First pass at reading directories.

Syscall support.
Readdirnames returns array of strings of contents of directory.

R=rsc
DELTA=216  (201 added, 0 deleted, 15 changed)
OCL=24642
CL=24655

src/lib/os/Makefile

@@ -4,7 +4,7 @@
 
 # DO NOT EDIT.  Automatically generated by gobuild.
 # gobuild -m os_env.go os_error.go os_file.go os_test.go os_time.go\
-#    os_types.go stat_amd64_linux.go >Makefile
+#    os_types.go stat_amd64_linux.go dir_amd64_linux.go >Makefile
 O=6
 GC=$(O)g
 CC=$(O)c -w
@@ -44,7 +44,10 @@ O2=\
 O3=\
 	os_file.$O\
 
-os.a: a1 a2 a3
+O4=\
+	dir_$(GOARCH)_$(GOOS).$O\
+
+os.a: a1 a2 a3 a4
 
 a1:	$(O1)
 	$(AR) grc os.a os_error.$O os_types.$O
@@ -58,12 +61,17 @@ a3:	$(O3)
 	$(AR) grc os.a os_file.$O
 	rm -f $(O3)
 
+a4:	$(O4)
+	$(AR) grc os.a dir_$(GOARCH)_$(GOOS).$O
+	rm -f $(O4)
+
 newpkg: clean
 	$(AR) grc os.a
 
 $(O1): newpkg
 $(O2): a1
 $(O3): a2
+$(O4): a3
 
 nuke: clean
 	rm -f $(GOROOT)/pkg/os.a

src/lib/os/dir_amd64_darwin.go

@@ -0,0 +1,58 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package os
+
+import (
+	"syscall";
+	"os";
+	"unsafe";
+)
+
+// Negative count means read until EOF.
+func Readdirnames(fd *FD, count int) (names []string, err *os.Error) {
+	// Getdirentries needs the file offset - it's too hard for the kernel to remember
+	// a number it already has written down.
+	base, err1 := syscall.Seek(fd.fd, 0, 1);
+	if err1 != 0 {
+		return nil, os.ErrnoToError(err1)
+	}
+	// The buffer must be at least a block long.
+	// TODO(r): use fstatfs to find fs block size.
+	var buf = make([]byte, 8192);
+	names = make([]string, 0, 100);	// TODO: could be smarter about size
+	for {
+		if count == 0 {
+			break
+		}
+		ret, err2 := syscall.Getdirentries(fd.fd, &buf[0], len(buf), &base);
+		if ret < 0 || err2 != 0 {
+			return names, os.ErrnoToError(err2)
+		}
+		if ret == 0 {
+			break
+		}
+		for w, i := uintptr(0),uintptr(0); i < uintptr(ret); i += w {
+			if count == 0 {
+				break
+			}
+			dir := unsafe.Pointer((uintptr(unsafe.Pointer(&buf[0])) + i)).(*syscall.Dirent);
+			w = uintptr(dir.Reclen);
+			if dir.Ino == 0 {
+				continue
+			}
+			count--;
+			if len(names) == cap(names) {
+				nnames := make([]string, len(names), 2*len(names));
+				for i := 0; i < len(names); i++ {
+					nnames[i] = names[i]
+				}
+				names = nnames;
+			}
+			names = names[0:len(names)+1];
+			names[len(names)-1] = string(dir.Name[0:dir.Namlen]);
+		}
+	}
+	return names, nil;
+}

src/lib/os/dir_amd64_linux.go

@@ -0,0 +1,61 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package os
+
+import (
+	"syscall";
+	"os";
+	"unsafe";
+)
+
+func clen(n []byte) int {
+	for i := 0; i < len(n); i++ {
+		if n[i] == 0 {
+			return i
+		}
+	}
+	return len(n)
+}
+
+// Negative count means read until EOF.
+func Readdirnames(fd *FD, count int) (names []string, err *os.Error) {
+	// The buffer should be at least a block long.
+	// TODO(r): use fstatfs to find fs block size.
+	var buf = make([]syscall.Dirent, 8192/unsafe.Sizeof(*new(syscall.Dirent)));
+	names = make([]string, 0, 100);	// TODO: could be smarter about size
+	for {
+		if count == 0 {
+			break
+		}
+		ret, err2 := syscall.Getdents(fd.fd, &buf[0], int64(len(buf) * unsafe.Sizeof(buf[0])));
+		if ret < 0 || err2 != 0 {
+			return names, os.ErrnoToError(err2)
+		}
+		if ret == 0 {
+			break
+		}
+		for w, i := uintptr(0),uintptr(0); i < uintptr(ret); i += w {
+			if count == 0 {
+				break
+			}
+			dir := unsafe.Pointer((uintptr(unsafe.Pointer(&buf[0])) + i)).(*syscall.Dirent);
+			w = uintptr(dir.Reclen);
+			if dir.Ino == 0 {
+				continue
+			}
+			count--;
+			if len(names) == cap(names) {
+				nnames := make([]string, len(names), 2*len(names));
+				for i := 0; i < len(names); i++ {
+					nnames[i] = names[i]
+				}
+				names = nnames;
+			}
+			names = names[0:len(names)+1];
+			names[len(names)-1] = string(dir.Name[0:clen(dir.Name)]);
+		}
+	}
+	return names, nil;
+}

src/lib/os/os_test.go

@@ -77,3 +77,41 @@ func TestLstat(t *testing.T) {
 		t.Error("size should be ", filesize, "; is", dir.Size);
 	}
 }
+
+func TestReaddirnames(t *testing.T) {
+	fd, err := Open(".", O_RDONLY, 0);
+	defer fd.Close();
+	if err != nil {
+		t.Fatal("open . failed:", err);
+	}
+	s, err2 := Readdirnames(fd, -1);
+	if err2 != nil {
+		t.Fatal("readdirnames . failed:", err);
+	}
+	a := []string{
+		"dir_amd64_darwin.go",
+		"dir_amd64_linux.go",
+		"os_env.go",
+		"os_error.go",
+		"os_file.go",
+		"os_test.go",
+		"os_time.go",
+		"os_types.go",
+		"stat_amd64_darwin.go",
+		"stat_amd64_linux.go"
+	};
+	for i, m := range a {
+		found := false;
+		for j, n := range s {
+			if m == n {
+				if found {
+					t.Error("present twice:", m);
+				}
+				found = true
+			}
+		}
+		if !found {
+			t.Error("could not find", m);
+		}
+	}
+}

src/lib/syscall/file_darwin.go

@@ -40,6 +40,11 @@ func Write(fd int64, buf *byte, nbytes int64) (ret int64, errno int64) {
 	return r1, err;
 }
 
+func Seek(fd int64, offset int64, whence int64) (ret int64, errno int64) {
+	r1, r2, err := Syscall(SYS_LSEEK, fd, offset, whence);
+	return r1, err;
+}
+
 func Pipe(fds *[2]int64) (ret int64, errno int64) {
 	r1, r2, err := Syscall(SYS_PIPE, 0, 0, 0);
 	if r1 < 0 {
@@ -89,3 +94,7 @@ func Dup2(fd1, fd2 int64) (ret int64, errno int64) {
 	return r1, err;
 }
 
+func Getdirentries(fd int64, buf *byte, nbytes int64, basep *int64) (ret int64, errno int64) {
+	r1, r2, err := Syscall6(SYS_GETDIRENTRIES64, fd, int64(uintptr(unsafe.Pointer(buf))), nbytes, int64(uintptr(unsafe.Pointer(basep))), 0, 0);
+	return r1, err;
+}

src/lib/syscall/file_linux.go

@@ -40,6 +40,11 @@ func Write(fd int64, buf *byte, nbytes int64) (ret int64, errno int64) {
 	return r1, err;
 }
 
+func Seek(fd int64, offset int64, whence int64) (ret int64, errno int64) {
+	r1, r2, err := Syscall(SYS_LSEEK, fd, offset, whence);
+	return r1, err;
+}
+
 func Pipe(fds *[2]int64) (ret int64, errno int64) {
 	var t [2] int32;
 	r1, r2, err := Syscall(SYS_PIPE, int64(uintptr(unsafe.Pointer(&t[0]))), 0, 0);
@@ -90,3 +95,8 @@ func Dup2(fd1, fd2 int64) (ret int64, errno int64) {
 	return r1, err;
 }
 
+func Getdents(fd int64, buf *Dirent, nbytes int64) (ret int64, errno int64) {
+	r1, r2, err := Syscall(SYS_GETDENTS64, fd, int64(uintptr(unsafe.Pointer(buf))), nbytes);
+	return r1, err;
+}
+

src/lib/syscall/types_amd64_darwin.go

@@ -65,6 +65,8 @@ const (
 	F_SETFL = 4;
 
 	FD_CLOEXEC = 1;
+
+	NAME_MAX = 255;
 )
 
 type Stat_t struct {
@@ -76,19 +78,27 @@ type Stat_t struct {
 	Gid	uint32;
 	Rdev	uint32;
 	Pad1	uint32;
-	Atime Timespec;
-	Mtime Timespec;
-	Ctime Timespec;
-	Birthtime Timespec;
-	Size uint64;
-	Blocks uint64;
-	Blksize uint32;
-	Flags uint32;
-	Gen uint32;
-	Lspare uint32;
-	Qspare [2]uint64;
+	Atime	Timespec;
+	Mtime	Timespec;
+	Ctime	Timespec;
+	Birthtime	Timespec;
+	Size	uint64;
+	Blocks	uint64;
+	Blksize	uint32;
+	Flags	uint32;
+	Gen	uint32;
+	Lspare	uint32;
+	Qspare	[2]uint64;
 }
 
+type Dirent struct {
+	Ino	uint64;
+	Off	uint64;
+	Reclen	uint16;
+	Namlen	uint16;
+	Type	uint8;
+	Name	[NAME_MAX+1]byte;
+}
 
 // Sockets
 

src/lib/syscall/types_amd64_linux.go

@@ -65,6 +65,8 @@ const (
 	F_SETFL = 4;
 
 	FD_CLOEXEC = 1;
+
+	NAME_MAX = 255;
 )
 
 type Stat_t struct {
@@ -85,6 +87,13 @@ type Stat_t struct {
 	_unused	[3]int64
 }
 
+type Dirent struct {
+	Ino	uint64;
+	Off	uint64;
+	Reclen	uint16;
+	Type	uint8;
+	Name	[NAME_MAX+1]byte;
+}
 
 // Sockets