| // Copyright 2020 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_test |
| |
| import ( |
| "bytes" |
| "internal/poll" |
| "io" |
| "math/rand" |
| "os" |
| . "os" |
| "path/filepath" |
| "strconv" |
| "strings" |
| "syscall" |
| "testing" |
| "time" |
| ) |
| |
| func TestCopyFileRange(t *testing.T) { |
| sizes := []int{ |
| 1, |
| 42, |
| 1025, |
| syscall.Getpagesize() + 1, |
| 32769, |
| } |
| t.Run("Basic", func(t *testing.T) { |
| for _, size := range sizes { |
| t.Run(strconv.Itoa(size), func(t *testing.T) { |
| testCopyFileRange(t, int64(size), -1) |
| }) |
| } |
| }) |
| t.Run("Limited", func(t *testing.T) { |
| t.Run("OneLess", func(t *testing.T) { |
| for _, size := range sizes { |
| t.Run(strconv.Itoa(size), func(t *testing.T) { |
| testCopyFileRange(t, int64(size), int64(size)-1) |
| }) |
| } |
| }) |
| t.Run("Half", func(t *testing.T) { |
| for _, size := range sizes { |
| t.Run(strconv.Itoa(size), func(t *testing.T) { |
| testCopyFileRange(t, int64(size), int64(size)/2) |
| }) |
| } |
| }) |
| t.Run("More", func(t *testing.T) { |
| for _, size := range sizes { |
| t.Run(strconv.Itoa(size), func(t *testing.T) { |
| testCopyFileRange(t, int64(size), int64(size)+7) |
| }) |
| } |
| }) |
| }) |
| t.Run("DoesntTryInAppendMode", func(t *testing.T) { |
| dst, src, data, hook := newCopyFileRangeTest(t, 42) |
| |
| dst2, err := OpenFile(dst.Name(), O_RDWR|O_APPEND, 0755) |
| if err != nil { |
| t.Fatal(err) |
| } |
| defer dst2.Close() |
| |
| if _, err := io.Copy(dst2, src); err != nil { |
| t.Fatal(err) |
| } |
| if hook.called { |
| t.Fatal("called poll.CopyFileRange for destination in O_APPEND mode") |
| } |
| mustSeekStart(t, dst2) |
| mustContainData(t, dst2, data) // through traditional means |
| }) |
| t.Run("CopyFileItself", func(t *testing.T) { |
| hook := hookCopyFileRange(t) |
| |
| f, err := os.CreateTemp("", "file-readfrom-itself-test") |
| if err != nil { |
| t.Fatalf("failed to create tmp file: %v", err) |
| } |
| t.Cleanup(func() { |
| f.Close() |
| os.Remove(f.Name()) |
| }) |
| |
| data := []byte("hello world!") |
| if _, err := f.Write(data); err != nil { |
| t.Fatalf("failed to create and feed the file: %v", err) |
| } |
| |
| if err := f.Sync(); err != nil { |
| t.Fatalf("failed to save the file: %v", err) |
| } |
| |
| // Rewind it. |
| if _, err := f.Seek(0, io.SeekStart); err != nil { |
| t.Fatalf("failed to rewind the file: %v", err) |
| } |
| |
| // Read data from the file itself. |
| if _, err := io.Copy(f, f); err != nil { |
| t.Fatalf("failed to read from the file: %v", err) |
| } |
| |
| if !hook.called || hook.written != 0 || hook.handled || hook.err != nil { |
| t.Fatalf("poll.CopyFileRange should be called and return the EINVAL error, but got hook.called=%t, hook.err=%v", hook.called, hook.err) |
| } |
| |
| // Rewind it. |
| if _, err := f.Seek(0, io.SeekStart); err != nil { |
| t.Fatalf("failed to rewind the file: %v", err) |
| } |
| |
| data2, err := io.ReadAll(f) |
| if err != nil { |
| t.Fatalf("failed to read from the file: %v", err) |
| } |
| |
| // It should wind up a double of the original data. |
| if strings.Repeat(string(data), 2) != string(data2) { |
| t.Fatalf("data mismatch: %s != %s", string(data), string(data2)) |
| } |
| }) |
| t.Run("NotRegular", func(t *testing.T) { |
| t.Run("BothPipes", func(t *testing.T) { |
| hook := hookCopyFileRange(t) |
| |
| pr1, pw1, err := Pipe() |
| if err != nil { |
| t.Fatal(err) |
| } |
| defer pr1.Close() |
| defer pw1.Close() |
| |
| pr2, pw2, err := Pipe() |
| if err != nil { |
| t.Fatal(err) |
| } |
| defer pr2.Close() |
| defer pw2.Close() |
| |
| // The pipe is empty, and PIPE_BUF is large enough |
| // for this, by (POSIX) definition, so there is no |
| // need for an additional goroutine. |
| data := []byte("hello") |
| if _, err := pw1.Write(data); err != nil { |
| t.Fatal(err) |
| } |
| pw1.Close() |
| |
| n, err := io.Copy(pw2, pr1) |
| if err != nil { |
| t.Fatal(err) |
| } |
| if n != int64(len(data)) { |
| t.Fatalf("transferred %d, want %d", n, len(data)) |
| } |
| if !hook.called { |
| t.Fatalf("should have called poll.CopyFileRange") |
| } |
| pw2.Close() |
| mustContainData(t, pr2, data) |
| }) |
| t.Run("DstPipe", func(t *testing.T) { |
| dst, src, data, hook := newCopyFileRangeTest(t, 255) |
| dst.Close() |
| |
| pr, pw, err := Pipe() |
| if err != nil { |
| t.Fatal(err) |
| } |
| defer pr.Close() |
| defer pw.Close() |
| |
| n, err := io.Copy(pw, src) |
| if err != nil { |
| t.Fatal(err) |
| } |
| if n != int64(len(data)) { |
| t.Fatalf("transferred %d, want %d", n, len(data)) |
| } |
| if !hook.called { |
| t.Fatalf("should have called poll.CopyFileRange") |
| } |
| pw.Close() |
| mustContainData(t, pr, data) |
| }) |
| t.Run("SrcPipe", func(t *testing.T) { |
| dst, src, data, hook := newCopyFileRangeTest(t, 255) |
| src.Close() |
| |
| pr, pw, err := Pipe() |
| if err != nil { |
| t.Fatal(err) |
| } |
| defer pr.Close() |
| defer pw.Close() |
| |
| // The pipe is empty, and PIPE_BUF is large enough |
| // for this, by (POSIX) definition, so there is no |
| // need for an additional goroutine. |
| if _, err := pw.Write(data); err != nil { |
| t.Fatal(err) |
| } |
| pw.Close() |
| |
| n, err := io.Copy(dst, pr) |
| if err != nil { |
| t.Fatal(err) |
| } |
| if n != int64(len(data)) { |
| t.Fatalf("transferred %d, want %d", n, len(data)) |
| } |
| if !hook.called { |
| t.Fatalf("should have called poll.CopyFileRange") |
| } |
| mustSeekStart(t, dst) |
| mustContainData(t, dst, data) |
| }) |
| }) |
| t.Run("Nil", func(t *testing.T) { |
| var nilFile *File |
| anyFile, err := os.CreateTemp("", "") |
| if err != nil { |
| t.Fatal(err) |
| } |
| defer Remove(anyFile.Name()) |
| defer anyFile.Close() |
| |
| if _, err := io.Copy(nilFile, nilFile); err != ErrInvalid { |
| t.Errorf("io.Copy(nilFile, nilFile) = %v, want %v", err, ErrInvalid) |
| } |
| if _, err := io.Copy(anyFile, nilFile); err != ErrInvalid { |
| t.Errorf("io.Copy(anyFile, nilFile) = %v, want %v", err, ErrInvalid) |
| } |
| if _, err := io.Copy(nilFile, anyFile); err != ErrInvalid { |
| t.Errorf("io.Copy(nilFile, anyFile) = %v, want %v", err, ErrInvalid) |
| } |
| |
| if _, err := nilFile.ReadFrom(nilFile); err != ErrInvalid { |
| t.Errorf("nilFile.ReadFrom(nilFile) = %v, want %v", err, ErrInvalid) |
| } |
| if _, err := anyFile.ReadFrom(nilFile); err != ErrInvalid { |
| t.Errorf("anyFile.ReadFrom(nilFile) = %v, want %v", err, ErrInvalid) |
| } |
| if _, err := nilFile.ReadFrom(anyFile); err != ErrInvalid { |
| t.Errorf("nilFile.ReadFrom(anyFile) = %v, want %v", err, ErrInvalid) |
| } |
| }) |
| } |
| |
| func testCopyFileRange(t *testing.T, size int64, limit int64) { |
| dst, src, data, hook := newCopyFileRangeTest(t, size) |
| |
| // If we have a limit, wrap the reader. |
| var ( |
| realsrc io.Reader |
| lr *io.LimitedReader |
| ) |
| if limit >= 0 { |
| lr = &io.LimitedReader{N: limit, R: src} |
| realsrc = lr |
| if limit < int64(len(data)) { |
| data = data[:limit] |
| } |
| } else { |
| realsrc = src |
| } |
| |
| // Now call ReadFrom (through io.Copy), which will hopefully call |
| // poll.CopyFileRange. |
| n, err := io.Copy(dst, realsrc) |
| if err != nil { |
| t.Fatal(err) |
| } |
| |
| // If we didn't have a limit, we should have called poll.CopyFileRange |
| // with the right file descriptor arguments. |
| if limit > 0 && !hook.called { |
| t.Fatal("never called poll.CopyFileRange") |
| } |
| if hook.called && hook.dstfd != int(dst.Fd()) { |
| t.Fatalf("wrong destination file descriptor: got %d, want %d", hook.dstfd, dst.Fd()) |
| } |
| if hook.called && hook.srcfd != int(src.Fd()) { |
| t.Fatalf("wrong source file descriptor: got %d, want %d", hook.srcfd, src.Fd()) |
| } |
| |
| // Check that the offsets after the transfer make sense, that the size |
| // of the transfer was reported correctly, and that the destination |
| // file contains exactly the bytes we expect it to contain. |
| dstoff, err := dst.Seek(0, io.SeekCurrent) |
| if err != nil { |
| t.Fatal(err) |
| } |
| srcoff, err := src.Seek(0, io.SeekCurrent) |
| if err != nil { |
| t.Fatal(err) |
| } |
| if dstoff != srcoff { |
| t.Errorf("offsets differ: dstoff = %d, srcoff = %d", dstoff, srcoff) |
| } |
| if dstoff != int64(len(data)) { |
| t.Errorf("dstoff = %d, want %d", dstoff, len(data)) |
| } |
| if n != int64(len(data)) { |
| t.Errorf("short ReadFrom: wrote %d bytes, want %d", n, len(data)) |
| } |
| mustSeekStart(t, dst) |
| mustContainData(t, dst, data) |
| |
| // If we had a limit, check that it was updated. |
| if lr != nil { |
| if want := limit - n; lr.N != want { |
| t.Fatalf("didn't update limit correctly: got %d, want %d", lr.N, want) |
| } |
| } |
| } |
| |
| // newCopyFileRangeTest initializes a new test for copy_file_range. |
| // |
| // It creates source and destination files, and populates the source file |
| // with random data of the specified size. It also hooks package os' call |
| // to poll.CopyFileRange and returns the hook so it can be inspected. |
| func newCopyFileRangeTest(t *testing.T, size int64) (dst, src *File, data []byte, hook *copyFileRangeHook) { |
| t.Helper() |
| |
| hook = hookCopyFileRange(t) |
| tmp := t.TempDir() |
| |
| src, err := Create(filepath.Join(tmp, "src")) |
| if err != nil { |
| t.Fatal(err) |
| } |
| t.Cleanup(func() { src.Close() }) |
| |
| dst, err = Create(filepath.Join(tmp, "dst")) |
| if err != nil { |
| t.Fatal(err) |
| } |
| t.Cleanup(func() { dst.Close() }) |
| |
| // Populate the source file with data, then rewind it, so it can be |
| // consumed by copy_file_range(2). |
| prng := rand.New(rand.NewSource(time.Now().Unix())) |
| data = make([]byte, size) |
| prng.Read(data) |
| if _, err := src.Write(data); err != nil { |
| t.Fatal(err) |
| } |
| if _, err := src.Seek(0, io.SeekStart); err != nil { |
| t.Fatal(err) |
| } |
| |
| return dst, src, data, hook |
| } |
| |
| // mustContainData ensures that the specified file contains exactly the |
| // specified data. |
| func mustContainData(t *testing.T, f *File, data []byte) { |
| t.Helper() |
| |
| got := make([]byte, len(data)) |
| if _, err := io.ReadFull(f, got); err != nil { |
| t.Fatal(err) |
| } |
| if !bytes.Equal(got, data) { |
| t.Fatalf("didn't get the same data back from %s", f.Name()) |
| } |
| if _, err := f.Read(make([]byte, 1)); err != io.EOF { |
| t.Fatalf("not at EOF") |
| } |
| } |
| |
| func mustSeekStart(t *testing.T, f *File) { |
| if _, err := f.Seek(0, io.SeekStart); err != nil { |
| t.Fatal(err) |
| } |
| } |
| |
| func hookCopyFileRange(t *testing.T) *copyFileRangeHook { |
| h := new(copyFileRangeHook) |
| h.install() |
| t.Cleanup(h.uninstall) |
| return h |
| } |
| |
| type copyFileRangeHook struct { |
| called bool |
| dstfd int |
| srcfd int |
| remain int64 |
| |
| written int64 |
| handled bool |
| err error |
| |
| original func(dst, src *poll.FD, remain int64) (int64, bool, error) |
| } |
| |
| func (h *copyFileRangeHook) install() { |
| h.original = *PollCopyFileRangeP |
| *PollCopyFileRangeP = func(dst, src *poll.FD, remain int64) (int64, bool, error) { |
| h.called = true |
| h.dstfd = dst.Sysfd |
| h.srcfd = src.Sysfd |
| h.remain = remain |
| h.written, h.handled, h.err = h.original(dst, src, remain) |
| return h.written, h.handled, h.err |
| } |
| } |
| |
| func (h *copyFileRangeHook) uninstall() { |
| *PollCopyFileRangeP = h.original |
| } |
| |
| // On some kernels copy_file_range fails on files in /proc. |
| func TestProcCopy(t *testing.T) { |
| const cmdlineFile = "/proc/self/cmdline" |
| cmdline, err := os.ReadFile(cmdlineFile) |
| if err != nil { |
| t.Skipf("can't read /proc file: %v", err) |
| } |
| in, err := os.Open(cmdlineFile) |
| if err != nil { |
| t.Fatal(err) |
| } |
| defer in.Close() |
| outFile := filepath.Join(t.TempDir(), "cmdline") |
| out, err := os.Create(outFile) |
| if err != nil { |
| t.Fatal(err) |
| } |
| if _, err := io.Copy(out, in); err != nil { |
| t.Fatal(err) |
| } |
| if err := out.Close(); err != nil { |
| t.Fatal(err) |
| } |
| copy, err := os.ReadFile(outFile) |
| if err != nil { |
| t.Fatal(err) |
| } |
| if !bytes.Equal(cmdline, copy) { |
| t.Errorf("copy of %q got %q want %q\n", cmdlineFile, copy, cmdline) |
| } |
| } |