first version of EnumerateListBlock.

It is missing the method for getSome, and only works for json lists.

arangod/Aql/ExecutionBlock.h

@@ -1032,6 +1032,237 @@ namespace triagens {
 
     };
 
+// -----------------------------------------------------------------------------
+// --SECTION--                                          EnumerateListBlock
+// -----------------------------------------------------------------------------
+
+    class EnumerateListBlock : public ExecutionBlock {
+
+      public:
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief constructor
+////////////////////////////////////////////////////////////////////////////////
+
+        EnumerateListBlock (AQL_TRANSACTION_V8* trx,
+                                  EnumerateListNode const* ep) 
+          : ExecutionBlock(trx, ep), _trx(nullptr) {
+          
+          int res = _trx->begin();
+
+          if (res != TRI_ERROR_NO_ERROR) {
+            // transaction failure
+            delete _trx;
+            THROW_ARANGO_EXCEPTION(res);
+          }
+
+        }
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief destructor
+////////////////////////////////////////////////////////////////////////////////
+
+        ~EnumerateListBlock () {
+          if (_trx != nullptr) {
+            // finalize our own transaction
+            delete _trx;
+          }
+        }
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief initialize fetching of documents
+////////////////////////////////////////////////////////////////////////////////
+
+        // void initDocuments () {
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief continue fetching of documents
+////////////////////////////////////////////////////////////////////////////////
+
+        //bool moreDocuments () {
+        
+////////////////////////////////////////////////////////////////////////////////
+/// @brief initialize, here we get the inVariable
+////////////////////////////////////////////////////////////////////////////////
+
+        int initialize () {
+          int res = ExecutionBlock::initialize();
+
+          if (res != TRI_ERROR_NO_ERROR) {
+            return res;
+          }
+
+          auto en = reinterpret_cast<EnumerateListNode const*>(_exeNode);
+          
+          // get the inVariable register id . . .
+          // staticAnalysis has been run, so _varOverview is set up
+          
+          auto it = _varOverview->varInfo.find(en->_inVariable->id);
+          if (it == _varOverview->varInfo.end()){
+            THROW_ARANGO_EXCEPTION(TRI_ERROR_INTERNAL);
+          }
+          
+          _inVarRegId = (*it).second.registerId;
+          
+          _index = 0; // index in _inVariable for current run
+
+          return TRI_ERROR_NO_ERROR;
+        }
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief execute, here we release our docs from this collection
+////////////////////////////////////////////////////////////////////////////////
+
+        int execute () {
+          int res = ExecutionBlock::execute();
+
+          if (res != TRI_ERROR_NO_ERROR) {
+            return res;
+          }
+
+          // handle local data (if any) 
+
+          return TRI_ERROR_NO_ERROR;
+        }
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief getOne
+////////////////////////////////////////////////////////////////////////////////
+
+        AqlItemBlock* getOne () {
+          
+          if (_done) {
+            return nullptr;
+          }
+
+          if (_buffer.empty()) {
+            if (! ExecutionBlock::getBlock(1, DefaultBatchSize)) {
+              _done = true;
+              return nullptr;
+            }
+            _pos = 0;           // this is in the first block
+          } 
+            
+          // if we make it here, then _buffer.front() exists
+          AqlItemBlock* cur = _buffer.front();
+
+          // copy stuff from the incoming block . . .
+          auto res = new AqlItemBlock(1, _varOverview->nrRegs[_depth]);
+          TRI_ASSERT(cur->getNrRegs() <= res->getNrRegs());
+          for (RegisterId i = 0; i < cur->getNrRegs(); i++) {
+            res->setValue(0, i, cur->getValue(_pos, i).clone());
+            res->setDocumentCollection(i, cur->getDocumentCollection(i));
+          }
+          
+          // get the thing we are looping over
+          triagens::basics::Json inVariable = cur->getValue(_pos, _inVarRegId)._json;
+          
+          // add the new register value and corresponding doc. collection
+          res->setValue(0, cur->getNrRegs(), 
+              AqlValue(new basics::Json(inVariable.at(_pos).json())));
+          res->setDocumentCollection(cur->getNrRegs(), _trx->documentCollection());
+
+          // advance read position in the current block
+          if (++_pos == cur->size() ) {
+            delete cur;
+            _buffer.pop_front();
+            _pos = 0;
+          }
+          return res;
+        }
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief getSome
+////////////////////////////////////////////////////////////////////////////////
+
+      /*  AqlItemBlock* getSome (size_t atLeast, size_t atMost) {
+          if (_done) {
+            return nullptr;
+          }
+
+          if (_buffer.empty()) {
+            if (! ExecutionBlock::getBlock(DefaultBatchSize, DefaultBatchSize)) {
+              _done = true;
+              return nullptr;
+            }
+            _pos = 0;           // this is in the first block
+            _posInAllDocs = 0;  // Note that we know _allDocs.size() > 0,
+                                // otherwise _done would be true already
+          }
+
+          // If we get here, we do have _buffer.front()
+          AqlItemBlock* cur = _buffer.front();
+          size_t const curRegs = cur->getNrRegs();
+
+          size_t available = _documents.size() - _posInAllDocs;
+          size_t toSend = std::min(atMost, available);
+            
+          auto res = new AqlItemBlock(toSend, _varOverview->nrRegs[_depth]);
+          TRI_ASSERT(curRegs <= res->getNrRegs());
+
+          // only copy 1st row of registers inherited from previous frame(s)
+          for (RegisterId i = 0; i < curRegs; i++) {
+            res->setValue(0, i, cur->getValue(_pos, i).clone());
+          }
+          res->getDocumentCollections().at(curRegs)
+            = _trx->documentCollection();
+
+          for (size_t j = 0; j < toSend; j++) {
+            if (j > 0) {
+              // re-use already copied aqlvalues
+              for (RegisterId i = 0; i < curRegs; i++) {
+                res->setValue(j, i, res->getValue(0, i));
+              }
+            }
+
+            // The result is in the first variable of this depth,
+            // we do not need to do a lookup in _varOverview->varInfo,
+            // but can just take cur->getNrRegs() as registerId:
+            res->setValue(j, curRegs, AqlValue(reinterpret_cast<TRI_df_marker_t const*>(_documents[_posInAllDocs++].getDataPtr())));
+          }
+
+          // Advance read position:
+          if (_posInAllDocs >= _documents.size()) {
+            // we have exhausted our local documents buffer
+            _posInAllDocs = 0;
+
+            // fetch more documents into our buffer
+            if (! moreDocuments()) {
+              // nothing more to read, re-initialize fetching of documents
+              initDocuments();
+              if (++_pos >= cur->size()) {
+                _buffer.pop_front();
+                delete cur;
+                _pos = 0;
+              }
+            }
+          }
+          return res;
+        } */
+
+      private:
+
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief current position in the _inVariable
+////////////////////////////////////////////////////////////////////////////////
+        
+        size_t _index;
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief the register index containing the inVariable of the EnumerateListNode
+////////////////////////////////////////////////////////////////////////////////
+                                  
+        RegisterId _inVarRegId;
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief currently ongoing transaction
+////////////////////////////////////////////////////////////////////////////////
+                                  
+        triagens::arango::SingleCollectionReadOnlyTransaction<triagens::arango::V8TransactionContext<true>>* _trx;
+
+    };
+
 // -----------------------------------------------------------------------------
 // --SECTION--                                                  CalculationBlock
 // -----------------------------------------------------------------------------