27,7 @@ public OIteratorResultSet(Iterator iter) {
       return (OResult) val;
     }
 
-    OResult result = new OResult();
+    OResultInternal result = new OResultInternal();
     if (val instanceof OIdentifiable) {
       result.setElement((OIdentifiable) val);
     } else {