/
table_iter.go
86 lines (72 loc) · 1.92 KB
/
table_iter.go
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// Copyright 2020-2021 Dolthub, 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 sql
import (
"io"
)
// TableRowIter is an iterator over the partitions in a table.
type TableRowIter struct {
ctx *Context
table Table
partitions PartitionIter
partition Partition
rows RowIter
}
// NewTableRowIter returns a new iterator over the rows in the partitions of the table given.
func NewTableRowIter(ctx *Context, table Table, partitions PartitionIter) *TableRowIter {
return &TableRowIter{ctx: ctx, table: table, partitions: partitions}
}
func (i *TableRowIter) Next() (Row, error) {
if i.ctx.Err() != nil {
return nil, i.ctx.Err()
}
if i.partition == nil {
partition, err := i.partitions.Next()
if err != nil {
if err == io.EOF {
if e := i.partitions.Close(i.ctx); e != nil {
return nil, e
}
}
return nil, err
}
i.partition = partition
}
if i.rows == nil {
rows, err := i.table.PartitionRows(i.ctx, i.partition)
if err != nil {
return nil, err
}
i.rows = rows
}
row, err := i.rows.Next()
if err != nil && err == io.EOF {
if err = i.rows.Close(i.ctx); err != nil {
return nil, err
}
i.partition = nil
i.rows = nil
return i.Next()
}
return row, err
}
func (i *TableRowIter) Close(ctx *Context) error {
if i.rows != nil {
if err := i.rows.Close(ctx); err != nil {
_ = i.partitions.Close(ctx)
return err
}
}
return i.partitions.Close(ctx)
}