yq/pkg/yqlib/all_at_once_evaluator.go

84 lines
2.5 KiB
Go

package yqlib
import (
"container/list"
yaml "gopkg.in/yaml.v3"
)
// A yaml expression evaluator that runs the expression once against all files/nodes in memory.
type Evaluator interface {
EvaluateFiles(expression string, filenames []string, printer Printer, decoder Decoder) error
// EvaluateNodes takes an expression and one or more yaml nodes, returning a list of matching candidate nodes
EvaluateNodes(expression string, nodes ...*yaml.Node) (*list.List, error)
// EvaluateCandidateNodes takes an expression and list of candidate nodes, returning a list of matching candidate nodes
EvaluateCandidateNodes(expression string, inputCandidateNodes *list.List) (*list.List, error)
}
type allAtOnceEvaluator struct {
treeNavigator DataTreeNavigator
}
func NewAllAtOnceEvaluator() Evaluator {
InitExpressionParser()
return &allAtOnceEvaluator{treeNavigator: NewDataTreeNavigator()}
}
func (e *allAtOnceEvaluator) EvaluateNodes(expression string, nodes ...*yaml.Node) (*list.List, error) {
inputCandidates := list.New()
for _, node := range nodes {
inputCandidates.PushBack(&CandidateNode{Node: node})
}
return e.EvaluateCandidateNodes(expression, inputCandidates)
}
func (e *allAtOnceEvaluator) EvaluateCandidateNodes(expression string, inputCandidates *list.List) (*list.List, error) {
node, err := ExpressionParser.ParseExpression(expression)
if err != nil {
return nil, err
}
context, err := e.treeNavigator.GetMatchingNodes(Context{MatchingNodes: inputCandidates}, node)
if err != nil {
return nil, err
}
return context.MatchingNodes, nil
}
func (e *allAtOnceEvaluator) EvaluateFiles(expression string, filenames []string, printer Printer, decoder Decoder) error {
fileIndex := 0
var allDocuments = list.New()
for _, filename := range filenames {
reader, err := readStream(filename)
if err != nil {
return err
}
fileDocuments, err := readDocuments(reader, filename, fileIndex, decoder)
if err != nil {
return err
}
allDocuments.PushBackList(fileDocuments)
fileIndex = fileIndex + 1
}
if allDocuments.Len() == 0 {
candidateNode := &CandidateNode{
Document: 0,
Filename: "",
Node: &yaml.Node{Kind: yaml.DocumentNode, Content: []*yaml.Node{{Tag: "!!null", Kind: yaml.ScalarNode}}},
FileIndex: 0,
LeadingContent: "",
}
allDocuments.PushBack(candidateNode)
}
matches, err := e.EvaluateCandidateNodes(expression, allDocuments)
if err != nil {
return err
}
return printer.PrintResults(matches)
}