polardbxengine/storage/innobase/eval/eval0proc.cc

261 lines
6.6 KiB
C++

/*****************************************************************************
Copyright (c) 1998, 2018, Oracle and/or its affiliates. All Rights Reserved.
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License, version 2.0, as published by the
Free Software Foundation.
This program is also distributed with certain software (including but not
limited to OpenSSL) that is licensed under separate terms, as designated in a
particular file or component or in included license documentation. The authors
of MySQL hereby grant you an additional permission to link the program and
your derivative works with the separately licensed software that they have
included with MySQL.
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, version 2.0,
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.,
51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*****************************************************************************/
/** @file eval/eval0proc.cc
Executes SQL stored procedures and their control structures
Created 1/20/1998 Heikki Tuuri
*******************************************************/
#include "eval0proc.h"
#include <stddef.h>
/** Performs an execution step of an if-statement node.
@return query thread to run next or NULL */
que_thr_t *if_step(que_thr_t *thr) /*!< in: query thread */
{
if_node_t *node;
elsif_node_t *elsif_node;
ut_ad(thr);
node = static_cast<if_node_t *>(thr->run_node);
ut_ad(que_node_get_type(node) == QUE_NODE_IF);
if (thr->prev_node == que_node_get_parent(node)) {
/* Evaluate the condition */
eval_exp(node->cond);
if (eval_node_get_ibool_val(node->cond)) {
/* The condition evaluated to TRUE: start execution
from the first statement in the statement list */
thr->run_node = node->stat_list;
} else if (node->else_part) {
thr->run_node = node->else_part;
} else if (node->elsif_list) {
elsif_node = node->elsif_list;
for (;;) {
eval_exp(elsif_node->cond);
if (eval_node_get_ibool_val(elsif_node->cond)) {
/* The condition evaluated to TRUE:
start execution from the first
statement in the statement list */
thr->run_node = elsif_node->stat_list;
break;
}
elsif_node = static_cast<elsif_node_t *>(que_node_get_next(elsif_node));
if (elsif_node == NULL) {
thr->run_node = NULL;
break;
}
}
} else {
thr->run_node = NULL;
}
} else {
/* Move to the next statement */
ut_ad(que_node_get_next(thr->prev_node) == NULL);
thr->run_node = NULL;
}
if (thr->run_node == NULL) {
thr->run_node = que_node_get_parent(node);
}
return (thr);
}
/** Performs an execution step of a while-statement node.
@return query thread to run next or NULL */
que_thr_t *while_step(que_thr_t *thr) /*!< in: query thread */
{
while_node_t *node;
ut_ad(thr);
node = static_cast<while_node_t *>(thr->run_node);
ut_ad(que_node_get_type(node) == QUE_NODE_WHILE);
ut_ad((thr->prev_node == que_node_get_parent(node)) ||
(que_node_get_next(thr->prev_node) == NULL));
/* Evaluate the condition */
eval_exp(node->cond);
if (eval_node_get_ibool_val(node->cond)) {
/* The condition evaluated to TRUE: start execution
from the first statement in the statement list */
thr->run_node = node->stat_list;
} else {
thr->run_node = que_node_get_parent(node);
}
return (thr);
}
/** Performs an execution step of an assignment statement node.
@return query thread to run next or NULL */
que_thr_t *assign_step(que_thr_t *thr) /*!< in: query thread */
{
assign_node_t *node;
ut_ad(thr);
node = static_cast<assign_node_t *>(thr->run_node);
ut_ad(que_node_get_type(node) == QUE_NODE_ASSIGNMENT);
/* Evaluate the value to assign */
eval_exp(node->val);
eval_node_copy_val(node->var->alias, node->val);
thr->run_node = que_node_get_parent(node);
return (thr);
}
/** Performs an execution step of a for-loop node.
@return query thread to run next or NULL */
que_thr_t *for_step(que_thr_t *thr) /*!< in: query thread */
{
for_node_t *node;
que_node_t *parent;
lint loop_var_value;
ut_ad(thr);
node = static_cast<for_node_t *>(thr->run_node);
ut_ad(que_node_get_type(node) == QUE_NODE_FOR);
parent = que_node_get_parent(node);
if (thr->prev_node != parent) {
/* Move to the next statement */
thr->run_node = que_node_get_next(thr->prev_node);
if (thr->run_node != NULL) {
return (thr);
}
/* Increment the value of loop_var */
loop_var_value = 1 + eval_node_get_int_val(node->loop_var);
} else {
/* Initialize the loop */
eval_exp(node->loop_start_limit);
eval_exp(node->loop_end_limit);
loop_var_value = eval_node_get_int_val(node->loop_start_limit);
node->loop_end_value = (int)eval_node_get_int_val(node->loop_end_limit);
}
/* Check if we should do another loop */
if (loop_var_value > node->loop_end_value) {
/* Enough loops done */
thr->run_node = parent;
} else {
eval_node_set_int_val(node->loop_var, loop_var_value);
thr->run_node = node->stat_list;
}
return (thr);
}
/** Performs an execution step of an exit statement node.
@return query thread to run next or NULL */
que_thr_t *exit_step(que_thr_t *thr) /*!< in: query thread */
{
exit_node_t *node;
que_node_t *loop_node;
ut_ad(thr);
node = static_cast<exit_node_t *>(thr->run_node);
ut_ad(que_node_get_type(node) == QUE_NODE_EXIT);
/* Loops exit by setting thr->run_node as the loop node's parent, so
find our containing loop node and get its parent. */
loop_node = que_node_get_containing_loop_node(node);
/* If someone uses an EXIT statement outside of a loop, this will
trigger. */
ut_a(loop_node);
thr->run_node = que_node_get_parent(loop_node);
return (thr);
}
/** Performs an execution step of a return-statement node.
@return query thread to run next or NULL */
que_thr_t *return_step(que_thr_t *thr) /*!< in: query thread */
{
return_node_t *node;
que_node_t *parent;
ut_ad(thr);
node = static_cast<return_node_t *>(thr->run_node);
ut_ad(que_node_get_type(node) == QUE_NODE_RETURN);
parent = node;
while (que_node_get_type(parent) != QUE_NODE_PROC) {
parent = que_node_get_parent(parent);
}
ut_a(parent);
thr->run_node = que_node_get_parent(parent);
return (thr);
}