tidb aggfuncs 代码
文件路径：/executor/aggfuncs/aggfuncs.go
/ Copyright 2018 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 aggfuncs
import (
"unsafe"
"github.com/pingcap/tidb/expression"
"github.com/pingcap/tidb/sessionctx"
"github.com/pingcap/tidb/types"
"github.com/pingcap/tidb/util/chunk"
)
/ All the AggFunc implementations are listed here for navigation.
var (
/ All the AggFunc implementations for "COUNT" are listed here.
_ AggFunc = (*countPartial)(nil)
_ AggFunc = (*countOriginal4Int)(nil)
_ AggFunc = (*countOriginal4Real)(nil)
_ AggFunc = (*countOriginal4Decimal)(nil)
_ AggFunc = (*countOriginal4Time)(nil)
_ AggFunc = (*countOriginal4Duration)(nil)
_ AggFunc = (*countOriginal4JSON)(nil)
_ AggFunc = (*countOriginal4String)(nil)
_ AggFunc = (*countOriginalWithDistinct4Int)(nil)
_ AggFunc = (*countOriginalWithDistinct4Real)(nil)
_ AggFunc = (*countOriginalWithDistinct4Decimal)(nil)
_ AggFunc = (*countOriginalWithDistinct4Duration)(nil)
_ AggFunc = (*countOriginalWithDistinct4String)(nil)
_ AggFunc = (*countOriginalWithDistinct)(nil)
/ All the AggFunc implementations for "APPROX_COUNT_DISTINCT" are listed here.
_ AggFunc = (*approxCountDistinctOriginal)(nil)
_ AggFunc = (*approxCountDistinctPartial1)(nil)
_ AggFunc = (*approxCountDistinctPartial2)(nil)
_ AggFunc = (*approxCountDistinctFinal)(nil)
/ All the AggFunc implementations for "APPROX_PERCENTILE" are listed here.
_ AggFunc = (*percentileOriginal4Int)(nil)
_ AggFunc = (*percentileOriginal4Real)(nil)
_ AggFunc = (*percentileOriginal4Decimal)(nil)
/ All the AggFunc implementations for "FIRSTROW" are listed here.
_ AggFunc = (*firstRow4Decimal)(nil)
_ AggFunc = (*firstRow4Int)(nil)
_ AggFunc = (*firstRow4Time)(nil)
_ AggFunc = (*firstRow4String)(nil)
_ AggFunc = (*firstRow4Duration)(nil)
_ AggFunc = (*firstRow4Float32)(nil)
_ AggFunc = (*firstRow4Float64)(nil)
_ AggFunc = (*firstRow4JSON)(nil)
_ AggFunc = (*firstRow4Enum)(nil)
_ AggFunc = (*firstRow4Set)(nil)
/ All the AggFunc implementations for "MAX"/"MIN" are listed here.
_ AggFunc = (*maxMin4Int)(nil)
_ AggFunc = (*maxMin4Uint)(nil)
_ AggFunc = (*maxMin4Float32)(nil)
_ AggFunc = (*maxMin4Float64)(nil)
_ AggFunc = (*maxMin4Decimal)(nil)
_ AggFunc = (*maxMin4String)(nil)
_ AggFunc = (*maxMin4Duration)(nil)
_ AggFunc = (*maxMin4JSON)(nil)
_ AggFunc = (*maxMin4Enum)(nil)
_ AggFunc = (*maxMin4Set)(nil)
/ All the AggFunc implementations for "AVG" are listed here.
_ AggFunc = (*avgOriginal4Decimal)(nil)
_ AggFunc = (*avgOriginal4DistinctDecimal)(nil)
_ AggFunc = (*avgPartial4Decimal)(nil)
_ AggFunc = (*avgOriginal4Float64)(nil)
_ AggFunc = (*avgPartial4Float64)(nil)
_ AggFunc = (*avgOriginal4DistinctFloat64)(nil)
/ All the AggFunc implementations for "SUM" are listed here.
_ AggFunc = (*sum4DistinctFloat64)(nil)
_ AggFunc = (*sum4DistinctDecimal)(nil)
_ AggFunc = (*sum4Decimal)(nil)
_ AggFunc = (*sum4Float64)(nil)
/ All the AggFunc implementations for "GROUP_CONCAT" are listed here.
_ AggFunc = (*groupConcatDistinct)(nil)
_ AggFunc = (*groupConcat)(nil)
/ All the AggFunc implementations for "BIT_OR" are listed here.
_ AggFunc = (*bitOrUint64)(nil)
/ All the AggFunc implementations for "BIT_XOR" are listed here.
_ AggFunc = (*bitXorUint64)(nil)
/ All the AggFunc implementations for "BIT_AND" are listed here.
_ AggFunc = (*bitAndUint64)(nil)
/ All the AggFunc implementations for "JSON_ARRAYAGG" are listed here
_ AggFunc = (*jsonArrayagg)(nil)
/ All the AggFunc implementations for "JSON_OBJECTAGG" are listed here
_ AggFunc = (*jsonObjectAgg)(nil)
)
const (
/ DefUint32Size is the size of uint32
DefUint32Size = int64(unsafe.Sizeof(uint32(0)))
/ DefUint64Size is the size of uint64
DefUint64Size = int64(unsafe.Sizeof(uint64(0)))
/ DefInt64Size is the size of int64
DefInt64Size = int64(unsafe.Sizeof(int64(0)))
/ DefFloat64Size is the size of float64
DefFloat64Size = int64(unsafe.Sizeof(float64(0)))
/ DefTimeSize is the size of time
DefTimeSize = int64(unsafe.Sizeof(types.Time{}))
/ DefRowSize is the size of row
DefRowSize = int64(unsafe.Sizeof(chunk.Row{}))
/ DefBoolSize is the size of bool
DefBoolSize = int64(unsafe.Sizeof(false))
/ DefInterfaceSize is the size of interface
DefInterfaceSize = int64(16)
/ DefMyDecimalSize is the size of MyDecimal
DefMyDecimalSize = int64(unsafe.Sizeof(types.MyDecimal{}))
/ DefDurationSize is the size of duration
DefDurationSize = int64(unsafe.Sizeof(types.Duration{}))
)
/ PartialResult represents data structure to store the partial result for the
/ aggregate functions. Here we use unsafe.Pointer to allow the partial result
/ to be any type.
type PartialResult unsafe.Pointer
/ AggFunc is the interface to evaluate the aggregate functions.
type AggFunc interface {
/ AllocPartialResult allocates a specific data structure to store the
/ partial result, initializes it, and converts it to PartialResult to
/ return back. The second returned value is the memDelta used to trace
/ memory usage. Aggregate operator implementation, no matter it's a hash
/ or stream, should hold this allocated PartialResult for the further
/ operations like: "ResetPartialResult", "UpdatePartialResult".
AllocPartialResult() (pr PartialResult, memDelta int64)
/ ResetPartialResult resets the partial result to the original state for a
/ specific aggregate function. It converts the input PartialResult to the
/ specific data structure which stores the partial result and then reset
/ every field to the proper original state.
ResetPartialResult(pr PartialResult)
/ UpdatePartialResult updates the specific partial result for an aggregate
/ function using the input rows which all belonging to the same data group.
/ It converts the PartialResult to the specific data structure which stores
/ the partial result and then iterates on the input rows and update that
/ partial result according to the functionality and the state of the
/ aggregate function. The returned value is the memDelta used to trace memory
/ usage.
UpdatePartialResult(sctx sessionctx.Context, rowsInGroup []chunk.Row, pr PartialResult) (memDelta int64, err error)
/ MergePartialResult will be called in the final phase when parallelly
/ executing. It converts the PartialResult `src`, `dst` to the same specific
/ data structure which stores the partial results, and then evaluate the
/ final result using the partial results as input values. The returned value
/ is the memDelta used to trace memory usage.
MergePartialResult(sctx sessionctx.Context, src, dst PartialResult) (memDelta int64, err error)
/ AppendFinalResult2Chunk finalizes the partial result and append the
/ final result to the input chunk. Like other operations, it converts the
/ input PartialResult to the specific data structure which stores the
/ partial result and then calculates the final result and append that
/ final result to the chunk provided.
AppendFinalResult2Chunk(sctx sessionctx.Context, pr PartialResult, chk *chunk.Chunk) error
}
type baseAggFunc struct {
/ args stores the input arguments for an aggregate function, we should
/ call arg.EvalXXX to get the actual input data for this function.
args []expression.Expression
/ ordinal stores the ordinal of the columns in the output chunk, which is
/ used to append the final result of this function.
ordinal int
/ retTp means the target type of the final agg should return.
retTp *types.FieldType
}
func (*baseAggFunc) MergePartialResult(sctx sessionctx.Context, src, dst PartialResult) (memDelta int64, err error) {
return 0, nil
}
/ SlidingWindowAggFunc is the interface to evaluate the aggregate functions using sliding window.
type SlidingWindowAggFunc interface {
/ Slide evaluates the aggregate functions using a sliding window. The input
/ lastStart and lastEnd are the interval of the former sliding window,
/ shiftStart, shiftEnd mean the sliding window offset. Note that the input
/ PartialResult stores the intermediate result which will be used in the next
/ sliding window, ensure call ResetPartialResult after a frame are evaluated
/ completely.
Slide(sctx sessionctx.Context, getRow func(uint64) chunk.Row, lastStart, lastEnd uint64, shiftStart, shiftEnd uint64, pr PartialResult) error
}
/ MaxMinSlidingWindowAggFunc is the interface to evaluate the max/min agg function using sliding window
type MaxMinSlidingWindowAggFunc interface {
/ SetWindowStart sets the start position of window
SetWindowStart(start uint64)
}