27 lines
898 B
Go
27 lines
898 B
Go
// Copyright 2015 PingCAP, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package optimizer
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// Aggregator is the interface to
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// compute aggregate function result.
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type Aggregator interface {
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// Input adds an input value to aggregator.
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// The input values are accumulated in the aggregator.
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Input(in ...interface{}) error
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// Output uses input values to compute the aggregated result.
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Output() interface{}
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// Clear clears the input values.
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Clear()
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}
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