Add capacity to obidistribute to save gzipped files

pkg/goutils/gzipfile.go

@@ -0,0 +1,69 @@
+package goutils
+
+import (
+	"bufio"
+	"compress/gzip"
+	"os"
+)
+
+type Wfile struct {
+	compressed bool
+	f          *os.File
+	gf         *gzip.Writer
+	fw         *bufio.Writer
+}
+
+func OpenWritingFile(name string, compressed bool, append bool) (*Wfile, error) {
+
+	flags := os.O_WRONLY | os.O_CREATE
+
+	if append {
+		flags |= os.O_APPEND
+	}
+	fi, err := os.OpenFile(name, flags, 0660)
+	if err != nil {
+		return nil, err
+	}
+
+	var gf *gzip.Writer
+	var fw *bufio.Writer
+
+	if compressed {
+		gf = gzip.NewWriter(fi)
+		fw = bufio.NewWriter(gf)
+	} else {
+		gf = nil
+		fw = bufio.NewWriter(fi)
+	}
+
+	return &Wfile{compressed: compressed,
+		f:  fi,
+		gf: gf,
+		fw: fw,
+	}, nil
+}
+
+func (w *Wfile) Write(p []byte) (n int, err error) {
+	return w.fw.Write(p)
+}
+
+func (w *Wfile) WriteString(s string) (n int, err error) {
+	return w.fw.Write([]byte(s))
+}
+
+func (w *Wfile) Close() error {
+	var err error
+	err = nil
+
+	if w.compressed {
+		err = w.gf.Close()
+	}
+
+	err2 := w.f.Close()
+
+	if err == nil {
+		err = err2
+	}
+
+	return err
+}