From dc6dba1ef4adc3cb83f6ca1d889dc271e192b7c9 Mon Sep 17 00:00:00 2001
From: Willi Goesgens <willi@arangodb.com>
Date: Thu, 2 Oct 2014 13:15:02 +0200
Subject: [PATCH] Cluster Communication: serialize a global set of the
 currently available variables.

---
 arangod/Aql/ExecutionEngine.cpp   |  1 +
 arangod/Aql/Query.cpp             |  1 +
 arangod/Aql/VariableGenerator.cpp | 32 +++++++++++++++++++++++++++++++
 arangod/Aql/VariableGenerator.h   | 12 ++++++++++++
 4 files changed, 46 insertions(+)

diff --git a/arangod/Aql/ExecutionEngine.cpp b/arangod/Aql/ExecutionEngine.cpp
index f3d9d7b1d6..16688b4ea2 100644
--- a/arangod/Aql/ExecutionEngine.cpp
+++ b/arangod/Aql/ExecutionEngine.cpp
@@ -475,6 +475,7 @@ std::cout << "REGISTERING QUERY ON COORDINATOR WITH ID: " << id << "\n";
 
       result.set("plan", jsonNodesList);
       result.set("part", triagens::basics::Json("main")); // TODO: set correct query type
+      result.set("variables", query->ast()->variables()->toJson(TRI_UNKNOWN_MEM_ZONE));
 
       std::unique_ptr<std::string> body(new std::string(triagens::basics::JsonHelper::toString(result.json())));
     
diff --git a/arangod/Aql/Query.cpp b/arangod/Aql/Query.cpp
index 7f7e0091aa..45ce90b8b2 100644
--- a/arangod/Aql/Query.cpp
+++ b/arangod/Aql/Query.cpp
@@ -387,6 +387,7 @@ QueryResult Query::prepare (QueryRegistry* registry) {
       enterState(PLAN_INSTANCIATION);
       ExecutionPlan::getCollectionsFromJson(parser->ast(), _queryJson);
 
+      parser->ast()->variables()->fromJson(_queryJson);
       // creating the plan may have produced some collections
       // we need to add them to the transaction now (otherwise the query will fail)
       int res = _trx->addCollectionList(_collections.collections());
diff --git a/arangod/Aql/VariableGenerator.cpp b/arangod/Aql/VariableGenerator.cpp
index 1ef1c26624..deaf480ae8 100644
--- a/arangod/Aql/VariableGenerator.cpp
+++ b/arangod/Aql/VariableGenerator.cpp
@@ -27,9 +27,11 @@
 /// @author Copyright 2012-2013, triAGENS GmbH, Cologne, Germany
 ////////////////////////////////////////////////////////////////////////////////
 
+#include "Utils/Exception.h"
 #include "Aql/VariableGenerator.h"
 
 using namespace triagens::aql;
+using Json = triagens::basics::Json;
 
 // -----------------------------------------------------------------------------
 // --SECTION--                                        constructors / destructors
@@ -202,6 +204,36 @@ std::string VariableGenerator::nextName () const {
   return std::to_string(_id); // to_string: c++11
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief export to JSON, returns an AUTOFREE Json object
+////////////////////////////////////////////////////////////////////////////////
+
+triagens::basics::Json VariableGenerator::toJson (TRI_memory_zone_t* zone) const {
+  Json jsonAllVariablesList(Json::List, _variables.size());
+  for (auto oneVariable: _variables) {
+    jsonAllVariablesList(oneVariable.second->toJson());
+  }
+  return jsonAllVariablesList;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief import from JSON
+////////////////////////////////////////////////////////////////////////////////
+
+void VariableGenerator::fromJson (Json const& query) {
+  
+  Json jsonAllVariablesList = query.get("variables");
+  if (!jsonAllVariablesList.isList()) {
+    THROW_ARANGO_EXCEPTION_MESSAGE(TRI_ERROR_INTERNAL, "variables needs to be a list");
+  }
+  
+  auto len = jsonAllVariablesList.size();
+  _variables.reserve(len);
+  for (size_t i = 0; i < len; i++) {
+    createVariable(jsonAllVariablesList.at(i));
+  }
+}
+
 // -----------------------------------------------------------------------------
 // --SECTION--                                                       END-OF-FILE
 // -----------------------------------------------------------------------------
diff --git a/arangod/Aql/VariableGenerator.h b/arangod/Aql/VariableGenerator.h
index 479d1c39d4..edba34b46c 100644
--- a/arangod/Aql/VariableGenerator.h
+++ b/arangod/Aql/VariableGenerator.h
@@ -117,6 +117,18 @@ namespace triagens {
   
         std::string nextName () const;
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief export to JSON, returns an AUTOFREE Json object
+////////////////////////////////////////////////////////////////////////////////
+
+        triagens::basics::Json toJson (TRI_memory_zone_t*) const;
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief import from JSON
+////////////////////////////////////////////////////////////////////////////////
+
+        void fromJson (triagens::basics::Json const& jsonAllVariablesList);
+
 // -----------------------------------------------------------------------------
 // --SECTION--                                                 private functions
 // -----------------------------------------------------------------------------