ErrNegativeOffset = errors.New("cannot seek to negative offset")
ErrFileExists = errors.New("file exists")
ErrInvalidOperation = errors.New("invalid operation")
+ ErrInvalidArgument = errors.New("invalid argument")
ErrDirectoryNotEmpty = errors.New("directory not empty")
+ ErrWriteOnlyMode = errors.New("file is O_WRONLY")
+ ErrSyncNotSupported = errors.New("O_SYNC flag is not supported")
+ ErrIsDirectory = errors.New("cannot rename file to overwrite existing directory")
ErrPermission = os.ErrPermission
maxBlockSize = 1 << 26
)
+// A File is an *os.File-like interface for reading and writing files
+// in a CollectionFileSystem.
type File interface {
io.Reader
io.Writer
}
// A CollectionFileSystem is an http.Filesystem plus Stat() and
-// support for opening writable files.
+// support for opening writable files. All methods are safe to call
+// from multiple goroutines.
type CollectionFileSystem interface {
http.FileSystem
+
+ // analogous to os.Stat()
Stat(name string) (os.FileInfo, error)
+
+ // analogous to os.Create(): create/truncate a file and open it O_RDWR.
Create(name string) (File, error)
+
+ // Like os.OpenFile(): create or open a file or directory.
+ //
+ // If flag&os.O_EXCL==0, it opens an existing file or
+ // directory if one exists. If flag&os.O_CREATE!=0, it creates
+ // a new empty file or directory if one does not already
+ // exist.
+ //
+ // When creating a new item, perm&os.ModeDir determines
+ // whether it is a file or a directory.
+ //
+ // A file can be opened multiple times and used concurrently
+ // from multiple goroutines. However, each File object should
+ // be used by only one goroutine at a time.
OpenFile(name string, flag int, perm os.FileMode) (File, error)
+
Mkdir(name string, perm os.FileMode) error
Remove(name string) error
- MarshalManifest(string) (string, error)
+ RemoveAll(name string) error
+ Rename(oldname, newname string) error
+
+ // Flush all file data to Keep and return a snapshot of the
+ // filesystem suitable for saving as (Collection)ManifestText.
+ // Prefix (normally ".") is a top level directory, effectively
+ // prepended to all paths in the returned manifest.
+ MarshalManifest(prefix string) (string, error)
}
type fileSystem struct {
}
func (fs *fileSystem) OpenFile(name string, flag int, perm os.FileMode) (File, error) {
- return fs.dirnode.OpenFile(path.Clean(name), flag, perm)
+ return fs.dirnode.OpenFile(name, flag, perm)
}
func (fs *fileSystem) Open(name string) (http.File, error) {
- return fs.dirnode.OpenFile(path.Clean(name), os.O_RDONLY, 0)
+ return fs.dirnode.OpenFile(name, os.O_RDONLY, 0)
}
func (fs *fileSystem) Create(name string) (File, error) {
- return fs.dirnode.OpenFile(path.Clean(name), os.O_CREATE|os.O_RDWR|os.O_TRUNC, 0)
+ return fs.dirnode.OpenFile(name, os.O_CREATE|os.O_RDWR|os.O_TRUNC, 0)
}
-func (fs *fileSystem) Stat(name string) (os.FileInfo, error) {
- f, err := fs.OpenFile(name, os.O_RDONLY, 0)
- if err != nil {
- return nil, err
+func (fs *fileSystem) Stat(name string) (fi os.FileInfo, err error) {
+ node := fs.dirnode.lookupPath(name)
+ if node == nil {
+ err = os.ErrNotExist
+ } else {
+ fi = node.Stat()
}
- defer f.Close()
- return f.Stat()
+ return
}
type inode interface {
type filenode struct {
fileinfo fileinfo
parent *dirnode
- extents []extent
- repacked int64 // number of times anything in []extents has changed len
- memsize int64 // bytes in memExtents
+ segments []segment
+ // number of times `segments` has changed in a
+ // way that might invalidate a filenodePtr
+ repacked int64
+ memsize int64 // bytes in memSegments
sync.RWMutex
}
// filenodePtr is an offset into a file that is (usually) efficient to
// seek to. Specifically, if filenode.repacked==filenodePtr.repacked
-// then filenode.extents[filenodePtr.extentIdx][filenodePtr.extentOff]
+// then
+// filenode.segments[filenodePtr.segmentIdx][filenodePtr.segmentOff]
// corresponds to file offset filenodePtr.off. Otherwise, it is
-// necessary to reexamine len(filenode.extents[0]) etc. to find the
-// correct extent and offset.
+// necessary to reexamine len(filenode.segments[0]) etc. to find the
+// correct segment and offset.
type filenodePtr struct {
- off int64
- extentIdx int
- extentOff int
- repacked int64
+ off int64
+ segmentIdx int
+ segmentOff int
+ repacked int64
}
// seek returns a ptr that is consistent with both startPtr.off and
// the current state of fn. The caller must already hold fn.RLock() or
// fn.Lock().
//
-// If startPtr points beyond the end of the file, ptr will point to
-// exactly the end of the file.
+// If startPtr is beyond EOF, ptr.segment* will indicate precisely
+// EOF.
//
// After seeking:
//
-// ptr.extentIdx == len(filenode.extents) // i.e., at EOF
+// ptr.segmentIdx == len(filenode.segments) // i.e., at EOF
// ||
-// filenode.extents[ptr.extentIdx].Len() >= ptr.extentOff
+// filenode.segments[ptr.segmentIdx].Len() > ptr.segmentOff
func (fn *filenode) seek(startPtr filenodePtr) (ptr filenodePtr) {
ptr = startPtr
if ptr.off < 0 {
// meaningless anyway
return
} else if ptr.off >= fn.fileinfo.size {
- ptr.off = fn.fileinfo.size
- ptr.extentIdx = len(fn.extents)
- ptr.extentOff = 0
+ ptr.segmentIdx = len(fn.segments)
+ ptr.segmentOff = 0
ptr.repacked = fn.repacked
return
} else if ptr.repacked == fn.repacked {
- // extentIdx and extentOff accurately reflect ptr.off,
- // but might have fallen off the end of an extent
- if ptr.extentOff >= fn.extents[ptr.extentIdx].Len() {
- ptr.extentIdx++
- ptr.extentOff = 0
+ // segmentIdx and segmentOff accurately reflect
+ // ptr.off, but might have fallen off the end of a
+ // segment
+ if ptr.segmentOff >= fn.segments[ptr.segmentIdx].Len() {
+ ptr.segmentIdx++
+ ptr.segmentOff = 0
}
return
}
ptr.repacked = fn.repacked
}()
if ptr.off >= fn.fileinfo.size {
- ptr.extentIdx, ptr.extentOff = len(fn.extents), 0
+ ptr.segmentIdx, ptr.segmentOff = len(fn.segments), 0
return
}
- // Recompute extentIdx and extentOff. We have already
+ // Recompute segmentIdx and segmentOff. We have already
// established fn.fileinfo.size > ptr.off >= 0, so we don't
// have to deal with edge cases here.
var off int64
- for ptr.extentIdx, ptr.extentOff = 0, 0; off < ptr.off; ptr.extentIdx++ {
+ for ptr.segmentIdx, ptr.segmentOff = 0, 0; off < ptr.off; ptr.segmentIdx++ {
// This would panic (index out of range) if
// fn.fileinfo.size were larger than
- // sum(fn.extents[i].Len()) -- but that can't happen
+ // sum(fn.segments[i].Len()) -- but that can't happen
// because we have ensured fn.fileinfo.size is always
// accurate.
- extLen := int64(fn.extents[ptr.extentIdx].Len())
- if off+extLen > ptr.off {
- ptr.extentOff = int(ptr.off - off)
+ segLen := int64(fn.segments[ptr.segmentIdx].Len())
+ if off+segLen > ptr.off {
+ ptr.segmentOff = int(ptr.off - off)
break
}
- off += extLen
+ off += segLen
}
return
}
-func (fn *filenode) appendExtent(e extent) {
- fn.Lock()
- defer fn.Unlock()
- fn.extents = append(fn.extents, e)
+// caller must have lock
+func (fn *filenode) appendSegment(e segment) {
+ fn.segments = append(fn.segments, e)
fn.fileinfo.size += int64(e.Len())
}
func (fn *filenode) Parent() inode {
+ fn.RLock()
+ defer fn.RUnlock()
return fn.parent
}
return nil
}
+// Read reads file data from a single segment, starting at startPtr,
+// into p. startPtr is assumed not to be up-to-date. Caller must have
+// RLock or Lock.
func (fn *filenode) Read(p []byte, startPtr filenodePtr) (n int, ptr filenodePtr, err error) {
- fn.RLock()
- defer fn.RUnlock()
ptr = fn.seek(startPtr)
if ptr.off < 0 {
err = ErrNegativeOffset
return
}
- if ptr.extentIdx >= len(fn.extents) {
+ if ptr.segmentIdx >= len(fn.segments) {
err = io.EOF
return
}
- n, err = fn.extents[ptr.extentIdx].ReadAt(p, int64(ptr.extentOff))
+ n, err = fn.segments[ptr.segmentIdx].ReadAt(p, int64(ptr.segmentOff))
if n > 0 {
ptr.off += int64(n)
- ptr.extentOff += n
- if ptr.extentOff == fn.extents[ptr.extentIdx].Len() {
- ptr.extentIdx++
- ptr.extentOff = 0
- if ptr.extentIdx < len(fn.extents) && err == io.EOF {
+ ptr.segmentOff += n
+ if ptr.segmentOff == fn.segments[ptr.segmentIdx].Len() {
+ ptr.segmentIdx++
+ ptr.segmentOff = 0
+ if ptr.segmentIdx < len(fn.segments) && err == io.EOF {
err = nil
}
}
func (fn *filenode) Truncate(size int64) error {
fn.Lock()
defer fn.Unlock()
+ return fn.truncate(size)
+}
+
+func (fn *filenode) truncate(size int64) error {
+ if size == fn.fileinfo.size {
+ return nil
+ }
+ fn.repacked++
if size < fn.fileinfo.size {
- ptr := fn.seek(filenodePtr{off: size, repacked: fn.repacked - 1})
- for i := ptr.extentIdx; i < len(fn.extents); i++ {
- if ext, ok := fn.extents[i].(*memExtent); ok {
- fn.memsize -= int64(ext.Len())
+ ptr := fn.seek(filenodePtr{off: size})
+ for i := ptr.segmentIdx; i < len(fn.segments); i++ {
+ if seg, ok := fn.segments[i].(*memSegment); ok {
+ fn.memsize -= int64(seg.Len())
}
}
- if ptr.extentOff == 0 {
- fn.extents = fn.extents[:ptr.extentIdx]
+ if ptr.segmentOff == 0 {
+ fn.segments = fn.segments[:ptr.segmentIdx]
} else {
- fn.extents = fn.extents[:ptr.extentIdx+1]
- switch ext := fn.extents[ptr.extentIdx].(type) {
- case *memExtent:
- ext.Truncate(ptr.extentOff)
- fn.memsize += int64(ext.Len())
+ fn.segments = fn.segments[:ptr.segmentIdx+1]
+ switch seg := fn.segments[ptr.segmentIdx].(type) {
+ case *memSegment:
+ seg.Truncate(ptr.segmentOff)
+ fn.memsize += int64(seg.Len())
default:
- fn.extents[ptr.extentIdx] = ext.Slice(0, ptr.extentOff)
+ fn.segments[ptr.segmentIdx] = seg.Slice(0, ptr.segmentOff)
}
}
fn.fileinfo.size = size
- fn.repacked++
return nil
}
for size > fn.fileinfo.size {
grow := size - fn.fileinfo.size
- var e writableExtent
+ var seg *memSegment
var ok bool
- if len(fn.extents) == 0 {
- e = &memExtent{}
- fn.extents = append(fn.extents, e)
- } else if e, ok = fn.extents[len(fn.extents)-1].(writableExtent); !ok || e.Len() >= maxBlockSize {
- e = &memExtent{}
- fn.extents = append(fn.extents, e)
- } else {
- fn.repacked++
+ if len(fn.segments) == 0 {
+ seg = &memSegment{}
+ fn.segments = append(fn.segments, seg)
+ } else if seg, ok = fn.segments[len(fn.segments)-1].(*memSegment); !ok || seg.Len() >= maxBlockSize {
+ seg = &memSegment{}
+ fn.segments = append(fn.segments, seg)
}
- if maxgrow := int64(maxBlockSize - e.Len()); maxgrow < grow {
+ if maxgrow := int64(maxBlockSize - seg.Len()); maxgrow < grow {
grow = maxgrow
}
- e.Truncate(e.Len() + int(grow))
+ seg.Truncate(seg.Len() + int(grow))
fn.fileinfo.size += grow
fn.memsize += grow
}
return nil
}
+// Write writes data from p to the file, starting at startPtr,
+// extending the file size if necessary. Caller must have Lock.
func (fn *filenode) Write(p []byte, startPtr filenodePtr) (n int, ptr filenodePtr, err error) {
- fn.Lock()
- defer fn.Unlock()
+ if startPtr.off > fn.fileinfo.size {
+ if err = fn.truncate(startPtr.off); err != nil {
+ return 0, startPtr, err
+ }
+ }
ptr = fn.seek(startPtr)
if ptr.off < 0 {
err = ErrNegativeOffset
if len(cando) > maxBlockSize {
cando = cando[:maxBlockSize]
}
- // Rearrange/grow fn.extents (and shrink cando if
+ // Rearrange/grow fn.segments (and shrink cando if
// needed) such that cando can be copied to
- // fn.extents[ptr.extentIdx] at offset ptr.extentOff.
- cur := ptr.extentIdx
- prev := ptr.extentIdx - 1
+ // fn.segments[ptr.segmentIdx] at offset
+ // ptr.segmentOff.
+ cur := ptr.segmentIdx
+ prev := ptr.segmentIdx - 1
var curWritable bool
- if cur < len(fn.extents) {
- _, curWritable = fn.extents[cur].(writableExtent)
+ if cur < len(fn.segments) {
+ _, curWritable = fn.segments[cur].(*memSegment)
}
var prevAppendable bool
- if prev >= 0 && fn.extents[prev].Len() < maxBlockSize {
- _, prevAppendable = fn.extents[prev].(writableExtent)
+ if prev >= 0 && fn.segments[prev].Len() < maxBlockSize {
+ _, prevAppendable = fn.segments[prev].(*memSegment)
}
- if ptr.extentOff > 0 && !curWritable {
+ if ptr.segmentOff > 0 && !curWritable {
// Split a non-writable block.
- if max := fn.extents[cur].Len() - ptr.extentOff; max <= len(cando) {
+ if max := fn.segments[cur].Len() - ptr.segmentOff; max <= len(cando) {
// Truncate cur, and insert a new
- // extent after it.
+ // segment after it.
cando = cando[:max]
- fn.extents = append(fn.extents, nil)
- copy(fn.extents[cur+1:], fn.extents[cur:])
+ fn.segments = append(fn.segments, nil)
+ copy(fn.segments[cur+1:], fn.segments[cur:])
} else {
// Split cur into two copies, truncate
// the one on the left, shift the one
// on the right, and insert a new
- // extent between them.
- fn.extents = append(fn.extents, nil, nil)
- copy(fn.extents[cur+2:], fn.extents[cur:])
- fn.extents[cur+2] = fn.extents[cur+2].Slice(ptr.extentOff+len(cando), -1)
+ // segment between them.
+ fn.segments = append(fn.segments, nil, nil)
+ copy(fn.segments[cur+2:], fn.segments[cur:])
+ fn.segments[cur+2] = fn.segments[cur+2].Slice(ptr.segmentOff+len(cando), -1)
}
cur++
prev++
- e := &memExtent{}
- e.Truncate(len(cando))
+ seg := &memSegment{}
+ seg.Truncate(len(cando))
fn.memsize += int64(len(cando))
- fn.extents[cur] = e
- fn.extents[prev] = fn.extents[prev].Slice(0, ptr.extentOff)
- ptr.extentIdx++
- ptr.extentOff = 0
+ fn.segments[cur] = seg
+ fn.segments[prev] = fn.segments[prev].Slice(0, ptr.segmentOff)
+ ptr.segmentIdx++
+ ptr.segmentOff = 0
fn.repacked++
ptr.repacked++
} else if curWritable {
- if fit := int(fn.extents[cur].Len()) - ptr.extentOff; fit < len(cando) {
+ if fit := int(fn.segments[cur].Len()) - ptr.segmentOff; fit < len(cando) {
cando = cando[:fit]
}
} else {
if prevAppendable {
- // Shrink cando if needed to fit in prev extent.
- if cangrow := maxBlockSize - fn.extents[prev].Len(); cangrow < len(cando) {
+ // Shrink cando if needed to fit in
+ // prev segment.
+ if cangrow := maxBlockSize - fn.segments[prev].Len(); cangrow < len(cando) {
cando = cando[:cangrow]
}
}
- if cur == len(fn.extents) {
+ if cur == len(fn.segments) {
// ptr is at EOF, filesize is changing.
fn.fileinfo.size += int64(len(cando))
- } else if el := fn.extents[cur].Len(); el <= len(cando) {
+ } else if el := fn.segments[cur].Len(); el <= len(cando) {
// cando is long enough that we won't
// need cur any more. shrink cando to
// be exactly as long as cur
// (otherwise we'd accidentally shift
// the effective position of all
- // extents after cur).
+ // segments after cur).
cando = cando[:el]
- copy(fn.extents[cur:], fn.extents[cur+1:])
- fn.extents = fn.extents[:len(fn.extents)-1]
+ copy(fn.segments[cur:], fn.segments[cur+1:])
+ fn.segments = fn.segments[:len(fn.segments)-1]
} else {
// shrink cur by the same #bytes we're growing prev
- fn.extents[cur] = fn.extents[cur].Slice(len(cando), -1)
+ fn.segments[cur] = fn.segments[cur].Slice(len(cando), -1)
}
if prevAppendable {
// Grow prev.
- ptr.extentIdx--
- ptr.extentOff = fn.extents[prev].Len()
- fn.extents[prev].(writableExtent).Truncate(ptr.extentOff + len(cando))
+ ptr.segmentIdx--
+ ptr.segmentOff = fn.segments[prev].Len()
+ fn.segments[prev].(*memSegment).Truncate(ptr.segmentOff + len(cando))
fn.memsize += int64(len(cando))
ptr.repacked++
fn.repacked++
} else {
- // Insert an extent between prev and cur, and advance prev/cur.
- fn.extents = append(fn.extents, nil)
- if cur < len(fn.extents) {
- copy(fn.extents[cur+1:], fn.extents[cur:])
+ // Insert a segment between prev and
+ // cur, and advance prev/cur.
+ fn.segments = append(fn.segments, nil)
+ if cur < len(fn.segments) {
+ copy(fn.segments[cur+1:], fn.segments[cur:])
ptr.repacked++
fn.repacked++
} else {
- // appending a new extent does
+ // appending a new segment does
// not invalidate any ptrs
}
- e := &memExtent{}
- e.Truncate(len(cando))
+ seg := &memSegment{}
+ seg.Truncate(len(cando))
fn.memsize += int64(len(cando))
- fn.extents[cur] = e
+ fn.segments[cur] = seg
cur++
prev++
}
}
- // Finally we can copy bytes from cando to the current extent.
- fn.extents[ptr.extentIdx].(writableExtent).WriteAt(cando, ptr.extentOff)
+ // Finally we can copy bytes from cando to the current segment.
+ fn.segments[ptr.segmentIdx].(*memSegment).WriteAt(cando, ptr.segmentOff)
n += len(cando)
p = p[len(cando):]
ptr.off += int64(len(cando))
- ptr.extentOff += len(cando)
- if ptr.extentOff >= maxBlockSize {
- fn.pruneMemExtents()
+ ptr.segmentOff += len(cando)
+ if ptr.segmentOff >= maxBlockSize {
+ fn.pruneMemSegments()
}
- if fn.extents[ptr.extentIdx].Len() == ptr.extentOff {
- ptr.extentOff = 0
- ptr.extentIdx++
+ if fn.segments[ptr.segmentIdx].Len() == ptr.segmentOff {
+ ptr.segmentOff = 0
+ ptr.segmentIdx++
}
+
+ fn.fileinfo.modTime = time.Now()
}
return
}
// Write some data out to disk to reduce memory use. Caller must have
// write lock.
-func (fn *filenode) pruneMemExtents() {
+func (fn *filenode) pruneMemSegments() {
// TODO: async (don't hold Lock() while waiting for Keep)
// TODO: share code with (*dirnode)sync()
// TODO: pack/flush small blocks too, when fragmented
- for idx, ext := range fn.extents {
- ext, ok := ext.(*memExtent)
- if !ok || ext.Len() < maxBlockSize {
+ for idx, seg := range fn.segments {
+ seg, ok := seg.(*memSegment)
+ if !ok || seg.Len() < maxBlockSize {
continue
}
- locator, _, err := fn.parent.kc.PutB(ext.buf)
+ locator, _, err := fn.parent.kc.PutB(seg.buf)
if err != nil {
// TODO: stall (or return errors from)
// subsequent writes until flushing
// starts to succeed
continue
}
- fn.memsize -= int64(ext.Len())
- fn.extents[idx] = storedExtent{
+ fn.memsize -= int64(seg.Len())
+ fn.segments[idx] = storedSegment{
kc: fn.parent.kc,
locator: locator,
- size: ext.Len(),
+ size: seg.Len(),
offset: 0,
- length: ext.Len(),
+ length: seg.Len(),
}
}
}
// FileSystem returns a CollectionFileSystem for the collection.
func (c *Collection) FileSystem(client *Client, kc keepClient) (CollectionFileSystem, error) {
+ var modTime time.Time
+ if c.ModifiedAt == nil {
+ modTime = time.Now()
+ } else {
+ modTime = *c.ModifiedAt
+ }
fs := &fileSystem{dirnode: dirnode{
- client: client,
- kc: kc,
- fileinfo: fileinfo{name: ".", mode: os.ModeDir | 0755},
- parent: nil,
- inodes: make(map[string]inode),
+ client: client,
+ kc: kc,
+ fileinfo: fileinfo{
+ name: ".",
+ mode: os.ModeDir | 0755,
+ modTime: modTime,
+ },
+ parent: nil,
+ inodes: make(map[string]inode),
}}
fs.dirnode.parent = &fs.dirnode
if err := fs.dirnode.loadManifest(c.ManifestText); err != nil {
return fs, nil
}
-type file struct {
+type filehandle struct {
inode
ptr filenodePtr
append bool
+ readable bool
writable bool
unreaddirs []os.FileInfo
}
-func (f *file) Read(p []byte) (n int, err error) {
+func (f *filehandle) Read(p []byte) (n int, err error) {
+ if !f.readable {
+ return 0, ErrWriteOnlyMode
+ }
+ f.inode.RLock()
+ defer f.inode.RUnlock()
n, f.ptr, err = f.inode.Read(p, f.ptr)
return
}
-func (f *file) Seek(off int64, whence int) (pos int64, err error) {
+func (f *filehandle) Seek(off int64, whence int) (pos int64, err error) {
size := f.inode.Size()
ptr := f.ptr
switch whence {
- case os.SEEK_SET:
+ case io.SeekStart:
ptr.off = off
- case os.SEEK_CUR:
+ case io.SeekCurrent:
ptr.off += off
- case os.SEEK_END:
+ case io.SeekEnd:
ptr.off = size + off
}
if ptr.off < 0 {
return f.ptr.off, ErrNegativeOffset
}
- if ptr.off > size {
- ptr.off = size
- }
if ptr.off != f.ptr.off {
f.ptr = ptr
// force filenode to recompute f.ptr fields on next
return f.ptr.off, nil
}
-func (f *file) Truncate(size int64) error {
+func (f *filehandle) Truncate(size int64) error {
return f.inode.Truncate(size)
}
-func (f *file) Write(p []byte) (n int, err error) {
+func (f *filehandle) Write(p []byte) (n int, err error) {
if !f.writable {
return 0, ErrReadOnlyFile
}
+ f.inode.Lock()
+ defer f.inode.Unlock()
+ if fn, ok := f.inode.(*filenode); ok && f.append {
+ f.ptr = filenodePtr{
+ off: fn.fileinfo.size,
+ segmentIdx: len(fn.segments),
+ segmentOff: 0,
+ repacked: fn.repacked,
+ }
+ }
n, f.ptr, err = f.inode.Write(p, f.ptr)
return
}
-func (f *file) Readdir(count int) ([]os.FileInfo, error) {
+func (f *filehandle) Readdir(count int) ([]os.FileInfo, error) {
if !f.inode.Stat().IsDir() {
return nil, ErrInvalidOperation
}
return ret, nil
}
-func (f *file) Stat() (os.FileInfo, error) {
+func (f *filehandle) Stat() (os.FileInfo, error) {
return f.inode.Stat(), nil
}
-func (f *file) Close() error {
- // FIXME: flush
+func (f *filehandle) Close() error {
return nil
}
}
block := make([]byte, 0, maxBlockSize)
for _, sb := range sbs {
- block = append(block, sb.fn.extents[sb.idx].(*memExtent).buf...)
+ block = append(block, sb.fn.segments[sb.idx].(*memSegment).buf...)
}
locator, _, err := dn.kc.PutB(block)
if err != nil {
}
off := 0
for _, sb := range sbs {
- data := sb.fn.extents[sb.idx].(*memExtent).buf
- sb.fn.extents[sb.idx] = storedExtent{
+ data := sb.fn.segments[sb.idx].(*memSegment).buf
+ sb.fn.segments[sb.idx] = storedSegment{
kc: dn.kc,
locator: locator,
size: len(block),
}
fn.Lock()
defer fn.Unlock()
- for idx, ext := range fn.extents {
- ext, ok := ext.(*memExtent)
+ for idx, seg := range fn.segments {
+ seg, ok := seg.(*memSegment)
if !ok {
continue
}
- if ext.Len() > maxBlockSize/2 {
+ if seg.Len() > maxBlockSize/2 {
if err := flush([]shortBlock{{fn, idx}}); err != nil {
return err
}
continue
}
- if pendingLen+ext.Len() > maxBlockSize {
+ if pendingLen+seg.Len() > maxBlockSize {
if err := flush(pending); err != nil {
return err
}
pendingLen = 0
}
pending = append(pending, shortBlock{fn, idx})
- pendingLen += ext.Len()
+ pendingLen += seg.Len()
}
}
return flush(pending)
// caller must have read lock.
func (dn *dirnode) marshalManifest(prefix string) (string, error) {
var streamLen int64
- type m1segment struct {
+ type filepart struct {
name string
offset int64
length int64
}
- var segments []m1segment
+ var fileparts []filepart
var subdirs string
var blocks []string
sort.Strings(names)
for _, name := range names {
- node := dn.inodes[name]
- switch node := node.(type) {
+ switch node := dn.inodes[name].(type) {
case *dirnode:
subdir, err := node.marshalManifest(prefix + "/" + name)
if err != nil {
}
subdirs = subdirs + subdir
case *filenode:
- for _, e := range node.extents {
- switch e := e.(type) {
- case storedExtent:
- if len(blocks) > 0 && blocks[len(blocks)-1] == e.locator {
- streamLen -= int64(e.size)
+ if len(node.segments) == 0 {
+ fileparts = append(fileparts, filepart{name: name})
+ break
+ }
+ for _, seg := range node.segments {
+ switch seg := seg.(type) {
+ case storedSegment:
+ if len(blocks) > 0 && blocks[len(blocks)-1] == seg.locator {
+ streamLen -= int64(seg.size)
} else {
- blocks = append(blocks, e.locator)
+ blocks = append(blocks, seg.locator)
}
- segments = append(segments, m1segment{
+ next := filepart{
name: name,
- offset: streamLen + int64(e.offset),
- length: int64(e.length),
- })
- streamLen += int64(e.size)
+ offset: streamLen + int64(seg.offset),
+ length: int64(seg.length),
+ }
+ if prev := len(fileparts) - 1; prev >= 0 &&
+ fileparts[prev].name == name &&
+ fileparts[prev].offset+fileparts[prev].length == next.offset {
+ fileparts[prev].length += next.length
+ } else {
+ fileparts = append(fileparts, next)
+ }
+ streamLen += int64(seg.size)
default:
// This can't happen: we
// haven't unlocked since
// calling sync().
- panic(fmt.Sprintf("can't marshal extent type %T", e))
+ panic(fmt.Sprintf("can't marshal segment type %T", seg))
}
}
default:
}
}
var filetokens []string
- for _, s := range segments {
+ for _, s := range fileparts {
filetokens = append(filetokens, fmt.Sprintf("%d:%d:%s", s.offset, s.length, manifestEscape(s.name)))
}
if len(filetokens) == 0 {
}
func (dn *dirnode) loadManifest(txt string) error {
- // FIXME: faster
var dirname string
streams := strings.Split(txt, "\n")
if streams[len(streams)-1] != "" {
return fmt.Errorf("line %d: no trailing newline", len(streams))
}
- for i, stream := range streams[:len(streams)-1] {
+ streams = streams[:len(streams)-1]
+ segments := []storedSegment{}
+ for i, stream := range streams {
lineno := i + 1
- var extents []storedExtent
var anyFileTokens bool
+ var pos int64
+ var segIdx int
+ segments = segments[:0]
for i, token := range strings.Split(stream, " ") {
if i == 0 {
dirname = manifestUnescape(token)
if err != nil || length < 0 {
return fmt.Errorf("line %d: bad locator %q", lineno, token)
}
- extents = append(extents, storedExtent{
+ segments = append(segments, storedSegment{
locator: token,
size: int(length),
offset: 0,
length: int(length),
})
continue
- } else if len(extents) == 0 {
+ } else if len(segments) == 0 {
return fmt.Errorf("line %d: bad locator %q", lineno, token)
}
- toks := strings.Split(token, ":")
+ toks := strings.SplitN(token, ":", 3)
if len(toks) != 3 {
return fmt.Errorf("line %d: bad file segment %q", lineno, token)
}
if err != nil || length < 0 {
return fmt.Errorf("line %d: bad file segment %q", lineno, token)
}
- name := path.Clean(dirname + "/" + manifestUnescape(toks[2]))
- dn.makeParentDirs(name)
- f, err := dn.OpenFile(name, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0700)
+ name := dirname + "/" + manifestUnescape(toks[2])
+ fnode, err := dn.createFileAndParents(name)
if err != nil {
- return fmt.Errorf("line %d: cannot append to %q: %s", lineno, name, err)
- }
- if f.inode.Stat().IsDir() {
- f.Close()
- return fmt.Errorf("line %d: cannot append to %q: is a directory", lineno, name)
+ return fmt.Errorf("line %d: cannot use path %q: %s", lineno, name, err)
}
// Map the stream offset/range coordinates to
// block/offset/range coordinates and add
- // corresponding storedExtents to the filenode
- var pos int64
- for _, e := range extents {
- next := pos + int64(e.Len())
- if next < offset {
+ // corresponding storedSegments to the filenode
+ if pos > offset {
+ // Can't continue where we left off.
+ // TODO: binary search instead of
+ // rewinding all the way (but this
+ // situation might be rare anyway)
+ segIdx, pos = 0, 0
+ }
+ for next := int64(0); segIdx < len(segments); segIdx++ {
+ seg := segments[segIdx]
+ next = pos + int64(seg.Len())
+ if next <= offset || seg.Len() == 0 {
pos = next
continue
}
- if pos > offset+length {
+ if pos >= offset+length {
break
}
var blkOff int
if pos < offset {
blkOff = int(offset - pos)
}
- blkLen := e.Len() - blkOff
+ blkLen := seg.Len() - blkOff
if pos+int64(blkOff+blkLen) > offset+length {
blkLen = int(offset + length - pos - int64(blkOff))
}
- f.inode.(*filenode).appendExtent(storedExtent{
+ fnode.appendSegment(storedSegment{
kc: dn.kc,
- locator: e.locator,
- size: e.size,
+ locator: seg.locator,
+ size: seg.size,
offset: blkOff,
length: blkLen,
})
- pos = next
+ if next > offset+length {
+ break
+ } else {
+ pos = next
+ }
}
- f.Close()
- if pos < offset+length {
+ if segIdx == len(segments) && pos < offset+length {
return fmt.Errorf("line %d: invalid segment in %d-byte stream: %q", lineno, pos, token)
}
}
if !anyFileTokens {
return fmt.Errorf("line %d: no file segments", lineno)
- } else if len(extents) == 0 {
+ } else if len(segments) == 0 {
return fmt.Errorf("line %d: no locators", lineno)
} else if dirname == "" {
return fmt.Errorf("line %d: no stream name", lineno)
return nil
}
-func (dn *dirnode) makeParentDirs(name string) (err error) {
- names := strings.Split(name, "/")
+// only safe to call from loadManifest -- no locking
+func (dn *dirnode) createFileAndParents(path string) (fn *filenode, err error) {
+ names := strings.Split(path, "/")
+ basename := names[len(names)-1]
+ if basename == "" || basename == "." || basename == ".." {
+ err = fmt.Errorf("invalid filename")
+ return
+ }
for _, name := range names[:len(names)-1] {
- f, err := dn.mkdir(name)
- if err != nil {
- return err
- }
- defer f.Close()
- var ok bool
- dn, ok = f.inode.(*dirnode)
- if !ok {
- return ErrFileExists
+ switch name {
+ case "", ".":
+ case "..":
+ dn = dn.parent
+ default:
+ switch node := dn.inodes[name].(type) {
+ case nil:
+ dn = dn.newDirnode(name, 0755, dn.fileinfo.modTime)
+ case *dirnode:
+ dn = node
+ case *filenode:
+ err = ErrFileExists
+ return
+ }
}
}
- return nil
+ switch node := dn.inodes[basename].(type) {
+ case nil:
+ fn = dn.newFilenode(basename, 0755, dn.fileinfo.modTime)
+ case *filenode:
+ fn = node
+ case *dirnode:
+ err = ErrIsDirectory
+ }
+ return
}
-func (dn *dirnode) mkdir(name string) (*file, error) {
+func (dn *dirnode) mkdir(name string) (*filehandle, error) {
return dn.OpenFile(name, os.O_CREATE|os.O_EXCL, os.ModeDir|0755)
}
func (dn *dirnode) Mkdir(name string, perm os.FileMode) error {
f, err := dn.mkdir(name)
- if err != nil {
- f.Close()
+ if err == nil {
+ err = f.Close()
}
return err
}
func (dn *dirnode) Remove(name string) error {
+ return dn.remove(strings.TrimRight(name, "/"), false)
+}
+
+func (dn *dirnode) RemoveAll(name string) error {
+ err := dn.remove(strings.TrimRight(name, "/"), true)
+ if os.IsNotExist(err) {
+ // "If the path does not exist, RemoveAll returns
+ // nil." (see "os" pkg)
+ err = nil
+ }
+ return err
+}
+
+func (dn *dirnode) remove(name string, recursive bool) error {
dirname, name := path.Split(name)
if name == "" || name == "." || name == ".." {
- return ErrInvalidOperation
+ return ErrInvalidArgument
}
dn, ok := dn.lookupPath(dirname).(*dirnode)
if !ok {
case *dirnode:
node.RLock()
defer node.RUnlock()
- if len(node.inodes) > 0 {
+ if !recursive && len(node.inodes) > 0 {
return ErrDirectoryNotEmpty
}
}
return nil
}
+func (dn *dirnode) Rename(oldname, newname string) error {
+ olddir, oldname := path.Split(oldname)
+ if oldname == "" || oldname == "." || oldname == ".." {
+ return ErrInvalidArgument
+ }
+ olddirf, err := dn.OpenFile(olddir+".", os.O_RDONLY, 0)
+ if err != nil {
+ return fmt.Errorf("%q: %s", olddir, err)
+ }
+ defer olddirf.Close()
+ newdir, newname := path.Split(newname)
+ if newname == "." || newname == ".." {
+ return ErrInvalidArgument
+ } else if newname == "" {
+ // Rename("a/b", "c/") means Rename("a/b", "c/b")
+ newname = oldname
+ }
+ newdirf, err := dn.OpenFile(newdir+".", os.O_RDONLY, 0)
+ if err != nil {
+ return fmt.Errorf("%q: %s", newdir, err)
+ }
+ defer newdirf.Close()
+
+ // When acquiring locks on multiple nodes, all common
+ // ancestors must be locked first in order to avoid
+ // deadlock. This is assured by locking the path from root to
+ // newdir, then locking the path from root to olddir, skipping
+ // any already-locked nodes.
+ needLock := []sync.Locker{}
+ for _, f := range []*filehandle{olddirf, newdirf} {
+ node := f.inode
+ needLock = append(needLock, node)
+ for node.Parent() != node {
+ node = node.Parent()
+ needLock = append(needLock, node)
+ }
+ }
+ locked := map[sync.Locker]bool{}
+ for i := len(needLock) - 1; i >= 0; i-- {
+ if n := needLock[i]; !locked[n] {
+ n.Lock()
+ defer n.Unlock()
+ locked[n] = true
+ }
+ }
+
+ olddn := olddirf.inode.(*dirnode)
+ newdn := newdirf.inode.(*dirnode)
+ oldinode, ok := olddn.inodes[oldname]
+ if !ok {
+ return os.ErrNotExist
+ }
+ if locked[oldinode] {
+ // oldinode cannot become a descendant of itself.
+ return ErrInvalidArgument
+ }
+ if existing, ok := newdn.inodes[newname]; ok {
+ // overwriting an existing file or dir
+ if dn, ok := existing.(*dirnode); ok {
+ if !oldinode.Stat().IsDir() {
+ return ErrIsDirectory
+ }
+ dn.RLock()
+ defer dn.RUnlock()
+ if len(dn.inodes) > 0 {
+ return ErrDirectoryNotEmpty
+ }
+ }
+ } else {
+ if newdn.inodes == nil {
+ newdn.inodes = make(map[string]inode)
+ }
+ newdn.fileinfo.size++
+ }
+ newdn.inodes[newname] = oldinode
+ switch n := oldinode.(type) {
+ case *dirnode:
+ n.parent = newdn
+ case *filenode:
+ n.parent = newdn
+ default:
+ panic(fmt.Sprintf("bad inode type %T", n))
+ }
+ delete(olddn.inodes, oldname)
+ olddn.fileinfo.size--
+ return nil
+}
+
func (dn *dirnode) Parent() inode {
dn.RLock()
defer dn.RUnlock()
return
}
-func (dn *dirnode) OpenFile(name string, flag int, perm os.FileMode) (*file, error) {
+func (dn *dirnode) newDirnode(name string, perm os.FileMode, modTime time.Time) *dirnode {
+ child := &dirnode{
+ parent: dn,
+ client: dn.client,
+ kc: dn.kc,
+ fileinfo: fileinfo{
+ name: name,
+ mode: os.ModeDir | perm,
+ modTime: modTime,
+ },
+ }
+ if dn.inodes == nil {
+ dn.inodes = make(map[string]inode)
+ }
+ dn.inodes[name] = child
+ dn.fileinfo.size++
+ return child
+}
+
+func (dn *dirnode) newFilenode(name string, perm os.FileMode, modTime time.Time) *filenode {
+ child := &filenode{
+ parent: dn,
+ fileinfo: fileinfo{
+ name: name,
+ mode: perm,
+ modTime: modTime,
+ },
+ }
+ if dn.inodes == nil {
+ dn.inodes = make(map[string]inode)
+ }
+ dn.inodes[name] = child
+ dn.fileinfo.size++
+ return child
+}
+
+// OpenFile is analogous to os.OpenFile().
+func (dn *dirnode) OpenFile(name string, flag int, perm os.FileMode) (*filehandle, error) {
+ if flag&os.O_SYNC != 0 {
+ return nil, ErrSyncNotSupported
+ }
dirname, name := path.Split(name)
dn, ok := dn.lookupPath(dirname).(*dirnode)
if !ok {
return nil, os.ErrNotExist
}
- writeMode := flag&(os.O_RDWR|os.O_WRONLY|os.O_CREATE) != 0
- if !writeMode {
+ var readable, writable bool
+ switch flag & (os.O_RDWR | os.O_RDONLY | os.O_WRONLY) {
+ case os.O_RDWR:
+ readable = true
+ writable = true
+ case os.O_RDONLY:
+ readable = true
+ case os.O_WRONLY:
+ writable = true
+ default:
+ return nil, fmt.Errorf("invalid flags 0x%x", flag)
+ }
+ if !writable {
// A directory can be opened via "foo/", "foo/.", or
// "foo/..".
switch name {
case ".", "":
- return &file{inode: dn}, nil
+ return &filehandle{inode: dn}, nil
case "..":
- return &file{inode: dn.Parent()}, nil
+ return &filehandle{inode: dn.Parent()}, nil
}
}
createMode := flag&os.O_CREATE != 0
return nil, os.ErrNotExist
}
if perm.IsDir() {
- n = &dirnode{
- parent: dn,
- client: dn.client,
- kc: dn.kc,
- fileinfo: fileinfo{
- name: name,
- mode: os.ModeDir | 0755,
- },
- }
+ n = dn.newDirnode(name, 0755, time.Now())
} else {
- n = &filenode{
- parent: dn,
- fileinfo: fileinfo{
- name: name,
- mode: 0755,
- },
- }
- }
- if dn.inodes == nil {
- dn.inodes = make(map[string]inode)
+ n = dn.newFilenode(name, 0755, time.Now())
}
- dn.inodes[name] = n
- dn.fileinfo.size++
} else if flag&os.O_EXCL != 0 {
return nil, ErrFileExists
+ } else if flag&os.O_TRUNC != 0 {
+ if !writable {
+ return nil, fmt.Errorf("invalid flag O_TRUNC in read-only mode")
+ } else if fn, ok := n.(*filenode); !ok {
+ return nil, fmt.Errorf("invalid flag O_TRUNC when opening directory")
+ } else {
+ fn.Truncate(0)
+ }
}
- return &file{
+ return &filehandle{
inode: n,
append: flag&os.O_APPEND != 0,
- writable: flag&(os.O_WRONLY|os.O_RDWR) != 0,
+ readable: readable,
+ writable: writable,
}, nil
}
-type extent interface {
+type segment interface {
io.ReaderAt
Len() int
- // Return a new extent with a subsection of the data from this
+ // Return a new segment with a subsection of the data from this
// one. length<0 means length=Len()-off.
- Slice(off int, length int) extent
-}
-
-type writableExtent interface {
- extent
- WriteAt(p []byte, off int)
- Truncate(n int)
+ Slice(off int, length int) segment
}
-type memExtent struct {
+type memSegment struct {
buf []byte
}
-func (me *memExtent) Len() int {
+func (me *memSegment) Len() int {
return len(me.buf)
}
-func (me *memExtent) Slice(off, length int) extent {
+func (me *memSegment) Slice(off, length int) segment {
if length < 0 {
length = len(me.buf) - off
}
buf := make([]byte, length)
copy(buf, me.buf[off:])
- return &memExtent{buf: buf}
+ return &memSegment{buf: buf}
}
-func (me *memExtent) Truncate(n int) {
+func (me *memSegment) Truncate(n int) {
if n > cap(me.buf) {
newsize := 1024
for newsize < n {
me.buf = me.buf[:n]
}
-func (me *memExtent) WriteAt(p []byte, off int) {
+func (me *memSegment) WriteAt(p []byte, off int) {
if off+len(p) > len(me.buf) {
- panic("overflowed extent")
+ panic("overflowed segment")
}
copy(me.buf[off:], p)
}
-func (me *memExtent) ReadAt(p []byte, off int64) (n int, err error) {
+func (me *memSegment) ReadAt(p []byte, off int64) (n int, err error) {
if off > int64(me.Len()) {
err = io.EOF
return
return
}
-type storedExtent struct {
+type storedSegment struct {
kc keepClient
locator string
- size int
- offset int
- length int
+ size int // size of stored block (also encoded in locator)
+ offset int // position of segment within the stored block
+ length int // bytes in this segment (offset + length <= size)
}
-func (se storedExtent) Len() int {
+func (se storedSegment) Len() int {
return se.length
}
-func (se storedExtent) Slice(n, size int) extent {
+func (se storedSegment) Slice(n, size int) segment {
se.offset += n
se.length -= n
if size >= 0 && se.length > size {
return se
}
-func (se storedExtent) ReadAt(p []byte, off int64) (n int, err error) {
+func (se storedSegment) ReadAt(p []byte, off int64) (n int, err error) {
if off > int64(se.length) {
return 0, io.EOF
}
return name
}
-var manifestEscapeSeq = regexp.MustCompile(`\\([0-9]{3}|\\)`)
+var manifestEscapeSeq = regexp.MustCompile(`\\([0-7]{3}|\\)`)
func manifestUnescapeFunc(seq string) string {
if seq == `\\` {
return manifestEscapeSeq.ReplaceAllStringFunc(s, manifestUnescapeFunc)
}
-var manifestEscapedChar = regexp.MustCompile(`[^\.\w/]`)
+var manifestEscapedChar = regexp.MustCompile(`[\000-\040:\s\\]`)
func manifestEscapeFunc(seq string) string {
return fmt.Sprintf("\\%03o", byte(seq[0]))
projects / arvados.git / blobdiff