matterbridge/vendor/github.com/GeertJohan/go.rice/virtual.go

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2017-02-18 22:00:46 +00:00
package rice
import (
"errors"
"io"
"os"
"path/filepath"
"sort"
"github.com/GeertJohan/go.rice/embedded"
)
//++ TODO: IDEA: merge virtualFile and virtualDir, this decreases work done by rice.File
// Error indicating some function is not implemented yet (but available to satisfy an interface)
var ErrNotImplemented = errors.New("not implemented yet")
// virtualFile is a 'stateful' virtual file.
// virtualFile wraps an *EmbeddedFile for a call to Box.Open() and virtualizes 'read cursor' (offset) and 'closing'.
// virtualFile is only internally visible and should be exposed through rice.File
type virtualFile struct {
*embedded.EmbeddedFile // the actual embedded file, embedded to obtain methods
offset int64 // read position on the virtual file
closed bool // closed when true
}
// create a new virtualFile for given EmbeddedFile
func newVirtualFile(ef *embedded.EmbeddedFile) *virtualFile {
vf := &virtualFile{
EmbeddedFile: ef,
offset: 0,
closed: false,
}
return vf
}
//++ TODO check for nil pointers in all these methods. When so: return os.PathError with Err: os.ErrInvalid
func (vf *virtualFile) close() error {
if vf.closed {
return &os.PathError{
Op: "close",
Path: vf.EmbeddedFile.Filename,
Err: errors.New("already closed"),
}
}
vf.EmbeddedFile = nil
vf.closed = true
return nil
}
func (vf *virtualFile) stat() (os.FileInfo, error) {
if vf.closed {
return nil, &os.PathError{
Op: "stat",
Path: vf.EmbeddedFile.Filename,
Err: errors.New("bad file descriptor"),
}
}
return (*embeddedFileInfo)(vf.EmbeddedFile), nil
}
func (vf *virtualFile) readdir(count int) ([]os.FileInfo, error) {
if vf.closed {
return nil, &os.PathError{
Op: "readdir",
Path: vf.EmbeddedFile.Filename,
Err: errors.New("bad file descriptor"),
}
}
//TODO: return proper error for a readdir() call on a file
return nil, ErrNotImplemented
}
func (vf *virtualFile) read(bts []byte) (int, error) {
if vf.closed {
return 0, &os.PathError{
Op: "read",
Path: vf.EmbeddedFile.Filename,
Err: errors.New("bad file descriptor"),
}
}
end := vf.offset + int64(len(bts))
if end >= int64(len(vf.Content)) {
// end of file, so return what we have + EOF
n := copy(bts, vf.Content[vf.offset:])
vf.offset = 0
return n, io.EOF
}
n := copy(bts, vf.Content[vf.offset:end])
vf.offset += int64(n)
return n, nil
}
func (vf *virtualFile) seek(offset int64, whence int) (int64, error) {
if vf.closed {
return 0, &os.PathError{
Op: "seek",
Path: vf.EmbeddedFile.Filename,
Err: errors.New("bad file descriptor"),
}
}
var e error
//++ TODO: check if this is correct implementation for seek
switch whence {
case os.SEEK_SET:
//++ check if new offset isn't out of bounds, set e when it is, then break out of switch
vf.offset = offset
case os.SEEK_CUR:
//++ check if new offset isn't out of bounds, set e when it is, then break out of switch
vf.offset += offset
case os.SEEK_END:
//++ check if new offset isn't out of bounds, set e when it is, then break out of switch
vf.offset = int64(len(vf.EmbeddedFile.Content)) - offset
}
if e != nil {
return 0, &os.PathError{
Op: "seek",
Path: vf.Filename,
Err: e,
}
}
return vf.offset, nil
}
// virtualDir is a 'stateful' virtual directory.
// virtualDir wraps an *EmbeddedDir for a call to Box.Open() and virtualizes 'closing'.
// virtualDir is only internally visible and should be exposed through rice.File
type virtualDir struct {
*embedded.EmbeddedDir
offset int // readdir position on the directory
closed bool
}
// create a new virtualDir for given EmbeddedDir
func newVirtualDir(ed *embedded.EmbeddedDir) *virtualDir {
vd := &virtualDir{
EmbeddedDir: ed,
offset: 0,
closed: false,
}
return vd
}
func (vd *virtualDir) close() error {
//++ TODO: needs sync mutex?
if vd.closed {
return &os.PathError{
Op: "close",
Path: vd.EmbeddedDir.Filename,
Err: errors.New("already closed"),
}
}
vd.closed = true
return nil
}
func (vd *virtualDir) stat() (os.FileInfo, error) {
if vd.closed {
return nil, &os.PathError{
Op: "stat",
Path: vd.EmbeddedDir.Filename,
Err: errors.New("bad file descriptor"),
}
}
return (*embeddedDirInfo)(vd.EmbeddedDir), nil
}
func (vd *virtualDir) readdir(n int) (fi []os.FileInfo, err error) {
if vd.closed {
return nil, &os.PathError{
Op: "readdir",
Path: vd.EmbeddedDir.Filename,
Err: errors.New("bad file descriptor"),
}
}
// Build up the array of our contents
var files []os.FileInfo
// Add the child directories
for _, child := range vd.ChildDirs {
child.Filename = filepath.Base(child.Filename)
files = append(files, (*embeddedDirInfo)(child))
}
// Add the child files
for _, child := range vd.ChildFiles {
child.Filename = filepath.Base(child.Filename)
files = append(files, (*embeddedFileInfo)(child))
}
// Sort it by filename (lexical order)
sort.Sort(SortByName(files))
// Return all contents if that's what is requested
if n <= 0 {
vd.offset = 0
return files, nil
}
// If user has requested past the end of our list
// return what we can and send an EOF
if vd.offset+n >= len(files) {
offset := vd.offset
vd.offset = 0
return files[offset:], io.EOF
}
offset := vd.offset
vd.offset += n
return files[offset : offset+n], nil
}
func (vd *virtualDir) read(bts []byte) (int, error) {
if vd.closed {
return 0, &os.PathError{
Op: "read",
Path: vd.EmbeddedDir.Filename,
Err: errors.New("bad file descriptor"),
}
}
return 0, &os.PathError{
Op: "read",
Path: vd.EmbeddedDir.Filename,
Err: errors.New("is a directory"),
}
}
func (vd *virtualDir) seek(offset int64, whence int) (int64, error) {
if vd.closed {
return 0, &os.PathError{
Op: "seek",
Path: vd.EmbeddedDir.Filename,
Err: errors.New("bad file descriptor"),
}
}
return 0, &os.PathError{
Op: "seek",
Path: vd.Filename,
Err: errors.New("is a directory"),
}
}