tidb mem_reader 源码
tidb mem_reader 代码
文件路径：/executor/mem_reader.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,
// 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 executor
import (
"context"
"github.com/opentracing/opentracing-go"
"github.com/pingcap/errors"
"github.com/pingcap/tidb/distsql"
"github.com/pingcap/tidb/expression"
"github.com/pingcap/tidb/kv"
"github.com/pingcap/tidb/parser/model"
"github.com/pingcap/tidb/parser/mysql"
plannercore "github.com/pingcap/tidb/planner/core"
"github.com/pingcap/tidb/sessionctx"
transaction "github.com/pingcap/tidb/store/driver/txn"
"github.com/pingcap/tidb/table"
"github.com/pingcap/tidb/table/tables"
"github.com/pingcap/tidb/tablecodec"
"github.com/pingcap/tidb/types"
"github.com/pingcap/tidb/util/chunk"
"github.com/pingcap/tidb/util/codec"
"github.com/pingcap/tidb/util/rowcodec"
)
type memReader interface {
getMemRows(ctx context.Context) ([][]types.Datum, error)
getMemRowsHandle() ([]kv.Handle, error)
}
var (
_ memReader = &memIndexReader{}
_ memReader = &memTableReader{}
_ memReader = &memIndexLookUpReader{}
_ memReader = &memIndexMergeReader{}
)
type memIndexReader struct {
ctx sessionctx.Context
index *model.IndexInfo
table *model.TableInfo
kvRanges []kv.KeyRange
desc bool
conditions []expression.Expression
addedRows [][]types.Datum
addedRowsLen int
retFieldTypes []*types.FieldType
outputOffset []int
// belowHandleCols is the handle's position of the below scan plan.
belowHandleCols plannercore.HandleCols
cacheTable kv.MemBuffer
}
func buildMemIndexReader(ctx context.Context, us *UnionScanExec, idxReader *IndexReaderExecutor) *memIndexReader {
if span := opentracing.SpanFromContext(ctx); span != nil && span.Tracer() != nil {
span1 := span.Tracer().StartSpan("buildMemIndexReader", opentracing.ChildOf(span.Context()))
defer span1.Finish()
opentracing.ContextWithSpan(ctx, span1)
}
kvRanges := idxReader.kvRanges
outputOffset := make([]int, 0, len(us.columns))
for _, col := range idxReader.outputColumns {
outputOffset = append(outputOffset, col.Index)
}
return &memIndexReader{
ctx: us.ctx,
index: idxReader.index,
table: idxReader.table.Meta(),
kvRanges: kvRanges,
desc: us.desc,
conditions: us.conditions,
retFieldTypes: retTypes(us),
outputOffset: outputOffset,
belowHandleCols: us.belowHandleCols,
cacheTable: us.cacheTable,
}
}
func (m *memIndexReader) getMemRows(ctx context.Context) ([][]types.Datum, error) {
if span := opentracing.SpanFromContext(ctx); span != nil && span.Tracer() != nil {
span1 := span.Tracer().StartSpan("memIndexReader.getMemRows", opentracing.ChildOf(span.Context()))
defer span1.Finish()
opentracing.ContextWithSpan(ctx, span1)
}
tps := make([]*types.FieldType, 0, len(m.index.Columns)+1)
cols := m.table.Columns
for _, col := range m.index.Columns {
tps = append(tps, &cols[col.Offset].FieldType)
}
switch {
case m.table.PKIsHandle:
for _, col := range m.table.Columns {
if mysql.HasPriKeyFlag(col.GetFlag()) {
tps = append(tps, &(col.FieldType))
break
}
}
case m.table.IsCommonHandle:
pkIdx := tables.FindPrimaryIndex(m.table)
for _, pkCol := range pkIdx.Columns {
colInfo := m.table.Columns[pkCol.Offset]
tps = append(tps, &colInfo.FieldType)
}
default: // ExtraHandle Column tp.
tps = append(tps, types.NewFieldType(mysql.TypeLonglong))
}
mutableRow := chunk.MutRowFromTypes(m.retFieldTypes)
err := iterTxnMemBuffer(m.ctx, m.cacheTable, m.kvRanges, func(key, value []byte) error {
data, err := m.decodeIndexKeyValue(key, value, tps)
if err != nil {
return err
}
mutableRow.SetDatums(data...)
matched, _, err := expression.EvalBool(m.ctx, m.conditions, mutableRow.ToRow())
if err != nil || !matched {
return err
}
m.addedRows = append(m.addedRows, data)
return nil
})
if err != nil {
return nil, err
}
// TODO: After refine `IterReverse`, remove below logic and use `IterReverse` when do reverse scan.
if m.desc {
reverseDatumSlice(m.addedRows)
}
return m.addedRows, nil
}
func (m *memIndexReader) decodeIndexKeyValue(key, value []byte, tps []*types.FieldType) ([]types.Datum, error) {
hdStatus := tablecodec.HandleDefault
if mysql.HasUnsignedFlag(tps[len(tps)-1].GetFlag()) {
hdStatus = tablecodec.HandleIsUnsigned
}
colInfos := tables.BuildRowcodecColInfoForIndexColumns(m.index, m.table)
colInfos = tables.TryAppendCommonHandleRowcodecColInfos(colInfos, m.table)
values, err := tablecodec.DecodeIndexKV(key, value, len(m.index.Columns), hdStatus, colInfos)
if err != nil {
return nil, errors.Trace(err)
}
ds := make([]types.Datum, 0, len(m.outputOffset))
for _, offset := range m.outputOffset {
d, err := tablecodec.DecodeColumnValue(values[offset], tps[offset], m.ctx.GetSessionVars().Location())
if err != nil {
return nil, err
}
ds = append(ds, d)
}
return ds, nil
}
type memTableReader struct {
ctx sessionctx.Context
table *model.TableInfo
columns []*model.ColumnInfo
kvRanges []kv.KeyRange
desc bool
conditions []expression.Expression
addedRows [][]types.Datum
retFieldTypes []*types.FieldType
colIDs map[int64]int
buffer allocBuf
pkColIDs []int64
cacheTable kv.MemBuffer
offsets []int
}
type allocBuf struct {
// cache for decode handle.
handleBytes []byte
rd *rowcodec.BytesDecoder
}
func buildMemTableReader(ctx context.Context, us *UnionScanExec, tblReader *TableReaderExecutor) *memTableReader {
if span := opentracing.SpanFromContext(ctx); span != nil && span.Tracer() != nil {
span1 := span.Tracer().StartSpan("buildMemTableReader", opentracing.ChildOf(span.Context()))
defer span1.Finish()
opentracing.ContextWithSpan(ctx, span1)
}
colIDs := make(map[int64]int, len(us.columns))
for i, col := range us.columns {
colIDs[col.ID] = i
}
colInfo := make([]rowcodec.ColInfo, 0, len(us.columns))
for i := range us.columns {
col := us.columns[i]
colInfo = append(colInfo, rowcodec.ColInfo{
ID: col.ID,
IsPKHandle: us.table.Meta().PKIsHandle && mysql.HasPriKeyFlag(col.GetFlag()),
Ft: rowcodec.FieldTypeFromModelColumn(col),
})
}
pkColIDs := tables.TryGetCommonPkColumnIds(us.table.Meta())
if len(pkColIDs) == 0 {
pkColIDs = []int64{-1}
}
rd := rowcodec.NewByteDecoder(colInfo, pkColIDs, nil, us.ctx.GetSessionVars().Location())
return &memTableReader{
ctx: us.ctx,
table: us.table.Meta(),
columns: us.columns,
kvRanges: tblReader.kvRanges,
desc: us.desc,
conditions: us.conditions,
retFieldTypes: retTypes(us),
colIDs: colIDs,
buffer: allocBuf{
handleBytes: make([]byte, 0, 16),
rd: rd,
},
pkColIDs: pkColIDs,
cacheTable: us.cacheTable,
}
}
// TODO: Try to make memXXXReader lazy, There is no need to decode many rows when parent operator only need 1 row.
func (m *memTableReader) getMemRows(ctx context.Context) ([][]types.Datum, error) {
if span := opentracing.SpanFromContext(ctx); span != nil && span.Tracer() != nil {
span1 := span.Tracer().StartSpan("memTableReader.getMemRows", opentracing.ChildOf(span.Context()))
defer span1.Finish()
opentracing.ContextWithSpan(ctx, span1)
}
mutableRow := chunk.MutRowFromTypes(m.retFieldTypes)
resultRows := make([]types.Datum, len(m.columns))
m.offsets = make([]int, len(m.columns))
for i, col := range m.columns {
m.offsets[i] = m.colIDs[col.ID]
}
err := iterTxnMemBuffer(m.ctx, m.cacheTable, m.kvRanges, func(key, value []byte) error {
var err error
resultRows, err = m.decodeRecordKeyValue(key, value, &resultRows)
if err != nil {
return err
}
mutableRow.SetDatums(resultRows...)
matched, _, err := expression.EvalBool(m.ctx, m.conditions, mutableRow.ToRow())
if err != nil || !matched {
return err
}
m.addedRows = append(m.addedRows, resultRows)
resultRows = make([]types.Datum, len(m.columns))
return nil
})
if err != nil {
return nil, err
}
// TODO: After refine `IterReverse`, remove below logic and use `IterReverse` when do reverse scan.
if m.desc {
reverseDatumSlice(m.addedRows)
}
return m.addedRows, nil
}
func (m *memTableReader) decodeRecordKeyValue(key, value []byte, resultRows *[]types.Datum) ([]types.Datum, error) {
handle, err := tablecodec.DecodeRowKey(key)
if err != nil {
return nil, errors.Trace(err)
}
return m.decodeRowData(handle, value, resultRows)
}
// decodeRowData uses to decode row data value.
func (m *memTableReader) decodeRowData(handle kv.Handle, value []byte, resultRows *[]types.Datum) ([]types.Datum, error) {
values, err := m.getRowData(handle, value)
if err != nil {
return nil, err
}
for i, col := range m.columns {
var datum types.Datum
err := tablecodec.DecodeColumnValueWithDatum(values[m.offsets[i]], &col.FieldType, m.ctx.GetSessionVars().Location(), &datum)
if err != nil {
return nil, err
}
(*resultRows)[i] = datum
}
return *resultRows, nil
}
// getRowData decodes raw byte slice to row data.
func (m *memTableReader) getRowData(handle kv.Handle, value []byte) ([][]byte, error) {
colIDs := m.colIDs
pkIsHandle := m.table.PKIsHandle
buffer := &m.buffer
ctx := m.ctx.GetSessionVars().StmtCtx
if rowcodec.IsNewFormat(value) {
return buffer.rd.DecodeToBytes(colIDs, handle, value, buffer.handleBytes)
}
values, err := tablecodec.CutRowNew(value, colIDs)
if err != nil {
return nil, errors.Trace(err)
}
if values == nil {
values = make([][]byte, len(colIDs))
}
// Fill the handle and null columns.
for _, col := range m.columns {
id := col.ID
offset := colIDs[id]
if m.table.IsCommonHandle {
for i, colID := range m.pkColIDs {
if colID == col.ID && !types.NeedRestoredData(&col.FieldType) {
// Only try to decode handle when there is no corresponding column in the value.
// This is because the information in handle may be incomplete in some cases.
// For example, prefixed clustered index like 'primary key(col1(1))' only store the leftmost 1 char in the handle.
if values[offset] == nil {
values[offset] = handle.EncodedCol(i)
break
}
}
}
} else if (pkIsHandle && mysql.HasPriKeyFlag(col.GetFlag())) || id == model.ExtraHandleID {
var handleDatum types.Datum
if mysql.HasUnsignedFlag(col.GetFlag()) {
// PK column is Unsigned.
handleDatum = types.NewUintDatum(uint64(handle.IntValue()))
} else {
handleDatum = types.NewIntDatum(handle.IntValue())
}
handleData, err1 := codec.EncodeValue(ctx, buffer.handleBytes, handleDatum)
if err1 != nil {
return nil, errors.Trace(err1)
}
values[offset] = handleData
continue
}
if hasColVal(values, colIDs, id) {
continue
}
// no need to fill default value.
values[offset] = []byte{codec.NilFlag}
}
return values, nil
}
// getMemRowsHandle is called when memIndexMergeReader.partialPlans[i] is TableScan.
func (m *memTableReader) getMemRowsHandle() ([]kv.Handle, error) {
handles := make([]kv.Handle, 0, 16)
err := iterTxnMemBuffer(m.ctx, m.cacheTable, m.kvRanges, func(key, value []byte) error {
handle, err := tablecodec.DecodeRowKey(key)
if err != nil {
return err
}
handles = append(handles, handle)
return nil
})
if err != nil {
return nil, err
}
if m.desc {
for i, j := 0, len(handles)-1; i < j; i, j = i+1, j-1 {
handles[i], handles[j] = handles[j], handles[i]
}
}
return handles, nil
}
func hasColVal(data [][]byte, colIDs map[int64]int, id int64) bool {
offset, ok := colIDs[id]
if ok && data[offset] != nil {
return true
}
return false
}
type processKVFunc func(key, value []byte) error
func iterTxnMemBuffer(ctx sessionctx.Context, cacheTable kv.MemBuffer, kvRanges []kv.KeyRange, fn processKVFunc) error {
txn, err := ctx.Txn(true)
if err != nil {
return err
}
for _, rg := range kvRanges {
iter := txn.GetMemBuffer().SnapshotIter(rg.StartKey, rg.EndKey)
snapCacheIter, err := getSnapIter(ctx, cacheTable, rg)
if err != nil {
return err
}
if snapCacheIter != nil {
iter, err = transaction.NewUnionIter(iter, snapCacheIter, false)
if err != nil {
return err
}
}
for ; iter.Valid(); err = iter.Next() {
if err != nil {
return err
}
// check whether the key was been deleted.
if len(iter.Value()) == 0 {
continue
}
err = fn(iter.Key(), iter.Value())
if err != nil {
return err
}
}
}
return nil
}
func getSnapIter(ctx sessionctx.Context, cacheTable kv.MemBuffer, rg kv.KeyRange) (kv.Iterator, error) {
var snapCacheIter kv.Iterator
tempTableData := ctx.GetSessionVars().TemporaryTableData
if tempTableData != nil {
snapIter, err := tempTableData.Iter(rg.StartKey, rg.EndKey)
if err != nil {
return nil, err
}
snapCacheIter = snapIter
} else if cacheTable != nil {
cacheIter, err := cacheTable.Iter(rg.StartKey, rg.EndKey)
if err != nil {
return nil, errors.Trace(err)
}
snapCacheIter = cacheIter
}
return snapCacheIter, nil
}
func reverseDatumSlice(rows [][]types.Datum) {
for i, j := 0, len(rows)-1; i < j; i, j = i+1, j-1 {
rows[i], rows[j] = rows[j], rows[i]
}
}
func (m *memIndexReader) getMemRowsHandle() ([]kv.Handle, error) {
handles := make([]kv.Handle, 0, m.addedRowsLen)
err := iterTxnMemBuffer(m.ctx, m.cacheTable, m.kvRanges, func(key, value []byte) error {
handle, err := tablecodec.DecodeIndexHandle(key, value, len(m.index.Columns))
if err != nil {
return err
}
handles = append(handles, handle)
return nil
})
if err != nil {
return nil, err
}
if m.desc {
for i, j := 0, len(handles)-1; i < j; i, j = i+1, j-1 {
handles[i], handles[j] = handles[j], handles[i]
}
}
return handles, nil
}
type memIndexLookUpReader struct {
ctx sessionctx.Context
index *model.IndexInfo
columns []*model.ColumnInfo
table table.Table
desc bool
conditions []expression.Expression
retFieldTypes []*types.FieldType
idxReader *memIndexReader
// partition mode
partitionMode bool // if it is accessing a partition table
partitionTables []table.PhysicalTable // partition tables to access
partitionKVRanges [][]kv.KeyRange // kv ranges for these partition tables
cacheTable kv.MemBuffer
}
func buildMemIndexLookUpReader(ctx context.Context, us *UnionScanExec, idxLookUpReader *IndexLookUpExecutor) *memIndexLookUpReader {
if span := opentracing.SpanFromContext(ctx); span != nil && span.Tracer() != nil {
span1 := span.Tracer().StartSpan("buildMemIndexLookUpReader", opentracing.ChildOf(span.Context()))
defer span1.Finish()
opentracing.ContextWithSpan(ctx, span1)
}
kvRanges := idxLookUpReader.kvRanges
outputOffset := []int{len(idxLookUpReader.index.Columns)}
memIdxReader := &memIndexReader{
ctx: us.ctx,
index: idxLookUpReader.index,
table: idxLookUpReader.table.Meta(),
kvRanges: kvRanges,
desc: idxLookUpReader.desc,
retFieldTypes: retTypes(us),
outputOffset: outputOffset,
belowHandleCols: us.belowHandleCols,
cacheTable: us.cacheTable,
}
return &memIndexLookUpReader{
ctx: us.ctx,
index: idxLookUpReader.index,
columns: idxLookUpReader.columns,
table: idxLookUpReader.table,
desc: idxLookUpReader.desc,
conditions: us.conditions,
retFieldTypes: retTypes(us),
idxReader: memIdxReader,
partitionMode: idxLookUpReader.partitionTableMode,
partitionKVRanges: idxLookUpReader.partitionKVRanges,
partitionTables: idxLookUpReader.prunedPartitions,
cacheTable: us.cacheTable,
}
}
func (m *memIndexLookUpReader) getMemRows(ctx context.Context) ([][]types.Datum, error) {
if span := opentracing.SpanFromContext(ctx); span != nil && span.Tracer() != nil {
span1 := span.Tracer().StartSpan("memIndexLookUpReader.getMemRows", opentracing.ChildOf(span.Context()))
defer span1.Finish()
ctx = opentracing.ContextWithSpan(ctx, span1)
}
kvRanges := [][]kv.KeyRange{m.idxReader.kvRanges}
tbls := []table.Table{m.table}
if m.partitionMode {
m.idxReader.desc = false // keep-order if always false for IndexLookUp reading partitions so this parameter makes no sense
kvRanges = m.partitionKVRanges
tbls = tbls[:0]
for _, p := range m.partitionTables {
tbls = append(tbls, p)
}
}
tblKVRanges := make([]kv.KeyRange, 0, 16)
numHandles := 0
for i, tbl := range tbls {
m.idxReader.kvRanges = kvRanges[i]
handles, err := m.idxReader.getMemRowsHandle()
if err != nil {
return nil, err
}
if len(handles) == 0 {
continue
}
numHandles += len(handles)
tblKVRanges = append(tblKVRanges, distsql.TableHandlesToKVRanges(getPhysicalTableID(tbl), handles)...)
}
if numHandles == 0 {
return nil, nil
}
colIDs, pkColIDs, rd := getColIDAndPkColIDs(m.table, m.columns)
memTblReader := &memTableReader{
ctx: m.ctx,
table: m.table.Meta(),
columns: m.columns,
kvRanges: tblKVRanges,
conditions: m.conditions,
addedRows: make([][]types.Datum, 0, numHandles),
retFieldTypes: m.retFieldTypes,
colIDs: colIDs,
pkColIDs: pkColIDs,
buffer: allocBuf{
handleBytes: make([]byte, 0, 16),
rd: rd,
},
cacheTable: m.cacheTable,
}
return memTblReader.getMemRows(ctx)
}
func (m *memIndexLookUpReader) getMemRowsHandle() ([]kv.Handle, error) {
return nil, errors.New("getMemRowsHandle has not been implemented for memIndexLookUpReader")
}
type memIndexMergeReader struct {
ctx sessionctx.Context
columns []*model.ColumnInfo
table table.Table
conditions []expression.Expression
retFieldTypes []*types.FieldType
indexMergeReader *IndexMergeReaderExecutor
memReaders []memReader
// partition mode
partitionMode bool // if it is accessing a partition table
partitionTables []table.PhysicalTable // partition tables to access
partitionKVRanges [][][]kv.KeyRange // kv ranges for these partition tables
}
func buildMemIndexMergeReader(ctx context.Context, us *UnionScanExec, indexMergeReader *IndexMergeReaderExecutor) *memIndexMergeReader {
if span := opentracing.SpanFromContext(ctx); span != nil && span.Tracer() != nil {
span1 := span.Tracer().StartSpan("buildMemIndexMergeReader", opentracing.ChildOf(span.Context()))
defer span1.Finish()
opentracing.ContextWithSpan(ctx, span1)
}
indexCount := len(indexMergeReader.indexes)
memReaders := make([]memReader, 0, indexCount)
for i := 0; i < indexCount; i++ {
if indexMergeReader.indexes[i] == nil {
colIDs, pkColIDs, rd := getColIDAndPkColIDs(indexMergeReader.table, indexMergeReader.columns)
memReaders = append(memReaders, &memTableReader{
ctx: us.ctx,
table: indexMergeReader.table.Meta(),
columns: indexMergeReader.columns,
kvRanges: nil,
conditions: us.conditions,
addedRows: make([][]types.Datum, 0),
retFieldTypes: retTypes(us),
colIDs: colIDs,
pkColIDs: pkColIDs,
buffer: allocBuf{
handleBytes: make([]byte, 0, 16),
rd: rd,
},
})
} else {
outputOffset := []int{len(indexMergeReader.indexes[i].Columns)}
memReaders = append(memReaders, &memIndexReader{
ctx: us.ctx,
index: indexMergeReader.indexes[i],
table: indexMergeReader.table.Meta(),
kvRanges: nil,
desc: indexMergeReader.descs[i],
retFieldTypes: retTypes(us),
outputOffset: outputOffset,
belowHandleCols: us.belowHandleCols,
})
}
}
return &memIndexMergeReader{
ctx: us.ctx,
table: indexMergeReader.table,
columns: indexMergeReader.columns,
conditions: us.conditions,
retFieldTypes: retTypes(us),
indexMergeReader: indexMergeReader,
memReaders: memReaders,
partitionMode: indexMergeReader.partitionTableMode,
partitionTables: indexMergeReader.prunedPartitions,
partitionKVRanges: indexMergeReader.partitionKeyRanges,
}
}
func (m *memIndexMergeReader) getMemRows(ctx context.Context) ([][]types.Datum, error) {
if span := opentracing.SpanFromContext(ctx); span != nil && span.Tracer() != nil {
span1 := span.Tracer().StartSpan("memIndexMergeReader.getMemRows", opentracing.ChildOf(span.Context()))
defer span1.Finish()
ctx = opentracing.ContextWithSpan(ctx, span1)
}
tbls := []table.Table{m.table}
// [partNum][indexNum][rangeNum]
var kvRanges [][][]kv.KeyRange
if m.partitionMode {
tbls = tbls[:0]
for _, p := range m.partitionTables {
tbls = append(tbls, p)
}
kvRanges = m.partitionKVRanges
} else {
kvRanges = append(kvRanges, m.indexMergeReader.keyRanges)
}
tblKVRanges := make([]kv.KeyRange, 0, 16)
numHandles := 0
for i, tbl := range tbls {
handles, err := m.unionHandles(kvRanges[i])
if err != nil {
return nil, err
}
if len(handles) == 0 {
continue
}
numHandles += len(handles)
tblKVRanges = append(tblKVRanges, distsql.TableHandlesToKVRanges(getPhysicalTableID(tbl), handles)...)
}
if numHandles == 0 {
return nil, nil
}
colIDs, pkColIDs, rd := getColIDAndPkColIDs(m.table, m.columns)
memTblReader := &memTableReader{
ctx: m.ctx,
table: m.table.Meta(),
columns: m.columns,
kvRanges: tblKVRanges,
conditions: m.conditions,
addedRows: make([][]types.Datum, 0, numHandles),
retFieldTypes: m.retFieldTypes,
colIDs: colIDs,
pkColIDs: pkColIDs,
buffer: allocBuf{
handleBytes: make([]byte, 0, 16),
rd: rd,
},
}
return memTblReader.getMemRows(ctx)
}
// Union all handles of different Indexes.
func (m *memIndexMergeReader) unionHandles(kvRanges [][]kv.KeyRange) (finalHandles []kv.Handle, err error) {
if len(m.memReaders) != len(kvRanges) {
return nil, errors.Errorf("len(kvRanges) should be equal to len(memReaders)")
}
hMap := kv.NewHandleMap()
var handles []kv.Handle
for i, reader := range m.memReaders {
switch r := reader.(type) {
case *memTableReader:
r.kvRanges = kvRanges[i]
case *memIndexReader:
r.kvRanges = kvRanges[i]
default:
return nil, errors.New("memReader have to be memTableReader or memIndexReader")
}
if handles, err = reader.getMemRowsHandle(); err != nil {
return nil, err
}
// Filter same row.
for _, h := range handles {
if _, ok := hMap.Get(h); !ok {
finalHandles = append(finalHandles, h)
hMap.Set(h, true)
}
}
}
return finalHandles, nil
}
func (m *memIndexMergeReader) getMemRowsHandle() ([]kv.Handle, error) {
return nil, errors.New("getMemRowsHandle has not been implemented for memIndexMergeReader")
}
func getColIDAndPkColIDs(table table.Table, columns []*model.ColumnInfo) (map[int64]int, []int64, *rowcodec.BytesDecoder) {
colIDs := make(map[int64]int, len(columns))
for i, col := range columns {
colIDs[col.ID] = i
}
tblInfo := table.Meta()
colInfos := make([]rowcodec.ColInfo, 0, len(columns))
for i := range columns {
col := columns[i]
colInfos = append(colInfos, rowcodec.ColInfo{
ID: col.ID,
IsPKHandle: tblInfo.PKIsHandle && mysql.HasPriKeyFlag(col.GetFlag()),
Ft: rowcodec.FieldTypeFromModelColumn(col),
})
}
pkColIDs := tables.TryGetCommonPkColumnIds(tblInfo)
if len(pkColIDs) == 0 {
pkColIDs = []int64{-1}
}
rd := rowcodec.NewByteDecoder(colInfos, pkColIDs, nil, nil)
return colIDs, pkColIDs, rd
}
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