Files
tidb/executor/aggfuncs/func_cume_dist.go

57 lines
1.5 KiB
Go

// Copyright 2019 PingCAP, Inc.
//
// 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,
// See the License for the specific language governing permissions and
// limitations under the License.
package aggfuncs
import (
"github.com/pingcap/tidb/sessionctx"
"github.com/pingcap/tidb/util/chunk"
)
type cumeDist struct {
baseAggFunc
rowComparer
}
type partialResult4CumeDist struct {
partialResult4Rank
cum int64
}
func (r *cumeDist) AllocPartialResult() PartialResult {
return PartialResult(&partialResult4CumeDist{})
}
func (r *cumeDist) ResetPartialResult(pr PartialResult) {
p := (*partialResult4CumeDist)(pr)
p.partialResult4Rank.reset()
p.cum = 0
}
func (r *cumeDist) UpdatePartialResult(sctx sessionctx.Context, rowsInGroup []chunk.Row, pr PartialResult) error {
p := (*partialResult4CumeDist)(pr)
p.partialResult4Rank.updatePartialResult(rowsInGroup, false, r.compareRows)
return nil
}
func (r *cumeDist) AppendFinalResult2Chunk(sctx sessionctx.Context, pr PartialResult, chk *chunk.Chunk) error {
p := (*partialResult4CumeDist)(pr)
numRows := int64(len(p.results))
for p.cum < numRows && p.results[p.cum] == p.results[p.curIdx] {
p.cum++
}
p.curIdx++
chk.AppendFloat64(r.ordinal, float64(p.cum)/float64(numRows))
return nil
}