Start line:  
End line:  

Snippet Preview

Snippet HTML Code

Stack Overflow Questions
  /*
   * 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;
 
 
 import static com.facebook.presto.spi.StandardErrorCode.INVALID_FUNCTION_ARGUMENT;
 import static com.facebook.presto.spi.type.BigintType.BIGINT;
 import static com.facebook.presto.spi.type.DoubleType.DOUBLE;
 import static com.facebook.presto.util.Failures.checkCondition;
 import static com.google.common.base.Preconditions.checkState;
 
 @AggregationFunction("approx_percentile")
 {
 
 
     @InputFunction
     public static void input(DigestAndPercentileState state, @SqlType(.long value, @SqlType(.double percentile)
     {
         QuantileDigest digest = state.getDigest();
 
         if (digest == null) {
             digest = new QuantileDigest(0.01);
             state.setDigest(digest);
             state.addMemoryUsage(digest.estimatedInMemorySizeInBytes());
         }
 
         state.addMemoryUsage(-digest.estimatedInMemorySizeInBytes());
         digest.add(value);
         state.addMemoryUsage(digest.estimatedInMemorySizeInBytes());
 
         // use last percentile
         state.setPercentile(percentile);
     }
 
     @InputFunction
     public static void weightedInput(DigestAndPercentileState state, @SqlType(.long value, @SqlType(.long weight, @SqlType(.double percentile)
     {
         QuantileDigest digest = state.getDigest();
 
         if (digest == null) {
             digest = new QuantileDigest(0.01);
             state.setDigest(digest);
             state.addMemoryUsage(digest.estimatedInMemorySizeInBytes());
         }
 
         state.addMemoryUsage(-digest.estimatedInMemorySizeInBytes());
         digest.add(valueweight);
         state.addMemoryUsage(digest.estimatedInMemorySizeInBytes());
 
         // use last percentile
         state.setPercentile(percentile);
     }
 
     public static void combine(DigestAndPercentileState stateDigestAndPercentileState otherState)
     {
         QuantileDigest input = otherState.getDigest();
 
         QuantileDigest previous = state.getDigest();
         if (previous == null) {
             state.setDigest(input);
             state.addMemoryUsage(input.estimatedInMemorySizeInBytes());
         }
         else {
             state.addMemoryUsage(-previous.estimatedInMemorySizeInBytes());
             previous.merge(input);
             state.addMemoryUsage(previous.estimatedInMemorySizeInBytes());
         }
         state.setPercentile(otherState.getPercentile());
     }
 
     public static void output(DigestAndPercentileState stateBlockBuilder out)
     {
         QuantileDigest digest = state.getDigest();
         double percentile = state.getPercentile();
         if (digest == null || digest.getCount() == 0.0) {
            out.appendNull();
        }
        else {
            checkState(percentile != -1.0, "Percentile is missing");
            checkCondition(0 <= percentile && percentile <= 1, "Percentile must be between 0 and 1");
            .writeLong(outdigest.getQuantile(percentile));
        }
    }
New to GrepCode? Check out our FAQ X