yq/pkg/yqlib/operator_group_by.go

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2021-10-26 04:07:50 +00:00
package yqlib
import (
"container/list"
"fmt"
"github.com/elliotchance/orderedmap"
yaml "gopkg.in/yaml.v3"
)
func processIntoGroups(d *dataTreeNavigator, context Context, rhsExp *ExpressionNode, node *yaml.Node) (*orderedmap.OrderedMap, error) {
var newMatches = orderedmap.NewOrderedMap()
for _, node := range node.Content {
child := &CandidateNode{Node: node}
rhs, err := d.GetMatchingNodes(context.SingleReadonlyChildContext(child), rhsExp)
if err != nil {
return nil, err
}
keyValue := "null"
if rhs.MatchingNodes.Len() > 0 {
first := rhs.MatchingNodes.Front()
keyCandidate := first.Value.(*CandidateNode)
keyValue = keyCandidate.Node.Value
}
groupList, exists := newMatches.Get(keyValue)
if !exists {
groupList = list.New()
newMatches.Set(keyValue, groupList)
}
groupList.(*list.List).PushBack(node)
}
return newMatches, nil
}
func groupBy(d *dataTreeNavigator, context Context, expressionNode *ExpressionNode) (Context, error) {
log.Debugf("-- groupBy Operator")
var results = list.New()
for el := context.MatchingNodes.Front(); el != nil; el = el.Next() {
candidate := el.Value.(*CandidateNode)
candidateNode := unwrapDoc(candidate.Node)
if candidateNode.Kind != yaml.SequenceNode {
return Context{}, fmt.Errorf("Only arrays are supported for group by")
}
newMatches, err := processIntoGroups(d, context, expressionNode.Rhs, candidateNode)
if err != nil {
return Context{}, err
}
resultNode := &yaml.Node{Kind: yaml.SequenceNode, Tag: "!!seq"}
for groupEl := newMatches.Front(); groupEl != nil; groupEl = groupEl.Next() {
groupResultNode := &yaml.Node{Kind: yaml.SequenceNode, Tag: "!!seq"}
groupList := groupEl.Value.(*list.List)
for groupItem := groupList.Front(); groupItem != nil; groupItem = groupItem.Next() {
groupResultNode.Content = append(groupResultNode.Content, groupItem.Value.(*yaml.Node))
}
resultNode.Content = append(resultNode.Content, groupResultNode)
}
results.PushBack(candidate.CreateChild(nil, resultNode))
}
return context.ChildContext(results), nil
}