glpsql.c

著名的大规模线性规划求解器源码GLPK.C语言版本,可以修剪.内有详细帮助文档.

   MYSQL           *con;   /*connection*/
   MYSQL_RES       *res;    /*result*/
   int              nf;
   /* number of fields in the csv file */
   int              ref[1+SQL_FIELD_MAX];
   /* ref[k] = k', if k-th field of the csv file corresponds to
      k'-th field in the table statement; if ref[k] = 0, k-th field
      of the csv file is ignored */
   char            *query;
   /* query generated by db_mysql_open */
};

void STDCALL dl_mysql_close(MYSQL *sock)
{
      typedef void STDCALL ep_mysql_close(MYSQL *sock);

      ep_mysql_close *fn;
      fn = (ep_mysql_close *) xdlsym(h_mysql, "mysql_close");
      xassert(fn != NULL);
      return (*fn)(sock);
}

const char * STDCALL dl_mysql_error(MYSQL *mysql)
{
      typedef const char * STDCALL ep_mysql_error(MYSQL *mysql);

      ep_mysql_error *fn;
      fn = (ep_mysql_error *) xdlsym(h_mysql, "mysql_error");
      xassert(fn != NULL);
      return (*fn)(mysql);
}

MYSQL_FIELD * STDCALL dl_mysql_fetch_fields(MYSQL_RES *res)
{
      typedef MYSQL_FIELD * STDCALL
         ep_mysql_fetch_fields(MYSQL_RES *res);

      ep_mysql_fetch_fields *fn;
   fn = (ep_mysql_fetch_fields *) xdlsym(h_mysql, "mysql_fetch_fields");
      xassert(fn != NULL);
      return (*fn)(res);
}

unsigned long * STDCALL dl_mysql_fetch_lengths(MYSQL_RES *result)
{
      typedef unsigned long * STDCALL
         ep_mysql_fetch_lengths(MYSQL_RES *result);

      ep_mysql_fetch_lengths *fn;
      fn = (ep_mysql_fetch_lengths *) xdlsym(h_mysql,
         "mysql_fetch_lengths");
      xassert(fn != NULL);
      return (*fn)(result);
}

MYSQL_ROW STDCALL dl_mysql_fetch_row(MYSQL_RES *result)
{
      typedef MYSQL_ROW STDCALL ep_mysql_fetch_row(MYSQL_RES *result);

      ep_mysql_fetch_row *fn;
      fn = (ep_mysql_fetch_row *) xdlsym(h_mysql, "mysql_fetch_row");
      xassert(fn != NULL);
      return (*fn)(result);
}

unsigned int STDCALL dl_mysql_field_count(MYSQL *mysql)
{
      typedef unsigned int STDCALL ep_mysql_field_count(MYSQL *mysql);

      ep_mysql_field_count *fn;
     fn = (ep_mysql_field_count *) xdlsym(h_mysql, "mysql_field_count");
      xassert(fn != NULL);
      return (*fn)(mysql);
}

MYSQL * STDCALL dl_mysql_init(MYSQL *mysql)
{
      typedef MYSQL * STDCALL ep_mysql_init(MYSQL *mysql);

      ep_mysql_init *fn;
      fn = (ep_mysql_init *) xdlsym(h_mysql, "mysql_init");
      xassert(fn != NULL);
      return (*fn)(mysql);
}

unsigned int STDCALL dl_mysql_num_fields(MYSQL_RES *res)
{
      typedef unsigned int STDCALL ep_mysql_num_fields(MYSQL_RES *res);

      ep_mysql_num_fields *fn;
      fn = (ep_mysql_num_fields *) xdlsym(h_mysql, "mysql_num_fields");
      xassert(fn != NULL);
      return (*fn)(res);
}

int STDCALL dl_mysql_query(MYSQL *mysql, const char *q)
{
      typedef int STDCALL ep_mysql_query(MYSQL *mysql, const char *q);

      ep_mysql_query *fn;
      fn = (ep_mysql_query *) xdlsym(h_mysql, "mysql_query");
      xassert(fn != NULL);
      return (*fn)(mysql, q);
}

MYSQL * STDCALL dl_mysql_real_connect(MYSQL *mysql, const char *host,
                                           const char *user,
                                           const char *passwd,
                                           const char *db,
                                           unsigned int port,
                                           const char *unix_socket,
                                           unsigned long clientflag)
{
      typedef MYSQL * STDCALL ep_mysql_real_connect(MYSQL *mysql,
            const char *host,
            const char *user,
            const char *passwd,
            const char *db,
            unsigned int port,
            const char *unix_socket,
            unsigned long clientflag);

      ep_mysql_real_connect *fn;
      fn = (ep_mysql_real_connect *) xdlsym(h_mysql,
         "mysql_real_connect");
      xassert(fn != NULL);
      return (*fn)(mysql, host, user, passwd, db, port, unix_socket,
         clientflag);
}

MYSQL_RES * STDCALL dl_mysql_use_result(MYSQL *mysql)
{
      typedef MYSQL_RES * STDCALL ep_mysql_use_result(MYSQL *mysql);
      ep_mysql_use_result *fn;
      fn = (ep_mysql_use_result *) xdlsym(h_mysql, "mysql_use_result");
      xassert(fn != NULL);
      return (*fn)(mysql);
}

void *db_mysql_open(TABDCA *dca, int mode)
{
   struct db_mysql *sql = NULL;
   char            *arg = NULL;
   const char      *field;
   MYSQL_FIELD     *fields;
   char            *keyword;
   char            *value;
   char            *query;
   char            *dsn;
/* "Server=[server_name];Database=[database_name];UID=[username];*/
/* PWD=[password];Port=[port]"*/
   char            *server   = NULL;        /* Server */
   char            *user     = NULL;        /* UID */
   char            *password = NULL;        /* PWD */
   char            *database = NULL;        /* Database */
   unsigned int     port = 0;               /* Port */
   int              narg;
   int              i, j, total;

   if (libmysql == NULL)
   {
      xprintf("No loader for shared MySQL library available\n");
      return NULL;
   }

   if (h_mysql == NULL)
   {
      h_mysql = xdlopen(libmysql);
      if (h_mysql == NULL)
      {  xprintf("unable to open library %s\n", libmysql);
         xprintf("%s\n", xerrmsg());
         return NULL;
      }
   }

   sql = (struct db_mysql *) xmalloc(sizeof(struct db_mysql));
   if (sql == NULL)
         return NULL;
   sql->mode = mode;
   sql->res = NULL;
   sql->query = NULL;
   sql->nf = mpl_tab_num_flds(dca);

   narg = mpl_tab_num_args(dca);
   if (narg < 3 )
      xprintf("MySQL driver: string list too short \n");

   /* get connection string*/
   dsn = (char *) mpl_tab_get_arg(dca, 2);
      /* copy connection string*/
   i = strlen(dsn);
   i++;
   arg = xmalloc(i * sizeof(char));
   strcpy(arg, dsn);
   /*tokenize connection string*/
   for (i = 1, keyword = strtok (arg, "="); (keyword != NULL);
      keyword = strtok (NULL, "="), i++)
   {
         value = strtok (NULL, ";");
      if (value==NULL)
         {
            xprintf("db_mysql_open: Missing value for keyword %s\n",
               keyword);
            xfree(arg);
            xfree(sql);
            return NULL;
      }
      if (0 == strcmp(keyword, "Server"))
            server = value;
      else if (0 == strcmp(keyword, "Database"))
             database = value;
      else if (0 == strcmp(keyword, "UID"))
             user = value;
      else if (0 == strcmp(keyword, "PWD"))
             password = value;
      else if (0 == strcmp(keyword, "Port"))
             port = (unsigned int) atol(value);
   }
   /* Connect to database */
   sql->con = dl_mysql_init(NULL);
  if (!dl_mysql_real_connect(sql->con, server, user, password, database,
      port, NULL, 0))
   {
      xprintf("db_mysql_open: Connect failed\n");
      xprintf("%s\n", dl_mysql_error(sql->con));
      xfree(arg);
      xfree(sql);
      return NULL;
   }
   xfree(arg);

   for (j = 3; j < narg; j++)
   {
      query = (char *) mpl_tab_get_arg(dca, j);
      xprintf("%s\n", query);
      if (dl_mysql_query(sql->con, query))
      {
         xprintf("db_mysql_open: Query\n\"%s\"\nfailed.\n", query);
         xprintf("%s\n",dl_mysql_error(sql->con));
         dl_mysql_close(sql->con);
         xfree(sql);
         return NULL;
      }
   }

   if ( sql->mode == 'R' )
   {
      sql->nf = mpl_tab_num_flds(dca);
      arg = (char *) mpl_tab_get_arg(dca, narg);
      total = strlen(arg);
      if (total > 7 && 0 == strncmp(arg, "SELECT ", 7))
      {
         total = strlen(arg);
         query = xmalloc( (total+1) * sizeof(char));
         strcpy (query, arg);
      }
      else
      {
         query = db_generate_select_stmt(dca);
      }
      xprintf("%s\n", query);
      if (dl_mysql_query(sql->con, query))
      {
         xprintf("db_mysql_open: Query\n\"%s\"\nfailed.\n", query);
         xprintf("%s\n",dl_mysql_error(sql->con));
         dl_mysql_close(sql->con);
         xfree(query);
         xfree(sql);
         return NULL;
      }
      xfree(query);
      sql->res = dl_mysql_use_result(sql->con);
      if (sql->res)
      {
         /* create references between query results and table fields*/
         total = dl_mysql_num_fields(sql->res);
         if (total > SQL_FIELD_MAX)
         {
    xprintf("db_mysql_open: Too many fields (> %d) in query.\n\"%s\"\n",
               SQL_FIELD_MAX, query);
            xprintf("%s\n",dl_mysql_error(sql->con));
            dl_mysql_close(sql->con);
            xfree(query);
                 xfree(sql);
            return NULL;
         }
         fields = dl_mysql_fetch_fields(sql->res);
         for (i = 1; i <= total; i++)
         {
               for (j = sql->nf; j >= 1; j--)
            {
               if (strcmp(mpl_tab_get_name(dca, j), fields[i-1].name)
                  == 0)
               break;
            }
            sql->ref[i] = j;
         }
      }
      else
      {
         if(dl_mysql_field_count(sql->con) == 0)
            {
            xprintf("db_mysql_open: Query was not a SELECT\n\"%s\"\n",
               query);
            xprintf("%s\n",dl_mysql_error(sql->con));
            xfree(query);
            xfree(sql);
            return NULL;
         }
         else
         {
            xprintf("db_mysql_open: Query\n\"%s\"\nfailed.\n", query);
            xprintf("%s\n",dl_mysql_error(sql->con));
            xfree(query);
            xfree(sql);
            return NULL;
         }
      }
   }
   else if ( sql->mode == 'W' )
   {
      arg = (char *) mpl_tab_get_arg(dca, narg);
      if (  NULL != strchr(arg, '?') )
      {
         total = strlen(arg);
         query = xmalloc( (total+1) * sizeof(char));
         strcpy (query, arg);
         }
      else
      {
         query = db_generate_insert_stmt(dca);
      }
      sql->query = query;
      xprintf("%s\n", query);
   }

   return sql;
}

int db_mysql_read(TABDCA *dca, void *link)
{
   struct db_mysql *sql;
   char            buf[255+1];
   char            **row;
   unsigned long   *lengths;
   MYSQL_FIELD     *fields;
   double          num;
   int             len;
   unsigned long   num_fields;
   int             i;

   sql = (struct db_mysql *) link;

   xassert(sql != NULL);
   xassert(sql->mode == 'R');
   if (NULL == sql->res)
   {
      xprintf("db_mysql_read: no result set available");
      return 1;
   }
   if (NULL==(row = (char **)dl_mysql_fetch_row(sql->res))) {
       return -1; /*EOF*/
   }
   lengths = dl_mysql_fetch_lengths(sql->res);
   fields = dl_mysql_fetch_fields(sql->res);
   num_fields = dl_mysql_num_fields(sql->res);
   for (i=1; i <= num_fields; i++)
   {
      len = (size_t) lengths[i-1];
      if (len > 255)
         len = 255;
      strncpy(buf, (const char *) row[i-1], len);
      buf[len] = 0x00;
      if (0 != (fields[i-1].flags & NUM_FLAG))
      {
         strspx(buf); /* remove spaces*/
         xassert(str2num(buf, &num) == 0);
         if (sql->ref[i] > 0)
            mpl_tab_set_num(dca, sql->ref[i], num);
         }
           else
         {
         if (sql->ref[i] > 0)
            mpl_tab_set_str(dca, sql->ref[i], strtrim(buf));
         }
         }
   return 0;
   }


int db_mysql_write(TABDCA *dca, void *link)
{
   struct db_mysql *sql;
   char            *part;
   char            *query;
   char            *template;
   char             num[50];
   int              k;
   int              len;
   int              nf;

   sql = (struct db_mysql *) link;
   xassert(sql != NULL);
   xassert(sql->mode == 'W');

   len      = strlen(sql->query);
   template = (char *) xmalloc( (len + 1) * sizeof(char) );
   strcpy(template, sql->query);

   nf = mpl_tab_num_flds(dca);
   for (k = 1; k <= nf; k++)
   {     switch (mpl_tab_get_type(dca, k))
      {  case 'N':
            len += 20;
            break;
         case 'S':
            len += db_escaped_string_length(mpl_tab_get_str(dca, k));
            len += 2;
            break;
              default:
                        xassert(dca != dca);
         }
   }
   query = xmalloc( (len + 1 ) * sizeof(char) );
   query[0] = 0x00;
   for (k = 1, part = strtok (template, "?"); (part != NULL);
      part = strtok (NULL, "?"), k++)
   {
      if (k > nf) break;
      strcat( query, part );
      switch (mpl_tab_get_type(dca, k))
      {  case 'N':
            sprintf(num, "%-18g",mpl_tab_get_num(dca, k));
            strcat( query, num );
            break;
         case 'S':
            strcat( query, "'");
            db_escape_string( query + strlen(query),
               mpl_tab_get_str(dca, k) );
            strcat( query, "'");
            break;
              default:
                        xassert(dca != dca);
         }
   }
   if (part != NULL)
      strcat(query, part);
   if (dl_mysql_query(sql->con, query))
   {
      xprintf("db_mysql_write: Query\n\"%s\"\nfailed.\n", query);
      xprintf("%s\n",dl_mysql_error(sql->con));
      xfree(query);
      xfree(template);
      return 1;
      }

   xfree(query);
   xfree(template);
   return 0;
   }

int db_mysql_close(TABDCA *dca, void *link)
{
   struct db_mysql *sql;

   sql = (struct db_mysql *) link;
   xassert(sql != NULL);
   dl_mysql_close(sql->con);
   if ( sql->mode == 'W' )
      xfree(sql->query);
   xfree(sql);
   dca->link = NULL;
   return 0;
}

#endif

/* eof */