Converted rest handler for explain from JS to C++. (#2907)

arangod/CMakeLists.txt

@@ -283,6 +283,7 @@ SET(ARANGOD_SOURCES
   RestHandler/RestEdgesHandler.cpp
   RestHandler/RestEndpointHandler.cpp
   RestHandler/RestEngineHandler.cpp
+  RestHandler/RestExplainHandler.cpp
   RestHandler/RestImportHandler.cpp
   RestHandler/RestIndexHandler.cpp
   RestHandler/RestJobHandler.cpp

arangod/GeneralServer/GeneralServerFeature.cpp

@@ -55,6 +55,7 @@
 #include "RestHandler/RestEdgesHandler.h"
 #include "RestHandler/RestEndpointHandler.h"
 #include "RestHandler/RestEngineHandler.h"
+#include "RestHandler/RestExplainHandler.h"
 #include "RestHandler/RestHandlerCreator.h"
 #include "RestHandler/RestImportHandler.h"
 #include "RestHandler/RestIndexHandler.h"
@@ -422,6 +423,9 @@ void GeneralServerFeature::defineHandlers() {
       "/_api/aql-builtin",
       RestHandlerCreator<RestAqlFunctionsHandler>::createNoData);
 
+  _handlerFactory->addPrefixHandler(
+      "/_api/explain", RestHandlerCreator<RestExplainHandler>::createNoData);
+
   _handlerFactory->addPrefixHandler(
       "/_api/query", RestHandlerCreator<RestQueryHandler>::createNoData);
 

arangod/RestHandler/RestExplainHandler.cpp

@@ -0,0 +1,168 @@
+////////////////////////////////////////////////////////////////////////////////
+/// DISCLAIMER
+///
+/// Copyright 2014-2016 ArangoDB GmbH, Cologne, Germany
+/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
+///
+/// Licensed under the Apache License, Version 2.0 (the "License");
+/// you may not use this file except in compliance with the License.
+/// You may obtain a copy of the License at
+///
+///     http://www.apache.org/licenses/LICENSE-2.0
+///
+/// Unless required by applicable law or agreed to in writing, software
+/// distributed under the License is distributed on an "AS IS" BASIS,
+/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+/// See the License for the specific language governing permissions and
+/// limitations under the License.
+///
+/// Copyright holder is ArangoDB GmbH, Cologne, Germany
+///
+/// @author Dr. Frank Celler
+////////////////////////////////////////////////////////////////////////////////
+
+#include "RestExplainHandler.h"
+
+#include "Aql/Query.h"
+#include "Aql/QueryString.h"
+#include "Logger/Logger.h"
+
+#include <velocypack/Builder.h>
+
+using namespace arangodb;
+using namespace arangodb::basics;
+using namespace arangodb::rest;
+
+RestExplainHandler::RestExplainHandler(GeneralRequest* request,
+                                       GeneralResponse* response)
+    : RestVocbaseBaseHandler(request, response) {}
+
+RestStatus RestExplainHandler::execute() {
+  // extract the sub-request type
+  auto const type = _request->requestType();
+
+  // execute one of the CRUD methods
+  switch (type) {
+    case rest::RequestType::POST:
+      explainQuery();
+      break;
+    default: { generateNotImplemented("Unsupported method"); }
+  }
+
+  // this handler is done
+  return RestStatus::DONE;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief was docuBlock REST_DOCUMENT_CREATE
+////////////////////////////////////////////////////////////////////////////////
+
+void RestExplainHandler::explainQuery() {
+  std::vector<std::string> const& suffixes = _request->suffixes();
+  if (suffixes.size() != 0) {
+    generateError(rest::ResponseCode::NOT_FOUND, TRI_ERROR_HTTP_NOT_FOUND);
+    return;
+  }
+
+  if (_vocbase == nullptr) {
+    generateError(rest::ResponseCode::NOT_FOUND,
+                  TRI_ERROR_ARANGO_DATABASE_NOT_FOUND);
+    return;
+  }
+
+  bool parseSuccess = true;
+  std::shared_ptr<VPackBuilder> parsedBody = parseVelocyPackBody(parseSuccess);
+
+  if (!parseSuccess) {
+    return;
+  }
+  VPackSlice body = parsedBody.get()->slice();
+
+  auto badParamError = [&](std::string const& msg) -> void {
+    generateError(rest::ResponseCode::BAD, TRI_ERROR_BAD_PARAMETER, msg);
+  };
+
+  if (!body.isObject() || body.length() < 1 || body.length() > 3) {
+    badParamError(
+        "expected usage: AQL_EXPLAIN(<queryString>, <bindVars>, "
+        "<options>)");
+    return;
+  }
+
+  VPackSlice const querySlice = body.get("query");
+  if (!querySlice.isString()) {
+    badParamError("expecting string for <queryString>");
+    return;
+  }
+  std::string const queryString(querySlice.copyString());
+
+  VPackSlice const bindSlice = body.get("bindVars");
+  if (!bindSlice.isNone() && !bindSlice.isObject()) {
+    badParamError("expecting object for <bindVars>");
+    return;
+  }
+
+  VPackSlice const optionsSlice = body.get("options");
+  if (!optionsSlice.isNone() && !optionsSlice.isObject()) {
+    badParamError("expecting object for <options>");
+    return;
+  }
+
+  auto bindBuilder = std::make_shared<VPackBuilder>();
+  bindBuilder->add(bindSlice);
+
+  auto optionsBuilder = std::make_shared<VPackBuilder>();
+  optionsBuilder->add(optionsSlice);
+
+  arangodb::aql::Query query(false, _vocbase, aql::QueryString(queryString),
+                             bindBuilder, optionsBuilder,
+                             arangodb::aql::PART_MAIN);
+
+  auto queryResult = query.explain();
+
+  if (queryResult.code != TRI_ERROR_NO_ERROR) {
+    auto code = rest::ResponseCode::BAD;
+
+    switch (queryResult.code) {
+      case TRI_ERROR_ARANGO_COLLECTION_NOT_FOUND:
+        code = rest::ResponseCode::NOT_FOUND;
+        break;
+    }
+
+    generateError(code, queryResult.code, queryResult.details);
+    return;
+  }
+
+  VPackBuilder result;
+  result.openObject();
+
+  if (query.queryOptions().allPlans) {
+    result.add("plans", queryResult.result->slice());
+  } else {
+    result.add("plan", queryResult.result->slice());
+    result.add("cacheable", VPackValue(queryResult.cached));
+  }
+
+  if (queryResult.warnings == nullptr) {
+    result.add("warnings", VPackSlice::emptyArraySlice());
+  } else {
+    result.add("warnings", queryResult.warnings->slice());
+  }
+  if (queryResult.stats != nullptr) {
+    VPackSlice stats = queryResult.stats->slice();
+    if (stats.isNone()) {
+      result.add("stats", VPackSlice::noneSlice());
+    } else {
+      result.add("stats", stats);
+    }
+  } else {
+    result.add("stats", VPackSlice::noneSlice());
+  }
+
+  result.add("error", VPackValue(false));
+  result.add("code", VPackValue(static_cast<int>(rest::ResponseCode::OK)));
+
+  result.close();
+
+  generateResult(rest::ResponseCode::OK, result.slice());
+}

arangod/RestHandler/RestExplainHandler.h

@@ -0,0 +1,44 @@
+////////////////////////////////////////////////////////////////////////////////
+/// DISCLAIMER
+///
+/// Copyright 2014-2016 ArangoDB GmbH, Cologne, Germany
+/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
+///
+/// Licensed under the Apache License, Version 2.0 (the "License");
+/// you may not use this file except in compliance with the License.
+/// You may obtain a copy of the License at
+///
+///     http://www.apache.org/licenses/LICENSE-2.0
+///
+/// Unless required by applicable law or agreed to in writing, software
+/// distributed under the License is distributed on an "AS IS" BASIS,
+/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+/// See the License for the specific language governing permissions and
+/// limitations under the License.
+///
+/// Copyright holder is ArangoDB GmbH, Cologne, Germany
+///
+/// @author Dr. Frank Celler
+////////////////////////////////////////////////////////////////////////////////
+
+#ifndef ARANGOD_REST_HANDLER_REST_EXPLAIN_HANDLER_H
+#define ARANGOD_REST_HANDLER_REST_EXPLAIN_HANDLER_H 1
+
+#include "Basics/Common.h"
+#include "RestHandler/RestVocbaseBaseHandler.h"
+
+namespace arangodb {
+class RestExplainHandler : public RestVocbaseBaseHandler {
+ public:
+  RestExplainHandler(GeneralRequest*, GeneralResponse*);
+
+ public:
+  RestStatus execute() override final;
+  char const* name() const override final { return "RestExplainHandler"; }
+
+ protected:
+  void explainQuery();
+};
+}
+
+#endif

js/actions/api-explain.js

@@ -1,99 +0,0 @@
-/* jshint strict: false */
-/* global AQL_EXPLAIN */
-
-// //////////////////////////////////////////////////////////////////////////////
-// / @brief query explain actions
-// /
-// / @file
-// /
-// / DISCLAIMER
-// /
-// / Copyright 2014 ArangoDB GmbH, Cologne, Germany
-// /
-// / Licensed under the Apache License, Version 2.0 (the "License")
-// / you may not use this file except in compliance with the License.
-// / You may obtain a copy of the License at
-// /
-// /     http://www.apache.org/licenses/LICENSE-2.0
-// /
-// / Unless required by applicable law or agreed to in writing, software
-// / distributed under the License is distributed on an "AS IS" BASIS,
-// / WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// / See the License for the specific language governing permissions and
-// / limitations under the License.
-// /
-// / Copyright holder is ArangoDB GmbH, Cologne, Germany
-// /
-// / @author Jan Steemann
-// / @author Copyright 2014, ArangoDB GmbH, Cologne, Germany
-// / @author Copyright 2012, triAGENS GmbH, Cologne, Germany
-// //////////////////////////////////////////////////////////////////////////////
-
-var actions = require('@arangodb/actions');
-var ERRORS = require('internal').errors;
-
-// //////////////////////////////////////////////////////////////////////////////
-// / @brief was docuBlock JSF_post_api_explain
-// //////////////////////////////////////////////////////////////////////////////
-
-function post_api_explain (req, res) {
-  if (req.suffix.length !== 0) {
-    actions.resultNotFound(req,
-      res,
-      ERRORS.ERROR_HTTP_NOT_FOUND.code,
-      ERRORS.ERROR_HTTP_NOT_FOUND.message);
-    return;
-  }
-
-  var json = actions.getJsonBody(req, res);
-
-  if (json === undefined) {
-    return;
-  }
-
-  var result = AQL_EXPLAIN(json.query, json.bindVars, json.options || { });
-
-  if (result instanceof Error) {
-    actions.resultException(req, res, result, undefined, false);
-    return;
-  }
-
-  if (result.hasOwnProperty('plans')) {
-    result = {
-      plans: result.plans,
-      warnings: result.warnings,
-      stats: result.stats
-    };
-  } else {
-    result = {
-      plan: result.plan,
-      warnings: result.warnings,
-      stats: result.stats,
-      cacheable: result.cacheable
-    };
-  }
-  actions.resultOk(req, res, actions.HTTP_OK, result);
-}
-
-// //////////////////////////////////////////////////////////////////////////////
-// / @brief explain gateway
-// //////////////////////////////////////////////////////////////////////////////
-
-actions.defineHttp({
-  url: '_api/explain',
-
-  callback: function (req, res) {
-    try {
-      switch (req.requestType) {
-        case actions.POST:
-          post_api_explain(req, res);
-          break;
-
-        default:
-          actions.resultUnsupported(req, res);
-      }
-    } catch (err) {
-      actions.resultException(req, res, err, undefined, false);
-    }
-  }
-});