Source
pub fn sendFile(
io_w: *std.Io.Writer,
file_reader: *Reader,
limit: std.Io.Limit,
) std.Io.Writer.FileError!usize {
const reader_buffered = file_reader.interface.buffered();
if (reader_buffered.len >= @intFromEnum(limit))
return sendFileBuffered(io_w, file_reader, reader_buffered);
const writer_buffered = io_w.buffered();
const file_limit = @intFromEnum(limit) - reader_buffered.len;
const w: *Writer = @alignCast(@fieldParentPtr("interface", io_w));
const out_fd = w.file.handle;
const in_fd = file_reader.file.handle;
if (file_reader.size) |size| {
if (size - file_reader.pos == 0) {
if (reader_buffered.len != 0) {
return sendFileBuffered(io_w, file_reader, reader_buffered);
} else {
return error.EndOfStream;
}
}
}
if (native_os == .freebsd and w.mode == .streaming) sf: {
// Try using sendfile on FreeBSD.
if (w.sendfile_err != null) break :sf;
const offset = std.math.cast(std.c.off_t, file_reader.pos) orelse break :sf;
var hdtr_data: std.c.sf_hdtr = undefined;
var headers: [2]posix.iovec_const = undefined;
var headers_i: u8 = 0;
if (writer_buffered.len != 0) {
headers[headers_i] = .{ .base = writer_buffered.ptr, .len = writer_buffered.len };
headers_i += 1;
}
if (reader_buffered.len != 0) {
headers[headers_i] = .{ .base = reader_buffered.ptr, .len = reader_buffered.len };
headers_i += 1;
}
const hdtr: ?*std.c.sf_hdtr = if (headers_i == 0) null else b: {
hdtr_data = .{
.headers = &headers,
.hdr_cnt = headers_i,
.trailers = null,
.trl_cnt = 0,
};
break :b &hdtr_data;
};
var sbytes: std.c.off_t = undefined;
const nbytes: usize = @min(file_limit, maxInt(usize));
const flags = 0;
switch (posix.errno(std.c.sendfile(in_fd, out_fd, offset, nbytes, hdtr, &sbytes, flags))) {
.SUCCESS, .INTR => {},
.INVAL, .OPNOTSUPP, .NOTSOCK, .NOSYS => w.sendfile_err = error.UnsupportedOperation,
.BADF => if (builtin.mode == .Debug) @panic("race condition") else {
w.sendfile_err = error.Unexpected;
},
.FAULT => if (builtin.mode == .Debug) @panic("segmentation fault") else {
w.sendfile_err = error.Unexpected;
},
.NOTCONN => w.sendfile_err = error.BrokenPipe,
.AGAIN, .BUSY => if (sbytes == 0) {
w.sendfile_err = error.WouldBlock;
},
.IO => w.sendfile_err = error.InputOutput,
.PIPE => w.sendfile_err = error.BrokenPipe,
.NOBUFS => w.sendfile_err = error.SystemResources,
else => |err| w.sendfile_err = posix.unexpectedErrno(err),
}
if (w.sendfile_err != null) {
// Give calling code chance to observe the error before trying
// something else.
return 0;
}
if (sbytes == 0) {
file_reader.size = file_reader.pos;
return error.EndOfStream;
}
const consumed = io_w.consume(@intCast(sbytes));
file_reader.seekTo(file_reader.pos + consumed) catch return error.ReadFailed;
return consumed;
}
if (native_os.isDarwin() and w.mode == .streaming) sf: {
// Try using sendfile on macOS.
if (w.sendfile_err != null) break :sf;
const offset = std.math.cast(std.c.off_t, file_reader.pos) orelse break :sf;
var hdtr_data: std.c.sf_hdtr = undefined;
var headers: [2]posix.iovec_const = undefined;
var headers_i: u8 = 0;
if (writer_buffered.len != 0) {
headers[headers_i] = .{ .base = writer_buffered.ptr, .len = writer_buffered.len };
headers_i += 1;
}
if (reader_buffered.len != 0) {
headers[headers_i] = .{ .base = reader_buffered.ptr, .len = reader_buffered.len };
headers_i += 1;
}
const hdtr: ?*std.c.sf_hdtr = if (headers_i == 0) null else b: {
hdtr_data = .{
.headers = &headers,
.hdr_cnt = headers_i,
.trailers = null,
.trl_cnt = 0,
};
break :b &hdtr_data;
};
const max_count = maxInt(i32); // Avoid EINVAL.
var len: std.c.off_t = @min(file_limit, max_count);
const flags = 0;
switch (posix.errno(std.c.sendfile(in_fd, out_fd, offset, &len, hdtr, flags))) {
.SUCCESS, .INTR => {},
.OPNOTSUPP, .NOTSOCK, .NOSYS => w.sendfile_err = error.UnsupportedOperation,
.BADF => if (builtin.mode == .Debug) @panic("race condition") else {
w.sendfile_err = error.Unexpected;
},
.FAULT => if (builtin.mode == .Debug) @panic("segmentation fault") else {
w.sendfile_err = error.Unexpected;
},
.INVAL => if (builtin.mode == .Debug) @panic("invalid API usage") else {
w.sendfile_err = error.Unexpected;
},
.NOTCONN => w.sendfile_err = error.BrokenPipe,
.AGAIN => if (len == 0) {
w.sendfile_err = error.WouldBlock;
},
.IO => w.sendfile_err = error.InputOutput,
.PIPE => w.sendfile_err = error.BrokenPipe,
else => |err| w.sendfile_err = posix.unexpectedErrno(err),
}
if (w.sendfile_err != null) {
// Give calling code chance to observe the error before trying
// something else.
return 0;
}
if (len == 0) {
file_reader.size = file_reader.pos;
return error.EndOfStream;
}
const consumed = io_w.consume(@bitCast(len));
file_reader.seekTo(file_reader.pos + consumed) catch return error.ReadFailed;
return consumed;
}
if (native_os == .linux and w.mode == .streaming) sf: {
// Try using sendfile on Linux.
if (w.sendfile_err != null) break :sf;
// Linux sendfile does not support headers.
if (writer_buffered.len != 0 or reader_buffered.len != 0)
return sendFileBuffered(io_w, file_reader, reader_buffered);
const max_count = 0x7ffff000; // Avoid EINVAL.
var off: std.os.linux.off_t = undefined;
const off_ptr: ?*std.os.linux.off_t, const count: usize = switch (file_reader.mode) {
.positional => o: {
const size = file_reader.getSize() catch return 0;
off = std.math.cast(std.os.linux.off_t, file_reader.pos) orelse return error.ReadFailed;
break :o .{ &off, @min(@intFromEnum(limit), size - file_reader.pos, max_count) };
},
.streaming => .{ null, limit.minInt(max_count) },
.streaming_reading, .positional_reading => break :sf,
.failure => return error.ReadFailed,
};
const n = std.os.linux.wrapped.sendfile(out_fd, in_fd, off_ptr, count) catch |err| switch (err) {
error.Unseekable => {
file_reader.mode = file_reader.mode.toStreaming();
const pos = file_reader.pos;
if (pos != 0) {
file_reader.pos = 0;
file_reader.seekBy(@intCast(pos)) catch {
file_reader.mode = .failure;
return error.ReadFailed;
};
}
return 0;
},
else => |e| {
w.sendfile_err = e;
return 0;
},
};
if (n == 0) {
file_reader.size = file_reader.pos;
return error.EndOfStream;
}
file_reader.pos += n;
w.pos += n;
return n;
}
const copy_file_range = switch (native_os) {
.freebsd => std.os.freebsd.copy_file_range,
.linux => if (std.c.versionCheck(if (builtin.abi.isAndroid()) .{ .major = 34, .minor = 0, .patch = 0 } else .{ .major = 2, .minor = 27, .patch = 0 })) std.os.linux.wrapped.copy_file_range else {},
else => {},
};
if (@TypeOf(copy_file_range) != void) cfr: {
if (w.copy_file_range_err != null) break :cfr;
if (writer_buffered.len != 0 or reader_buffered.len != 0)
return sendFileBuffered(io_w, file_reader, reader_buffered);
var off_in: i64 = undefined;
var off_out: i64 = undefined;
const off_in_ptr: ?*i64 = switch (file_reader.mode) {
.positional_reading, .streaming_reading => return error.Unimplemented,
.positional => p: {
off_in = @intCast(file_reader.pos);
break :p &off_in;
},
.streaming => null,
.failure => return error.WriteFailed,
};
const off_out_ptr: ?*i64 = switch (w.mode) {
.positional_reading, .streaming_reading => return error.Unimplemented,
.positional => p: {
off_out = @intCast(w.pos);
break :p &off_out;
},
.streaming => null,
.failure => return error.WriteFailed,
};
const n = copy_file_range(in_fd, off_in_ptr, out_fd, off_out_ptr, @intFromEnum(limit), 0) catch |err| {
w.copy_file_range_err = err;
return 0;
};
if (n == 0) {
file_reader.size = file_reader.pos;
return error.EndOfStream;
}
file_reader.pos += n;
w.pos += n;
return n;
}
if (builtin.os.tag.isDarwin()) fcf: {
if (w.fcopyfile_err != null) break :fcf;
if (file_reader.pos != 0) break :fcf;
if (w.pos != 0) break :fcf;
if (limit != .unlimited) break :fcf;
const size = file_reader.getSize() catch break :fcf;
if (writer_buffered.len != 0 or reader_buffered.len != 0)
return sendFileBuffered(io_w, file_reader, reader_buffered);
const rc = std.c.fcopyfile(in_fd, out_fd, null, .{ .DATA = true });
switch (posix.errno(rc)) {
.SUCCESS => {},
.INVAL => if (builtin.mode == .Debug) @panic("invalid API usage") else {
w.fcopyfile_err = error.Unexpected;
return 0;
},
.NOMEM => {
w.fcopyfile_err = error.OutOfMemory;
return 0;
},
.OPNOTSUPP => {
w.fcopyfile_err = error.OperationNotSupported;
return 0;
},
else => |err| {
w.fcopyfile_err = posix.unexpectedErrno(err);
return 0;
},
}
file_reader.pos = size;
w.pos = size;
return size;
}
return error.Unimplemented;
}