github.com/dolthub/go-mysql-server@v0.18.0/sql/plan/range_heap.go (about)

     1  // Copyright 2023 Dolthub, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package plan
    16  
    17  import (
    18  	"fmt"
    19  
    20  	"github.com/dolthub/go-mysql-server/sql"
    21  	"github.com/dolthub/go-mysql-server/sql/expression"
    22  )
    23  
    24  // RangeHeap is a Node that wraps a table with min and max range columns. When used as a secondary provider in Join
    25  // operations, it can efficiently compute the rows whose ranges bound the value from the other table. When the ranges
    26  // don't overlap, the amortized complexity is O(1) for each result row.
    27  type RangeHeap struct {
    28  	UnaryNode
    29  	ValueColumnIndex   int
    30  	MinColumnIndex     int
    31  	MaxColumnIndex     int
    32  	ValueColumnGf      sql.Expression
    33  	MinColumnGf        sql.Expression
    34  	MaxColumnGf        sql.Expression
    35  	ComparisonType     sql.Type
    36  	RangeIsClosedBelow bool
    37  	RangeIsClosedAbove bool
    38  }
    39  
    40  var _ sql.Node = (*RangeHeap)(nil)
    41  
    42  func NewRangeHeap(child sql.Node, value, min, max *expression.GetField, rangeIsClosedBelow, rangeIsClosedAbove bool) (*RangeHeap, error) {
    43  	newSr := &RangeHeap{
    44  		RangeIsClosedBelow: rangeIsClosedBelow,
    45  		RangeIsClosedAbove: rangeIsClosedAbove,
    46  		ValueColumnGf:      value,
    47  		MinColumnGf:        min,
    48  		MaxColumnGf:        max,
    49  	}
    50  	newSr.Child = child
    51  	return newSr, nil
    52  }
    53  
    54  func (s *RangeHeap) String() string {
    55  	return s.Child.String()
    56  }
    57  
    58  func (s *RangeHeap) DebugString() string {
    59  	return sql.DebugString(s.Child)
    60  }
    61  
    62  func (s *RangeHeap) IsReadOnly() bool {
    63  	return s.Child.IsReadOnly()
    64  }
    65  
    66  func (s *RangeHeap) WithChildren(children ...sql.Node) (sql.Node, error) {
    67  	if len(children) != 1 {
    68  		return nil, fmt.Errorf("ds")
    69  	}
    70  
    71  	s2 := *s
    72  	s2.UnaryNode = UnaryNode{Child: children[0]}
    73  	return &s2, nil
    74  }
    75  
    76  func (s *RangeHeap) CheckPrivileges(ctx *sql.Context, opChecker sql.PrivilegedOperationChecker) bool {
    77  	return s.Child.CheckPrivileges(ctx, opChecker)
    78  }
    79  
    80  var _ sql.Node = (*RangeHeap)(nil)