diff options
Diffstat (limited to 'src/pkg/os/dir_plan9.go')
| -rw-r--r-- | src/pkg/os/dir_plan9.go | 259 |
1 files changed, 28 insertions, 231 deletions
diff --git a/src/pkg/os/dir_plan9.go b/src/pkg/os/dir_plan9.go index 7fa4c7f44..8195c02a4 100644 --- a/src/pkg/os/dir_plan9.go +++ b/src/pkg/os/dir_plan9.go @@ -5,15 +5,11 @@ package os import ( - "errors" "io" "syscall" ) -var errShortStat = errors.New("short stat message") -var errBadStat = errors.New("bad stat message format") - -func (file *File) readdir(n int) (fi []FileInfo, err error) { +func (file *File) readdir(n int) ([]FileInfo, error) { // If this file has no dirinfo, create one. if file.dirinfo == nil { file.dirinfo = new(dirInfo) @@ -24,44 +20,47 @@ func (file *File) readdir(n int) (fi []FileInfo, err error) { size = 100 n = -1 } - result := make([]FileInfo, 0, size) // Empty with room to grow. + fi := make([]FileInfo, 0, size) // Empty with room to grow. for n != 0 { - // Refill the buffer if necessary + // Refill the buffer if necessary. if d.bufp >= d.nbuf { - d.bufp = 0 - var e error - d.nbuf, e = file.Read(d.buf[:]) - if e != nil && e != io.EOF { - return result, &PathError{"readdir", file.name, e} - } - if e == io.EOF { - break + nb, err := file.Read(d.buf[:]) + + // Update the buffer state before checking for errors. + d.bufp, d.nbuf = 0, nb + + if err != nil { + if err == io.EOF { + break + } + return fi, &PathError{"readdir", file.name, err} } - if d.nbuf < syscall.STATFIXLEN { - return result, &PathError{"readdir", file.name, errShortStat} + if nb < syscall.STATFIXLEN { + return fi, &PathError{"readdir", file.name, syscall.ErrShortStat} } } - // Get a record from buffer - m, _ := gbit16(d.buf[d.bufp:]) - m += 2 + // Get a record from the buffer. + b := d.buf[d.bufp:] + m := int(uint16(b[0])|uint16(b[1])<<8) + 2 if m < syscall.STATFIXLEN { - return result, &PathError{"readdir", file.name, errShortStat} + return fi, &PathError{"readdir", file.name, syscall.ErrShortStat} } - dir, e := UnmarshalDir(d.buf[d.bufp : d.bufp+int(m)]) - if e != nil { - return result, &PathError{"readdir", file.name, e} + + dir, err := syscall.UnmarshalDir(b[:m]) + if err != nil { + return fi, &PathError{"readdir", file.name, err} } - result = append(result, fileInfoFromStat(dir)) + fi = append(fi, fileInfoFromStat(dir)) - d.bufp += int(m) + d.bufp += m n-- } - if n >= 0 && len(result) == 0 { - return result, io.EOF + if n >= 0 && len(fi) == 0 { + return fi, io.EOF } - return result, nil + return fi, nil } func (file *File) readdirnames(n int) (names []string, err error) { @@ -72,205 +71,3 @@ func (file *File) readdirnames(n int) (names []string, err error) { } return } - -type Dir struct { - // system-modified data - Type uint16 // server type - Dev uint32 // server subtype - // file data - Qid Qid // unique id from server - Mode uint32 // permissions - Atime uint32 // last read time - Mtime uint32 // last write time - Length uint64 // file length - Name string // last element of path - Uid string // owner name - Gid string // group name - Muid string // last modifier name -} - -type Qid struct { - Path uint64 // the file server's unique identification for the file - Vers uint32 // version number for given Path - Type uint8 // the type of the file (syscall.QTDIR for example) -} - -var nullDir = Dir{ - ^uint16(0), - ^uint32(0), - Qid{^uint64(0), ^uint32(0), ^uint8(0)}, - ^uint32(0), - ^uint32(0), - ^uint32(0), - ^uint64(0), - "", - "", - "", - "", -} - -// Null assigns members of d with special "don't care" values indicating -// they should not be written by syscall.Wstat. -func (d *Dir) Null() { - *d = nullDir -} - -// pdir appends a 9P Stat message based on the contents of Dir d to a byte slice b. -func pdir(b []byte, d *Dir) []byte { - n := len(b) - b = pbit16(b, 0) // length, filled in later - b = pbit16(b, d.Type) - b = pbit32(b, d.Dev) - b = pqid(b, d.Qid) - b = pbit32(b, d.Mode) - b = pbit32(b, d.Atime) - b = pbit32(b, d.Mtime) - b = pbit64(b, d.Length) - b = pstring(b, d.Name) - b = pstring(b, d.Uid) - b = pstring(b, d.Gid) - b = pstring(b, d.Muid) - pbit16(b[0:n], uint16(len(b)-(n+2))) - return b -} - -// UnmarshalDir reads a 9P Stat message from a 9P protocol message stored in b, -// returning the corresponding Dir struct. -func UnmarshalDir(b []byte) (d *Dir, err error) { - n := uint16(0) - n, b = gbit16(b) - - if int(n) != len(b) { - return nil, errBadStat - } - - d = new(Dir) - d.Type, b = gbit16(b) - d.Dev, b = gbit32(b) - d.Qid, b = gqid(b) - d.Mode, b = gbit32(b) - d.Atime, b = gbit32(b) - d.Mtime, b = gbit32(b) - d.Length, b = gbit64(b) - d.Name, b = gstring(b) - d.Uid, b = gstring(b) - d.Gid, b = gstring(b) - d.Muid, b = gstring(b) - - if len(b) != 0 { - return nil, errBadStat - } - - return d, nil -} - -// gqid reads the qid part of a 9P Stat message from a 9P protocol message stored in b, -// returning the corresponding Qid struct and the remaining slice of b. -func gqid(b []byte) (Qid, []byte) { - var q Qid - q.Path, b = gbit64(b) - q.Vers, b = gbit32(b) - q.Type, b = gbit8(b) - return q, b -} - -// pqid appends a Qid struct q to a 9P message b. -func pqid(b []byte, q Qid) []byte { - b = pbit64(b, q.Path) - b = pbit32(b, q.Vers) - b = pbit8(b, q.Type) - return b -} - -// gbit8 reads a byte-sized numeric value from a 9P protocol message stored in b, -// returning the value and the remaining slice of b. -func gbit8(b []byte) (uint8, []byte) { - return uint8(b[0]), b[1:] -} - -// gbit16 reads a 16-bit numeric value from a 9P protocol message stored in b, -// returning the value and the remaining slice of b. -func gbit16(b []byte) (uint16, []byte) { - return uint16(b[0]) | uint16(b[1])<<8, b[2:] -} - -// gbit32 reads a 32-bit numeric value from a 9P protocol message stored in b, -// returning the value and the remaining slice of b. -func gbit32(b []byte) (uint32, []byte) { - return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24, b[4:] -} - -// gbit64 reads a 64-bit numeric value from a 9P protocol message stored in b, -// returning the value and the remaining slice of b. -func gbit64(b []byte) (uint64, []byte) { - lo, b := gbit32(b) - hi, b := gbit32(b) - return uint64(hi)<<32 | uint64(lo), b -} - -// gstring reads a string from a 9P protocol message stored in b, -// returning the value as a Go string and the remaining slice of b. -func gstring(b []byte) (string, []byte) { - n, b := gbit16(b) - return string(b[0:n]), b[n:] -} - -// pbit8 appends a byte-sized numeric value x to a 9P message b. -func pbit8(b []byte, x uint8) []byte { - n := len(b) - if n+1 > cap(b) { - nb := make([]byte, n, 100+2*cap(b)) - copy(nb, b) - b = nb - } - b = b[0 : n+1] - b[n] = x - return b -} - -// pbit16 appends a 16-bit numeric value x to a 9P message b. -func pbit16(b []byte, x uint16) []byte { - n := len(b) - if n+2 > cap(b) { - nb := make([]byte, n, 100+2*cap(b)) - copy(nb, b) - b = nb - } - b = b[0 : n+2] - b[n] = byte(x) - b[n+1] = byte(x >> 8) - return b -} - -// pbit32 appends a 32-bit numeric value x to a 9P message b. -func pbit32(b []byte, x uint32) []byte { - n := len(b) - if n+4 > cap(b) { - nb := make([]byte, n, 100+2*cap(b)) - copy(nb, b) - b = nb - } - b = b[0 : n+4] - b[n] = byte(x) - b[n+1] = byte(x >> 8) - b[n+2] = byte(x >> 16) - b[n+3] = byte(x >> 24) - return b -} - -// pbit64 appends a 64-bit numeric value x to a 9P message b. -func pbit64(b []byte, x uint64) []byte { - b = pbit32(b, uint32(x)) - b = pbit32(b, uint32(x>>32)) - return b -} - -// pstring appends a Go string s to a 9P message b. -func pstring(b []byte, s string) []byte { - if len(s) >= 1<<16 { - panic(errors.New("string too long")) - } - b = pbit16(b, uint16(len(s))) - b = append(b, s...) - return b -} |