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 /*
  * Licensed 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 com.facebook.presto.operator.aggregation;
@AggregationFunction("approx_set")
public final class ApproximateSetAggregation
    private static final int NUMBER_OF_BUCKETS = 4096;
    private ApproximateSetAggregation() {}
    public static void input(HyperLogLogState state, @SqlType(.double value)
    {
        HyperLogLog hll = getOrCreateHyperLogLog(state);
        state.addMemoryUsage(-hll.estimatedInMemorySize());
        hll.add(Double.doubleToLongBits(value));
        state.addMemoryUsage(hll.estimatedInMemorySize());
    }
    public static void input(HyperLogLogState state, @SqlType(.Slice value)
    {
        HyperLogLog hll = getOrCreateHyperLogLog(state);
        state.addMemoryUsage(-hll.estimatedInMemorySize());
        hll.add(value);
        state.addMemoryUsage(hll.estimatedInMemorySize());
    }
    public static void input(HyperLogLogState state, @SqlType(.long value)
    {
        HyperLogLog hll = getOrCreateHyperLogLog(state);
        state.addMemoryUsage(-hll.estimatedInMemorySize());
        hll.add(value);
        state.addMemoryUsage(hll.estimatedInMemorySize());
    }
    private static HyperLogLog getOrCreateHyperLogLog(HyperLogLogState state)
    {
        HyperLogLog hll = state.getHyperLogLog();
        if (hll == null) {
            hll = HyperLogLog.newInstance();
            state.setHyperLogLog(hll);
            state.addMemoryUsage(hll.estimatedInMemorySize());
        }
        return hll;
    }
    public static void combineState(HyperLogLogState stateHyperLogLogState otherState)
    {
        HyperLogLog input = otherState.getHyperLogLog();
        HyperLogLog previous = state.getHyperLogLog();
        if (previous == null) {
            state.setHyperLogLog(input);
            state.addMemoryUsage(input.estimatedInMemorySize());
        }
        else {
            state.addMemoryUsage(-previous.estimatedInMemorySize());
            previous.mergeWith(input);
            state.addMemoryUsage(previous.estimatedInMemorySize());
        }
    }
    public static void evaluateFinal(HyperLogLogState stateBlockBuilder out)
    {
        .serialize(stateout);
    }
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