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oceanbase/src/sql/engine/expr/ob_expr_replace.cpp
obdev c5756c1799 [FEAT MERGE] Functional_index
2023-04-27 11:11:24 +00:00

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/**
* Copyright (c) 2021 OceanBase
* OceanBase CE is licensed under Mulan PubL v2.
* You can use this software according to the terms and conditions of the Mulan PubL v2.
* You may obtain a copy of Mulan PubL v2 at:
* http://license.coscl.org.cn/MulanPubL-2.0
* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
* See the Mulan PubL v2 for more details.
*/
#define USING_LOG_PREFIX SQL_ENG
#include "sql/engine/expr/ob_expr_replace.h"
#include <limits.h>
#include <string.h>
#include "lib/oblog/ob_log.h"
#include "share/object/ob_obj_cast.h"
#include "sql/session/ob_sql_session_info.h"
#include "sql/engine/expr/ob_expr_result_type_util.h"
#include "sql/engine/expr/ob_expr_lob_utils.h"
namespace oceanbase
{
using namespace oceanbase::common;
namespace sql
{
ObExprReplace::ObExprReplace(ObIAllocator &alloc)
: ObStringExprOperator(alloc, T_FUN_SYS_REPLACE, N_REPLACE, TWO_OR_THREE, VALID_FOR_GENERATED_COL)
{
need_charset_convert_ = false;
}
ObExprReplace::~ObExprReplace()
{
}
int ObExprReplace::calc_result_typeN(ObExprResType &type,
ObExprResType *types_array,
int64_t param_num,
common::ObExprTypeCtx &type_ctx) const
{
int ret = OB_SUCCESS;
if (3 != param_num && !lib::is_oracle_mode()) {
ret = OB_INVALID_ARGUMENT;
LOG_WARN("Replace() should have three arguments in MySql Mode", K(ret), K(param_num), K(lib::is_oracle_mode()));
} else if (2 != param_num && 3 != param_num) {
ret = OB_INVALID_ARGUMENT;
LOG_WARN("Replace() should have three arguments in Oracle Mode", K(ret), K(param_num), K(lib::is_oracle_mode()));
} else if (OB_ISNULL(types_array) || OB_ISNULL(type_ctx.get_session())) {
ret = OB_ERR_UNEXPECTED;
LOG_WARN("unexpected error. types_array or session null",
K(ret), KP(types_array), KP(type_ctx.get_session()));
} else {
if (lib::is_oracle_mode()) {
ObSEArray<ObExprResType*, 3, ObNullAllocator> params;
OZ(params.push_back(&types_array[0]));
OZ(aggregate_string_type_and_charset_oracle(
*type_ctx.get_session(), params, type, PREFER_VAR_LEN_CHAR));
if (OB_SUCC(ret) && type.is_varchar_or_char()) {
type.set_length_semantics(type_ctx.get_session()->get_actual_nls_length_semantics());
}
for (int64_t i = 1; OB_SUCC(ret) && i < param_num; i++) {
OZ(params.push_back(&types_array[i]));
}
OZ(deduce_string_param_calc_type_and_charset(*type_ctx.get_session(), type, params, LS_BYTE));
} else {
if (types_array[0].is_lob()) {
type.set_type(types_array[0].get_type());
} else {
type.set_varchar();
type.set_length_semantics(type_ctx.get_session()->get_actual_nls_length_semantics());
}
if (3 == param_num) {
types_array[2].set_calc_type(ObVarcharType);
}
OZ(ObExprOperator::aggregate_charsets_for_string_result_with_comparison(
type, types_array, param_num, type_ctx.get_coll_type()));
for (int64_t i = 0; OB_SUCC(ret) && i < param_num; i++) {
types_array[i].set_calc_meta(type);
}
}
}
//deduce length
if (OB_SUCC(ret)) {
ObLength ori_len = 0;
ObLength from_len = 0;
ObLength to_len = 0;
int64_t result_len = 0;
if (lib::is_oracle_mode()) {
result_len = types_array[0].get_calc_length();
if (param_num == 2 || types_array[2].is_null()) {
// do nothing
} else {
OX(result_len *= types_array[2].get_calc_length());
if (OB_SUCC(ret) && (type.is_nchar() || type.is_nvarchar2())) {
const ObCharsetInfo *cs = ObCharset::get_charset(type.get_collation_type());
result_len = result_len * cs->mbmaxlen;
result_len = MIN(result_len, OB_MAX_ORACLE_VARCHAR_LENGTH) / cs->mbminlen;
}
}
OX(type.set_length(result_len));
} else {
ori_len = types_array[0].get_length();
from_len = types_array[1].get_length();
to_len = types_array[2].get_length();
if (from_len == 0 || from_len >= to_len) {
type.set_length(ori_len);
} else {
type.set_length(MIN(ori_len / from_len * to_len + ori_len % from_len,
OB_MAX_VARCHAR_LENGTH));
}
}
}
return ret;
}
int ObExprReplace::replace(ObString &ret_str,
const ObString &text,
const ObString &from,
const ObString &to,
ObExprStringBuf &string_buf)
{
int ret = OB_SUCCESS;
if (OB_UNLIKELY(text.length() <= 0)) {
// Return empty string
ret_str.reset();
} else if (OB_UNLIKELY(from.length() <= 0) || OB_UNLIKELY(to.length() < 0)) {
ret_str = text;
} else if (OB_ISNULL(from.ptr())) {
ret = OB_ERR_UNEXPECTED;
LOG_WARN("unexpected error. nullpointer(s)", K(ret), K(from), K(to));
} else if (OB_UNLIKELY(text.length() < from.length()) ||
OB_UNLIKELY(from == to)) {
ret_str = text;
} else {
int64_t length_text = text.length();
int64_t length_from = from.length();
int64_t length_to = to.length();
int64_t tot_length = 0;//total length for the result.
//locations is used to track the locations of 'from' in 'text'
ObSEArray<uint32_t, 4> locations(common::ObModIds::OB_SQL_EXPR_REPLACE,
common::OB_MALLOC_NORMAL_BLOCK_SIZE);
int64_t start_pos = 1;// the last parameter of locate starts from 1 NOT 0.
uint32_t index = 0;
int64_t count = 0;
while (OB_SUCC(ret)) { //while(1) will be better in terms of performance
index = ObCharset::locate(CS_TYPE_BINARY, text.ptr(), length_text,
from.ptr(), length_from,
start_pos);
if (0 != index && OB_SUCC(locations.push_back(index))) {
start_pos = index + length_from;
} else {
break;
}
}
if (OB_FAIL(ret)) {
LOG_WARN("push back failed", K(ret));
} else if (0 == (count = locations.count())) {
//no 'from' at all.
ret_str = text;
} else if (OB_UNLIKELY((OB_MAX_VARCHAR_LENGTH - length_text) / count < (length_to - length_from))) {
ret = OB_ERR_VARCHAR_TOO_LONG;
LOG_ERROR("Result of replace() was larger than OB_MAX_VARCHAR_LENGTH.",
K(length_text), K(length_from), K(length_to), K(OB_MAX_VARCHAR_LENGTH), K(ret));
ret_str.reset();
} else {
// Avoid realloc
if (OB_UNLIKELY((tot_length = length_text + (length_to - length_from) * count) <= 0)) {
// tot_length equals to 0 indicates that length_to is zero and "to" is empty string
ret_str.reset();
} else {
char *buf = static_cast<char *>(string_buf.alloc(tot_length));
if (OB_ISNULL(buf)) {
ret = OB_ALLOCATE_MEMORY_FAILED;
LOG_ERROR("alloc memory failed.", K(tot_length), K(ret));
} else {
// Core function
int64_t pos = 0;
const char * const text_ptr_start = text.ptr();
const char * const text_ptr_end = text.ptr() + length_text;
const char *text_ptr_lower = text.ptr();
const char *text_ptr_upper = text.ptr();
const char *to_ptr = to.ptr();
char *tmp_buf = buf;
for (int64_t i = 0; i < count; ++i) {
pos = locations.at(i);
text_ptr_upper = text_ptr_start + pos - 1;
MEMCPY(tmp_buf, text_ptr_lower, text_ptr_upper - text_ptr_lower);
tmp_buf += text_ptr_upper - text_ptr_lower;
text_ptr_lower = text_ptr_upper + length_from;
MEMCPY(tmp_buf, to_ptr, length_to);
tmp_buf += length_to;
}
if (text_ptr_lower < text_ptr_end) {
//deal with the tail parts of text
//such as text="xxxxxxxABCxxxxxABC1234" and from="ABC"
//we should also copy the "1234" to destination
MEMCPY(tmp_buf, text_ptr_lower, text_ptr_end - text_ptr_lower);
}
ret_str.assign_ptr(buf, static_cast<int32_t>(tot_length));
}
}
}
}
return ret;
}
int ObExprReplace::cg_expr(ObExprCGCtx &, const ObRawExpr &, ObExpr &rt_expr) const
{
int ret = OB_SUCCESS;
CK(2 == rt_expr.arg_cnt_ || 3 == rt_expr.arg_cnt_);
rt_expr.eval_func_ = &eval_replace;
return ret;
}
int ObExprReplace::eval_replace(const ObExpr &expr, ObEvalCtx &ctx, ObDatum &expr_datum)
{
int ret = OB_SUCCESS;
ObString res;
const bool is_mysql = lib::is_mysql_mode();
ObExprStrResAlloc alloc(expr, ctx);
ObDatum *text = NULL;
ObDatum *from = NULL;
ObDatum *to = NULL;
bool is_clob = expr.args_[0]->datum_meta_.is_clob();
bool is_lob_res = ob_is_text_tc(expr.datum_meta_.type_);
if (OB_FAIL(expr.eval_param_value(ctx, text, from, to))) {
LOG_WARN("evaluate parameters failed", K(ret));
} else if (text->is_null()
|| (is_mysql && from->is_null())
|| (is_mysql && NULL != to && to->is_null())) {
expr_datum.set_null();
} else if (is_clob && (0 == text->len_)) {
expr_datum.set_datum(*text);
} else if (!is_lob_res) { // non text tc inputs
if (OB_FAIL(replace(res,
text->get_string(),
!from->is_null() ? from->get_string() : ObString(),
(NULL != to && !to->is_null()) ? to->get_string() : ObString(),
alloc))) {
LOG_WARN("do replace failed", K(ret));
} else {
if (res.empty() && !is_mysql && !expr.args_[0]->datum_meta_.is_clob()) {
expr_datum.set_null();
} else {
expr_datum.set_string(res);
}
}
} else { // tc inputs
ObString text_data;
ObString to_data;
ObString from_data;
text_data = text->get_string();
from_data = from->get_string();
ObEvalCtx::TempAllocGuard tmp_alloc_g(ctx);
common::ObArenaAllocator &temp_allocator = tmp_alloc_g.get_allocator();
if (OB_FAIL(ObTextStringHelper::read_real_string_data(temp_allocator, *text,
expr.args_[0]->datum_meta_, expr.args_[0]->obj_meta_.has_lob_header(), text_data))) {
LOG_WARN("failed to get string data", K(ret), K(expr.args_[0]->datum_meta_));
} else if (OB_FAIL(ObTextStringHelper::read_real_string_data(temp_allocator, *from,
expr.args_[1]->datum_meta_, expr.args_[1]->obj_meta_.has_lob_header(), from_data))) {
LOG_WARN("failed to get string data", K(ret), K(expr.args_[1]->datum_meta_));
} else if (NULL == to) {
to_data.reset();
} else if (OB_FALSE_IT(to_data = to->get_string())) {
} else if (OB_FAIL(ObTextStringHelper::read_real_string_data(temp_allocator, *to,
expr.args_[2]->datum_meta_, expr.args_[2]->obj_meta_.has_lob_header(), to_data))) {
LOG_WARN("failed to get string data", K(ret), K(expr.args_[2]->datum_meta_));
}
if (OB_SUCC(ret)) {
if (OB_FAIL(replace(res, text_data, from_data, to_data, temp_allocator))) {
LOG_WARN("do replace for lob resutl failed", K(ret), K(expr.datum_meta_.type_));
} else if (OB_FAIL(ObTextStringHelper::string_to_templob_result(expr, ctx, expr_datum, res))) {
LOG_WARN("set lob result failed", K(ret));
}
}
}
return ret;
}
} // namespace sql
} // namespace oceanbase
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