Helper API refactor (#40)

* api cleaup

* updates

* wtf

* updates

* snapshot.

* tweaks

* snapshot

* api tweaks.

* updates

* updates

* updates

* changes.

* updates

* updates

* sequence => seq

* dont need to use curl, just using wget

* fixing examples

util/file_util.go

@@ -0,0 +1,57 @@
+package util
+
+import (
+	"bufio"
+	"io"
+	"os"
+)
+
+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) error {
+	var f *os.File
+	var err error
+	if f, err = os.Open(filePath); err == nil {
+		defer f.Close()
+		var line string
+		scanner := bufio.NewScanner(f)
+		for scanner.Scan() {
+			line = scanner.Text()
+			err = handler(line)
+			if err != nil {
+				return err
+			}
+		}
+	}
+	return err
+
+}
+
+// ReadByChunks reads a file in `chunkSize` pieces, dispatched to the handler.
+func (fu fileUtil) ReadByChunks(filePath string, chunkSize int, handler func(line []byte) error) error {
+	var f *os.File
+	var err 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]
+			err = handler(readData)
+			if err != nil {
+				return err
+			}
+		}
+	}
+	return err
+}