wip

pkg/yqlib/operator_load.go

@@ -0,0 +1,97 @@
+package yqlib
+
+import (
+	"bufio"
+	"container/list"
+	"fmt"
+	"io/ioutil"
+	"os"
+
+	"gopkg.in/yaml.v3"
+)
+
+type loadPrefs struct {
+	loadAsString bool
+}
+
+func loadString(filename string) (*CandidateNode, error) {
+	// ignore CWE-22 gosec issue - that's more targetted for http based apps that run in a public directory,
+	// and ensuring that it's not possible to give a path to a file outside that directory.
+
+	filebytes, err := ioutil.ReadFile(filename) // #nosec
+	if err != nil {
+		return nil, err
+	}
+
+	return &CandidateNode{Node: &yaml.Node{Kind: yaml.ScalarNode, Tag: "!!str", Value: string(filebytes)}}, nil
+}
+
+func loadYaml(filename string) (*CandidateNode, error) {
+
+	file, err := os.Open(filename) // #nosec
+	if err != nil {
+		return nil, err
+	}
+	reader := bufio.NewReader(file)
+
+	documents, err := readDocuments(reader, filename, 0)
+	if err != nil {
+		return nil, err
+	}
+
+	if documents.Len() == 0 {
+		// return null candidate
+		return &CandidateNode{Node: &yaml.Node{Kind: yaml.ScalarNode, Tag: "!!null"}}, nil
+	} else if documents.Len() == 1 {
+		return documents.Front().Value.(*CandidateNode), nil
+
+	} else {
+		sequenceNode := &CandidateNode{Node: &yaml.Node{Kind: yaml.SequenceNode}}
+		for doc := documents.Front(); doc != nil; doc = doc.Next() {
+			sequenceNode.Node.Content = append(sequenceNode.Node.Content, doc.Value.(*CandidateNode).Node)
+		}
+		return sequenceNode, nil
+	}
+}
+
+func loadYamlOperator(d *dataTreeNavigator, context Context, expressionNode *ExpressionNode) (Context, error) {
+	log.Debugf("loadYamlOperator")
+
+	loadPrefs := expressionNode.Operation.Preferences.(loadPrefs)
+
+	// need to evaluate the 1st parameter against the context
+	// and return the data accordingly.
+
+	var results = list.New()
+
+	for el := context.MatchingNodes.Front(); el != nil; el = el.Next() {
+		candidate := el.Value.(*CandidateNode)
+
+		rhs, err := d.GetMatchingNodes(context.SingleReadonlyChildContext(candidate), expressionNode.Rhs)
+		if err != nil {
+			return Context{}, err
+		}
+		if rhs.MatchingNodes.Front() == nil {
+			return Context{}, fmt.Errorf("Filename expression returned nil")
+		}
+		nameCandidateNode := rhs.MatchingNodes.Front().Value.(*CandidateNode)
+
+		filename := nameCandidateNode.Node.Value
+
+		var contentsCandidate *CandidateNode
+
+		if loadPrefs.loadAsString {
+			contentsCandidate, err = loadString(filename)
+		} else {
+			contentsCandidate, err = loadYaml(filename)
+		}
+		if err != nil {
+			return Context{}, fmt.Errorf("Failed to load %v: %w", filename, err)
+		}
+
+		results.PushBack(contentsCandidate)
+
+	}
+
+	return context.ChildContext(results), nil
+}