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doris/be/src/exprs/hll_function.h
2020-02-19 14:33:05 +08:00

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// 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.
#ifndef DORIS_BE_SRC_QUERY_EXPRS_HLL_FUNCTION_H
#define DORIS_BE_SRC_QUERY_EXPRS_HLL_FUNCTION_H
#include "udf/udf.h"
namespace doris {
class HllFunctions {
public:
static void init();
static StringVal hll_hash(FunctionContext* ctx, const StringVal& dest_base);
static StringVal hll_empty(FunctionContext* ctx);
static void hll_init(FunctionContext*, StringVal* dst);
template <typename T>
static void hll_update(FunctionContext*, const T& src, StringVal* dst);
static void hll_merge(FunctionContext*,const StringVal& src, StringVal* dst);
static BigIntVal hll_finalize(FunctionContext*, const StringVal& src);
// Get the hll cardinality, the difference from hll_finalize method is
// hll_get_value method doesn't free memory, this function is used in analytic get_value function
static BigIntVal hll_get_value(FunctionContext*, const StringVal& src);
static StringVal hll_serialize(FunctionContext* ctx, const StringVal& src);
static BigIntVal hll_cardinality(FunctionContext* ctx, const StringVal& src);
};
}
#endif