[Function] add BE bitmap function bitmap_max (#6942)

Support bitmap_max.

be/src/exprs/bitmap_function.cpp

@@ -597,6 +597,19 @@ BooleanVal BitmapFunctions::bitmap_has_any(FunctionContext* ctx, const StringVal
     return {bitmap.cardinality() != 0};
 }
 
+BigIntVal BitmapFunctions::bitmap_max(FunctionContext* ctx, const StringVal& src) {
+    if (src.is_null) {
+        return BigIntVal::null();
+    }
+
+    if (src.len == 0) {
+        return reinterpret_cast<BitmapValue*>(src.ptr)->maximum();
+    } else {
+        auto bitmap = BitmapValue((char*)src.ptr);
+        return bitmap.maximum();
+    }
+}
+
 template void BitmapFunctions::bitmap_update_int<TinyIntVal>(FunctionContext* ctx,
                                                              const TinyIntVal& src, StringVal* dst);
 template void BitmapFunctions::bitmap_update_int<SmallIntVal>(FunctionContext* ctx,

be/src/exprs/bitmap_function.h

@@ -91,6 +91,7 @@ public:
     static StringVal bitmap_intersect_serialize(FunctionContext* ctx, const StringVal& src);
     template <typename T>
     static BigIntVal bitmap_intersect_finalize(FunctionContext* ctx, const StringVal& src);
+    static BigIntVal bitmap_max(FunctionContext* ctx, const StringVal& str);
 };
 } // namespace doris
 #endif //DORIS_BE_SRC_QUERY_EXPRS_BITMAP_FUNCTION_H

be/src/util/bitmap_value.h

@@ -1439,6 +1439,18 @@ public:
         return ss.str();
     }
 
+
+    doris_udf::BigIntVal maximum() {
+        switch (_type) {
+            case SINGLE:
+                return doris_udf::BigIntVal(_sv);
+            case BITMAP:
+                return doris_udf::BigIntVal(_bitmap.maximum());
+            default:
+                return doris_udf::BigIntVal::null();
+        }
+    }
+
 private:
     void _convert_to_smaller_type() {
         if (_type == BITMAP) {

be/test/exprs/bitmap_function_test.cpp

@@ -446,6 +446,32 @@ TEST_F(BitmapFunctionsTest, bitmap_from_string) {
     }
 }
 
+TEST_F(BitmapFunctionsTest, bitmap_max) {
+    BigIntVal result = BitmapFunctions::bitmap_max(ctx, StringVal::null());
+    ASSERT_TRUE(result.is_null);
+
+    BitmapValue bitmap1;
+    StringVal empty_str = convert_bitmap_to_string(ctx, bitmap1);
+    result = BitmapFunctions::bitmap_max(ctx, empty_str);
+    ASSERT_TRUE(result.is_null);
+
+    BitmapValue bitmap2 = BitmapValue(1024);
+    StringVal bitmap_str = convert_bitmap_to_string(ctx, bitmap2);
+    result = BitmapFunctions::bitmap_max(ctx, bitmap_str);
+    ASSERT_EQ(BigIntVal(1024), result);
+
+    BitmapValue bitmap3 = BitmapValue({1024, 1});
+    bitmap_str = convert_bitmap_to_string(ctx, bitmap3);
+    result = BitmapFunctions::bitmap_max(ctx, bitmap_str);
+    ASSERT_EQ(BigIntVal(1024), result);
+
+    BitmapValue bitmap4 = BitmapValue({1024, 3, 2});
+    bitmap_str = convert_bitmap_to_string(ctx, bitmap4);
+    result = BitmapFunctions::bitmap_max(ctx, bitmap_str);
+    ASSERT_EQ(BigIntVal(1024), result);
+}
+
+
 } // namespace doris
 
 int main(int argc, char** argv) {

docs/.vuepress/sidebar/en.js

@@ -420,6 +420,7 @@ module.exports = [
               "bitmap_union",
               "bitmap_xor",
               "to_bitmap",
+              "bitmap_max",
             ],
           },
           {

docs/.vuepress/sidebar/zh-CN.js

@@ -424,6 +424,7 @@ module.exports = [
               "bitmap_union",
               "bitmap_xor",
               "to_bitmap",
+              "bitmap_max",
             ],
           },
           {

docs/en/sql-reference/sql-functions/bitmap-functions/bitmap_max.md

@@ -0,0 +1,55 @@
+---
+{
+    "title": "bitmap_max",
+    "language": "en"
+}
+---
+
+<!-- 
+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.
+-->
+
+# bitmap_max
+## description
+### Syntax
+
+`BIGINT BITMAP_MAX(BITMAP input)`
+
+Calculate and return the max values of a bitmap.
+
+## example
+
+```
+mysql> select bitmap_max(bitmap_from_string('')) value;
++-------+
+| value |
++-------+
+|  NULL |
++-------+
+
+mysql> select bitmap_max(bitmap_from_string('1,9999999999')) value;
++------------+
+| value      |
++------------+
+| 9999999999 |
++------------+
+```
+
+## keyword
+
+    BITMAP_MAX,BITMAP

docs/zh-CN/sql-reference/sql-functions/bitmap-functions/bitmap_max.md

@@ -0,0 +1,55 @@
+---
+{
+    "title": "bitmap_max",
+    "language": "zh-CN"
+}
+---
+
+<!-- 
+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.
+-->
+
+# bitmap_max
+## description
+### Syntax
+
+`BIGINT BITMAP_MAX(BITMAP input)`
+
+计算并返回 bitmap 中的最大值.
+
+## example
+
+```
+mysql> select bitmap_max(bitmap_from_string('')) value;
++-------+
+| value |
++-------+
+|  NULL |
++-------+
+
+mysql> select bitmap_max(bitmap_from_string('1,9999999999')) value;
++------------+
+| value      |
++------------+
+| 9999999999 |
++------------+
+```
+
+## keyword
+
+    BITMAP_MAX,BITMAP

gensrc/script/doris_builtins_functions.py

@@ -1202,6 +1202,9 @@ visible_functions = [
     [['bitmap_min'], 'BIGINT', ['BITMAP'],
         '_ZN5doris15BitmapFunctions10bitmap_minEPN9doris_udf15FunctionContextERKNS1_9StringValE',
         '', '', 'vec', ''],
+    [['bitmap_max'], 'BIGINT', ['BITMAP'],
+        '_ZN5doris15BitmapFunctions10bitmap_maxEPN9doris_udf15FunctionContextERKNS1_9StringValE',
+        '', '', '', ''],
 
     # hash functions
     [['murmur_hash3_32'], 'INT', ['VARCHAR', '...'],