/* 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; version 2 of the License. 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_handler_index() * sizeof(sp_handler_t))) || !(m_hstack= (uint*)thd->alloc(m_root_parsing_ctx->max_handler_index() * sizeof(uint))) || !(m_in_handler= (uint*)thd->alloc(m_root_parsing_ctx->max_handler_index() * sizeof(uint))) || !(m_cstack= (sp_cursor**)thd->alloc(m_root_parsing_ctx->max_cursor_index() * 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->max_var_index()) return FALSE; m_root_parsing_ctx->retrieve_field_definitions(&field_def_lst); DBUG_ASSERT(field_def_lst.elements == m_root_parsing_ctx->max_var_index()); 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->max_var_index(); 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') /* Find a handler for the given errno. This is called from all error message functions (e.g. push_warning, net_send_error, et al) when a sp_rcontext is in effect. If a handler is found, no error is sent, and the the SP execution loop will instead invoke the found handler. This might be called several times before we get back to the execution loop, so m_hfound can be >= 0 if a handler has already been found. (In which case we don't search again - the first found handler will be used.) Handlers are pushed on the stack m_handler, with the latest/innermost one on the top; we then search for matching handlers from the top and down. We search through all the handlers, looking for the most specific one (sql_errno more specific than sqlstate more specific than the rest). Note that mysql error code handlers is a MySQL extension, not part of the standard. SYNOPSIS sql_errno The error code level Warning level RETURN 1 if a handler was found, m_hfound is set to its index (>= 0) 0 if not found, m_hfound is -1 */ 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; /* Search handlers from the latest (innermost) to the oldest (outermost) */ while (i--) { sp_cond_type_t *cond= m_handler[i].cond; int j= m_ihsp; /* Check active handlers, to avoid invoking one recursively */ 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 < 0 || m_handler[found].cond->type > sp_cond_type_t::number)) 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; } /* Handle the error for a given errno. The severity of the error is adjusted depending of the current sql_mode. If an handler is present for the error (see find_handler()), this function will return true. If a handler is found and if the severity of the error indicate that the current instruction executed should abort, the flag thd->net.report_error is also set. This will cause the execution of the current instruction in a sp_instr* to fail, and give control to the handler code itself in the sp_head::execute() loop. SYNOPSIS sql_errno The error code level Warning level thd The current thread - thd->net.report_error is an optional output. RETURN TRUE if a handler was found. FALSE if no handler was found. */ bool sp_rcontext::handle_error(uint sql_errno, MYSQL_ERROR::enum_warning_level level, THD *thd) { bool handled= FALSE; MYSQL_ERROR::enum_warning_level elevated_level= level; /* Depending on the sql_mode of execution, warnings may be considered errors */ if ((level == MYSQL_ERROR::WARN_LEVEL_WARN) && thd->really_abort_on_warning()) { elevated_level= MYSQL_ERROR::WARN_LEVEL_ERROR; } if (find_handler(sql_errno, elevated_level)) { if (elevated_level == MYSQL_ERROR::WARN_LEVEL_ERROR) { /* Forces to abort the current instruction execution. NOTE: This code is altering the original meaning of the net.report_error flag (send an error to the client). In the context of stored procedures with error handlers, the flag is reused to cause error propagation, until the error handler is reached. No messages will be sent to the client in that context. */ thd->net.report_error= 1; } handled= TRUE; } return handled; } 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_ptr) { Item *case_expr_item= sp_prepare_func_item(thd, case_expr_item_ptr); if (!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 spvar_iter(*spvar_list); List_iterator_fast item_iter(items); sp_variable_t *spvar; 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 (; spvar= spvar_iter++, item= item_iter++; ) { if (thd->spcont->set_variable(thd, spvar->offset, &item)) return TRUE; } return FALSE; }