[feature](vectorized) support lateral view (#8448)

be/src/vec/exprs/table_function/vexplode_split.cpp

@@ -0,0 +1,99 @@
+// 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 "vec/exprs/table_function/vexplode_split.h"
+
+#include "common/status.h"
+#include "gutil/strings/split.h"
+#include "vec/columns/column.h"
+#include "vec/exprs/vexpr.h"
+
+namespace doris {
+
+VExplodeSplitTableFunction::VExplodeSplitTableFunction() {
+    _fn_name = "vexplode_split";
+}
+
+Status VExplodeSplitTableFunction::open() {
+    return Status::OK();
+}
+
+Status VExplodeSplitTableFunction::process_init(vectorized::Block* block) {
+    CHECK(_vexpr_context->root()->children().size() == 2)
+            << "VExplodeSplitTableFunction must be have 2 children but have "
+            << _vexpr_context->root()->children().size();
+
+    int text_column_idx = -1;
+    int delimiter_column_idx = -1;
+
+    _vexpr_context->root()->children()[0]->execute(_vexpr_context, block, &text_column_idx);
+    _vexpr_context->root()->children()[1]->execute(_vexpr_context, block, &delimiter_column_idx);
+
+    _text_column = block->get_by_position(text_column_idx).column;
+    _delimiter_column = block->get_by_position(delimiter_column_idx).column;
+
+    return Status::OK();
+}
+
+Status VExplodeSplitTableFunction::process_row(size_t row_idx) {
+    _is_current_empty = false;
+    _eos = false;
+
+    StringRef text = _text_column->get_data_at(row_idx);
+    StringRef delimiter = _delimiter_column->get_data_at(row_idx);
+
+    if (text.data == nullptr) {
+        _is_current_empty = true;
+        _cur_size = 0;
+        _cur_offset = 0;
+    } else {
+        //TODO: implement non-copy split string reference
+        _backup = strings::Split(StringPiece((char*)text.data, text.size),
+                                 StringPiece((char*)delimiter.data, delimiter.size));
+
+        _cur_size = _backup.size();
+        _cur_offset = 0;
+        _is_current_empty = (_cur_size == 0);
+    }
+    return Status::OK();
+}
+
+Status VExplodeSplitTableFunction::process_close() {
+    _text_column = nullptr;
+    _delimiter_column = nullptr;
+    return Status::OK();
+}
+
+Status VExplodeSplitTableFunction::get_value(void** output) {
+    if (_is_current_empty) {
+        *output = nullptr;
+    } else {
+        *output = _backup[_cur_offset].data();
+    }
+    return Status::OK();
+}
+
+Status VExplodeSplitTableFunction::get_value_length(int64_t* length) {
+    if (_is_current_empty) {
+        *length = -1;
+    } else {
+        *length = _backup[_cur_offset].length();
+    }
+    return Status::OK();
+}
+
+} // namespace doris