campo-sirio/include/odbcrset.cpp

#include <odbcrset.h>
#include <utility.h>

///////////////////////////////////////////////////////////
// TODBC_connections
///////////////////////////////////////////////////////////

class TODBC_connections
{
  TString _dsn, _usr;
  XVT_ODBC _odbc;

protected:
  void close();

public:
  XVT_ODBC get(const char* dsn, const char* usr, const char* pwd, const char* dir);
  TODBC_connections();
  ~TODBC_connections();
};

TODBC_connections _connections;

void TODBC_connections::close()
{
  if (_odbc != NULL)
  {
    xvt_odbc_free_connection(_odbc);
    _odbc = NULL;
  }
}

XVT_ODBC TODBC_connections::get(const char* dsn, const char* usr, const char* pwd, const char* dir)
{
  if (_odbc == NULL || _dsn != dsn || _usr != usr)
  {
    close();
    if (dsn && *dsn)
      _odbc = xvt_odbc_get_connection(_dsn = dsn, _usr = usr, pwd, dir);
  }
  return _odbc;
}

TODBC_connections::TODBC_connections() : _odbc(NULL)
{}

TODBC_connections::~TODBC_connections()
{
  close();
}

///////////////////////////////////////////////////////////
// TODBC_recordset
///////////////////////////////////////////////////////////

XVT_ODBC TODBC_recordset::connection() const
{
  return _connections.get(_dsn, _usr, _pwd, _dir);
}

bool TODBC_recordset::connect(const char* dsn, const char* usr, const char* pwd, const char* dir)
{
  _dsn = dsn; _usr = usr; _pwd = pwd; _dir = dir;
  return connection() != NULL;
}

const TString& TODBC_recordset::query_text() const
{
  return _sql;
}

void TODBC_recordset::reset()
{
  _first_row = 0;
  _items = 0;
  _current_row = -1;
  _pagesize = 512;
  _page.destroy();
  _column.destroy();
  _columns_loaded = false;
}

int TODBC_recordset::on_get_columns(int argc, char** values, char** columns)
{
  static unsigned long _counter = 0;

  if (_column.empty())
  {
    _counter = 0;
    for (int i = 0; i < argc; i++)
    {
      const char* fldtype = NULL;
      TRecordset_column_info* info = new TRecordset_column_info;
      info->_width = 1;
      info->_type = _alfafld;

      if (columns != NULL)
      {
        info->_name = columns[i];
        fldtype = columns[argc+i];
      }
      else
        info->_name.format("FIELD%d", i+1);
      
      if (fldtype != NULL)
      {
        if (xvt_str_compare_ignoring_case(fldtype, "DATE") == 0)
        {
          info->_type = _datefld; 
          info->_width = 10;
        } else
        if (xvt_str_compare_ignoring_case(fldtype, "NUMERIC") == 0)
        {
          info->_type = _realfld;
        } else
        if (xvt_str_compare_ignoring_case(fldtype, "BLOB") == 0)
        {
          info->_type = _memofld;
          info->_width = 50;
        }
      }
      _column.add(info);
    }
  }

  const bool processed = _counter++ < 128;
  if (processed)
  {
    for (int i = 0; i < argc; i++) if (values[i] && *values[i])
    {
      TRecordset_column_info& info = (TRecordset_column_info&)_column[i];
      if (info._type == _alfafld || info._type == _realfld)
      {
        const int len = strlen(values[i]);
        if (len > info._width)
          info._width = len;
      }
    }
  }

  return processed ? 0 : -1;  
}

static int query_get_columns(void* jolly, int argc, char** values, char** columns)
{
  TODBC_recordset* q = (TODBC_recordset*)jolly;
  return q->on_get_columns(argc, values, columns);
}

void TODBC_recordset::requery()
{
  _items = 0;
  _current_row = -1;
  _page.destroy();
}

int TODBC_recordset::on_get_items(int argc, char** values, char** columns)
{
  if (!_columns_loaded)
    on_get_rows(argc, values, columns);
  return 0;
}
static int query_get_items(void* jolly, int argc, char** values, char** columns)
{
  TODBC_recordset* q = (TODBC_recordset*)jolly;
  return q->on_get_items(argc, values, columns);
}

TRecnotype TODBC_recordset::items() const
{
  if (_items == 0)
  {
    TString sql; parsed_text(sql);
    TPerformance_profiler prof("ODBC count");

    TRecnotype& i = (TRecnotype&)_items;
    if (!_columns_loaded)
    {
      TODBC_recordset* myself = (TODBC_recordset*)this;
      myself->_page.destroy();
      myself->_cursor_pos = 0;
      i = xvt_odbc_execute(connection(), sql, query_get_items, (void*)this);
      myself->_columns_loaded = true;
    }
    else
      i = xvt_odbc_execute(connection(), sql, NULL, NULL);
  }
  return _items;
}

unsigned int TODBC_recordset::columns() const
{
  if (!_columns_loaded && _column.items() == 0)
  {
    TODBC_recordset* myself = (TODBC_recordset*)this;
    TString sql; parsed_text(sql);
    TPerformance_profiler prof("ODBC info");
    myself->_cursor_pos = 0;
    xvt_odbc_execute(connection(), sql, query_get_columns, (void*)this);
    myself->_columns_loaded = true;
  }
  return _column.items();
}
 
const TRecordset_column_info& TODBC_recordset::column_info(unsigned int c) const
{
  if (c >= columns())  // Generare column infos if needed
    c = 0;
  return (const TRecordset_column_info&)_column[c];
}

// Funzione chiamata per riempire la pagina corrente delle righe della query
int TODBC_recordset::on_get_rows(int argc, char** values, char** columns)
{
  if (!_columns_loaded)
    on_get_columns(argc, values, columns);

  if (_page.items() >= _pagesize)
    return -1;

  if (_cursor_pos++ < _first_row)
    return 0; // Ignora le righe prima del LIMIT
  
  TArray* a = new TArray;
  for (int c = 0; c < argc; c++)
  {
    TVariant* var = new TVariant;
    switch (column_info(c)._type)
    {
    case _alfafld: 
      var->set(values[c]);
      break;
    case _memofld: 
      if (values[c])
      {
        TFixed_string memo(values[c]);
        memo.replace(char(0xB6), '\n');
        var->set(memo); 
      }
      break;
    case _datefld: 
      var->set(TDate(values[c])); 
      break;
    default: 
      var->set(real(values[c]));
      break;
    }      
    a->add(var, c);
  }
  _page.add(a);
  return 0;
}

static int query_get_rows(void* jolly, int argc, char** values, char** columns)
{
  TODBC_recordset* rs = (TODBC_recordset*)jolly;
  return rs->on_get_rows(argc, values, columns);
}

bool TODBC_recordset::move_to(TRecnotype n)
{
  const TRecnotype tot = items();
  _current_row = n;
  if (n < 0 || n >= tot)
  {
    _page.destroy(); // Forza rilettura la prossima volta
    _first_row = 0;
    return false;
  }

  if (n < _first_row || n >= _first_row+_page.items())
  {
    TString sql; parsed_text(sql);
    if (tot > _pagesize && sql.find("LIMIT ") < 0)
    {
      const int semicolon = sql.rfind(';');
      if (semicolon >= 0)
        sql.cut(semicolon);
      sql.trim();
      _page.destroy();
      if (n >= _pagesize)
        _first_row = n-32; // Prendo qualche riga dalla pagina precedente, per velocizzare il pagina su
      else
        _first_row = n;
    }
    TPerformance_profiler prof("ODBC query");
    _cursor_pos = 0;
    xvt_odbc_execute(connection(), sql, query_get_rows, this);
    if (!_columns_loaded)
      _columns_loaded = true;  // Brutto posto ma necessario
  }

  return true;
}

long TODBC_recordset::exec(const char* sql)
{
  TPerformance_profiler prof("ODBC command");
	set(sql); 
	TString cmd; parsed_text(cmd);
  return xvt_odbc_execute(connection(), cmd, NULL, NULL);
}

TRecnotype TODBC_recordset::current_row() const
{
  return _current_row;
}

const TArray* TODBC_recordset::row(TRecnotype n)
{
  const TArray* a = NULL;
  if (move_to(n))
    a = (const TArray*)_page.objptr(n-_first_row);
  return a;
}

const TVariant& TODBC_recordset::get(unsigned int c) const
{
  const TArray* a = (const TArray*)_page.objptr(_current_row-_first_row);
  if (a != NULL)
  {
    const TVariant* s = (const TVariant*)a->objptr(c);
    if (s != NULL)
      return *s;
  }
  return NULL_VARIANT;
}

const TVariant& TODBC_recordset::get(const char* name) const
{
  return TRecordset::get(name);
}

void TODBC_recordset::set(const char* sql) 
{ 
  reset(); 
  _sql = sql;
  if (_sql.starts_with("ODBC", true))
  {
    _sql.ltrim(4); _sql.trim();
    if (_sql[0] == '(')
    {
      const int par = _sql.find(')');
      if (par > 0)
      {
        TToken_string conn(_sql.sub(1, par), ',');
        _sql.ltrim(par+1); _sql.trim();
 
        TString dsn = conn.get(); dsn.strip("\"");
        TString usr = conn.get(); usr.strip("\"");
        TString pwd = conn.get(); pwd.strip("\"");
        TString dir = conn.get(); dir.strip("\"");
        if (!connect(dsn, usr, pwd, dir))
          error_box("Couldn't connect to %s", (const char*)dsn);
      }
    }
  }
  if (_sql.find("SELECT") >= 0 || _sql.find("select") >= 0)
    find_and_reset_vars();
}

TODBC_recordset::TODBC_recordset(const char* sql)
{
  set(sql);
}

TODBC_recordset::~TODBC_recordset()
{ }

///////////////////////////////////////////////////////////
// Creazione "intelligente" del recordset appropriato in base alla query
///////////////////////////////////////////////////////////

TRecordset* create_recordset(const TString& sql)
{
  TRecordset* rex = NULL;
  if (sql.full())
  {
    if (sql.starts_with("US", true))
      rex = new TISAM_recordset(sql);
    else
    {
      if (sql.starts_with("ODBC", true))
        rex = new TODBC_recordset(sql);
      else
        rex = new TSQL_recordset(sql);
    }
  }
  return rex;
}