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

     1  // Copyright 2022 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  	"strings"
    20  
    21  	"github.com/dolthub/go-mysql-server/sql"
    22  )
    23  
    24  // NamedWindows is a list of WINDOW clause definitions
    25  // to be resolved and merged into OVER clause sql.Window
    26  // nodes.
    27  type NamedWindows struct {
    28  	UnaryNode
    29  	WindowDefs map[string]*sql.WindowDefinition
    30  }
    31  
    32  var _ sql.Node = (*NamedWindows)(nil)
    33  var _ sql.CollationCoercible = (*NamedWindows)(nil)
    34  
    35  func NewNamedWindows(windowDefs map[string]*sql.WindowDefinition, child sql.Node) *NamedWindows {
    36  	return &NamedWindows{
    37  		UnaryNode:  UnaryNode{Child: child},
    38  		WindowDefs: windowDefs,
    39  	}
    40  }
    41  
    42  func (n *NamedWindows) IsReadOnly() bool {
    43  	return n.Child.IsReadOnly()
    44  }
    45  
    46  // String implements sql.Node
    47  func (n *NamedWindows) String() string {
    48  	var sb strings.Builder
    49  	sb.WriteString("NamedWindows(")
    50  	var sep string
    51  	for n, def := range n.WindowDefs {
    52  		sb.WriteString(strings.ReplaceAll(fmt.Sprintf("%s%s %s", sep, n, def), "over", "as"))
    53  		sep = ", "
    54  	}
    55  	pr := sql.NewTreePrinter()
    56  	sb.WriteString(")")
    57  	_ = pr.WriteNode(sb.String())
    58  	_ = pr.WriteChildren(n.Child.String())
    59  	return pr.String()
    60  }
    61  
    62  // DebugString implements sql.Node
    63  func (n *NamedWindows) DebugString() string {
    64  	var sb strings.Builder
    65  	sb.WriteString("NamedWindows(")
    66  	var sep string
    67  	for n, def := range n.WindowDefs {
    68  		sb.WriteString(strings.ReplaceAll(fmt.Sprintf("%s%s %s", sep, n, def.DebugString()), "over", "as"))
    69  		sep = ", "
    70  	}
    71  	pr := sql.NewTreePrinter()
    72  	sb.WriteString(")")
    73  	_ = pr.WriteNode(sb.String())
    74  	_ = pr.WriteChildren(sql.DebugString(n.Child))
    75  	return pr.String()
    76  }
    77  
    78  // RowIter implements sql.Node
    79  func (n *NamedWindows) RowIter(ctx *sql.Context, row sql.Row) (sql.RowIter, error) {
    80  	panic("cannot iterate *plan.NamedWindows")
    81  }
    82  
    83  // WithChildren implements sql.Node
    84  func (n *NamedWindows) WithChildren(nodes ...sql.Node) (sql.Node, error) {
    85  	if len(nodes) != 1 {
    86  		return nil, sql.ErrInvalidChildrenNumber.New(n, len(nodes), 1)
    87  	}
    88  	return NewNamedWindows(n.WindowDefs, nodes[0]), nil
    89  }
    90  
    91  // CheckPrivileges implements sql.Node
    92  func (n *NamedWindows) CheckPrivileges(ctx *sql.Context, opChecker sql.PrivilegedOperationChecker) bool {
    93  	return n.Child.CheckPrivileges(ctx, opChecker)
    94  }
    95  
    96  // CollationCoercibility implements the interface sql.CollationCoercible.
    97  func (n *NamedWindows) CollationCoercibility(ctx *sql.Context) (collation sql.CollationID, coercibility byte) {
    98  	return sql.GetCoercibility(ctx, n.Child)
    99  }