Initial commit

vendor/github.com/gobuffalo/packd/file.go

@@ -0,0 +1,128 @@
+package packd
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"time"
+
+	"github.com/pkg/errors"
+)
+
+var _ File = &virtualFile{}
+var _ io.Reader = &virtualFile{}
+var _ io.Writer = &virtualFile{}
+var _ fmt.Stringer = &virtualFile{}
+
+type virtualFile struct {
+	io.Reader
+	name     string
+	info     fileInfo
+	original []byte
+}
+
+func (f virtualFile) Name() string {
+	return f.name
+}
+
+func (f *virtualFile) Seek(offset int64, whence int) (int64, error) {
+	return f.Reader.(*bytes.Reader).Seek(offset, whence)
+}
+
+func (f virtualFile) FileInfo() (os.FileInfo, error) {
+	return f.info, nil
+}
+
+func (f *virtualFile) Close() error {
+	return nil
+}
+
+func (f virtualFile) Readdir(count int) ([]os.FileInfo, error) {
+	return []os.FileInfo{f.info}, nil
+}
+
+func (f virtualFile) Stat() (os.FileInfo, error) {
+	return f.info, nil
+}
+
+func (f virtualFile) String() string {
+	return string(f.original)
+}
+
+// Read reads the next len(p) bytes from the virtualFile and
+// rewind read offset to 0 when it met EOF.
+func (f *virtualFile) Read(p []byte) (int, error) {
+	i, err := f.Reader.Read(p)
+
+	if i == 0 || err == io.EOF {
+		f.Seek(0, io.SeekStart)
+	}
+	return i, err
+}
+
+// Write copies byte slice p to content of virtualFile.
+func (f *virtualFile) Write(p []byte) (int, error) {
+	return f.write(p)
+}
+
+// write copies byte slice or data from io.Reader to content of the
+// virtualFile and update related information of the virtualFile.
+func (f *virtualFile) write(d interface{}) (c int, err error) {
+	bb := &bytes.Buffer{}
+	switch d.(type) {
+	case []byte:
+		c, err = bb.Write(d.([]byte))
+	case io.Reader:
+		if d != nil {
+			i64, e := io.Copy(bb, d.(io.Reader))
+			c = int(i64)
+			err = e
+		}
+	default:
+		err = errors.New("unknown type of argument")
+	}
+
+	if err != nil {
+		return c, errors.WithStack(err)
+	}
+
+	f.info.size = int64(c)
+	f.info.modTime = time.Now()
+	f.original = bb.Bytes()
+	f.Reader = bytes.NewReader(f.original)
+	return c, nil
+}
+
+// NewFile returns a new "virtual" file
+func NewFile(name string, r io.Reader) (File, error) {
+	return buildFile(name, r)
+}
+
+// NewDir returns a new "virtual" directory
+func NewDir(name string) (File, error) {
+	v, err := buildFile(name, nil)
+	if err != nil {
+		return v, errors.WithStack(err)
+	}
+	v.info.isDir = true
+	return v, nil
+}
+
+func buildFile(name string, r io.Reader) (*virtualFile, error) {
+	vf := &virtualFile{
+		name: name,
+		info: fileInfo{
+			Path:    name,
+			modTime: time.Now(),
+		},
+	}
+
+	var err error
+	if r != nil {
+		_, err = vf.write(r)
+	} else {
+		_, err = vf.write([]byte{}) // for safety
+	}
+	return vf, errors.Wrap(err, "could not make virtual file")
+}