jdbc/driver/nativeapi/library_loader.cpp

/*
 * Copyright (c) 2009, 2018, Oracle and/or its affiliates. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2.0, as
 * published by the Free Software Foundation.
 *
 * This program is also distributed with certain software (including
 * but not limited to OpenSSL) that is licensed under separate terms,
 * as designated in a particular file or component or in included license
 * documentation.  The authors of MySQL hereby grant you an
 * additional permission to link the program and your derivative works
 * with the separately licensed software that they have included with
 * MySQL.
 *
 * Without limiting anything contained in the foregoing, this file,
 * which is part of MySQL Connector/C++, is also subject to the
 * Universal FOSS Exception, version 1.0, a copy of which can be found at
 * http://oss.oracle.com/licenses/universal-foss-exception.
 *
 * 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, version 2.0, 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
 */



//#include "binding_config.h"
#ifndef MYSQLCLIENT_STATIC_BINDING

#include <string>
#include <stdexcept>


// Needed to make SetDllDirectory available
#define _WIN32_WINNT	0x0502
#include "library_loader.h"

/* TODO consider using of dlopen, dlsym and dlclose definitions in my_global.h
 * sort of doesn't like that.
 */
#ifndef _WIN32
#define LoadLibrary(p)			::dlopen(p, RTLD_LAZY)
#define FreeLibrary(p)			::dlclose(p)
#define GetProcAddress(p1,p2)	::dlsym(p1,p2)
#endif


namespace sql {
namespace mysql {
namespace util {

std::string ErrorMessage()
{
#ifdef _WIN32
  TCHAR buffer[255];
  DWORD _errcode = GetLastError();
  ::FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM,
          NULL, _errcode, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
          buffer, sizeof(buffer), NULL);

  return buffer;
#else
  return dlerror();
#endif
}

/* {{{ LibraryLoader::LibraryLoader() */
LibraryLoader::LibraryLoader(const std::string & path2libFile)
  : loadedLibHandle (NULL)
{
  if ((loadedLibHandle = LoadLibrary(path2libFile.c_str())) == NULL) {
    throw std::runtime_error(std::string("Couldn't load library ") + path2libFile + ": " + ErrorMessage());
  }
}
/* }}} */


/* {{{ LibraryLoader::LibraryLoader() */
LibraryLoader::LibraryLoader(const std::string & dir2look, const std::string & libFileName)
  : loadedLibHandle(NULL)
{

#if _WIN32
  SetDllDirectory(dir2look.c_str());
  if ((loadedLibHandle= LoadLibrary(libFileName.c_str())) == NULL) {
#else
  std::string fullname(dir2look);
  fullname += "/";
  fullname += libFileName;
  if ((loadedLibHandle = LoadLibrary(fullname.c_str())) == NULL) {
#endif
    throw std::runtime_error(std::string("Couldn't load library ") + libFileName + ": " + ErrorMessage());
  }
}
/* }}} */


/* {{{ LibraryLoader::~LibraryLoader() */
LibraryLoader::~LibraryLoader()
{
  FreeLibrary(loadedLibHandle);
}
/* }}} */


/* {{{ LibraryLoader::GetProcAddr() */
SymbolHandle
LibraryLoader::GetProcAddr(const std::string & name)
{
  if (loadedLibHandle == NULL) {
    return NULL;
  }

  ProcCache::const_iterator cit = functions.find(name);

  if (cit != functions.end()) {
    return cit->second;
  }

  SymbolHandle proc = GetProcAddress(loadedLibHandle, name.c_str());

  if (proc == NULL) {
    throw std::runtime_error("Couldn't find symbol " + name);
  }

  functions.insert(std::make_pair(name, proc));

  return proc;
}
/* }}} */


} /* namespace util */
} /* namespace mysql */
} /* namespace sql */

#endif

/*
 * Local variables:
 * tab-width: 4
 * c-basic-offset: 4
 * End:
 * vim600: noet sw=4 ts=4 fdm=marker
 * vim<600: noet sw=4 ts=4
 */