wip - write in place

pkg/yqlib/file_utils.go

@@ -0,0 +1,50 @@
+package yqlib
+
+import (
+	"io"
+	"os"
+)
+
+func safelyRenameFile(from string, to string) {
+	if renameError := os.Rename(from, to); renameError != nil {
+		log.Debugf("Error renaming from %v to %v, attempting to copy contents", from, to)
+		log.Debug(renameError.Error())
+		// can't do this rename when running in docker to a file targeted in a mounted volume,
+		// so gracefully degrade to copying the entire contents.
+		if copyError := copyFileContents(from, to); copyError != nil {
+			log.Errorf("Failed copying from %v to %v", from, to)
+			log.Error(copyError.Error())
+		} else {
+			removeErr := os.Remove(from)
+			if removeErr != nil {
+				log.Errorf("failed removing original file: %s", from)
+			}
+		}
+	}
+}
+
+// thanks https://stackoverflow.com/questions/21060945/simple-way-to-copy-a-file-in-golang
+func copyFileContents(src, dst string) (err error) {
+	in, err := os.Open(src) // nolint gosec
+	if err != nil {
+		return err
+	}
+	defer safelyCloseFile(in)
+	out, err := os.Create(dst)
+	if err != nil {
+		return err
+	}
+	defer safelyCloseFile(out)
+	if _, err = io.Copy(out, in); err != nil {
+		return err
+	}
+	return out.Sync()
+}
+
+func safelyCloseFile(file *os.File) {
+	err := file.Close()
+	if err != nil {
+		log.Error("Error closing file!")
+		log.Error(err.Error())
+	}
+}

pkg/yqlib/lib.go

@@ -18,6 +18,7 @@ type OperationType struct {
 
 // operators TODO:
 // - cookbook doc for common things
+// - existStatus
 // - write in place
 // - mergeEmpty (sets only if the document is empty, do I do that now?)
 // - compare ??

pkg/yqlib/printer.go

@@ -5,7 +5,7 @@ import (
 	"container/list"
 	"io"
 
-	"gopkg.in/yaml.v3"
+	yaml "gopkg.in/yaml.v3"
 )
 
 type Printer interface {
@@ -53,6 +53,13 @@ func (p *resultsPrinter) writeString(writer io.Writer, txt string) error {
 	return errorWriting
 }
 
+func (p *resultsPrinter) safelyFlush(writer *bufio.Writer) {
+	if err := writer.Flush(); err != nil {
+		log.Error("Error flushing writer!")
+		log.Error(err.Error())
+	}
+}
+
 func (p *resultsPrinter) PrintResults(matchingNodes *list.List) error {
 	log.Debug("PrintResults for %v matches", matchingNodes.Len())
 	var err error
@@ -66,7 +73,7 @@ func (p *resultsPrinter) PrintResults(matchingNodes *list.List) error {
 	}
 
 	bufferedWriter := bufio.NewWriter(p.writer)
-	defer safelyFlush(bufferedWriter)
+	defer p.safelyFlush(bufferedWriter)
 
 	if matchingNodes.Len() == 0 {
 		log.Debug("no matching results, nothing to print")

pkg/yqlib/utils.go

@@ -9,8 +9,6 @@ import (
 	yaml "gopkg.in/yaml.v3"
 )
 
-//TODO: convert to interface + struct
-
 var treeNavigator = NewDataTreeNavigator()
 var treeCreator = NewPathTreeCreator()
 
@@ -52,54 +50,3 @@ func readDocuments(reader io.Reader, filename string, fileIndex int) (*list.List
 		currentIndex = currentIndex + 1
 	}
 }
-
-// func safelyRenameFile(from string, to string) {
-// 	if renameError := os.Rename(from, to); renameError != nil {
-// 		log.Debugf("Error renaming from %v to %v, attempting to copy contents", from, to)
-// 		log.Debug(renameError.Error())
-// 		// can't do this rename when running in docker to a file targeted in a mounted volume,
-// 		// so gracefully degrade to copying the entire contents.
-// 		if copyError := copyFileContents(from, to); copyError != nil {
-// 			log.Errorf("Failed copying from %v to %v", from, to)
-// 			log.Error(copyError.Error())
-// 		} else {
-// 			removeErr := os.Remove(from)
-// 			if removeErr != nil {
-// 				log.Errorf("failed removing original file: %s", from)
-// 			}
-// 		}
-// 	}
-// }
-
-// thanks https://stackoverflow.com/questions/21060945/simple-way-to-copy-a-file-in-golang
-// func copyFileContents(src, dst string) (err error) {
-// 	in, err := os.Open(src) // nolint gosec
-// 	if err != nil {
-// 		return err
-// 	}
-// 	defer safelyCloseFile(in)
-// 	out, err := os.Create(dst)
-// 	if err != nil {
-// 		return err
-// 	}
-// 	defer safelyCloseFile(out)
-// 	if _, err = io.Copy(out, in); err != nil {
-// 		return err
-// 	}
-// 	return out.Sync()
-// }
-
-func safelyFlush(writer *bufio.Writer) {
-	if err := writer.Flush(); err != nil {
-		log.Error("Error flushing writer!")
-		log.Error(err.Error())
-	}
-
-}
-func safelyCloseFile(file *os.File) {
-	err := file.Close()
-	if err != nil {
-		log.Error("Error closing file!")
-		log.Error(err.Error())
-	}
-}

pkg/yqlib/write_in_place_handler.go

@@ -0,0 +1,55 @@
+package yqlib
+
+import (
+	"io/ioutil"
+	"os"
+)
+
+type WriteInPlaceHandler interface {
+	CreateTempFile() (*os.File, error)
+	FinishWriteInPlace(evaluatedSuccessfully bool)
+}
+
+type writeInPlaceHandler struct {
+	inputFilename string
+	tempFile      *os.File
+}
+
+func NewWriteInPlaceHandler(inputFile string) WriteInPlaceHandler {
+
+	return &writeInPlaceHandler{inputFile, nil}
+}
+
+func (w *writeInPlaceHandler) CreateTempFile() (*os.File, error) {
+	info, err := os.Stat(w.inputFilename)
+	if err != nil {
+		return nil, err
+	}
+	_, err = os.Stat(os.TempDir())
+	if os.IsNotExist(err) {
+		err = os.Mkdir(os.TempDir(), 0700)
+		if err != nil {
+			return nil, err
+		}
+	} else if err != nil {
+		return nil, err
+	}
+
+	file, err := ioutil.TempFile("", "temp")
+	if err != nil {
+		return nil, err
+	}
+
+	err = os.Chmod(file.Name(), info.Mode())
+	w.tempFile = file
+	return file, err
+}
+
+func (w *writeInPlaceHandler) FinishWriteInPlace(evaluatedSuccessfully bool) {
+	safelyCloseFile(w.tempFile)
+	if evaluatedSuccessfully {
+		safelyRenameFile(w.tempFile.Name(), w.inputFilename)
+	} else {
+		os.Remove(w.tempFile.Name())
+	}
+}