// Licensed to the Apache Software Foundation (ASF) under one

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// 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 "exprs/table_function/vexplode_map.h"

#include <glog/logging.h>

#include <ostream>

#include "common/status.h"

#include "core/block/block.h"

#include "core/block/column_with_type_and_name.h"

#include "core/column/column.h"

#include "exprs/vexpr.h"

#include "exprs/vexpr_context.h"

namespace doris {

VExplodeMapTableFunction::VExplodeMapTableFunction() {

_fn_name = "vexplode_map";

}

bool extract_column_map_info(const IColumn& src, ColumnMapExecutionData& data) {

const IColumn* map_col = &src;

// extract array nullable info

if (is_column_nullable(src)) {

const auto& null_col = reinterpret_cast<const ColumnNullable&>(src);

// map column's nullmap

data.map_nullmap_data = null_col.get_null_map_data().data();

map_col = null_col.get_nested_column_ptr().get();

}

if (data.map_col = check_and_get_column<ColumnMap>(map_col); !data.map_col) {

return false;

}

data.offsets_ptr = &data.map_col->get_offsets();

return true;

}

Status VExplodeMapTableFunction::process_init(Block* block, RuntimeState* state) {

CHECK(_expr_context->root()->children().size() == 1)

<< "VExplodeMapTableFunction only support 1 child but has "

<< _expr_context->root()->children().size();

ColumnPtr value_column;

RETURN_IF_ERROR(_expr_context->root()->children()[0]->execute_column(

_expr_context.get(), block, nullptr, block->rows(), value_column));

_collection_column = value_column->convert_to_full_column_if_const();

if (!extract_column_map_info(*_collection_column, _map_detail)) {

return Status::NotSupported("column type {} not supported now, only support array or map",

_collection_column->get_name());

}

return Status::OK();

}

void VExplodeMapTableFunction::process_row(size_t row_idx) {

DCHECK(row_idx < _collection_column->size());

TableFunction::process_row(row_idx);

if (!_map_detail.map_nullmap_data || !_map_detail.map_nullmap_data[row_idx]) {

_collection_offset = (*_map_detail.offsets_ptr)[row_idx - 1];

_cur_size = (*_map_detail.offsets_ptr)[row_idx] - _collection_offset;

}

}

void VExplodeMapTableFunction::process_close() {

_collection_column = nullptr;

_map_detail.reset();

_collection_offset = 0;

}

void VExplodeMapTableFunction::get_same_many_values(MutableColumnPtr& column, int length) {

// now we only support map column explode to struct column

size_t pos = _collection_offset + _cur_offset;

// if current is empty map row, also append a default value

if (current_empty()) {

column->insert_many_defaults(length);

return;

}

ColumnStruct* ret = nullptr;

// this _is_nullable is whole output column's nullable

if (_is_nullable) {

// make map kv value into struct

ret = assert_cast<ColumnStruct*>(

assert_cast<ColumnNullable*>(column.get())->get_nested_column_ptr().get());

assert_cast<ColumnNullable*>(column.get())

->get_null_map_column_ptr()

->insert_many_defaults(length);

} else if (is_column<ColumnStruct>(column.get())) {

ret = assert_cast<ColumnStruct*>(column.get());

} else {

throw Exception(ErrorCode::INTERNAL_ERROR,

"only support map column explode to struct column");

}

if (!ret || ret->tuple_size() != 2) {

throw Exception(

ErrorCode::INTERNAL_ERROR,

"only support map column explode to two column, but given: ", ret->tuple_size());

}

ret->get_column(0).insert_many_from(_map_detail.map_col->get_keys(), pos, length);

ret->get_column(1).insert_many_from(_map_detail.map_col->get_values(), pos, length);

}

int VExplodeMapTableFunction::get_value(MutableColumnPtr& column, int max_step) {

max_step = std::min(max_step, (int)(_cur_size - _cur_offset));

size_t pos = _collection_offset + _cur_offset;

if (current_empty()) {

column->insert_default();

max_step = 1;

} else {

ColumnStruct* struct_column = nullptr;

if (_is_nullable) {

auto* nullable_column = assert_cast<ColumnNullable*>(column.get());

struct_column =

assert_cast<ColumnStruct*>(nullable_column->get_nested_column_ptr().get());

auto* nullmap_column = nullable_column->get_null_map_column_ptr().get();

// here nullmap_column insert max_step many defaults as if MAP[row_idx] is NULL

// will be not update value, _cur_size = 0, means current_empty;

// so here could insert directly

nullmap_column->insert_many_defaults(max_step);

} else {

struct_column = assert_cast<ColumnStruct*>(column.get());

}

if (!struct_column || struct_column->tuple_size() != 2) {

throw Exception(ErrorCode::INTERNAL_ERROR,

"only support map column explode to two column, but given: ",

struct_column->tuple_size());

}

struct_column->get_column(0).insert_range_from(_map_detail.map_col->get_keys(), pos,

max_step);

struct_column->get_column(1).insert_range_from(_map_detail.map_col->get_values(), pos,

max_step);

}

forward(max_step);

return max_step;

}

} // namespace doris