本文整理汇总了Golang中github.com/pingcap/tidb/kv.Iterator类的典型用法代码示例。如果您正苦于以下问题:Golang Iterator类的具体用法?Golang Iterator怎么用?Golang Iterator使用的例子?那么恭喜您, 这里精选的类代码示例或许可以为您提供帮助。
在下文中一共展示了Iterator类的5个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于我们的系统推荐出更棒的Golang代码示例。
示例1: getIndexRowFromRange
func (rs *localRegion) getIndexRowFromRange(ctx *selectContext, ran kv.KeyRange, desc bool, limit int64) (count int64, err error) {
idxInfo := ctx.sel.IndexInfo
txn := ctx.txn
var seekKey kv.Key
if desc {
seekKey = ran.EndKey
} else {
seekKey = ran.StartKey
}
ids := make([]int64, len(idxInfo.Columns))
for i, col := range idxInfo.Columns {
ids[i] = col.GetColumnId()
}
for {
if limit == 0 {
break
}
var it kv.Iterator
if desc {
it, err = txn.SeekReverse(seekKey)
if err != nil {
return 0, errors.Trace(err)
}
seekKey = it.Key()
} else {
it, err = txn.Seek(seekKey)
if err != nil {
return 0, errors.Trace(err)
}
seekKey = it.Key().PrefixNext()
}
if !it.Valid() {
break
}
if desc {
if it.Key().Cmp(ran.StartKey) < 0 {
break
}
} else {
if it.Key().Cmp(ran.EndKey) >= 0 {
break
}
}
values, b, err1 := tablecodec.CutIndexKey(it.Key(), ids)
if err1 != nil {
return 0, errors.Trace(err1)
}
var handle int64
if len(b) > 0 {
var handleDatum types.Datum
_, handleDatum, err = codec.DecodeOne(b)
if err != nil {
return 0, errors.Trace(err)
}
handle = handleDatum.GetInt64()
} else {
handle, err = decodeHandle(it.Value())
if err != nil {
return 0, errors.Trace(err)
}
}
gotRow, err := rs.valuesToRow(ctx, handle, values)
if err != nil {
return 0, errors.Trace(err)
}
if gotRow {
limit--
count++
}
}
return count, nil
}
开发者ID:jmptrader,项目名称:tidb,代码行数:72,代码来源:local_region.go
示例2: getRowsFromRange
func (rs *localRegion) getRowsFromRange(ctx *selectContext, ran kv.KeyRange, limit int64, desc bool) (count int64, err error) {
if limit == 0 {
return 0, nil
}
if ran.IsPoint() {
var value []byte
value, err = ctx.txn.Get(ran.StartKey)
if terror.ErrorEqual(err, kv.ErrNotExist) {
return 0, nil
} else if err != nil {
return 0, errors.Trace(err)
}
var h int64
h, err = tablecodec.DecodeRowKey(ran.StartKey)
if err != nil {
return 0, errors.Trace(err)
}
gotRow, err1 := rs.handleRowData(ctx, h, value)
if err1 != nil {
return 0, errors.Trace(err1)
}
if gotRow {
count++
}
return
}
var seekKey kv.Key
if desc {
seekKey = ran.EndKey
} else {
seekKey = ran.StartKey
}
for {
if limit == 0 {
break
}
var (
it kv.Iterator
err error
)
if desc {
it, err = ctx.txn.SeekReverse(seekKey)
} else {
it, err = ctx.txn.Seek(seekKey)
}
if err != nil {
return 0, errors.Trace(err)
}
if !it.Valid() {
break
}
if desc {
if it.Key().Cmp(ran.StartKey) < 0 {
break
}
seekKey = tablecodec.TruncateToRowKeyLen(it.Key())
} else {
if it.Key().Cmp(ran.EndKey) >= 0 {
break
}
seekKey = it.Key().PrefixNext()
}
h, err := tablecodec.DecodeRowKey(it.Key())
if err != nil {
return 0, errors.Trace(err)
}
gotRow, err := rs.handleRowData(ctx, h, it.Value())
if err != nil {
return 0, errors.Trace(err)
}
if gotRow {
limit--
count++
}
}
return count, nil
}
开发者ID:jmptrader,项目名称:tidb,代码行数:78,代码来源:local_region.go
示例3: getRowsFromRange
func (rs *localRegion) getRowsFromRange(ctx *selectContext, ran kv.KeyRange, limit int64, desc bool) ([]*tipb.Row, error) {
if limit == 0 {
return nil, nil
}
var rows []*tipb.Row
if ran.IsPoint() {
_, err := ctx.txn.Get(ran.StartKey)
if terror.ErrorEqual(err, kv.ErrNotExist) {
return nil, nil
} else if err != nil {
return nil, errors.Trace(err)
}
h, err := tablecodec.DecodeRowKey(ran.StartKey)
if err != nil {
return nil, errors.Trace(err)
}
match, err := rs.evalWhereForRow(ctx, h)
if err != nil {
return nil, errors.Trace(err)
}
if !match {
return nil, nil
}
row, err := rs.getRowByHandle(ctx, h)
if err != nil {
return nil, errors.Trace(err)
}
if row != nil {
rows = append(rows, row)
}
return rows, nil
}
var seekKey kv.Key
if desc {
seekKey = ran.EndKey
} else {
seekKey = ran.StartKey
}
for {
if limit == 0 {
break
}
var (
it kv.Iterator
err error
)
if desc {
it, err = ctx.txn.SeekReverse(seekKey)
} else {
it, err = ctx.txn.Seek(seekKey)
}
if err != nil {
return nil, errors.Trace(err)
}
if !it.Valid() {
break
}
if desc {
if it.Key().Cmp(ran.StartKey) < 0 {
break
}
seekKey = tablecodec.TruncateToRowKeyLen(it.Key())
} else {
if it.Key().Cmp(ran.EndKey) >= 0 {
break
}
seekKey = it.Key().PrefixNext()
}
h, err := tablecodec.DecodeRowKey(it.Key())
if err != nil {
return nil, errors.Trace(err)
}
match, err := rs.evalWhereForRow(ctx, h)
if err != nil {
return nil, errors.Trace(err)
}
if !match {
continue
}
row, err := rs.getRowByHandle(ctx, h)
if err != nil {
return nil, errors.Trace(err)
}
if row != nil {
rows = append(rows, row)
limit--
}
}
return rows, nil
}
开发者ID:anywhy,项目名称:tidb,代码行数:90,代码来源:local_region.go
示例4: getIndexRowFromRange
func getIndexRowFromRange(idxInfo *tipb.IndexInfo, txn kv.Transaction, ran kv.KeyRange, desc bool, limit int64) ([]*tipb.Row, error) {
var rows []*tipb.Row
var seekKey kv.Key
if desc {
seekKey = ran.EndKey
} else {
seekKey = ran.StartKey
}
for {
if limit == 0 {
break
}
var it kv.Iterator
var err error
if desc {
it, err = txn.SeekReverse(seekKey)
if err != nil {
return nil, errors.Trace(err)
}
seekKey = it.Key()
} else {
it, err = txn.Seek(seekKey)
if err != nil {
return nil, errors.Trace(err)
}
seekKey = it.Key().PrefixNext()
}
if !it.Valid() {
break
}
if desc {
if it.Key().Cmp(ran.StartKey) < 0 {
break
}
} else {
if it.Key().Cmp(ran.EndKey) >= 0 {
break
}
}
datums, err := tablecodec.DecodeIndexKey(it.Key())
if err != nil {
return nil, errors.Trace(err)
}
var handle types.Datum
if len(datums) > len(idxInfo.Columns) {
handle = datums[len(idxInfo.Columns)]
datums = datums[:len(idxInfo.Columns)]
} else {
var intHandle int64
intHandle, err = decodeHandle(it.Value())
if err != nil {
return nil, errors.Trace(err)
}
handle.SetInt64(intHandle)
}
data, err := codec.EncodeValue(nil, datums...)
if err != nil {
return nil, errors.Trace(err)
}
handleData, err := codec.EncodeValue(nil, handle)
if err != nil {
return nil, errors.Trace(err)
}
row := &tipb.Row{Handle: handleData, Data: data}
rows = append(rows, row)
limit--
}
return rows, nil
}
开发者ID:anywhy,项目名称:tidb,代码行数:71,代码来源:local_region.go
示例5: valToStr
func valToStr(c *C, iter kv.Iterator) string {
val := iter.Value()
return string(val)
}
开发者ID:yangxuanjia,项目名称:tidb,代码行数:4,代码来源:store_test.go
注:本文中的github.com/pingcap/tidb/kv.Iterator类示例由纯净天空整理自Github/MSDocs等源码及文档管理平台,相关代码片段筛选自各路编程大神贡献的开源项目,源码版权归原作者所有,传播和使用请参考对应项目的License;未经允许,请勿转载。 |
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