missing files.

file_util.go

@@ -0,0 +1,52 @@
+package chart
+
+import (
+	"bufio"
+	"io"
+	"os"
+
+	exception "github.com/blendlabs/go-exception"
+)
+
+var (
+	// File contains file utility functions
+	File = fileUtil{}
+)
+
+type fileUtil struct{}
+
+// ReadByLines reads a file and calls the handler for each line.
+func (fu fileUtil) ReadByLines(filePath string, handler func(line string)) error {
+	if f, err := os.Open(filePath); err == nil {
+		defer f.Close()
+
+		scanner := bufio.NewScanner(f)
+		for scanner.Scan() {
+			line := scanner.Text()
+			handler(line)
+		}
+	} else {
+		return exception.Wrap(err)
+	}
+	return nil
+}
+
+// ReadByChunks reads a file in `chunkSize` pieces, dispatched to the handler.
+func (fu fileUtil) ReadByChunks(filePath string, chunkSize int, handler func(line []byte)) error {
+	if f, err := os.Open(filePath); err == nil {
+		defer f.Close()
+
+		chunk := make([]byte, chunkSize)
+		for {
+			readBytes, err := f.Read(chunk)
+			if err == io.EOF {
+				break
+			}
+			readData := chunk[:readBytes]
+			handler(readData)
+		}
+	} else {
+		return exception.Wrap(err)
+	}
+	return nil
+}