xbase.cpp

一个通讯管理机的源代码。比较好用。推荐

/***************************************************************************
                          xbase.cpp  -  description
                             -------------------
    begin                : Thu Jan 17 2002
    copyright            : (C) 2002 by 
    email                : 
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/
/*  $Id: xbase.cpp,v 1.8 2000/11/10 19:04:17 dbryson Exp $

    Xbase project source code

    This file contains logic for the basic Xbase class.

    Copyright (C) 1997  Startech, Gary A. Kunkel   

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    Contact:

      Mail:

        Technology Associates, Inc.
        XBase Project
        1455 Deming Way #11
        Sparks, NV 89434
        USA

      Email:

        [e-mail]

      See our website at:

        xdb.sourceforge.net


    V 1.0   10/10/97   - Initial release of software
    V 1.5   1/2/97     - Added memo field support
    V 1.6a  4/1/98     - Added expression support
    V 1.6b  4/8/98     - Numeric index keys
    V 1.7.1 5/25/98    - Big Endian support
*/

#ifdef __GNUG__
  #pragma implementation "xbase.h"
#endif

#ifdef __WIN32__
#include "xbconfigw32.h"
#else
#include "xbconfig.h"
#endif

#include "xbase.h"
#include <ctype.h>
#include <string>
using namespace std;

#include "xbexcept.h"

/*! \file xbase.cpp
*/

/*************************************************************************/
//! Constructor.
/*!
*/
xbXBase::xbXBase( void )
{
   xbShort e = 1;
   EndianType = *(char *) &e;
   if( EndianType )
      EndianType = 'L';
   else
      EndianType = 'B';
   DbfList = NULL;
   FreeDbfList = NULL;
}

/*************************************************************************/
//! Get pointer to named dbf.
/*!
  Looks up an open DBF file by Name.
  
  \param Name
  \returns A pointer to the xbDbf class instance if found or NULL if
    not found.
*/
xbDbf *xbXBase::GetDbfPtr(const char *Name) {
  xbDbList *t;

  t = DbfList;
  xbShort len = strlen(Name);

  /* check for -> embedded in the name */
  for( xbShort i = 0; i < (len-1); i++ )
    if( Name[i] == '-' && Name[i+1] == '>' )
      len = i-1;

  while (t) {
    if (strncmp(Name, t->DbfName, len) == 0 )
      return t->dbf;
    t = t->NextDbf;
  }
  return NULL;
}

/*************************************************************************/
//! Destructor.
/*!
*/
xbXBase::~xbXBase()
{
   xbDbList *i = FreeDbfList;
   while (i) {
      xbDbList *t = i->NextDbf;
      if (i->DbfName) {
         free(i->DbfName);
      }
      free(i);
      i = t;
   }
}

/*************************************************************************/
//! Add dbf to dbf list.
/*!
  Adds an xbDbf class instance to the list of dbf's.
  
  \param d the xbDbf instance to be added
  \param DatabaseName name of the database
  
  \returns One of the following return codes:
    \htmlonly
      <p>
      <table border=2><tr><th>Return Code</th><th>Description</th></tr>
        <tr><td>XB_NO_ERROR</td><td>No error</td></tr>
        <tr><td>XB_NO_MEMORY</td><td>Out of memory</td></tr>
      </table>
    \endhtmlonly
    \latexonly
      \\
      \\
      \begin{tabular}{|l|l|} \hline
        \textbf{Return Code} & \textbf{Description} \\ \hline \hline
        XB\_NO\_ERROR & No Error \\ \hline
        XB\_NO\_MEMORY & Out of memory \\ \hline
      \end{tabular}
    \endlatexonly
*/
xbShort xbXBase::AddDbfToDbfList(xbDbf *d, const char *DatabaseName) {
   xbDbList *i, *s, *t;

   if(!FreeDbfList) {
      if((i = (xbDbList *)malloc(sizeof(xbDbList))) == NULL) {
         xb_memory_error;
      }
   } else {
      i = FreeDbfList;
      FreeDbfList = i->NextDbf;
   }
   memset(i, 0x00, sizeof(xbDbList));

   i->DbfName  = strdup(DatabaseName);
   i->dbf      = d;

   s = NULL;
   t = DbfList;
   while(t && strcmp(t->DbfName, DatabaseName) < 0) {
      s = t;
      t = t->NextDbf;
   }
   i->NextDbf = t;
   if (s == NULL)
      DbfList = i;
   else
      s->NextDbf = i;
      
   return 0;
}

/***********************************************************************/
//!  Remove dbf from dbf list.
/*!
  Removes the specified xbDbf class instance from the list of dbf's.
  
  \param d xbDbf to be removed
  
  \returns One of the following return codes:
    \htmlonly
      <p>
      <table border=2><tr><th>Return Code</th><th>Description</th></tr>
        <tr><td>XB_NO_ERROR</td><td>No error</td></tr>
      </table>
    \endhtmlonly
    \latexonly
      \\
      \\
      \begin{tabular}{|l|l|} \hline
        \textbf{Return Code} & \textbf{Description} \\ \hline \hline
        XB\_NO\_ERROR & No Error \\ \hline
      \end{tabular}
    \endlatexonly
*/
xbShort xbXBase::RemoveDbfFromDbfList(xbDbf *d) {
   xbDbList *i, *s;

   i = DbfList;
   s = NULL;

   while (i) {
      if(i->dbf == d) {
         /* remove it from current chain */
         if(s)
            s->NextDbf = i->NextDbf;
         else
            DbfList = i->NextDbf;

         /* add i to the current free chain */
         i->NextDbf = FreeDbfList;
         FreeDbfList = i;
         free(FreeDbfList->DbfName);
         FreeDbfList->DbfName = NULL;
         FreeDbfList->NextDbf = NULL; 
         break;
      } else {
         s = i;
         i = i->NextDbf;
      }
   }
   return XB_NO_ERROR;
} 

// FIXME: byte reverse methods are awful, compared to bitwise shifts  -- willy

/************************************************************************/
//! Get a portable short value.
/*!
  Converts a short (16 bit integer) value stored at p from a portable 
  format to the machine format.
  
  \param p pointer to memory containing the portable short value
  
  \returns the short value.
*/
/* This routine returns a short value from a 2 byte character stream */
xbShort xbXBase::GetShort(const char *p) {
   xbShort s, i;
   const char *sp;
   char *tp;

   s = 0;
   tp = (char *) &s;
   sp = p;
   if( EndianType == 'L' )
      for( i = 0; i < 2; i++ ) *tp++ = *sp++;
   else
   {
      sp++;
      for( i = 0; i < 2; i++ ) *tp++ = *sp--;
   }  
   return s;
}

//! Get a portable long value.
/*!
  Converts a long (32 bit integer) value stored at p from a portable 
  format to the machine format.
  
  \param p pointer to memory containing the portable long value
  
  \returns the long value.
*/
/* This routine returns a long value from a 4 byte character stream */
xbLong xbXBase::GetLong( const char *p )
{
   xbLong l;
   const char *sp;
   char *tp;
   xbShort i;

   tp = (char *) &l;
   sp = p;
   if( EndianType == 'L' )
      for( i = 0; i < 4; i++ ) *tp++ = *sp++;
   else
   {
      sp+=3;
      for( i = 0; i < 4; i++ )  *tp++ = *sp--;
   }  
   return l;
}

//! Get a portable unsigned long value.
/*!
  Converts an unsigned long (32 bit integer) value stored at p from a portable 
  format to the machine format.
  
  \param p pointer to memory containing the portable unsigned long value
  
  \returns the unsigned long value.
*/
/* This routine returns a long value from a 4 byte character stream */
xbULong xbXBase::GetULong( const char *p )
{
  xbULong l;
  char *tp;
  xbShort i;
  
  tp = (char *) &l;
  if( EndianType == 'L' )
    for( i = 0; i < 4; i++ ) *tp++ = *p++;
  else{