/* 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 */ #include "mysql_priv.h" #ifdef USE_PRAGMA_IMPLEMENTATION #pragma implementation #endif #if defined(WIN32) || defined(__WIN__) #undef SAFEMALLOC /* Problems with threads */ #endif #include "mysql.h" #include "sp_head.h" #include "sql_cursor.h" #include "sp_rcontext.h" #include "sp_pcontext.h" sp_rcontext::sp_rcontext(sp_pcontext *root_parsing_ctx, Field *return_value_fld, sp_rcontext *prev_runtime_ctx) :m_root_parsing_ctx(root_parsing_ctx), m_var_table(0), m_var_items(0), m_return_value_fld(return_value_fld), m_return_value_set(FALSE), m_hcount(0), m_hsp(0), m_ihsp(0), m_hfound(-1), m_ccount(0), m_case_expr_holders(0), m_prev_runtime_ctx(prev_runtime_ctx) { } sp_rcontext::~sp_rcontext() { if (m_var_table) free_blobs(m_var_table); } /* Initialize sp_rcontext instance. SYNOPSIS thd Thread handle RETURN FALSE on success TRUE on error */ bool sp_rcontext::init(THD *thd) { if (init_var_table(thd) || init_var_items()) return TRUE; return !(m_handler= (sp_handler_t*)thd->alloc(m_root_parsing_ctx->max_handlers() * sizeof(sp_handler_t))) || !(m_hstack= (uint*)thd->alloc(m_root_parsing_ctx->max_handlers() * sizeof(uint))) || !(m_in_handler= (uint*)thd->alloc(m_root_parsing_ctx->max_handlers() * sizeof(uint))) || !(m_cstack= (sp_cursor**)thd->alloc(m_root_parsing_ctx->max_cursors() * sizeof(sp_cursor*))) || !(m_case_expr_holders= (Item_cache**)thd->calloc(m_root_parsing_ctx->get_num_case_exprs() * sizeof (Item_cache*))); } /* Create and initialize a table to store SP-vars. SYNOPSIS thd Thread handler. RETURN FALSE on success TRUE on error */ bool sp_rcontext::init_var_table(THD *thd) { List field_def_lst; if (!m_root_parsing_ctx->total_pvars()) return FALSE; m_root_parsing_ctx->retrieve_field_definitions(&field_def_lst); DBUG_ASSERT(field_def_lst.elements == m_root_parsing_ctx->total_pvars()); if (!(m_var_table= create_virtual_tmp_table(thd, field_def_lst))) return TRUE; m_var_table->copy_blobs= TRUE; m_var_table->alias= ""; return FALSE; } /* Create and initialize an Item-adapter (Item_field) for each SP-var field. RETURN FALSE on success TRUE on error */ bool sp_rcontext::init_var_items() { uint idx; uint num_vars= m_root_parsing_ctx->total_pvars(); if (!(m_var_items= (Item**) sql_alloc(num_vars * sizeof (Item *)))) return TRUE; for (idx = 0; idx < num_vars; ++idx) { if (!(m_var_items[idx]= new Item_field(m_var_table->field[idx]))) return TRUE; } return FALSE; } bool sp_rcontext::set_return_value(THD *thd, Item *return_value_item) { DBUG_ASSERT(m_return_value_fld); m_return_value_set = TRUE; return sp_eval_expr(thd, m_return_value_fld, return_value_item); } #define IS_WARNING_CONDITION(S) ((S)[0] == '0' && (S)[1] == '1') #define IS_NOT_FOUND_CONDITION(S) ((S)[0] == '0' && (S)[1] == '2') #define IS_EXCEPTION_CONDITION(S) ((S)[0] != '0' || (S)[1] > '2') bool sp_rcontext::find_handler(uint sql_errno, MYSQL_ERROR::enum_warning_level level) { if (m_hfound >= 0) return 1; // Already got one const char *sqlstate= mysql_errno_to_sqlstate(sql_errno); int i= m_hcount, found= -1; while (i--) { sp_cond_type_t *cond= m_handler[i].cond; int j= m_ihsp; while (j--) if (m_in_handler[j] == m_handler[i].handler) break; if (j >= 0) continue; // Already executing this handler switch (cond->type) { case sp_cond_type_t::number: if (sql_errno == cond->mysqlerr) found= i; // Always the most specific break; case sp_cond_type_t::state: if (strcmp(sqlstate, cond->sqlstate) == 0 && (found < 0 || m_handler[found].cond->type > sp_cond_type_t::state)) found= i; break; case sp_cond_type_t::warning: if ((IS_WARNING_CONDITION(sqlstate) || level == MYSQL_ERROR::WARN_LEVEL_WARN) && found < 0) found= i; break; case sp_cond_type_t::notfound: if (IS_NOT_FOUND_CONDITION(sqlstate) && found < 0) found= i; break; case sp_cond_type_t::exception: if (IS_EXCEPTION_CONDITION(sqlstate) && level == MYSQL_ERROR::WARN_LEVEL_ERROR && found < 0) found= i; break; } } if (found < 0) { /* Only "exception conditions" are propagated to handlers in calling contexts. If no handler is found locally for a "completion condition" (warning or "not found") we will simply resume execution. */ if (m_prev_runtime_ctx && IS_EXCEPTION_CONDITION(sqlstate) && level == MYSQL_ERROR::WARN_LEVEL_ERROR) return m_prev_runtime_ctx->find_handler(sql_errno, level); return FALSE; } m_hfound= found; return TRUE; } void sp_rcontext::push_cursor(sp_lex_keeper *lex_keeper, sp_instr_cpush *i) { m_cstack[m_ccount++]= new sp_cursor(lex_keeper, i); } void sp_rcontext::pop_cursors(uint count) { while (count--) { delete m_cstack[--m_ccount]; } } int sp_rcontext::set_variable(THD *thd, uint var_idx, Item *value) { return set_variable(thd, m_var_table->field[var_idx], value); } int sp_rcontext::set_variable(THD *thd, Field *field, Item *value) { if (!value) { field->set_null(); return 0; } return sp_eval_expr(thd, field, value); } Item * sp_rcontext::get_item(uint var_idx) { return m_var_items[var_idx]; } Item ** sp_rcontext::get_item_addr(uint var_idx) { return m_var_items + var_idx; } /* * * sp_cursor * */ sp_cursor::sp_cursor(sp_lex_keeper *lex_keeper, sp_instr_cpush *i) :m_lex_keeper(lex_keeper), server_side_cursor(NULL), m_i(i) { /* currsor can't be stored in QC, so we should prevent opening QC for try to write results which are absent. */ lex_keeper->disable_query_cache(); } /* Open an SP cursor SYNOPSIS open() THD Thread handler RETURN 0 in case of success, -1 otherwise */ int sp_cursor::open(THD *thd) { if (server_side_cursor) { my_message(ER_SP_CURSOR_ALREADY_OPEN, ER(ER_SP_CURSOR_ALREADY_OPEN), MYF(0)); return -1; } if (mysql_open_cursor(thd, (uint) ALWAYS_MATERIALIZED_CURSOR, &result, &server_side_cursor)) return -1; return 0; } int sp_cursor::close(THD *thd) { if (! server_side_cursor) { my_message(ER_SP_CURSOR_NOT_OPEN, ER(ER_SP_CURSOR_NOT_OPEN), MYF(0)); return -1; } destroy(); return 0; } void sp_cursor::destroy() { delete server_side_cursor; server_side_cursor= 0; } int sp_cursor::fetch(THD *thd, List *vars) { if (! server_side_cursor) { my_message(ER_SP_CURSOR_NOT_OPEN, ER(ER_SP_CURSOR_NOT_OPEN), MYF(0)); return -1; } if (vars->elements != result.get_field_count()) { my_message(ER_SP_WRONG_NO_OF_FETCH_ARGS, ER(ER_SP_WRONG_NO_OF_FETCH_ARGS), MYF(0)); return -1; } result.set_spvar_list(vars); /* Attempt to fetch one row */ if (server_side_cursor->is_open()) server_side_cursor->fetch(1); /* If the cursor was pointing after the last row, the fetch will close it instead of sending any rows. */ if (! server_side_cursor->is_open()) { my_message(ER_SP_FETCH_NO_DATA, ER(ER_SP_FETCH_NO_DATA), MYF(0)); return -1; } return 0; } /* Create an instance of appropriate Item_cache class depending on the specified type in the callers arena. SYNOPSIS thd thread handler result_type type of the expression RETURN Pointer to valid object on success NULL on error NOTE We should create cache items in the callers arena, as they are used between in several instructions. */ Item_cache * sp_rcontext::create_case_expr_holder(THD *thd, Item_result result_type) { Item_cache *holder; Query_arena current_arena; thd->set_n_backup_active_arena(thd->spcont->callers_arena, ¤t_arena); holder= Item_cache::get_cache(result_type); thd->restore_active_arena(thd->spcont->callers_arena, ¤t_arena); return holder; } /* Set CASE expression to the specified value. SYNOPSIS thd thread handler case_expr_id identifier of the CASE expression case_expr_item a value of the CASE expression RETURN FALSE on success TRUE on error NOTE The idea is to reuse Item_cache for the expression of the one CASE statement. This optimization takes place when there is CASE statement inside of a loop. So, in other words, we will use the same object on each iteration instead of creating a new one for each iteration. TODO Hypothetically, a type of CASE expression can be different for each iteration. For instance, this can happen if the expression contains a session variable (something like @@VAR) and its type is changed from one iteration to another. In order to cope with this problem, we check type each time, when we use already created object. If the type does not match, we re-create Item. This also can (should?) be optimized. */ int sp_rcontext::set_case_expr(THD *thd, int case_expr_id, Item *case_expr_item) { if (!(case_expr_item= sp_prepare_func_item(thd, &case_expr_item))) return TRUE; if (!m_case_expr_holders[case_expr_id] || m_case_expr_holders[case_expr_id]->result_type() != case_expr_item->result_type()) { m_case_expr_holders[case_expr_id]= create_case_expr_holder(thd, case_expr_item->result_type()); } m_case_expr_holders[case_expr_id]->store(case_expr_item); return FALSE; } Item * sp_rcontext::get_case_expr(int case_expr_id) { return m_case_expr_holders[case_expr_id]; } Item ** sp_rcontext::get_case_expr_addr(int case_expr_id) { return (Item**) m_case_expr_holders + case_expr_id; } /*************************************************************************** Select_fetch_into_spvars ****************************************************************************/ int Select_fetch_into_spvars::prepare(List &fields, SELECT_LEX_UNIT *u) { /* Cache the number of columns in the result set in order to easily return an error if column count does not match value count. */ field_count= fields.elements; return select_result_interceptor::prepare(fields, u); } bool Select_fetch_into_spvars::send_data(List &items) { List_iterator_fast pv_iter(*spvar_list); List_iterator_fast item_iter(items); sp_pvar_t *pv; Item *item; /* Must be ensured by the caller */ DBUG_ASSERT(spvar_list->elements == items.elements); /* Assign the row fetched from a server side cursor to stored procedure variables. */ for (; pv= pv_iter++, item= item_iter++; ) { if (thd->spcont->set_variable(thd, pv->offset, item)) return TRUE; } return FALSE; }