Merge lp:~mohyt/drizzle/json_server_schema into lp:drizzle

[Mohit Srivastava]

Added create & drop Schema functionality on json server

[Stewart Smith (stewart)]

Minor fixes:
- Copyright date should be 2011-2013 rather than just 2011
- It would be good to have a comment in plugin/json_server/ddl/schema.cc that it's mostly just a copy from drizzled/statement/create_schema.cc and friends.
- Where you use a static buffer for processing input (buffer[1024]) please also provide i a test that tests the limits of this buffer to ensure that there are not exploitable buffer overflows.

Questions:
- Why is num_threads set to 1? I don't think this should be here.

Otherwise looks good.

review: Needs Fixing

[lp:~mohyt/drizzle/json_server_schema]

2639. By Mohit Srivastava on 2013-08-13

Changes related to Review.

[Mohit Srivastava (mohyt)]

Changes done. Ready to merge.
No change related to buffer overflow as it already handle by libevent.

[Stewart Smith (stewart)]

review: Approve

=== added directory 'plugin/json_server/ddl'
=== added file 'plugin/json_server/ddl/schema.cc'
--- plugin/json_server/ddl/schema.cc	1970-01-01 00:00:00 +0000
+++ plugin/json_server/ddl/schema.cc	2013-08-13 04:20:40 +0000
@@ -0,0 +1,158 @@
+/* mode: c; c-basic-offset: 2; indent-tabs-mode: nil;
+ * vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
+ *   
+ * Copyright (C) 2011-2013 Stewart Smith, Henrik Ingo, Mohit Srivastava
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *  
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+/**
+ * @file Implements a class Schema to handle various operations related to schema.Its just a copy of drizzled/schema.cc and its friends.
+ */
+
+ #include <config.h>
+ 
+ #include <drizzled/show.h>
+ #include <drizzled/session.h>
+ #include <drizzled/schema.h>
+ #include <drizzled/message.h>
+ #include <drizzled/sql_lex.h>
+ #include <drizzled/plugin/event_observer.h>
+ #include <drizzled/catalog/instance.h>
+ #include <plugin/json_server/ddl/schema.h>
+ #include <drizzled/plugin/authorization.h>
+ #include <drizzled/plugin/storage_engine.h>
+ 
+ #include <string>
+
+
+ using namespace std;
+ using namespace drizzled;
+
+ namespace drizzle_plugin {
+ namespace json_server {
+
+    bool Schema::createSchema()
+    {
+      if (not validateSchemaOptions())
+        return true;
+      
+      if (session().inTransaction())
+      {
+        my_error(ER_TRANSACTIONAL_DDL_NOT_SUPPORTED, MYF(0));
+        return true;
+      }
+
+      drizzled::identifier::Schema schema_identifier(session().catalog().identifier(),_db_name);
+
+      if (not check(schema_identifier))
+        return false;
+
+      drizzled::message::schema::init(schema_message, schema_identifier);
+      message::set_definer(schema_message, *session().user());
+        
+      bool res =false;
+      std::string path = schema_identifier.getSQLPath();
+         
+        if (unlikely(plugin::EventObserver::beforeCreateDatabase(session(), path)))
+        {
+          my_error(ER_EVENT_OBSERVER_PLUGIN, MYF(0), path.c_str());
+        }
+        else
+        {
+          res= schema::create(session(), schema_message, false);
+          if (unlikely(plugin::EventObserver::afterCreateDatabase(session(), path, res)))
+          {
+            my_error(ER_EVENT_OBSERVER_PLUGIN, schema_identifier);
+            res = false;
+          }                      
+        }
+        return not res; 
+    }
+
+    bool Schema::dropSchema()
+    {
+      if (session().inTransaction())
+      {
+        my_error(ER_TRANSACTIONAL_DDL_NOT_SUPPORTED, MYF(0));
+        return true;
+      }
+      
+      drizzled::identifier::Schema schema_identifier(session().catalog().identifier(),_db_name);
+
+      if (not schema::check(session(),schema_identifier))
+      {
+        my_error(ER_WRONG_DB_NAME, schema_identifier);
+        return false;
+      }
+      
+      if (session().inTransaction())
+      {
+        my_message(ER_LOCK_OR_ACTIVE_TRANSACTION, ER(ER_LOCK_OR_ACTIVE_TRANSACTION), MYF(0));
+        return true;
+      }
+
+      bool res = true;
+      std::string path = schema_identifier.getSQLPath();
+      if (unlikely(plugin::EventObserver::beforeDropDatabase(session(), path)))
+      {
+        my_error(ER_EVENT_OBSERVER_PLUGIN, schema_identifier);      
+      }
+      else
+      {
+        res= schema::drop(session(), schema_identifier, false);
+        if (unlikely(plugin::EventObserver::afterDropDatabase(session(), path, res)))
+        {
+          my_error(ER_EVENT_OBSERVER_PLUGIN, MYF(0), path.c_str());
+          res = false;
+        }                                 
+      }
+
+      return res;
+    
+    }
+
+    bool Schema::validateSchemaOptions()
+    {
+      size_t num_engine_options= schema_message.engine().options_size();
+      bool rc= num_engine_options ? false : true;
+          
+      for (size_t y= 0; y < num_engine_options; ++y)
+      {
+        my_error(ER_UNKNOWN_SCHEMA_OPTION, MYF(0),schema_message.engine().options(y).name().c_str(),schema_message.engine().options(y).state().c_str());
+        rc= false;
+      }
+      return rc;
+
+    }
+
+    bool Schema::check(const identifier::Schema &identifier)
+    {
+      if (not identifier.isValid())
+        return false;
+      
+      if (not plugin::Authorization::isAuthorized(*session().user(), identifier))
+        return false;
+
+      if (plugin::StorageEngine::doesSchemaExist(identifier))
+      {
+        my_error(ER_DB_CREATE_EXISTS, identifier);
+        return false;
+      }
+
+      return true;
+    }
+}
+}
+ 
 
=== added file 'plugin/json_server/ddl/schema.h'
--- plugin/json_server/ddl/schema.h	1970-01-01 00:00:00 +0000
+++ plugin/json_server/ddl/schema.h	2013-08-13 04:20:40 +0000
@@ -0,0 +1,110 @@
+/** - mode: c; c-basic-offset: 2; indent-tabs-mode: nil; -*-
+ *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
+ *
+ * Copyright (C) 2011-2013 Stewart Smith, Henrik Ingo, Mohit Srivastava
+ *        
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *              
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *                           
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */                                                    
+/**
+ * @file Declare a class Schema to perform various operations related to schema. 
+ */ 
+#include <drizzled/session.h>
+#include <drizzled/statement.h>
+#include <drizzled/message/schema.pb.h>
+#include <uuid/uuid.h>
+#include <drizzled/definitions.h>
+#include <drizzled/error.h>
+#include <drizzled/sql_parse.h>
+#include <drizzled/sql_base.h>
+#include <string>
+using namespace std;
+using namespace drizzled; 
+namespace drizzle_plugin {
+namespace json_server {
+  /**
+   * a class.
+   *
+   * To perform various operations related to schema.
+   */
+  class Schema
+    {
+      public:
+        /**
+         * Constructor.
+         *
+         * @param in_session a session object.
+         * @param db_name a schema name string.
+         */
+      Schema(Session *in_session,string db_name) : 
+        _session(*in_session),_db_name(db_name)
+      {}
+      /**
+       * Stores whether schema exist or not.
+       */
+      bool is_if_not_exists;
+      /**
+       * Stores schema message.
+       */
+      message::Schema schema_message;
+      /**
+       * create a new schema if it not exists.
+       *
+       * @return false Success.
+       * @return true Failure.
+       */
+      bool createSchema();
+      /**
+       * drop a schema if it exists.
+       *
+       * @return false Success.
+       * @reutrn true Failure.
+       */
+      bool dropSchema();
+      /**
+       * Get a session object.
+       *
+       * @return a session object.
+       */
+      Session& session() const{
+        return _session;
+      }
+
+      private:
+      /**
+       * Validates various schema options.
+       *
+       * @return false Success.
+       * @return true Failure.
+       */
+      bool validateSchemaOptions();
+      /**
+       * Checks whether schema exists or not already.
+       *
+       * @return false Success.
+       * @return true Failure.
+       */ 
+      bool check(const identifier::Schema &identifier);
+      /**
+       * Stores a session object.
+       */
+      Session& _session;
+      /**
+       * Stores a schema name.
+       */
+      string _db_name;
+    };
+
+}
+}
 
=== added file 'plugin/json_server/error.cc'
--- plugin/json_server/error.cc	1970-01-01 00:00:00 +0000
+++ plugin/json_server/error.cc	2013-08-13 04:20:40 +0000
@@ -0,0 +1,58 @@
+ /* - mode: c; c-basic-offset: 2; indent-tabs-mode: nil; -*-
+  * vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
+  *
+  * Copyright (C) 2011-2013 Stewart Smith, Henrik Ingo, Mohit Srivastava
+  *       
+  * This program is free software; you can redistribute it and/or modify
+  * it under the terms of the GNU General Public License as published by
+  * the Free Software Foundation; either version 2 of the License, or
+  * (at your option) any later version.
+  *                 
+  * This program is distributed in the hope that it will be useful,
+  * but WITHOUT ANY WARRANTY; without even the implied warranty of
+  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  * GNU General Public License for more details.
+  *                           
+  * You should have received a copy of the GNU General Public License
+  * along with this program; if not, write to the Free Software
+  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+  */
+/**
+ * @file Implements JsonErrorArea class which handles errors of json server.
+ */
+#include <plugin/json_server/error.h>
+#include <drizzled/error/sql_state.h>
+
+namespace drizzle_plugin
+{
+namespace json_server
+{
+  JsonErrorArea::JsonErrorArea()
+  {
+    reset_jsonerror_area();
+  }
+  
+  void JsonErrorArea::reset_jsonerror_area()
+  {
+    er_type = ER_EMPTY;
+    error_no = drizzled::EE_OK;
+    error_msg= "";
+    sql_state="00000";
+  }
+
+  void JsonErrorArea::set_error(enum_error_type error_type_arg,drizzled::error_t error_no_arg,const char * error_msg_arg)
+  {
+    if(error_type_arg != ER_EMPTY)
+    {
+      er_type = error_type_arg;
+      error_msg = error_msg_arg;
+
+      if(error_type_arg == ER_SQL)
+      {
+        error_no = error_no_arg;
+        sql_state = drizzled::error::convert_to_sqlstate(error_no_arg);
+      }
+    }
+  }
+}
+}
 
=== added file 'plugin/json_server/error.h'
--- plugin/json_server/error.h	1970-01-01 00:00:00 +0000
+++ plugin/json_server/error.h	2013-08-13 04:20:40 +0000
@@ -0,0 +1,158 @@
+ /* - mode: c; c-basic-offset: 2; indent-tabs-mode: nil; -*-
+  * vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
+  *
+  * Copyright (C) 2011-2013 Stewart Smith, Henrik Ingo, Mohit Srivastava
+  *       
+  * This program is free software; you can redistribute it and/or modify
+  * it under the terms of the GNU General Public License as published by
+  * the Free Software Foundation; either version 2 of the License, or
+  * (at your option) any later version.
+  *                 
+  * This program is distributed in the hope that it will be useful,
+  * but WITHOUT ANY WARRANTY; without even the implied warranty of
+  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  * GNU General Public License for more details.
+  *                           
+  * You should have received a copy of the GNU General Public License
+  * along with this program; if not, write to the Free Software
+  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+  */
+/**
+ * @file Declare a class to handle errors in json server.
+ */ 
+#include <config.h>
+
+#include <drizzled/error_t.h>
+#include <string> 
+namespace drizzle_plugin
+{
+namespace json_server
+{
+  /**
+   * a class
+   * used to handle various errors of json server.
+   */ 
+  class JsonErrorArea
+  {
+    public:
+      /**
+       * an enumerated data type for different type of error in json server.
+       */
+      enum enum_error_type
+      {
+        ER_EMPTY=0,
+        ER_SQL,
+        ER_JSON,
+        ER_HTTP,
+        ER_UNKNOWN
+      };
+      /**
+       *  Constructor.
+       */  
+      JsonErrorArea();
+      /**
+       * Reset the memeber values.
+       */ 
+      void reset_jsonerror_area();
+      /**
+       * Set an error with details.
+       */ 
+      void set_error(enum_error_type type,drizzled::error_t sql_errno_arg,const char *message_arg);
+      /**
+       * Check whether error or not.
+       *
+       * @return true Success.
+       * @return false Failure.
+       */
+      bool is_error(){return er_type!= ER_EMPTY;}
+      /**
+       * Check whether sql error or not.
+       *
+       * @return true Success.
+       * @return false Failure.
+       */
+      bool is_sqlerror(){return er_type == ER_SQL;}
+      /**
+       * Check whether json error or not.
+       *
+       * @return true Success.
+       * @return false Failure.
+       */ 
+      bool is_jsonerror(){return er_type == ER_JSON;}
+      /**
+       * Check whether http error or not.
+       *
+       * @return true Success.
+       * @return false Failure.
+       */ 
+      bool is_httperror(){return er_type == ER_HTTP;}
+      /**
+       * Check whether unknown error or not.
+       *
+       * @return true Success.
+       * @return false Failure.
+       */ 
+      bool is_unknownerror(){return er_type == ER_UNKNOWN;}
+      /**
+       * Get an error number.
+       *
+       * @return a error number.
+       */ 
+      drizzled::error_t get_error_no() const { return error_no;}
+      /**
+       * Get an error message.
+       *
+       * @return a const error message string.
+       */ 
+      const char* get_error_msg() const { return error_msg;}
+      /**
+       * Get sql state.
+       *
+       * @return a const sql state string.
+       */
+      const char* get_sql_state() const { return sql_state;}
+      /**
+       * Get error type.
+       *
+       * @return a error type.
+       */
+      enum_error_type get_error_type() const { return er_type;}
+      /**
+       * Get error type string.
+       *
+       * @return a error type string.
+       */
+      std::string get_error_type_string() const {
+        std::string error_str;
+        switch(er_type)
+        {
+          case ER_EMPTY: {error_str="NO ERROR"; break;}
+          case ER_SQL: {error_str="SQL ERROR"; break;}
+          case ER_JSON: {error_str="JSON ERROR"; break;}
+          case ER_HTTP: {error_str="HTTP ERROR"; break;}
+          case ER_UNKNOWN: {error_str="UNKNOWN ERROR"; break;}              
+        }
+        return error_str;
+      }
+
+    private:
+      /**
+       * Stores error type.
+       */
+      enum_error_type er_type;
+      /**
+       * Stores error number.
+       */
+      drizzled::error_t error_no;
+      /**
+       * Stores error message.
+       */
+      const char *error_msg;
+      /**
+       * Stores sql state.
+       */
+      const char *sql_state;
+
+  };
+}
+}
 
=== added file 'plugin/json_server/json_handler.cc'
--- plugin/json_server/json_handler.cc	1970-01-01 00:00:00 +0000
+++ plugin/json_server/json_handler.cc	2013-08-13 04:20:40 +0000
@@ -0,0 +1,101 @@
+ /* - mode: c; c-basic-offset: 2; indent-tabs-mode: nil; -*-
+  *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
+  *
+  *  Copyright (C) 2011-2013 Stewart Smith, Henrik Ingo, Mohit Srivastava
+  *       
+  *  This program is free software; you can redistribute it and/or modify
+  *  it under the terms of the GNU General Public License as published by
+  *  the Free Software Foundation; either version 2 of the License, or
+  *  (at your option) any later version.
+  *               
+  *  This program is distributed in the hope that it will be useful,
+  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  *  GNU General Public License for more details.
+  *                           
+  *  You should have received a copy of the GNU General Public License
+  *  along with this program; if not, write to the Free Software
+  *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+  */
+/*
+ * @file Implements a class JsonHandler which handles the operations related to Json.
+ */ 
+#include <plugin/json_server/json_handler.h>
+#include <string.h>
+using namespace drizzled;
+namespace drizzle_plugin
+{
+namespace json_server
+{
+  void JsonHandler::generate_input_query(struct evhttp_request *req_arg)
+  {
+    evhttp_parse_query(evhttp_request_uri(req_arg), req_arg->input_headers);
+    if(req_arg->type== EVHTTP_REQ_POST )
+    {
+      char buffer[1024];
+      int l=0;
+      do
+      {
+        l= evbuffer_remove(req_arg->input_buffer, buffer, 1024);
+        _input_query.append(buffer, l);
+      }
+      while(l);
+    }
+    else
+    {
+      const char* _query;
+      _query= (char *)evhttp_find_header(req_arg->input_headers, "query");
+      if(_query == NULL || strcmp(_query,"")==0)
+      {
+        _query="{}";
+      }
+      _input_query.append(_query,strlen(_query));
+    }
+
+  }
+
+  void JsonHandler::generate_input_json(struct evhttp_request *req_arg,JsonErrorArea &_json_error_area)
+  {
+    generate_input_query(req_arg);
+    Json::Features _json_conf;
+    Json::Reader reader(_json_conf);
+    bool retval = reader.parse(_input_query,_json_in);
+    if(retval!=true)
+    {
+      _json_error_area.set_error(JsonErrorArea::ER_JSON,drizzled::EE_OK,reader.getFormatedErrorMessages().c_str()); 
+    }
+  }
+
+  void JsonHandler::generate_output_json(JsonErrorArea& _json_error_area)
+  {
+    if(_json_error_area.is_error())
+    {
+      if(_json_error_area.is_sqlerror())
+      {
+        _json_out["error_type"]=_json_error_area.get_error_type_string();
+        _json_out["error_no"]=_json_error_area.get_error_no();
+        _json_out["error_message"]=_json_error_area.get_error_msg();
+        _json_out["sql_state"]=_json_error_area.get_sql_state();
+      
+      }
+      else
+      {
+        _json_out["error_type"]=_json_error_area.get_error_type_string();
+        _json_out["error_message"]=_json_error_area.get_error_msg();
+      }
+    }
+    else
+    {
+      _json_out["sql_state"]=_json_error_area.get_sql_state();
+    }
+    
+  }
+  
+  void JsonHandler::generate_output_query(JsonErrorArea& _json_error_area)
+  {
+    generate_output_json(_json_error_area);
+    Json::StyledWriter writer;
+    _output_query= writer.write(_json_out);
+  }
+}
+}
 
=== added file 'plugin/json_server/json_handler.h'
--- plugin/json_server/json_handler.h	1970-01-01 00:00:00 +0000
+++ plugin/json_server/json_handler.h	2013-08-13 04:20:40 +0000
@@ -0,0 +1,125 @@
+ /* - mode: c; c-basic-offset: 2; indent-tabs-mode: nil; -*-
+  * vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
+  *
+  * Copyright (C) 2011-2013 Stewart Smith, Henrik Ingo, Mohit Srivastava
+  *       
+  * This program is free software; you can redistribute it and/or modify
+  * it under the terms of the GNU General Public License as published by
+  * the Free Software Foundation; either version 2 of the License, or
+  * (at your option) any later version.
+  *               
+  * This program is distributed in the hope that it will be useful,
+  * but WITHOUT ANY WARRANTY; without even the implied warranty of
+  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  * GNU General Public License for more details.
+  *                           
+  * You should have received a copy of the GNU General Public License
+  * along with this program; if not, write to the Free Software
+  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+  */
+/**
+ * @file Declare a class JsonHandler which handles the operations related to Json. 
+ **/
+
+#include <config.h>
+
+#include <plugin/json_server/json/json.h>
+#include <evhttp.h>
+#include <event.h>
+#include <drizzled/session.h>
+#include <plugin/json_server/error.h>
+
+using namespace drizzled;
+namespace drizzle_plugin
+{
+namespace json_server
+{
+  /*
+   * a class.
+   * used to handle operations related to Json.
+   */  
+  class JsonHandler
+  {
+    public:
+      /*
+       * Generate an input query from http request object.
+       *
+       * @param req_arg the http request object.
+       */ 
+      void generate_input_query(struct evhttp_request *req_arg);
+      /*
+       * Generate an input json from http request object.
+       *
+       * @param req_arg the http request object.
+       * @param _json_error_area the JsonErrorArea object to handle error.
+       */ 
+      void generate_input_json(struct evhttp_request *req_arg,JsonErrorArea &_json_error_area);
+      /*
+       * Generate an output query string.
+       *
+       * @param _json_error_area the JsonErrorArea object to handle error.
+       */  
+      void generate_output_query(JsonErrorArea& _json_error_area);
+      /*
+       * Generate an output Json.
+       *
+       * @param _json_error_area the JsonErrorArea object to handle error.
+       */ 
+      void generate_output_json(JsonErrorArea& _json_error_area);
+      /*
+       * Get an output query string.
+       *
+       * @return a const output query string.
+       */
+      const std::string& get_output_query() const
+      {
+        return _output_query;
+      }
+      /*
+       * Get an input query string.
+       *
+       * @return a const input query string.
+       */  
+      const std::string& get_input_query() const
+      {
+        return _input_query;
+      }
+      /*
+       * Get an output json object.
+       *
+       * @return a const json object.
+       */
+      const Json::Value get_output_json() const
+      {
+        return _json_out;
+      }
+      /*
+       * Get an input json object.
+       *
+       * @return a const json object.
+       */ 
+      const Json::Value get_input_json() const
+      {
+        return _json_in;
+      }
+    
+    private:
+      /*
+       * Stores input json object.
+       */ 
+      Json::Value _json_in;
+      /*
+       * Stores output json object.
+       */ 
+      Json::Value _json_out;
+      /*
+       * Stores input string.
+       */
+      std::string _input_query;
+      /*
+       * Stores output string.
+       */ 
+      std::string _output_query;
+  };
+}
+}
 
=== modified file 'plugin/json_server/json_server.cc'
--- plugin/json_server/json_server.cc	2012-07-17 09:30:57 +0000
+++ plugin/json_server/json_server.cc	2013-08-13 04:20:40 +0000
@@ -1,7 +1,7 @@
 /* - mode: c; c-basic-offset: 2; indent-tabs-mode: nil; -*-
  *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
  *
- *  Copyright (C) 2011 Stewart Smith, Henrik Ingo, Mohit Srivastava
+ *  Copyright (C) 2011-2013 Stewart Smith, Henrik Ingo, Mohit Srivastava
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -46,10 +46,11 @@
 #include <event.h>
 #include <drizzled/execute.h>
 #include <drizzled/sql/result_set.h>
-
+#include <drizzled/diagnostics_area.h>
 #include <drizzled/plugin/listen.h>
 #include <drizzled/plugin/client.h>
 #include <drizzled/catalog/local.h>
+#include <drizzled/current_session.h>
 
 #include <drizzled/pthread_globals.h>
 #include <boost/bind.hpp>
@@ -60,6 +61,8 @@
 #include <plugin/json_server/db_access.h>
 #include <plugin/json_server/http_handler.h>
 #include <plugin/json_server/http_server.h>
+#include <plugin/json_server/ddl/schema.h>
+#include <plugin/json_server/json_handler.h>
 
 namespace po= boost::program_options;
 using namespace drizzled;
@@ -95,6 +98,8 @@
 extern "C" void process_version_req(struct evhttp_request *req, void* );
 extern "C" void process_sql_req(struct evhttp_request *req, void* );
 extern "C" void process_json_req(struct evhttp_request *req, void* );
+extern "C" void process_json_ddl_schema_create_req(struct evhttp_request *req, void* );
+extern "C" void process_json_ddl_schema_drop_req(struct evhttp_request *req, void* );
 extern "C" void process_request(struct evhttp_request *req, void* )
 {
   struct evbuffer *buf = evbuffer_new();
@@ -357,6 +362,104 @@
   delete(handler);
 }
 
+/**
+ * Transform a HTTP Request for create schema and returns results based on the input json.
+ *
+ * @param req a HTTP request parameter,
+ *
+ */ 
+
+extern "C" void process_json_ddl_schema_create_req(struct evhttp_request *req, void* )
+{
+ drizzled::Session::shared_ptr _session= drizzled::Session::make_shared(drizzled::plugin::Listen::getNullClient(),
+                                               drizzled::catalog::local());
+ drizzled::identifier::user::mptr user_id= identifier::User::make_shared();
+ _session->main_da().reset_diagnostics_area();
+ setCurrentSession(_session.get());
+
+ std::string query;
+ std::string db_name;
+ std::string output;
+ Json::Value json_out;
+ Json::Value json_in;
+ const char *http_response_text="OK";
+ int http_response_code=HTTP_OK;
+
+ JsonErrorArea _json_error;
+ JsonHandler* _json_handler = new JsonHandler();
+
+ _json_handler->generate_input_json(req,_json_error);
+ if(!_json_error.is_jsonerror())
+ {
+   json_in = _json_handler->get_input_json();
+   db_name=json_in["query"]["name"].asString();
+   Schema *_schema = new Schema(_session.get(),db_name);
+   _schema->createSchema();
+   if(_session->main_da().is_error())
+   {
+     _json_error.set_error(JsonErrorArea::ER_SQL,_session->main_da().sql_errno(),_session->main_da().message());
+   }
+ }
+ _json_handler->generate_output_query(_json_error);
+ output = _json_handler->get_output_query();
+ struct evbuffer *buf = evbuffer_new();
+ if(buf == NULL)
+ {
+   return;            
+ }
+ evbuffer_add(buf, output.c_str(), output.length());
+ evhttp_send_reply( req, http_response_code, http_response_text, buf);
+}
+
+/**
+* Transform a HTTP Request for create schema and returns results based on the input json.
+* 
+* @param req a HTTP request parameter.
+*/
+extern "C" void process_json_ddl_schema_drop_req(struct evhttp_request *req, void* )
+{
+  drizzled::Session::shared_ptr _session= drizzled::Session::make_shared(drizzled::plugin::Listen::getNullClient(),
+                                                      drizzled::catalog::local());
+  drizzled::identifier::user::mptr user_id= identifier::User::make_shared();
+  _session->main_da().reset_diagnostics_area();
+  setCurrentSession(_session.get());
+         
+  std::string query;
+  std::string db_name;
+  std::string output;
+  Json::Value json_out;
+  Json::Value json_in;
+  const char *http_response_text="OK";
+  int http_response_code=HTTP_OK;
+                       
+  JsonErrorArea _json_error;
+  JsonHandler* _json_handler = new JsonHandler();
+
+  _json_handler->generate_input_json(req,_json_error);
+  if(!_json_error.is_jsonerror())
+  {
+    json_in = _json_handler->get_input_json();
+
+    db_name=json_in["query"]["name"].asString();
+    Schema *_schema = new Schema(_session.get(),db_name);
+    _schema->dropSchema();
+    if(_session->main_da().is_error())
+    {
+      _json_error.set_error(JsonErrorArea::ER_SQL,_session->main_da().sql_errno(),_session->main_da().message());
+    }
+  }
+  _json_handler->generate_output_query(_json_error);
+  output = _json_handler->get_output_query();
+  struct evbuffer *buf = evbuffer_new();
+  if(buf == NULL)
+  {
+    return;
+  }
+  evbuffer_add(buf, output.c_str(), output.length());
+  evhttp_send_reply( req, http_response_code, http_response_text, buf);
+}
+
+
 static void shutdown_event(int fd, short, void *arg)
 {
   struct event_base *base= (struct event_base *)arg;
@@ -466,6 +569,8 @@
       evhttp_set_cb(httpd, "/version", process_version_req, NULL);
       evhttp_set_cb(httpd, "/sql", process_sql_req, NULL);
       evhttp_set_cb(httpd, "/json", process_json_req, NULL);
+      evhttp_set_cb(httpd,"/json/ddl/schema/create", process_json_ddl_schema_create_req, NULL);
+      evhttp_set_cb(httpd,"/json/ddl/schema/drop", process_json_ddl_schema_drop_req, NULL);
         
 
         event_set(&wakeup_event, wakeup_fd[0], EV_READ | EV_PERSIST, shutdown_event, base);
 
=== modified file 'plugin/json_server/plugin.ini'
--- plugin/json_server/plugin.ini	2013-02-06 08:10:34 +0000
+++ plugin/json_server/plugin.ini	2013-08-13 04:20:40 +0000
@@ -5,7 +5,10 @@
   sql_to_json_generator.h
   http_handler.h
   http_server.h
+  json_handler.h
+  error.h
   db_access.h
+  ddl/schema.h
   json/autolink.h
   json/config.h
   json/features.h
@@ -25,7 +28,10 @@
   sql_to_json_generator.cc
   http_handler.cc
   http_server.cc
+  json_handler.cc
+  error.cc
   db_access.cc
+  ddl/schema.cc
   json/json_reader.cpp
   json/json_value.cpp
   json/json_writer.cpp
 
=== modified file 'plugin/json_server/tests/r/basic.result'
--- plugin/json_server/tests/r/basic.result	2012-07-14 14:10:13 +0000
+++ plugin/json_server/tests/r/basic.result	2013-08-13 04:20:40 +0000
@@ -287,3 +287,21 @@
 SET GLOBAL json_server_table="";
 SET GLOBAL json_server_schema="test";
 drop schema json;
+{
+   "sql_state" : "00000"
+}
+{
+   "error_message" : "Can't create schema 'json'; schema exists",
+   "error_no" : 1007,
+   "error_type" : "SQL ERROR",
+   "sql_state" : "HY000"
+}
+{
+   "sql_state" : "00000"
+}
+{
+   "error_message" : "Can't drop schema 'json'; schema doesn't exist",
+   "error_no" : 1008,
+   "error_type" : "SQL ERROR",
+   "sql_state" : "HY000"
+}
 
=== added file 'plugin/json_server/tests/t/basic.test'
--- plugin/json_server/tests/t/basic.test	1970-01-01 00:00:00 +0000
+++ plugin/json_server/tests/t/basic.test	2013-08-13 04:20:40 +0000
@@ -0,0 +1,94 @@
+create table t1 (a int primary key auto_increment, b varchar(100));
+--replace_result $JSON_SERVER_PORT PORT
+--eval select http_post("http://localhost:$JSON_SERVER_PORT/sql", 'select * from t1;');
+insert into t1 (b) values ("from MySQL protocol");
+--replace_result $JSON_SERVER_PORT PORT
+--eval select http_post('http://localhost:$JSON_SERVER_PORT/sql', 'select * from t1;');
+--replace_result $JSON_SERVER_PORT PORT
+--eval select http_post('http://localhost:$JSON_SERVER_PORT/sql', 'insert into t1 (b) values (\'from http\');');
+SELECT * from t1;
+drop table t1;
+
+create schema json;
+
+use json;
+
+--exec curl -H "Content-Type: application/json" -H "Accept: application/json" -X POST -d '{"query":{"_id":1,"document":{"firstname":"Henrik","lastname":"Ingo","age": 35}}}' 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=people'
+
+--exec curl 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=people&_id=1'
+
+--exec curl 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=people&query=%7B%22query%22%3A%7B%22_id%22%3A1%7D%7D'
+
+--exec curl -H "Content-Type: application/json" -H "Accept: application/json" -X POST -d '{"query":{"_id":1,"document":{"firstname":"Henrik","lastname":"Ingo","age": 36}}}' 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=people'
+
+--exec curl 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=people&_id=1'
+
+--exec curl -X POST 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=people&_id=2'
+
+--exec curl -H "Content-Type: application/json" -H "Accept: application/json" -X POST -d '{"query":{"_id":1,"document":{"firstname":"Henrik","lastname":"Ingo","age": 37}}}' 'http://localhost:$JSON_SERVER_PORT/json'
+
+--exec curl 'http://localhost:$JSON_SERVER_PORT/json?schema=json'
+
+--exec curl -H "Content-Type: application/json" -H "Accept: application/json" -X POST -d '{"query":{"document":{"firstname":"Mohit","lastname":"Srivastava","age": 21}}}' 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=people'
+
+--exec curl 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=people'
+
+--exec curl 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=people&query=%7B%22query%22%3A%7B%7D%7D'
+
+--exec curl 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=people&query=%7B%22query%22%3A%7B%22_id%22%3A%22%22%7D%7D'
+
+SET GLOBAL json_server_schema="json";
+
+--exec curl 'http://localhost:$JSON_SERVER_PORT/json?table=people'
+
+SET GLOBAL json_server_table="people";
+
+--exec curl 'http://localhost:$JSON_SERVER_PORT/json'
+
+--exec curl -H "Content-Type: application/json" -H "Accept: application/json" -X POST -d '{"query":{"_id":1 "document":{"firstname":"Henrik","lastname":"Ingo","age": 37}}}' 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=people'
+
+--exec curl -H "Content-Type: application/json" -H "Accept: application/json" -X POST -d '{"query":{"_id":1,"document":"It is for testing"}}' 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=people'
+
+--exec curl -H "Content-Type: application/json" -H "Accept: application/json" -X POST -d '{"query":{"_id":1,"document":98765}}' 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=people'
+
+--exec curl -H "Content-Type: application/json" -H "Accept: application/json" -X POST -d '{"query":{"_id":1,"document":{"firstname":"Henrik","lastname":"Ingo","age": 35},"metadata":{"interest":"opensource","nick":"hingo","dob":"16-feb-1977"}}}' 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=aboutpeople'
+
+--exec curl 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=aboutpeople'
+
+--exec curl -X DELETE 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=people&_id=1'
+
+--exec curl 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=people'
+
+--exec curl -X DELETE 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=people&query=%7B%22query%22%3A%7B%22_id%22%3A2%7D%7D'
+
+--exec curl 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=people'
+
+--exec curl -X DELETE 'http://localhost:$JSON_SERVER_PORT/json'
+
+--exec curl -X DELETE 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=people'
+
+--exec curl -X DELETE 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=people&query=%7B%22query%22%3A%7B%7D%7D'
+
+--exec curl -X DELETE 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=people&query=%7B%22query%22%3A%7B%22_id%22%3A%22%22%7D%7D'
+
+SET GLOBAL json_server_allow_drop_table="ON";
+
+--exec curl -X DELETE 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=people&query=%7B%22query%22%3A%7B%7D%7D'
+
+--exec curl 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=people'
+
+--exec curl -X DELETE 'http://localhost:$JSON_SERVER_PORT/json?schema=json&table=aboutpeople&query=%7B%22query%22%3A%7B%22_id%22%3A%22%22%7D%7D'
+
+SET GLOBAL json_server_allow_drop_table="OFF";
+SET GLOBAL json_server_table="";
+SET GLOBAL json_server_schema="test";
+
+drop schema json;
+
+--exec curl -H "Content-Type: application/json" -H "Accept: application/json" -X POST -d '{"query":{"name":"json"}}' 'http://localhost:$JSON_SERVER_PORT/json/ddl/schema/create'
+
+--exec curl -H "Content-Type: application/json" -H "Accept: application/json" -X POST -d '{"query":{"name":"json"}}' 'http://localhost:$JSON_SERVER_PORT/json/ddl/schema/create'
+
+--exec curl -H "Content-Type: application/json" -H "Accept: application/json" -X POST -d '{"query":{"name":"json"}}' 'http://localhost:$JSON_SERVER_PORT/json/ddl/schema/drop'
+
+--exec curl -H "Content-Type: application/json" -H "Accept: application/json" -X POST -d '{"query":{"name":"json"}}' 'http://localhost:$JSON_SERVER_PORT/json/ddl/schema/drop'