/* KInterbasDB Python Package - Implementation of "Exception-Raising" Functions
**
** Version 3.1
**
** The following contributors hold Copyright (C) over their respective
** portions of code (see license.txt for details):
**
** [Original Author (maintained through version 2.0-0.3.1):]
**   1998-2001 [alex]  Alexander Kuznetsov   <alexan@users.sourceforge.net>
** [Maintainers (after version 2.0-0.3.1):]
**   2001-2002 [maz]   Marek Isalski         <kinterbasdb@maz.nu>
**   2002-2004 [dsr]   David Rushby          <woodsplitter@rocketmail.com>
** [Contributors:]
**   2001      [eac]   Evgeny A. Cherkashin  <eugeneai@icc.ru>
**   2001-2002 [janez] Janez Jere            <janez.jere@void.si>
*/

/******************** EXCEPTION FUNCTIONS:BEGIN ********************/

#if (defined(FIREBIRD_2_0_OR_LATER) && !defined(COMPILER_IS_MINGW_WIN32))
  #define USE_MODERN_INTERP_FUNC
#endif


void raise_sql_exception(
    PyObject *excType, const char *preamble, ISC_STATUS *status_vector
  )
{
  /* Given the type of exception to raise ($excType), an introductory message
  ** ($preamble), and the status vector into which a Firebird API function has
  ** stored numeric error codes ($status_vector),
  ** set a Python exception bearing the following payload:
  ** (numeric database API error code, error message) */

  char buf[MAX_ISC_ERROR_MESSAGE_BUFFER_SIZE];
    /* DSR:  Buffer overflow potential here is low, since only values supplied
    ** by the database library's interpret function are placed in the
    ** fixed-size buffer, and presumably it checks the size of the input buffer
    ** (a parameter for this purpose was added in FB 2.0).
    **
    ** The only exception is the strcat that adds a period and a space, which
    ** is compensated for by the code.
    **
    ** The variable-length parameter $preamble is handled dynamically (with
    ** PyString_FromString), so it poses no risk. */
  ISC_LONG db_error_code;

  #ifdef USE_MODERN_INTERP_FUNC
    const
  #endif
  ISC_STATUS *ptr_status_vector =
      #ifdef USE_MODERN_INTERP_FUNC
        (const ISC_STATUS *)
      #endif
      status_vector
    ;

  PyObject *message = NULL;
  PyObject *next_message_segment = NULL;

  /* Not strictly necessary, but this code is far from performance-critical: */
  memset(buf, '\0', MAX_ISC_ERROR_MESSAGE_BUFFER_SIZE);

  message = PyString_FromString( (preamble != NULL ? preamble : "") );
  if (message == NULL) {
    goto LOW_MEMORY;
  }

 ENTER_DB_WITHOUT_LEAVING_PYTHON
  db_error_code = isc_sqlcode(status_vector);

#ifdef USE_MODERN_INTERP_FUNC
  while (fb_interpret(buf, MAX_ISC_ERROR_MESSAGE_BUFFER_SIZE - 3, &ptr_status_vector)) {
#else
  while (isc_interprete(buf, &ptr_status_vector)) {
#endif
    /* This strcat compensated for by '- 3' passed to fb_interpret: */
    strcat(buf, ". ");

    next_message_segment = PyString_FromString(buf);
    if (next_message_segment == NULL) {
      LEAVE_DB_WITHOUT_ENTERING_PYTHON
      goto LOW_MEMORY;
    }

    PyString_ConcatAndDel(&message, next_message_segment);
    /* PyString_ConcatAndDel has already DECREFed next_message_segment. */
    next_message_segment = NULL;
    if (message == NULL) {
      LEAVE_DB_WITHOUT_ENTERING_PYTHON
      goto LOW_MEMORY;
    }
  }
 LEAVE_DB_WITHOUT_ENTERING_PYTHON

  { /* Raise an exception whose payload consists of a tuple of the form
    ** (error_code, error_message): */
    PyObject *exceptionTuple = Py_BuildValue("(iO)", (long) db_error_code, message);
    if (exceptionTuple == NULL) {
      goto LOW_MEMORY;
    }
    PyErr_SetObject(excType, exceptionTuple);
    Py_DECREF(exceptionTuple);
  }

  /* Release the last Python string object stored in $message by
  ** PyString_ConcatAndDel: */
  Py_DECREF(message);

  return;

LOW_MEMORY:
  PyErr_NoMemory();
  Py_XDECREF(message);
} /* raise_sql_exception */


static void raise_exception_with_numeric_error_code(
    PyObject *excType, int error_code, const char *description
  )
{
  /* raise_exception_with_numeric_error_code allows the database API error code
  ** to be set directly, rather than having it extracted from a status vector.
  ** Thus, raise_exception_with_numeric_error_code might be said to "fall
  ** midway between raise_sql_exception and raise_exception". */
  PyObject *exceptionTuple = Py_BuildValue("(is)", error_code, description);
  if (exceptionTuple == NULL) {
    PyErr_NoMemory();
    return;
  }
  PyErr_SetObject(excType,  exceptionTuple);
  Py_DECREF(exceptionTuple);
} /* raise_exception_with_numeric_error_code */


void raise_exception(PyObject *excType, const char *description) {
  raise_exception_with_numeric_error_code(excType, 0, description);
} /* raise_exception */

/******************** EXCEPTION FUNCTIONS:END ********************/