sp_head.cc

/* Copyright (C) 2002 MySQL AB

   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.

   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 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

#ifdef __GNUC__
#pragma implementation
#endif

#include "mysql_priv.h"
#include "sp_head.h"
#include "sp.h"
#include "sp_pcontext.h"
#include "sp_rcontext.h"

Item_result
sp_map_result_type(enum enum_field_types type)
{
  switch (type)
  {
  case MYSQL_TYPE_TINY:
  case MYSQL_TYPE_SHORT:
  case MYSQL_TYPE_LONG:
  case MYSQL_TYPE_LONGLONG:
  case MYSQL_TYPE_INT24:
    return INT_RESULT;
  case MYSQL_TYPE_DECIMAL:
  case MYSQL_TYPE_FLOAT:
  case MYSQL_TYPE_DOUBLE:
    return REAL_RESULT;
  default:
    return STRING_RESULT;
  }
}

/* Evaluate a (presumed) func item. Always returns an item, the parameter
** if nothing else.
*/
static Item *
eval_func_item(THD *thd, Item *it, enum enum_field_types type)
{
  DBUG_ENTER("eval_func_item");
  it= it->this_item();
  DBUG_PRINT("info", ("type: %d", type));

  if (it->fix_fields(thd, 0, &it))
  {
    DBUG_PRINT("info", ("fix_fields() failed"));
    DBUG_RETURN(it);		// Shouldn't happen?
  }

  /* QQ How do we do this? Is there some better way? */
  if (type == MYSQL_TYPE_NULL)
    it= new Item_null();
  else
  {
    switch (sp_map_result_type(type)) {
    case INT_RESULT:
      DBUG_PRINT("info", ("INT_RESULT: %d", it->val_int()));
      it= new Item_int(it->val_int());
      break;
    case REAL_RESULT:
      DBUG_PRINT("info", ("REAL_RESULT: %g", it->val()));
      it= new Item_real(it->val());
      break;
    default:
      {
	char buffer[MAX_FIELD_WIDTH];
	String tmp(buffer, sizeof(buffer), it->charset());
	String *s= it->val_str(&tmp);

	DBUG_PRINT("info",("default result: %*s",s->length(),s->c_ptr_quick()));
	it= new Item_string(thd->strmake(s->c_ptr_quick(), s->length()),
			    s->length(), it->charset());
	break;
      }
    }
  }

  DBUG_RETURN(it);
}

void *
sp_head::operator new(size_t size)
{
  DBUG_ENTER("sp_head::operator new");
  MEM_ROOT own_root;
  sp_head *sp;

  bzero((char *)&own_root, sizeof(own_root));
  init_alloc_root(&own_root, MEM_ROOT_BLOCK_SIZE, MEM_ROOT_PREALLOC);
  sp= (sp_head *)alloc_root(&own_root, size);
  sp->m_mem_root= own_root;
  
  DBUG_RETURN(sp);
}

void 
sp_head::operator delete(void *ptr, size_t size)
{
  DBUG_ENTER("sp_head::operator delete");
  MEM_ROOT own_root;
  sp_head *sp= (sp_head *)ptr;

  memcpy(&own_root, (const void *)&sp->m_mem_root, sizeof(MEM_ROOT));
  free_root(&own_root, MYF(0));

  DBUG_VOID_RETURN;
}

sp_head::sp_head()
  : Sql_alloc(), m_simple_case(FALSE), m_multi_query(FALSE), m_free_list(NULL)
{
  DBUG_ENTER("sp_head::sp_head");

  m_backpatch.empty();
  m_lex.empty();
  DBUG_VOID_RETURN;
}

void
sp_head::init(LEX_STRING *name, LEX *lex, LEX_STRING *comment, char suid)
{
  DBUG_ENTER("sp_head::init");
  const char *dstr = (const char*)lex->buf;

  DBUG_PRINT("info", ("name: %*s", name->length, name->str));
  m_name.length= name->length;
  m_name.str= lex->thd->strmake(name->str, name->length);
  m_defstr.length= lex->end_of_query - lex->buf;
  m_defstr.str= lex->thd->strmake(dstr, m_defstr.length);

  m_comment.length= 0;
  m_comment.str= 0;
  if (comment)
  {
    m_comment.length= comment->length;
    m_comment.str= comment->str;
  }

  m_suid= suid;
  lex->spcont= m_pcont= new sp_pcontext();
  my_init_dynamic_array(&m_instr, sizeof(sp_instr *), 16, 8);
  DBUG_VOID_RETURN;
}

int
sp_head::create(THD *thd)
{
  DBUG_ENTER("sp_head::create");
  int ret;

  DBUG_PRINT("info", ("type: %d name: %s def: %s",
		      m_type, m_name.str, m_defstr.str));
  if (m_type == TYPE_ENUM_FUNCTION)
    ret= sp_create_function(thd,
			    m_name.str, m_name.length,
			    m_defstr.str, m_defstr.length,
			    m_comment.str, m_comment.length,
			    m_suid);
  else
    ret= sp_create_procedure(thd,
			     m_name.str, m_name.length,
			     m_defstr.str, m_defstr.length,
			     m_comment.str, m_comment.length,
			     m_suid);

  DBUG_RETURN(ret);
}

sp_head::~sp_head()
{
  destroy();
  if (m_thd)
    restore_thd_mem_root(m_thd);
}

void
sp_head::destroy()
{
  DBUG_ENTER("sp_head::destroy");
  DBUG_PRINT("info", ("name: %s", m_name.str));
  sp_instr *i;
  LEX *lex;

  for (uint ip = 0 ; (i = get_instr(ip)) ; ip++)
    delete i;
  delete_dynamic(&m_instr);
  m_pcont->destroy();
  free_items(m_free_list);
  while ((lex= (LEX *)m_lex.pop()))
  {
    if (lex != &m_thd->main_lex) // We got interrupted and have lex'es left
      delete lex;
  }
  DBUG_VOID_RETURN;
}

int
sp_head::execute(THD *thd)
{
  DBUG_ENTER("sp_head::execute");
  char olddbname[128];
  char *olddbptr= thd->db;
  int ret= 0;
  uint ip= 0;

  if (olddbptr)
  {
    uint i= 0;
    char *p= olddbptr;

    /* Fast inline strncpy without padding... */
    while (*p && i < sizeof(olddbname))
      olddbname[i++]= *p++;
    if (i == sizeof(olddbname))
      i-= 1;			// QQ Error or warning for truncate?
    olddbname[i]= '\0';
  }

  do
  {
    sp_instr *i;

    i = get_instr(ip);	// Returns NULL when we're done.
    if (i == NULL)
      break;
    DBUG_PRINT("execute", ("Instruction %u", ip));
    ret= i->execute(thd, &ip);
  } while (ret == 0 && !thd->killed);

  DBUG_PRINT("info", ("ret=%d killed=%d", ret, thd->killed));
  if (thd->killed)
    ret= -1;
  /* If the DB has changed, the pointer has changed too, but the
     original thd->db will then have been freed */
  if (olddbptr && olddbptr != thd->db)
  {
    /* QQ Maybe we should issue some special error message or warning here,
       if this fails?? */
    if (! thd->killed)
      ret= mysql_change_db(thd, olddbname);
  }
  DBUG_RETURN(ret);
}


int
sp_head::execute_function(THD *thd, Item **argp, uint argcount, Item **resp)
{
  DBUG_ENTER("sp_head::execute_function");
  DBUG_PRINT("info", ("function %s", m_name.str));
  uint csize = m_pcont->max_framesize();
  uint params = m_pcont->params();
  sp_rcontext *octx = thd->spcont;
  sp_rcontext *nctx = NULL;
  uint i;
  int ret;

  if (argcount != params)
  {
    // Need to use my_printf_error here, or it will not terminate the
    // invoking query properly.
    my_printf_error(ER_SP_WRONG_NO_OF_ARGS, ER(ER_SP_WRONG_NO_OF_ARGS), MYF(0),
		    "FUNCTION", m_name.str, params, argcount);
    DBUG_RETURN(-1);
  }

  // QQ Should have some error checking here? (types, etc...)
  nctx= new sp_rcontext(csize);
  for (i= 0 ; i < params && i < argcount ; i++)
  {
    sp_pvar_t *pvar = m_pcont->find_pvar(i);

    nctx->push_item(eval_func_item(thd, *argp++, pvar->type));
  }
  // Close tables opened for subselect in argument list
  close_thread_tables(thd);

  // The rest of the frame are local variables which are all IN.
  // QQ See comment in execute_procedure below.
  for (; i < csize ; i++)
    nctx->push_item(NULL);
  thd->spcont= nctx;

  ret= execute(thd);
  if (ret == 0)
    *resp= nctx->get_result();

  thd->spcont= octx;
  DBUG_RETURN(ret);
}

int
sp_head::execute_procedure(THD *thd, List<Item> *args)
{
  DBUG_ENTER("sp_head::execute_procedure");
  DBUG_PRINT("info", ("procedure %s", m_name.str));
  int ret;
  sp_instr *p;
  uint csize = m_pcont->max_framesize();
  uint params = m_pcont->params();
  sp_rcontext *octx = thd->spcont;
  sp_rcontext *nctx = NULL;
  my_bool tmp_octx = FALSE;	// True if we have allocated a temporary octx

  if (args->elements != params)
  {
    net_printf(thd, ER_SP_WRONG_NO_OF_ARGS, "PROCEDURE", m_name.str,
	       params, args->elements);
    DBUG_RETURN(-1);
  }

  if (csize > 0)
  {
    uint i;
    List_iterator_fast<Item> li(*args);
    Item *it;

    nctx = new sp_rcontext(csize);
    if (! octx)
    {				// Create a temporary old context
      octx = new sp_rcontext(csize);
      tmp_octx = TRUE;
    }
    // QQ: Should do type checking?
    for (i = 0 ; (it= li++) && i < params ; i++)
    {
      sp_pvar_t *pvar = m_pcont->find_pvar(i);

      if (! pvar)
	nctx->set_oindex(i, -1); // Shouldn't happen
      else
      {
	if (pvar->mode == sp_param_out)
	  nctx->push_item(NULL); // OUT
	else
	  nctx->push_item(eval_func_item(thd, it, pvar->type)); // IN or INOUT
	// Note: If it's OUT or INOUT, it must be a variable.
	// QQ: Need to handle "global" user/host variables too!!!
	if (pvar->mode == sp_param_in)
	  nctx->set_oindex(i, -1); // IN
	else			// OUT or INOUT
	  nctx->set_oindex(i, static_cast<Item_splocal *>(it)->get_offset());
      }
    }
    // Close tables opened for subselect in argument list
    close_thread_tables(thd);

    // The rest of the frame are local variables which are all IN.
    // QQ We haven't found any hint of what the value is when unassigned,
    //    so we set it to NULL for now. It's an error to refer to an
    //    unassigned variable anyway (which should be detected by the parser).
    for (; i < csize ; i++)
      nctx->push_item(NULL);
    thd->spcont= nctx;
  }

  ret= execute(thd);

  // Don't copy back OUT values if we got an error
  if (ret == 0 && csize > 0)
  {
    List_iterator_fast<Item> li(*args);
    Item *it;

    // Copy back all OUT or INOUT values to the previous frame, or
    // set global user variables
    for (uint i = 0 ; (it= li++) && i < params ; i++)
    {
      int oi = nctx->get_oindex(i);

      if (oi >= 0)
      {
	if (! tmp_octx)
	  octx->set_item(nctx->get_oindex(i), nctx->get_item(i));
	else
	{			// A global user variable
#if NOT_USED_NOW
	  // QQ This works if the parameter really is a user variable, but
	  // for the moment we can't assure that, so it will crash if it's
	  // something else. So for now, we just do nothing, to avoid a crash.
	  // Note: This also assumes we have a get_name() method in
	  //       the Item_func_get_user_var class.
	  Item *item= nctx->get_item(i);
	  Item_func_set_user_var *suv;
	  Item_func_get_user_var *guv= static_cast<Item_func_get_user_var*>(it);

	  suv= new Item_func_set_user_var(guv->get_name(), item);
	  suv->fix_fields(thd, NULL, &item);
	  suv->fix_length_and_dec();
	  suv->update();
#endif
	}
      }
    }

    if (tmp_octx)
      thd->spcont= NULL;
    else
      thd->spcont= octx;
  }

  DBUG_RETURN(ret);
}


// Reset lex during parsing, before we parse a sub statement.
void
sp_head::reset_lex(THD *thd)
{
  DBUG_ENTER("sp_head::reset_lex");
  LEX *sublex;
  LEX *oldlex= thd->lex;

  (void)m_lex.push_front(oldlex);
  thd->lex= sublex= new st_lex;
  sublex->yylineno= oldlex->yylineno;
  /* Reset most stuff. The length arguments doesn't matter here. */
  lex_start(thd, oldlex->buf, oldlex->end_of_query - oldlex->ptr);
  /* We must reset ptr and end_of_query again */
  sublex->ptr= oldlex->ptr;
  sublex->end_of_query= oldlex->end_of_query;
  sublex->tok_start= oldlex->tok_start;
  /* And keep the SP stuff too */
  sublex->sphead= oldlex->sphead;
  sublex->spcont= oldlex->spcont;
  mysql_init_query(thd, true);	// Only init lex
  sublex->sp_lex_in_use= FALSE;
  DBUG_VOID_RETURN;
}

// Restore lex during parsing, after we have parsed a sub statement.
void
sp_head::restore_lex(THD *thd)
{
  DBUG_ENTER("sp_head::restore_lex");
  LEX *sublex= thd->lex;
  LEX *oldlex= (LEX *)m_lex.pop();

  if (! oldlex)
    return;			// Nothing to restore

  // Update some state in the old one first
  oldlex->ptr= sublex->ptr;
  oldlex->next_state= sublex->next_state;

  // Collect some data from the sub statement lex.
  sp_merge_funs(oldlex, sublex);
#ifdef NOT_USED_NOW
  // QQ We're not using this at the moment.
  if (sublex.sql_command == SQLCOM_CALL)
  {
    // It would be slightly faster to keep the list sorted, but we need
    // an "insert before" method to do that.
    char *proc= sublex.udf.name.str;

    List_iterator_fast<char *> li(m_calls);
    char **it;

    while ((it= li++))
      if (my_strcasecmp(system_charset_info, proc, *it) == 0)
	break;
    if (! it)
      m_calls.push_back(&proc);

  }
  // Merge used tables
  // QQ ...or just open tables in thd->open_tables?
  //    This is not entirerly clear at the moment, but for now, we collect
  //    tables here.
  for (SELECT_LEX *sl= sublex.all_selects_list ;
       sl ;
       sl= sl->next_select())
  {
    for (TABLE_LIST *tables= sl->get_table_list() ;
	 tables ;
	 tables= tables->next)
    {
      List_iterator_fast<char *> li(m_tables);
      char **tb;

      while ((tb= li++))
	if (my_strcasecmp(system_charset_info, tables->real_name, *tb) == 0)
	  break;
      if (! tb)
	m_tables.push_back(&tables->real_name);
    }
  }
#endif
  if (! sublex->sp_lex_in_use)
    delete sublex;
  thd->lex= oldlex;
  DBUG_VOID_RETURN;
}

void
sp_head::push_backpatch(sp_instr *i, sp_label_t *lab)
{
  bp_t *bp= (bp_t *)sql_alloc(sizeof(bp_t));

  if (bp)
  {
    bp->lab= lab;
    bp->instr= i;
    (void)m_backpatch.push_front(bp);
  }
}

void
sp_head::backpatch(sp_label_t *lab)
{
  bp_t *bp;
  uint dest= instructions();
  List_iterator_fast<bp_t> li(m_backpatch);

  while ((bp= li++))
    if (bp->lab == lab)
    {
      sp_instr_jump *i= static_cast<sp_instr_jump *>(bp->instr);

      i->set_destination(dest);
    }
}


// ------------------------------------------------------------------

//
// sp_instr_stmt
//
sp_instr_stmt::~sp_instr_stmt()
{
  if (m_lex)
    delete m_lex;
}

int
sp_instr_stmt::execute(THD *thd, uint *nextp)
{
  DBUG_ENTER("sp_instr_stmt::execute");
  DBUG_PRINT("info", ("command: %d", m_lex->sql_command));
  LEX *olex;			// The other lex
  int res;

  olex= thd->lex;		// Save the other lex
  thd->lex= m_lex;		// Use my own lex
  thd->lex->thd = thd;		// QQ Not reentrant!
  thd->lex->unit.thd= thd;	// QQ Not reentrant

  res= mysql_execute_command(thd);
  if (thd->lock || thd->open_tables || thd->derived_tables)
  {
    thd->proc_info="closing tables";
    close_thread_tables(thd);			/* Free tables */
  }

  thd->lex= olex;		// Restore the other lex

  *nextp = m_ip+1;
  DBUG_RETURN(res);
}

//
// sp_instr_set
//
int
sp_instr_set::execute(THD *thd, uint *nextp)
{
  DBUG_ENTER("sp_instr_set::execute");
  DBUG_PRINT("info", ("offset: %u", m_offset));
  thd->spcont->set_item(m_offset, eval_func_item(thd, m_value, m_type));
  *nextp = m_ip+1;
  DBUG_RETURN(0);
}

//
// sp_instr_jump
//
int
sp_instr_jump::execute(THD *thd, uint *nextp)
{
  DBUG_ENTER("sp_instr_jump::execute");
  DBUG_PRINT("info", ("destination: %u", m_dest));

  *nextp= m_dest;
  DBUG_RETURN(0);
}

//
// sp_instr_jump_if
//
int
sp_instr_jump_if::execute(THD *thd, uint *nextp)
{
  DBUG_ENTER("sp_instr_jump_if::execute");
  DBUG_PRINT("info", ("destination: %u", m_dest));
  Item *it= eval_func_item(thd, m_expr, MYSQL_TYPE_TINY);

  if (it->val_int())
    *nextp = m_dest;
  else
    *nextp = m_ip+1;
  DBUG_RETURN(0);
}

//
// sp_instr_jump_if_not
//
int
sp_instr_jump_if_not::execute(THD *thd, uint *nextp)
{
  DBUG_ENTER("sp_instr_jump_if_not::execute");
  DBUG_PRINT("info", ("destination: %u", m_dest));
  Item *it= eval_func_item(thd, m_expr, MYSQL_TYPE_TINY);

  if (! it->val_int())
    *nextp = m_dest;
  else
    *nextp = m_ip+1;
  DBUG_RETURN(0);
}

//
// sp_instr_return
//
int
sp_instr_return::execute(THD *thd, uint *nextp)
{
  DBUG_ENTER("sp_instr_return::execute");
  thd->spcont->set_result(eval_func_item(thd, m_value, m_type));
  *nextp= UINT_MAX;
  DBUG_RETURN(0);
}