Remove previous POCs

Signed-off-by: Antonio Navarro Perez <antnavper@gmail.com>

iio/disk.go

@@ -0,0 +1,65 @@
+package iio
+
+import (
+	"io"
+	"io/ioutil"
+	"os"
+	"sync"
+)
+
+type DiskTeeReader struct {
+	io.ReaderAt
+	io.Closer
+	io.Reader
+
+	m sync.Mutex
+
+	fo int64
+	fr *os.File
+	to int64
+	tr io.Reader
+}
+
+func NewDiskTeeReader(r io.Reader) (*DiskTeeReader, error) {
+	fr, err := ioutil.TempFile("", "dtb_tmp")
+	if err != nil {
+		return nil, err
+	}
+	tr := io.TeeReader(r, fr)
+	return &DiskTeeReader{fr: fr, tr: tr}, nil
+}
+
+func (dtr *DiskTeeReader) ReadAt(p []byte, off int64) (int, error) {
+	dtr.m.Lock()
+	defer dtr.m.Unlock()
+	tb := off + int64(len(p))
+
+	if tb > dtr.fo {
+		w, err := io.CopyN(ioutil.Discard, dtr.tr, tb-dtr.fo)
+		dtr.to += w
+		if err != nil && err != io.EOF {
+			return 0, err
+		}
+	}
+
+	n, err := dtr.fr.ReadAt(p, off)
+	dtr.fo += int64(n)
+	return n, err
+}
+
+func (dtr *DiskTeeReader) Read(p []byte) (n int, err error) {
+	dtr.m.Lock()
+	defer dtr.m.Unlock()
+	// use directly tee reader here
+	n, err = dtr.tr.Read(p)
+	dtr.to += int64(n)
+	return
+}
+
+func (dtr *DiskTeeReader) Close() error {
+	if err := dtr.fr.Close(); err != nil {
+		return err
+	}
+
+	return os.Remove(dtr.fr.Name())
+}

iio/disk_test.go

@@ -0,0 +1,46 @@
+package iio
+
+import (
+	"bytes"
+	"io"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+var testData []byte = []byte("Hello World")
+
+func TestReadData(t *testing.T) {
+	require := require.New(t)
+
+	br := bytes.NewReader(testData)
+	r, err := NewDiskTeeReader(br)
+	require.NoError(err)
+
+	toRead := make([]byte, 5)
+
+	n, err := r.ReadAt(toRead, 6)
+	require.NoError(err)
+	require.Equal(5, n)
+	require.Equal("World", string(toRead))
+
+	r.ReadAt(toRead, 0)
+	require.NoError(err)
+	require.Equal(5, n)
+	require.Equal("Hello", string(toRead))
+}
+
+func TestReadDataEOF(t *testing.T) {
+	require := require.New(t)
+
+	br := bytes.NewReader(testData)
+	r, err := NewDiskTeeReader(br)
+	require.NoError(err)
+
+	toRead := make([]byte, 6)
+
+	n, err := r.ReadAt(toRead, 6)
+	require.Equal(io.EOF, err)
+	require.Equal(5, n)
+	require.Equal("World\x00", string(toRead))
+}

iio/utils.go

@@ -0,0 +1,21 @@
+package iio
+
+import (
+	"io"
+	"log"
+)
+
+func CloseIfCloseable(r interface{}) error {
+	log.Println("closing file...")
+	if r == nil {
+		return nil
+	}
+
+	closer, ok := r.(io.Closer)
+	if !ok {
+		log.Println("file is not implementing close method")
+		return nil
+	}
+
+	return closer.Close()
+}

iio/wrapper.go

@@ -0,0 +1,28 @@
+package iio
+
+import (
+	"io"
+	"sync"
+)
+
+type readAtWrapper struct {
+	mu sync.Mutex
+
+	io.ReadSeeker
+	io.ReaderAt
+}
+
+func NewReadAtWrapper(r io.ReadSeeker) io.ReaderAt {
+	return &readAtWrapper{ReadSeeker: r}
+}
+
+func (rw *readAtWrapper) ReadAt(p []byte, off int64) (int, error) {
+	rw.mu.Lock()
+	defer rw.mu.Unlock()
+	_, err := rw.Seek(off, io.SeekStart)
+	if err != nil {
+		return 0, err
+	}
+
+	return rw.Read(p)
+}