Commit a419a1aabc
lib/std/fs.zig
@@ -1823,7 +1823,7 @@ pub const Dir = struct {
var atomic_file = try dest_dir.atomicFile(dest_path, .{ .mode = mode });
defer atomic_file.deinit();
- try os.copy_file(in_file.handle, atomic_file.file.handle, .{});
+ try copy_file(in_file.handle, atomic_file.file.handle);
return atomic_file.finish();
}
@@ -2263,6 +2263,52 @@ pub fn realpathAlloc(allocator: *Allocator, pathname: []const u8) ![]u8 {
return allocator.dupe(u8, try os.realpath(pathname, &buf));
}
+const CopyFileError = error{SystemResources} || os.CopyFileRangeError || os.SendFileError;
+
+/// Transfer all the data between two file descriptors in the most efficient way.
+/// No metadata is transferred over.
+fn copy_file(fd_in: os.fd_t, fd_out: os.fd_t) CopyFileError!void {
+ if (comptime std.Target.current.isDarwin()) {
+ const rc = os.system.fcopyfile(fd_in, fd_out, null, os.system.COPYFILE_DATA);
+ switch (errno(rc)) {
+ 0 => return,
+ EINVAL => unreachable,
+ ENOMEM => return error.SystemResources,
+ // The source file was not a directory, symbolic link, or regular file.
+ // Try with the fallback path before giving up.
+ ENOTSUP => {},
+ else => |err| return unexpectedErrno(err),
+ }
+ }
+
+ if (std.Target.current.os.tag == .linux) {
+ // Try copy_file_range first as that works at the FS level and is the
+ // most efficient method (if available).
+ var offset: u64 = 0;
+ cfr_loop: while (true) {
+ // The kernel checks `offset+count` for overflow, use a 32 bit
+ // value so that the syscall won't return EINVAL except for
+ // impossibly large files.
+ const amt = try os.copy_file_range(fd_in, offset, fd_out, offset, math.maxInt(u32), 0);
+ // Terminate when no data was copied
+ if (amt == 0) break :cfr_loop;
+ offset += amt;
+ }
+ return;
+ }
+
+ // Sendfile is a zero-copy mechanism iff the OS supports it, otherwise the
+ // fallback code will copy the contents chunk by chunk.
+ const empty_iovec = [0]os.iovec_const{};
+ var offset: u64 = 0;
+ sendfile_loop: while (true) {
+ const amt = try os.sendfile(fd_out, fd_in, offset, 0, &empty_iovec, &empty_iovec, 0);
+ // Terminate when no data was copied
+ if (amt == 0) break :sendfile_loop;
+ offset += amt;
+ }
+}
+
test "" {
if (builtin.os.tag != .wasi) {
_ = makeDirAbsolute;
lib/std/os.zig
@@ -4945,6 +4945,7 @@ pub fn sendfile(
pub const CopyFileRangeError = error{
FileTooBig,
InputOutput,
+ InvalidFileDescriptor,
IsDir,
OutOfMemory,
NoSpaceLeft,
@@ -4978,6 +4979,11 @@ pub const CopyFileRangeError = error{
/// Other systems fall back to calling `pread` / `pwrite`.
///
/// Maximum offsets on Linux are `math.maxInt(i64)`.
+var has_copy_file_range_syscall = init: {
+ const kernel_has_syscall = comptime std.Target.current.os.isAtLeast(.linux, .{ .major = 4, .minor = 5 }) orelse true;
+ break :init std.atomic.Int(u1).init(@boolToInt(kernel_has_syscall));
+};
+
pub fn copy_file_range(fd_in: fd_t, off_in: u64, fd_out: fd_t, off_out: u64, len: usize, flags: u32) CopyFileRangeError!usize {
const use_c = std.c.versionCheck(.{ .major = 2, .minor = 27, .patch = 0 }).ok;
@@ -4992,7 +4998,7 @@ pub fn copy_file_range(fd_in: fd_t, off_in: u64, fd_out: fd_t, off_out: u64, len
const rc = sys.copy_file_range(fd_in, &off_in_copy, fd_out, &off_out_copy, len, flags);
switch (sys.getErrno(rc)) {
0 => return @intCast(usize, rc),
- EBADF => unreachable,
+ EBADF => return error.InvalidFileDescriptor,
EFBIG => return error.FileTooBig,
EIO => return error.InputOutput,
EISDIR => return error.IsDir,
@@ -5013,96 +5019,24 @@ pub fn copy_file_range(fd_in: fd_t, off_in: u64, fd_out: fd_t, off_out: u64, len
}
}
- var buf: [8 * 4096]u8 = undefined;
- const adjusted_count = math.min(buf.len, len);
- const amt_read = try pread(fd_in, buf[0..adjusted_count], off_in);
- // TODO without @as the line below fails to compile for wasm32-wasi:
- // error: integer value 0 cannot be coerced to type 'os.PWriteError!usize'
- if (amt_read == 0) return @as(usize, 0);
- return pwrite(fd_out, buf[0..amt_read], off_out);
-}
-
-var has_copy_file_range_syscall = std.atomic.Int(u1).init(1);
-
-pub const CopyFileOptions = struct {};
-
-pub const CopyFileError = error{
- BadFileHandle,
- SystemResources,
- FileTooBig,
- InputOutput,
- IsDir,
- OutOfMemory,
- NoSpaceLeft,
- Unseekable,
- PermissionDenied,
- FileBusy,
-} || FStatError || SendFileError;
+ var buf: [2 * 4096]u8 = undefined;
-/// Transfer all the data between two file descriptors in the most efficient way.
-/// No metadata is transferred over.
-pub fn copy_file(fd_in: fd_t, fd_out: fd_t, options: CopyFileOptions) CopyFileError!void {
- if (comptime std.Target.current.isDarwin()) {
- const rc = system.fcopyfile(fd_in, fd_out, null, system.COPYFILE_DATA);
- switch (errno(rc)) {
- 0 => return,
- EINVAL => unreachable,
- ENOMEM => return error.SystemResources,
- // The source file was not a directory, symbolic link, or regular file.
- // Try with the fallback path before giving up.
- ENOTSUP => {},
- else => |err| return unexpectedErrno(err),
- }
- }
-
- if (std.Target.current.os.tag == .linux) {
- // Try copy_file_range first as that works at the FS level and is the
- // most efficient method (if available).
- if (has_copy_file_range_syscall.get() != 0) {
- cfr_loop: while (true) {
- // The kernel checks `file_pos+count` for overflow, use a 32 bit
- // value so that the syscall won't return EINVAL except for
- // impossibly large files.
- const rc = linux.copy_file_range(fd_in, null, fd_out, null, math.maxInt(u32), 0);
- switch (errno(rc)) {
- 0 => {},
- EBADF => return error.BadFileHandle,
- EFBIG => return error.FileTooBig,
- EIO => return error.InputOutput,
- EISDIR => return error.IsDir,
- ENOMEM => return error.OutOfMemory,
- ENOSPC => return error.NoSpaceLeft,
- EOVERFLOW => return error.Unseekable,
- EPERM => return error.PermissionDenied,
- ETXTBSY => return error.FileBusy,
- // These may not be regular files, try fallback
- EINVAL => break :cfr_loop,
- // Support for cross-filesystem copy added in Linux 5.3, use fallback
- EXDEV => break :cfr_loop,
- // Syscall added in Linux 4.5, use fallback
- ENOSYS => {
- has_copy_file_range_syscall.set(0);
- break :cfr_loop;
- },
- else => |err| return unexpectedErrno(err),
- }
- // Terminate when no data was copied
- if (rc == 0) return;
- }
- // This point is reached when an error occurred, hopefully no data
- // was transferred yet
- }
+ var total_copied: usize = 0;
+ var read_off = off_in;
+ var write_off = off_out;
+ while (total_copied < len) {
+ const adjusted_count = math.min(buf.len, len - total_copied);
+ const amt_read = try pread(fd_in, buf[0..adjusted_count], read_off);
+ if (amt_read == 0) break;
+ const amt_written = try pwrite(fd_out, buf[0..amt_read], write_off);
+ // pwrite may write less than the specified amount, handle the remaining
+ // chunk of data in the next iteration
+ read_off += amt_written;
+ write_off += amt_written;
+ total_copied += amt_written;
}
- // Sendfile is a zero-copy mechanism iff the OS supports it, otherwise the
- // fallback code will copy the contents chunk by chunk.
- const empty_iovec = [0]iovec_const{};
- var offset: u64 = 0;
- sendfile_loop: while (true) {
- const amt = try sendfile(fd_out, fd_in, offset, 0, &empty_iovec, &empty_iovec, 0);
- if (amt == 0) break :sendfile_loop;
- offset += amt;
- }
+ return total_copied;
}
pub const PollError = error{