Drizzled Public API Documentation

connection_id.cc
00001 /* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
00002  *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
00003  *
00004  *  Copyright (C) 2008 Sun Microsystems, Inc.
00005  *
00006  *  This program is free software; you can redistribute it and/or modify
00007  *  it under the terms of the GNU General Public License as published by
00008  *  the Free Software Foundation; version 2 of the License.
00009  *
00010  *  This program is distributed in the hope that it will be useful,
00011  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00012  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00013  *  GNU General Public License for more details.
00014  *
00015  *  You should have received a copy of the GNU General Public License
00016  *  along with this program; if not, write to the Free Software
00017  *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
00018  */
00019 
00020 #include <config.h>
00021 #include <drizzled/function/math/int.h>
00022 #include <drizzled/plugin/function.h>
00023 #include <drizzled/session.h>
00024 #include <drizzled/system_variables.h>
00025 
00026 using namespace std;
00027 using namespace drizzled;
00028 
00029 class ConnectionIdFunction :public Item_int_func
00030 {
00031   int64_t value;
00032 public:
00033   ConnectionIdFunction() :Item_int_func() {}
00034   
00035   int64_t val_int() 
00036   {
00037     assert(fixed == true);
00038     return value;
00039   }
00040   
00041   const char *func_name() const 
00042   { 
00043     return "connection_id"; 
00044   }
00045 
00046   void fix_length_and_dec() 
00047   {
00048     Item_int_func::fix_length_and_dec();
00049     max_length= 10;
00050   }
00051 
00052   bool fix_fields(Session *session, Item **ref)
00053   {
00054     if (Item_int_func::fix_fields(session, ref))
00055     {
00056       return true;
00057     }
00058 
00059     value= session->variables.pseudo_thread_id;
00060     return false;
00061   }
00062 
00063   bool check_argument_count(int n)
00064   {
00065     return (n == 0);
00066   }
00067 };
00068 
00069 
00070 plugin::Create_function<ConnectionIdFunction> *connection_idudf= NULL;
00071 
00072 static int initialize(module::Context &context)
00073 {
00074   connection_idudf=
00075     new plugin::Create_function<ConnectionIdFunction>("connection_id");
00076   context.add(connection_idudf);
00077   return 0;
00078 }
00079 
00080 DRIZZLE_DECLARE_PLUGIN
00081 {
00082   DRIZZLE_VERSION_ID,
00083   "connection_id",
00084   "1.0",
00085   "Devananda van der Veen",
00086   "Return the current connection_id",
00087   PLUGIN_LICENSE_GPL,
00088   initialize, /* Plugin Init */
00089   NULL,   /* depends */
00090   NULL    /* config options */
00091 }
00092 DRIZZLE_DECLARE_PLUGIN_END;