75 lines
2.2 KiB
Go
75 lines
2.2 KiB
Go
// Copyright 2023 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,
|
|
// 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 statistics
|
|
|
|
import (
|
|
"time"
|
|
|
|
"github.com/pingcap/tidb/pkg/types"
|
|
"github.com/pingcap/tidb/pkg/util/codec"
|
|
"github.com/pingcap/tidb/pkg/util/hack"
|
|
)
|
|
|
|
// DatumMapCache is used to store the mapping from the string type to datum type.
|
|
// The datum is used to find the value in the histogram.
|
|
type DatumMapCache struct {
|
|
datumMap map[hack.MutableString]types.Datum
|
|
}
|
|
|
|
// NewDatumMapCache creates a new DatumMapCache.
|
|
func NewDatumMapCache() *DatumMapCache {
|
|
return &DatumMapCache{
|
|
datumMap: make(map[hack.MutableString]types.Datum),
|
|
}
|
|
}
|
|
|
|
// Get gets the datum from the cache.
|
|
func (d *DatumMapCache) Get(key hack.MutableString) (val types.Datum, ok bool) {
|
|
val, ok = d.datumMap[key]
|
|
return
|
|
}
|
|
|
|
// Put puts the datum into the cache.
|
|
func (d *DatumMapCache) Put(val TopNMeta, encodedVal hack.MutableString,
|
|
tp byte, isIndex bool, loc *time.Location) (dat types.Datum, err error) {
|
|
dat, err = topNMetaToDatum(val, tp, isIndex, loc)
|
|
if err != nil {
|
|
return dat, err
|
|
}
|
|
d.datumMap[encodedVal] = dat
|
|
return dat, nil
|
|
}
|
|
|
|
func topNMetaToDatum(val TopNMeta,
|
|
tp byte, isIndex bool, loc *time.Location) (dat types.Datum, err error) {
|
|
if isIndex {
|
|
dat.SetBytes(val.Encoded)
|
|
} else {
|
|
var err error
|
|
if types.IsTypeTime(tp) {
|
|
// Handle date time values specially since they are encoded to int and we'll get int values if using DecodeOne.
|
|
_, dat, err = codec.DecodeAsDateTime(val.Encoded, tp, loc)
|
|
} else if types.IsTypeFloat(tp) {
|
|
_, dat, err = codec.DecodeAsFloat32(val.Encoded, tp)
|
|
} else {
|
|
_, dat, err = codec.DecodeOne(val.Encoded)
|
|
}
|
|
if err != nil {
|
|
return dat, err
|
|
}
|
|
}
|
|
return dat, err
|
|
}
|