Drizzled Public API Documentation

uncompressed_length.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/plugin/function.h>
00022 #include <drizzled/function/math/int.h>
00023 #include <plugin/compression/uncompressed_length.h>
00024 
00025 #include <string>
00026 
00027 using namespace std;
00028 using namespace drizzled;
00029 
00030 
00031 int64_t Item_func_uncompressed_length::val_int()
00032 {
00033   assert(fixed == 1);
00034   String *res= args[0]->val_str(&value);
00035   if (!res)
00036   {
00037     null_value=1;
00038     return 0;
00039   }
00040   null_value=0;
00041   if (res->is_empty()) return 0;
00042 
00043   /*
00044     res->ptr() using is safe because we have tested that string is not empty,
00045     res->c_ptr() is not used because:
00046       - we do not need \0 terminated string to get first 4 bytes
00047       - c_ptr() tests simbol after string end (uninitialiozed memory) which
00048         confuse valgrind
00049   */
00050   return uint4korr(res->ptr()) & 0x3FFFFFFF;
00051 }
00052