[feature](json)support explode_json_object func

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

@@ -29,6 +29,7 @@
 #include "vec/exprs/table_function/vexplode.h"
 #include "vec/exprs/table_function/vexplode_bitmap.h"
 #include "vec/exprs/table_function/vexplode_json_array.h"
+#include "vec/exprs/table_function/vexplode_json_object.h"
 #include "vec/exprs/table_function/vexplode_map.h"
 #include "vec/exprs/table_function/vexplode_numbers.h"
 #include "vec/exprs/table_function/vexplode_split.h"
@@ -58,6 +59,7 @@ const std::unordered_map<std::string, std::function<std::unique_ptr<TableFunctio
                 {"explode_json_array_json", VExplodeJsonArrayCreator<ParsedDataJSON>()},
                 {"explode_bitmap", TableFunctionCreator<VExplodeBitmapTableFunction>()},
                 {"explode_map", TableFunctionCreator<VExplodeMapTableFunction> {}},
+                {"explode_json_object", TableFunctionCreator<VExplodeJsonObjectTableFunction> {}},
                 {"explode", TableFunctionCreator<VExplodeTableFunction> {}}};
 
 Status TableFunctionFactory::get_fn(const TFunction& t_fn, ObjectPool* pool, TableFunction** fn) {

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

@@ -0,0 +1,160 @@
+// 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_json_object.h"
+
+#include <glog/logging.h>
+
+#include <ostream>
+#include <vector>
+
+#include "common/status.h"
+#include "vec/columns/column.h"
+#include "vec/common/string_ref.h"
+#include "vec/core/block.h"
+#include "vec/core/column_with_type_and_name.h"
+#include "vec/exprs/vexpr.h"
+#include "vec/exprs/vexpr_context.h"
+
+namespace doris::vectorized {
+
+VExplodeJsonObjectTableFunction::VExplodeJsonObjectTableFunction() {
+    _fn_name = "vexplode_json_object";
+}
+
+Status VExplodeJsonObjectTableFunction::process_init(Block* block, RuntimeState* state) {
+    CHECK(_expr_context->root()->children().size() == 1)
+            << "VExplodeJsonObjectTableFunction only support 1 child but has "
+            << _expr_context->root()->children().size();
+
+    int text_column_idx = -1;
+    RETURN_IF_ERROR(_expr_context->root()->children()[0]->execute(_expr_context.get(), block,
+                                                                  &text_column_idx));
+
+    _json_object_column = block->get_by_position(text_column_idx).column;
+    return Status::OK();
+}
+
+void VExplodeJsonObjectTableFunction::process_row(size_t row_idx) {
+    TableFunction::process_row(row_idx);
+
+    StringRef text = _json_object_column->get_data_at(row_idx);
+    if (text.data != nullptr) {
+        JsonbDocument* doc = JsonbDocument::createDocument(text.data, text.size);
+        if (UNLIKELY(!doc || !doc->getValue())) {
+            // error jsonb, put null into output, cur_size = 0 , we will insert_default
+            return;
+        }
+        // value is NOT necessary to be deleted since JsonbValue will not allocate memory
+        JsonbValue* value = doc->getValue();
+        auto writer = std::make_unique<JsonbWriter>();
+        if (value->isObject()) {
+            _cur_size = value->length();
+            ObjectVal* obj = (ObjectVal*)value;
+            _object_pairs.first =
+                    ColumnNullable::create(ColumnString::create(), ColumnUInt8::create());
+            _object_pairs.second =
+                    ColumnNullable::create(ColumnString::create(), ColumnUInt8::create());
+            _object_pairs.first->reserve(_cur_size);
+            _object_pairs.second->reserve(_cur_size);
+            for (auto it = obj->begin(); it != obj->end(); ++it) {
+                _object_pairs.first->insert_data(it->getKeyStr(), it->klen());
+                writer->reset();
+                writer->writeValue(it->value());
+                if (it->value()->isNull()) {
+                    _object_pairs.second->insert_default();
+                } else {
+                    const std::string_view& jsonb_value = std::string_view(
+                            writer->getOutput()->getBuffer(), writer->getOutput()->getSize());
+                    _object_pairs.second->insert_data(jsonb_value.data(), jsonb_value.size());
+                }
+            }
+        }
+        // we do not support other json type except object
+    }
+}
+
+void VExplodeJsonObjectTableFunction::process_close() {
+    _json_object_column = nullptr;
+    _object_pairs.first = nullptr;
+    _object_pairs.second = nullptr;
+}
+
+void VExplodeJsonObjectTableFunction::get_same_many_values(MutableColumnPtr& column, int length) {
+    // 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<ColumnUInt8*>(
+                assert_cast<ColumnNullable*>(column.get())->get_null_map_column_ptr().get())
+                ->insert_many_defaults(length);
+    } else if (column->is_column_struct()) {
+        ret = assert_cast<ColumnStruct*>(column.get());
+    } else {
+        throw Exception(ErrorCode::INTERNAL_ERROR,
+                        "only support expand json object int to struct(kv pair), but given: ",
+                        column->get_name());
+    }
+    if (!ret || ret->tuple_size() != 2) {
+        throw Exception(ErrorCode::INTERNAL_ERROR,
+                        "only support expand json object int to kv pair column, but given: ",
+                        ret->tuple_size());
+    }
+    ret->get_column(0).insert_many_from(*_object_pairs.first, _cur_offset, length);
+    ret->get_column(1).insert_many_from(*_object_pairs.second, _cur_offset, length);
+}
+
+int VExplodeJsonObjectTableFunction::get_value(MutableColumnPtr& column, int max_step) {
+    max_step = std::min(max_step, (int)(_cur_size - _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 =
+                    assert_cast<ColumnUInt8*>(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 expand json object int to kv pair column, but given:  ",
+                            struct_column->tuple_size());
+        }
+        struct_column->get_column(0).insert_range_from(*_object_pairs.first, _cur_offset, max_step);
+        struct_column->get_column(1).insert_range_from(*_object_pairs.second, _cur_offset,
+                                                       max_step);
+    }
+    forward(max_step);
+    return max_step;
+}
+} // namespace doris::vectorized

be/src/vec/exprs/table_function/vexplode_json_object.h

@@ -0,0 +1,59 @@
+// 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.
+
+#pragma once
+
+#include <stddef.h>
+
+#include "common/status.h"
+#include "vec/columns/column_map.h"
+#include "vec/data_types/data_type.h"
+#include "vec/data_types/data_type_array.h"
+#include "vec/data_types/data_type_map.h"
+#include "vec/exprs/table_function/table_function.h"
+#include "vec/functions/array/function_array_utils.h"
+
+namespace doris::vectorized {
+class Block;
+} // namespace doris::vectorized
+
+namespace doris::vectorized {
+
+// explode_json_object("{\"a\": 1, \"b\": 2}") ->
+// | key | value |
+// | a   | 1     |
+// | b   | 2     |
+class VExplodeJsonObjectTableFunction : public TableFunction {
+    ENABLE_FACTORY_CREATOR(VExplodeJsonObjectTableFunction);
+
+public:
+    VExplodeJsonObjectTableFunction();
+
+    ~VExplodeJsonObjectTableFunction() override = default;
+
+    Status process_init(Block* block, RuntimeState* state) override;
+    void process_row(size_t row_idx) override;
+    void process_close() override;
+    void get_same_many_values(MutableColumnPtr& column, int length) override;
+    int get_value(MutableColumnPtr& column, int max_step) override;
+
+private:
+    ColumnPtr _json_object_column;
+    std::pair<MutableColumnPtr, MutableColumnPtr> _object_pairs; // ColumnNullable<ColumnString>
+};
+
+} // namespace doris::vectorized

be/src/vec/functions/function_fake.cpp

@@ -70,6 +70,19 @@ struct FunctionExplodeMap {
     static std::string get_error_msg() { return "Fake function do not support execute"; }
 };
 
+// explode json-object: expands json-object to struct with a pair of key and value in column string
+struct FunctionExplodeJsonObject {
+    static DataTypePtr get_return_type_impl(const DataTypes& arguments) {
+        DCHECK(WhichDataType(arguments[0]).is_json())
+                << " explode json object " << arguments[0]->get_name() << " not supported";
+        DataTypes fieldTypes(2);
+        fieldTypes[0] = make_nullable(std::make_shared<DataTypeString>());
+        fieldTypes[1] = make_nullable(std::make_shared<DataTypeJsonb>());
+        return make_nullable(std::make_shared<vectorized::DataTypeStruct>(fieldTypes));
+    }
+    static std::string get_error_msg() { return "Fake function do not support execute"; }
+};
+
 struct FunctionEsquery {
     static DataTypePtr get_return_type_impl(const DataTypes& arguments) {
         return FunctionFakeBaseImpl<DataTypeUInt8>::get_return_type_impl(arguments);
@@ -113,6 +126,7 @@ void register_function_fake(SimpleFunctionFactory& factory) {
     register_table_function_expand_outer<FunctionExplode>(factory, "explode");
     register_table_function_expand_outer<FunctionExplodeMap>(factory, "explode_map");
 
+    register_table_function_expand_outer<FunctionExplodeJsonObject>(factory, "explode_json_object");
     register_table_function_expand_outer_default<DataTypeString>(factory, "explode_split");
     register_table_function_expand_outer_default<DataTypeInt32>(factory, "explode_numbers");
     register_table_function_expand_outer_default<DataTypeInt64>(factory, "explode_json_array_int");

fe/fe-core/src/main/java/org/apache/doris/catalog/BuiltinTableGeneratingFunctions.java

@@ -28,6 +28,8 @@
 import org.apache.doris.nereids.trees.expressions.functions.generator.ExplodeJsonArrayJsonOuter;
 import org.apache.doris.nereids.trees.expressions.functions.generator.ExplodeJsonArrayString;
 import org.apache.doris.nereids.trees.expressions.functions.generator.ExplodeJsonArrayStringOuter;
+import org.apache.doris.nereids.trees.expressions.functions.generator.ExplodeJsonObject;
+import org.apache.doris.nereids.trees.expressions.functions.generator.ExplodeJsonObjectOuter;
 import org.apache.doris.nereids.trees.expressions.functions.generator.ExplodeMap;
 import org.apache.doris.nereids.trees.expressions.functions.generator.ExplodeMapOuter;
 import org.apache.doris.nereids.trees.expressions.functions.generator.ExplodeNumbers;
@@ -52,6 +54,8 @@ public class BuiltinTableGeneratingFunctions implements FunctionHelper {
             tableGenerating(ExplodeOuter.class, "explode_outer"),
             tableGenerating(ExplodeMap.class, "explode_map"),
             tableGenerating(ExplodeMapOuter.class, "explode_map_outer"),
+            tableGenerating(ExplodeJsonObject.class, "explode_json_object"),
+            tableGenerating(ExplodeJsonObjectOuter.class, "explode_json_object_outer"),
             tableGenerating(ExplodeNumbers.class, "explode_numbers"),
             tableGenerating(ExplodeNumbersOuter.class, "explode_numbers_outer"),
             tableGenerating(ExplodeBitmap.class, "explode_bitmap"),

fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/functions/generator/ExplodeJsonObject.java

@@ -0,0 +1,70 @@
+// 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.
+
+package org.apache.doris.nereids.trees.expressions.functions.generator;
+
+import org.apache.doris.catalog.FunctionSignature;
+import org.apache.doris.nereids.trees.expressions.Expression;
+import org.apache.doris.nereids.trees.expressions.functions.AlwaysNullable;
+import org.apache.doris.nereids.trees.expressions.literal.StructLiteral;
+import org.apache.doris.nereids.trees.expressions.shape.UnaryExpression;
+import org.apache.doris.nereids.trees.expressions.visitor.ExpressionVisitor;
+import org.apache.doris.nereids.types.JsonType;
+import org.apache.doris.nereids.types.StringType;
+
+import com.google.common.base.Preconditions;
+import com.google.common.collect.ImmutableList;
+
+import java.util.List;
+
+/**
+ * explode_json_object("{"amory":1, "doris": 2}") generate two column and two lines with:
+ *      key column: amory, doris
+ *      value column: 1, 2
+ */
+public class ExplodeJsonObject extends TableGeneratingFunction implements UnaryExpression, AlwaysNullable {
+
+    public static final List<FunctionSignature> SIGNATURES = ImmutableList.of(
+            FunctionSignature.ret(StructLiteral.constructStructType(
+                    ImmutableList.of(StringType.INSTANCE, JsonType.INSTANCE))).args(JsonType.INSTANCE));
+
+    /**
+     * constructor with 1 argument.
+     */
+    public ExplodeJsonObject(Expression arg) {
+        super("explode_json_object", arg);
+    }
+
+    /**
+     * withChildren.
+     */
+    @Override
+    public ExplodeJsonObject withChildren(List<Expression> children) {
+        Preconditions.checkArgument(children.size() == 1);
+        return new ExplodeJsonObject(children.get(0));
+    }
+
+    @Override
+    public List<FunctionSignature> getSignatures() {
+        return SIGNATURES;
+    }
+
+    @Override
+    public <R, C> R accept(ExpressionVisitor<R, C> visitor, C context) {
+        return visitor.visitExplodeJsonObject(this, context);
+    }
+}