[Bug] [Vectorized] add padding when load char type data (apache#9734)

be/CMakeLists.txt

@@ -396,7 +396,7 @@ set(CXX_COMMON_FLAGS "${CXX_COMMON_FLAGS} -DBOOST_SYSTEM_NO_DEPRECATED")
 set(CXX_COMMON_FLAGS "${CXX_COMMON_FLAGS} -DBRPC_ENABLE_CPU_PROFILER")
 
 if (USE_LLD)
-    set(CXX_COMMON_FLAGS "${CXX_COMMON_FLAGS} -fuse-ld=lld")
+    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -fuse-ld=lld")
 endif ()
 
 if (USE_LIBCPP AND COMPILER_CLANG)

be/src/olap/memtable.cpp

@@ -282,7 +282,7 @@ void MemTable::_collect_vskiplist_results() {
             _input_mutable_block.swap(_output_mutable_block);
             //TODO(weixang):opt here.
             std::unique_ptr<vectorized::Block> empty_input_block =
-                    std::move(in_block.create_same_struct_block(0));
+                    in_block.create_same_struct_block(0);
             _output_mutable_block =
                     vectorized::MutableBlock::build_mutable_block(empty_input_block.get());
             _output_mutable_block.clear_column_data();

be/src/vec/columns/column_string.h

@@ -45,6 +45,7 @@ class ColumnString final : public COWHelper<IColumn, ColumnString> {
 
 private:
     friend class COWHelper<IColumn, ColumnString>;
+    friend class OlapBlockDataConvertor;
 
     /// Maps i'th position to offset to i+1'th element. Last offset maps to the end of all chars (is the size of all chars).
     Offsets offsets;

be/src/vec/olap/olap_data_convertor.cpp

@@ -358,6 +358,12 @@ Status OlapBlockDataConvertor::OlapColumnDataConvertorChar::convert_to_olap() {
 
     assert(column_string);
 
+    // If column_string is not padded to full, we should do padding here.
+    if (should_padding(column_string, _length)) {
+        _column = clone_and_padding(column_string, _length);
+        column_string = assert_cast<const vectorized::ColumnString*>(_column.get());
+    }
+
     const ColumnString::Char* char_data = column_string->get_chars().data();
     const ColumnString::Offset* offset_cur = column_string->get_offsets().data() + _row_pos;
     const ColumnString::Offset* offset_end = offset_cur + _num_rows;

be/src/vec/olap/olap_data_convertor.h

@@ -17,6 +17,9 @@
 
 #pragma once
 #include "olap/tablet_schema.h"
+#include "vec/columns/column.h"
+#include "vec/columns/column_string.h"
+#include "vec/common/string_ref.h"
 #include "vec/core/block.h"
 
 namespace doris::vectorized {
@@ -99,8 +102,36 @@ class OlapBlockDataConvertor {
         Status convert_to_olap() override;
 
     private:
+        static bool should_padding(const ColumnString* column, size_t padding_length) {
+            // Check sum of data length, including terminating zero.
+            return column->size() * (padding_length + 1) != column->chars.size();
+        }
+
+        static ColumnPtr clone_and_padding(const ColumnString* input, size_t padding_length) {
+            auto column = vectorized::ColumnString::create();
+            auto padded_column =
+                    assert_cast<vectorized::ColumnString*>(column->assume_mutable().get());
+
+            column->offsets.resize(input->size());
+            column->chars.resize(input->size() * (padding_length + 1));
+            memset(padded_column->chars.data(), 0, input->size() * (padding_length + 1));
+
+            for (size_t i = 0; i < input->size(); i++) {
+                column->offsets[i] = (i + 1) * (padding_length + 1);
+
+                auto str = input->get_data_at(i);
+                if (str.size) {
+                    memcpy(padded_column->chars.data() + i * (padding_length + 1), str.data,
+                           str.size);
+                }
+            }
+
+            return column;
+        }
+
         size_t _length;
         PaddedPODArray<Slice> _slice;
+        ColumnPtr _column = nullptr;
     };
 
     class OlapColumnDataConvertorVarChar : public OlapColumnDataConvertorBase {

be/test/CMakeLists.txt

@@ -358,6 +358,7 @@ set(VEC_TEST_FILES
     vec/function/table_function_test.cpp
     vec/runtime/vdata_stream_test.cpp
     vec/utils/arrow_column_to_doris_column_test.cpp
+    vec/olap/char_type_padding_test.cpp
 )
 
 add_executable(doris_be_test

be/test/vec/exec/vtablet_sink_test.cpp

@@ -115,7 +115,7 @@ class VTestInternalService : public PBackendService {
     void tablet_writer_add_block(google::protobuf::RpcController* controller,
                                  const PTabletWriterAddBlockRequest* request,
                                  PTabletWriterAddBlockResult* response,
-                                 google::protobuf::Closure* done) {
+                                 google::protobuf::Closure* done) override {
         brpc::ClosureGuard done_guard(done);
         {
             std::lock_guard<std::mutex> l(_lock);

be/test/vec/olap/char_type_padding_test.cpp

@@ -0,0 +1,68 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+#include <gtest/gtest.h>
+
+#include "vec/columns/column_string.h"
+#include "vec/olap/olap_data_convertor.h"
+
+namespace doris::vectorized {
+
+using ConvertorChar = OlapBlockDataConvertor::OlapColumnDataConvertorChar;
+
+TEST(CharTypePaddingTest, CharTypePaddingFullTest) {
+    auto input = ColumnString::create();
+
+    std::string str = "Allemande";
+    size_t rows = 10;
+
+    for (size_t i = 0; i < rows; i++) {
+        input->insert_data(str.data(), str.length());
+    }
+    EXPECT_FALSE(ConvertorChar::should_padding(input, str.length()));
+
+    input->insert_data(str.data(), str.length() - 1);
+    EXPECT_TRUE(ConvertorChar::should_padding(input, str.length()));
+}
+
+TEST(CharTypePaddingTest, CharTypePaddingDataTest) {
+    auto input = ColumnString::create();
+
+    std::string str = "Allemande";
+
+    size_t rows = str.length();
+    for (int i = 0; i < rows; i++) {
+        input->insert_data(str.data(), str.length() - i);
+    }
+
+    auto output = ConvertorChar::clone_and_padding(input, str.length());
+
+    for (int i = 0; i < rows; i++) {
+        auto cell = output->get_data_at(i).to_string();
+        EXPECT_EQ(cell.length(), str.length());
+
+        auto str_real = std::string(cell.data(), str.length() - i);
+        auto str_expect = str.substr(0, str.length() - i);
+        EXPECT_EQ(str_real, str_expect);
+
+        for (int j = str.length() - i; j < str.length(); j++) {
+            EXPECT_EQ(cell[j], 0);
+        }
+    }
+}
+
+} // namespace doris::vectorized