Implement subquery block

arangod/Aql/ExecutionBlock.cpp

@@ -63,9 +63,9 @@ void ExecutionBlock::walk (WalkerWorker* worker) {
   }
   // Now handle a subquery:
   if (_exeNode->getType() == ExecutionNode::SUBQUERY) {
-    // auto p = static_cast<SubqueryBlock*>(this);
+    auto p = static_cast<SubqueryBlock*>(this);
     if (worker->enterSubquery(this, nullptr)) { ; // p->_subquery
-      // p->_subquery->walk(worker);
+            p->getSubquery()->walk(worker);
       worker->leaveSubquery(this, nullptr); // p->_subquery
     }
   }

arangod/Aql/ExecutionBlock.h

@@ -1088,6 +1088,109 @@ namespace triagens {
 
     };
 
+// -----------------------------------------------------------------------------
+// --SECTION--                                                     SubqueryBlock
+// -----------------------------------------------------------------------------
+
+    class SubqueryBlock : public ExecutionBlock {
+
+      public:
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief constructor
+////////////////////////////////////////////////////////////////////////////////
+
+        SubqueryBlock (AQL_TRANSACTION_V8* trx,
+                       SubqueryNode const* en,
+                       ExecutionBlock* subquery)
+                : ExecutionBlock(trx, en), _outReg(0),
+           _subquery(subquery) {
+        }
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief destructor
+////////////////////////////////////////////////////////////////////////////////
+
+        ~SubqueryBlock () {
+        }
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief initialize
+////////////////////////////////////////////////////////////////////////////////
+
+        int initialize () {
+          int res = ExecutionBlock::initialize();
+          if (res != TRI_ERROR_NO_ERROR) {
+            return res;
+          }
+
+          // We know that staticAnalysis has been run, so _varOverview is set up
+
+          auto en = static_cast<SubqueryNode const*>(getPlanNode());
+
+          auto it3 = _varOverview->varInfo.find(en->_outVariable->id);
+          TRI_ASSERT(it3 != _varOverview->varInfo.end());
+          _outReg = it3->second.registerId;
+
+          return TRI_ERROR_NO_ERROR;
+        }
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief getSome
+////////////////////////////////////////////////////////////////////////////////
+
+        virtual AqlItemBlock* getSome (size_t atLeast,
+                                       size_t atMost) {
+          AqlItemBlock* res = ExecutionBlock::getSome(atLeast, atMost);
+
+          if (res == nullptr) {
+            return nullptr;
+          }
+          for (size_t i = 0; i < res->size(); i++) {
+            _subquery->initialize();
+            _subquery->bind(res, i);
+            _subquery->execute();
+            auto results = new std::vector<AqlItemBlock*>;
+            do {
+              auto tmp = _subquery->getSome(DefaultBatchSize, DefaultBatchSize);
+              if (tmp == nullptr) {
+                break;
+              }
+              results->push_back(tmp);
+            } while(true);
+            res->setValue(i, _outReg, AqlValue(results));
+            _subquery->shutdown();
+          }
+          return res;
+        }
+
+        ExecutionBlock* getSubquery() {
+                return _subquery;
+        }
+////////////////////////////////////////////////////////////////////////////////
+/// @brief we hold a pointer to the expression in the plan
+////////////////////////////////////////////////////////////////////////////////
+
+      private:
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief output register
+////////////////////////////////////////////////////////////////////////////////
+
+        RegisterId _outReg;
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief we need to have an executionblock and where to write the result
+////////////////////////////////////////////////////////////////////////////////
+
+        ExecutionBlock* _subquery;
+    };
+
+
+////////////////////////////////////////////////////////////////////////////////l--------------------------------------------------------------------------------TODO
+
+
+
 // -----------------------------------------------------------------------------
 // --SECTION--                                                       FilterBlock
 // -----------------------------------------------------------------------------

arangod/Aql/ExecutionEngine.cpp

@@ -111,6 +111,17 @@ struct Instanciator : public ExecutionNode::WalkerWorker {
         root = eb;
         break;
       }
+      case ExecutionNode::SUBQUERY: {
+        auto es = static_cast<SubqueryNode*>(en);
+        auto it = cache.find(es->getSubquery());
+
+        TRI_ASSERT(it != cache.end());
+
+        eb = new SubqueryBlock(engine->getTransaction(),
+                               static_cast<SubqueryNode const*>(en),
+                               it->second);
+        break;
+      }
       case ExecutionNode::SORT: {
         eb = new SortBlock(engine->getTransaction(),
                              static_cast<SortNode const*>(en));