[BugFix] Fix the mem_leak of regex_replace (StarRocks#24475)

Fixes #issue

```
mysql> SELECT regexp_replace('a b c', " ", "-");
+-----------------------------------+
| regexp_replace('a b c', ' ', '-') |
+-----------------------------------+
| a-b-c                             |
+-----------------------------------+
1 row in set (0.01 sec)
```

```
Direct leak of 2319 byte(s) in 1 object(s) allocated from:
    #0 0x974c2af in __interceptor_malloc ../../.././libsanitizer/asan/asan_malloc_linux.cpp:145
    #1 0x14bdb529 in alloc_scratch /root/starrocks/thirdparty/src/hyperscan-5.4.0/src/scratch.c:121
    StarRocks#2 0x14bdbb3f in hs_clone_scratch /root/starrocks/thirdparty/src/hyperscan-5.4.0/src/scratch.c:399
    StarRocks#3 0x12d4f791 in regexp_replace_use_hyperscan /root/starrocks/be/src/exprs/string_functions.cpp:2846
    StarRocks#4 0x12d5044a in starrocks::StringFunctions::regexp_replace(starrocks::FunctionContext*, std::vector<std::shared_ptr<starrocks::Column>, std::allocator<std::shared_ptr<starrocks::Column> > > const&) /root/starrocks/be/src/exprs/string_functions.cpp:2913
    StarRocks#5 0xec8af37 in starrocks::VectorizedFunctionCallExpr::evaluate_checked(starrocks::ExprContext*, starrocks::Chunk*) /root/starrocks/be/src/exprs/function_call_expr.cpp:159
    StarRocks#6 0xd924e9b in starrocks::ExprContext::evaluate(starrocks::Expr*, starrocks::Chunk*, unsigned char*) /root/starrocks/be/src/exprs/expr_context.cpp:176
    StarRocks#7 0xd9246dc in starrocks::ExprContext::evaluate(starrocks::Chunk*, unsigned char*) /root/starrocks/be/src/exprs/expr_context.cpp:160
    StarRocks#8 0xab4f521 in starrocks::pipeline::ProjectOperator::push_chunk(starrocks::RuntimeState*, std::shared_ptr<starrocks::Chunk> const&) /root/starrocks/be/src/exec/pipeline/project_operator.cpp:55
    StarRocks#9 0x9c9ec7c in starrocks::pipeline::PipelineDriver::process(starrocks::RuntimeState*, int) /root/starrocks/be/src/exec/pipeline/pipeline_driver.cpp:320
    StarRocks#10 0x12a59131 in starrocks::pipeline::GlobalDriverExecutor::_worker_thread() /root/starrocks/be/src/exec/pipeline/pipeline_driver_executor.cpp:154
    StarRocks#11 0x12a57871 in operator() /root/starrocks/be/src/exec/pipeline/pipeline_driver_executor.cpp:69
    StarRocks#12 0x12a61555 in __invoke_impl<void, starrocks::pipeline::GlobalDriverExecutor::initialize(int)::<lambda()>&> /opt/gcc/usr/include/c++/10.3.0/bits/invoke.h:60
    StarRocks#13 0x12a60a5a in __invoke_r<void, starrocks::pipeline::GlobalDriverExecutor::initialize(int)::<lambda()>&> /opt/gcc/usr/include/c++/10.3.0/bits/invoke.h:110
    StarRocks#14 0x12a5fd64 in _M_invoke /opt/gcc/usr/include/c++/10.3.0/bits/std_function.h:291
    StarRocks#15 0x98e2d87 in std::function<void ()>::operator()() const /opt/gcc/usr/include/c++/10.3.0/bits/std_function.h:622
    StarRocks#16 0x1172d057 in starrocks::FunctionRunnable::run() /root/starrocks/be/src/util/threadpool.cpp:58
    StarRocks#17 0x11729e0c in starrocks::ThreadPool::dispatch_thread() /root/starrocks/be/src/util/threadpool.cpp:553
    StarRocks#18 0x11745a65 in void std::__invoke_impl<void, void (starrocks::ThreadPool::*&)(), starrocks::ThreadPool*&>(std::__invoke_memfun_deref, void (starrocks::ThreadPool::*&)(), starrocks::ThreadPool*&) /opt/gcc/usr/include/c++/10.3.0/bits/invoke.h:73
    StarRocks#19 0x117453be in std::__invoke_result<void (starrocks::ThreadPool::*&)(), starrocks::ThreadPool*&>::type std::__invoke<void (starrocks::ThreadPool::*&)(), starrocks::ThreadPool*&>(void (starrocks::ThreadPool::*&)(), starrocks::ThreadPool*&) /opt/gcc/usr/include/c++/10.
3.0/bits/invoke.h:95
    StarRocks#20 0x117447b5 in void std::_Bind<void (starrocks::ThreadPool::*(starrocks::ThreadPool*))()>::__call<void, , 0ul>(std::tuple<>&&, std::_Index_tuple<0ul>) /opt/gcc/usr/include/c++/10.3.0/functional:416
    StarRocks#21 0x11743117 in void std::_Bind<void (starrocks::ThreadPool::*(starrocks::ThreadPool*))()>::operator()<, void>() /opt/gcc/usr/include/c++/10.3.0/functional:499
    StarRocks#22 0x1174017b in void std::__invoke_impl<void, std::_Bind<void (starrocks::ThreadPool::*(starrocks::ThreadPool*))()>&>(std::__invoke_other, std::_Bind<void (starrocks::ThreadPool::*(starrocks::ThreadPool*))()>&) /opt/gcc/usr/include/c++/10.3.0/bits/invoke.h:60
    StarRocks#23 0x1173dadf in std::enable_if<is_invocable_r_v<void, std::_Bind<void (starrocks::ThreadPool::*(starrocks::ThreadPool*))()>&>, void>::type std::__invoke_r<void, std::_Bind<void (starrocks::ThreadPool::*(starrocks::ThreadPool*))()>&>(std::_Bind<void (starrocks::ThreadP
ool::*(starrocks::ThreadPool*))()>&) /opt/gcc/usr/include/c++/10.3.0/bits/invoke.h:110
    StarRocks#24 0x11739b48 in std::_Function_handler<void (), std::_Bind<void (starrocks::ThreadPool::*(starrocks::ThreadPool*))()> >::_M_invoke(std::_Any_data const&) /opt/gcc/usr/include/c++/10.3.0/bits/std_function.h:291
    StarRocks#25 0x98e2d87 in std::function<void ()>::operator()() const /opt/gcc/usr/include/c++/10.3.0/bits/std_function.h:622
    StarRocks#26 0x11711bc8 in starrocks::Thread::supervise_thread(void*) /root/starrocks/be/src/util/thread.cpp:364
    StarRocks#27 0x7fc585af0ea4 in start_thread (/lib64/libpthread.so.0+0x7ea4)

```

Signed-off-by: trueeyu <[email protected]>

be/src/exprs/vectorized/string_functions.cpp

@@ -2831,6 +2831,14 @@ static ColumnPtr regexp_replace_use_hyperscan(StringFunctionsState* state, const
         CHECK(false) << "ERROR: Unable to clone scratch space."
                      << " status: " << status;
     }
+    DeferOp op([&] {
+        if (scratch != nullptr) {
+            hs_error_t st;
+            if ((st = hs_free_scratch(scratch)) != HS_SUCCESS) {
+                LOG(ERROR) << "free scratch space failure. status: " << st;
+            }
+        }
+    });
 
     auto size = columns[0]->size();
     ColumnBuilder<TYPE_VARCHAR> result(size);
@@ -2852,7 +2860,7 @@ static ColumnPtr regexp_replace_use_hyperscan(StringFunctionsState* state, const
         const char* data =
                 (value_size) ? str_viewer.value(row).data : &StringFunctions::_DUMMY_STRING_FOR_EMPTY_PATTERN;
 
-        auto status = hs_scan(
+        auto st = hs_scan(
                 // Use &_DUMMY_STRING_FOR_EMPTY_PATTERN instead of nullptr to avoid crash.
                 state->database, data, value_size, 0, scratch,
                 [](unsigned int id, unsigned long long from, unsigned long long to, unsigned int flags,
@@ -2869,7 +2877,7 @@ static ColumnPtr regexp_replace_use_hyperscan(StringFunctionsState* state, const
                     return 0;
                 },
                 &match_info_chain);
-        DCHECK(status == HS_SUCCESS || status == HS_SCAN_TERMINATED) << " status: " << status;
+        DCHECK(st == HS_SUCCESS || st == HS_SCAN_TERMINATED) << " status: " << st;
 
         std::string result_str;
         result_str.reserve(value_size);

test/sql/test_function/R/test_regex

@@ -1,4 +1,4 @@
--- name: test regex
+-- name: test_regex
 CREATE TABLE `ts` (
   `str` varchar(65533) NULL COMMENT "",
   `regex` varchar(65533) NULL COMMENT "",
@@ -47,6 +47,10 @@ select regexp_replace('abc中文def', '[\\p{Han}]+', 'xx');
 -- result:
 abcxxdef
 -- !result
+SELECT regexp_replace('a b c', " ", "-");
+-- result:
+a-b-c
+-- !result
 select str, regex, replaced, regexp_replace(str, regex, replaced) from ts order by str, regex, replaced;
 -- result:
 None		xx	None

test/sql/test_function/T/test_regex

@@ -1,4 +1,4 @@
--- name: test regex
+-- name: test_regex
 
 CREATE TABLE `ts` (
   `str` varchar(65533) NULL COMMENT "",
@@ -20,6 +20,6 @@ select regexp_replace('', '', 'xx');
 select regexp_replace(NULL, '', 'xx');
 select regexp_replace('abc中文def', '中文', 'xx');
 select regexp_replace('abc中文def', '[\\p{Han}]+', 'xx');
-
+select regexp_replace('a b c', " ", "-");
 
 select str, regex, replaced, regexp_replace(str, regex, replaced) from ts order by str, regex, replaced;