add engine capabilities

arangod/Indexes/IndexFactory.h

@@ -55,6 +55,8 @@ class IndexFactory {
   virtual void fillSystemIndexes(
       arangodb::LogicalCollection* col,
       std::vector<std::shared_ptr<arangodb::Index>>& systemIndexes) const  = 0;
+
+  virtual std::vector<std::string> supportedIndexes() const = 0;
 };
 
 } // namespace arangodb

arangod/MMFiles/MMFilesIndexFactory.cpp

@@ -448,3 +448,7 @@ void MMFilesIndexFactory::fillSystemIndexes(
         std::make_shared<arangodb::MMFilesEdgeIndex>(1, col));
   }
 }
+  
+std::vector<std::string> MMFilesIndexFactory::supportedIndexes() const {
+  return std::vector<std::string>{ "primary", "edge", "hash", "skiplist", "persistent", "geo", "fulltext" };
+}

arangod/MMFiles/MMFilesIndexFactory.h

@@ -45,6 +45,8 @@ class MMFilesIndexFactory final : public IndexFactory {
   void fillSystemIndexes(arangodb::LogicalCollection* col,
                           std::vector<std::shared_ptr<arangodb::Index>>&
                               systemIndexes) const override;
+  
+  std::vector<std::string> supportedIndexes() const override;
 };
 
 }

arangod/RestHandler/RestEngineHandler.cpp

@@ -24,6 +24,7 @@
 #include "RestEngineHandler.h"
 #include "Rest/HttpRequest.h"
 #include "StorageEngine/EngineSelectorFeature.h"
+#include "StorageEngine/StorageEngine.h"
 
 #include <velocypack/Builder.h>
 #include <velocypack/velocypack-aliases.h>
@@ -38,9 +39,9 @@ RestEngineHandler::RestEngineHandler(GeneralRequest* request,
 
 RestStatus RestEngineHandler::execute() {
   VPackBuilder result;
-  result.add(VPackValue(VPackValueType::Object));
-  result.add("name", VPackValue(EngineSelectorFeature::engineName()));
-  result.close();
+  StorageEngine* engine = EngineSelectorFeature::ENGINE;
+  engine->getCapabilities(result);
+  
   generateResult(rest::ResponseCode::OK, result.slice());
   return RestStatus::DONE;
 }

arangod/RocksDBEngine/RocksDBEngine.h

@@ -235,7 +235,7 @@ class RocksDBEngine final : public StorageEngine {
                                      arangodb::velocypack::Slice info) override;
   void addParametersForNewIndex(arangodb::velocypack::Builder& builder,
                                 arangodb::velocypack::Slice info) override;
-
+  
   rocksdb::TransactionDB* db() const { return _db; }
 
   RocksDBComparator* cmp() const { return _cmp.get(); }

arangod/RocksDBEngine/RocksDBIndexFactory.cpp

@@ -421,3 +421,7 @@ void RocksDBIndexFactory::fillSystemIndexes(
         2, col, builder.slice(), StaticStrings::ToString));
   }
 }
+
+std::vector<std::string> RocksDBIndexFactory::supportedIndexes() const {
+  return std::vector<std::string>{ "primary", "edge", "hash", "skiplist", "persistent" };
+}

arangod/RocksDBEngine/RocksDBIndexFactory.h

@@ -45,6 +45,8 @@ class RocksDBIndexFactory final : public IndexFactory {
   void fillSystemIndexes(arangodb::LogicalCollection* col,
                           std::vector<std::shared_ptr<arangodb::Index>>&
                               systemIndexes) const override;
+  
+  std::vector<std::string> supportedIndexes() const override;
 };
 
 }

arangod/StorageEngine/StorageEngine.h

@@ -329,7 +329,7 @@ class StorageEngine : public application_features::ApplicationFeature {
   // Returns the StorageEngine-specific implementation
   // of the IndexFactory. This is used to validate
   // information about indexes.
-  IndexFactory const* indexFactory() {
+  IndexFactory const* indexFactory() const {
     // The factory has to be created by the implementation
     // and shall never be deleted
     TRI_ASSERT(_indexFactory.get() != nullptr);
@@ -406,6 +406,21 @@ class StorageEngine : public application_features::ApplicationFeature {
   virtual std::shared_ptr<arangodb::velocypack::Builder> getReplicationApplierConfiguration(TRI_vocbase_t*, int& status) = 0;
   virtual int removeReplicationApplierConfiguration(TRI_vocbase_t* vocbase) = 0;
   virtual int saveReplicationApplierConfiguration(TRI_vocbase_t* vocbase, arangodb::velocypack::Slice slice, bool doSync) = 0; 
+  
+  void getCapabilities(VPackBuilder& builder) const {
+    builder.openObject();
+    builder.add("name", VPackValue(typeName()));
+    builder.add("supports", VPackValue(VPackValueType::Object));
+    builder.add("indexes", VPackValue(VPackValueType::Array));
+
+    for (auto const& it : indexFactory()->supportedIndexes()) {
+      builder.add(VPackValue(it));
+    }
+
+    builder.close(); // indexes
+    builder.close(); // supports
+    builder.close(); // object
+  }
 
  protected:
   void registerCollection(TRI_vocbase_t* vocbase,

arangod/V8Server/v8-collection.cpp

@@ -2785,6 +2785,7 @@ static void JS_CompletionsVocbase(
   result->Set(j++, TRI_V8_ASCII_STRING("_drop()"));
   result->Set(j++, TRI_V8_ASCII_STRING("_dropDatabase()"));
   result->Set(j++, TRI_V8_ASCII_STRING("_dropView()"));
+  result->Set(j++, TRI_V8_ASCII_STRING("_engine()"));
   result->Set(j++, TRI_V8_ASCII_STRING("_executeTransaction()"));
   result->Set(j++, TRI_V8_ASCII_STRING("_exists()"));
   result->Set(j++, TRI_V8_ASCII_STRING("_id"));

arangod/V8Server/v8-vocbase.cpp

@@ -1694,10 +1694,12 @@ static void JS_EngineServer(v8::FunctionCallbackInfo<v8::Value> const& args) {
   TRI_V8_TRY_CATCH_BEGIN(isolate);
   v8::HandleScope scope(isolate);
 
-  // return engine name
-  v8::Handle<v8::Object> result = v8::Object::New(isolate);
-  result->Set(TRI_V8_ASCII_STRING("name"), TRI_V8_ASCII_STRING(EngineSelectorFeature::engineName()));
-  TRI_V8_RETURN(result);
+  // return engine data
+  StorageEngine* engine = EngineSelectorFeature::ENGINE;
+  VPackBuilder builder;
+  engine->getCapabilities(builder);
+
+  TRI_V8_RETURN(TRI_VPackToV8(isolate, builder.slice()));
 
   TRI_V8_TRY_CATCH_END
 }