Files
tidb/rset/rsets/limit.go
2015-09-08 19:25:50 +08:00

62 lines
1.6 KiB
Go

// Copyright 2014 The ql Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSES/QL-LICENSE file.
// Copyright 2015 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,
// See the License for the specific language governing permissions and
// limitations under the License.
package rsets
import (
"fmt"
"github.com/pingcap/tidb/context"
"github.com/pingcap/tidb/plan"
"github.com/pingcap/tidb/plan/plans"
)
var (
_ plan.Planner = (*LimitRset)(nil)
_ plan.Planner = (*OffsetRset)(nil)
)
// OffsetRset is record set for limit offset.
type OffsetRset struct {
Count uint64
Src plan.Plan
}
// Plan gets OffsetDefaultPlan.
func (r *OffsetRset) Plan(ctx context.Context) (plan.Plan, error) {
return &plans.OffsetDefaultPlan{Count: r.Count, Src: r.Src, Fields: r.Src.GetFields()}, nil
}
func (r *OffsetRset) String() string {
return fmt.Sprintf(" OFFSET %d", r.Count)
}
// LimitRset is record set for limit.
type LimitRset struct {
Count uint64
Src plan.Plan
}
// Plan gets LimitDefaultPlan.
func (r *LimitRset) Plan(ctx context.Context) (plan.Plan, error) {
return &plans.LimitDefaultPlan{Count: r.Count, Src: r.Src, Fields: r.Src.GetFields()}, nil
}
func (r *LimitRset) String() string {
return fmt.Sprintf(" LIMIT %d", r.Count)
}