zig/lib/std/io/c_out_stream.zig

44 lines
1.6 KiB
Zig

const std = @import("../std.zig");
const os = std.os;
const OutStream = std.io.OutStream;
const builtin = @import("builtin");
/// TODO make a proposal to make `std.fs.File` use *FILE when linking libc and this just becomes
/// std.io.FileOutStream because std.fs.File.write would do this when linking
/// libc.
pub const COutStream = struct {
pub const Error = std.fs.File.WriteError;
pub const Stream = OutStream(Error);
stream: Stream,
c_file: *std.c.FILE,
pub fn init(c_file: *std.c.FILE) COutStream {
return COutStream{
.c_file = c_file,
.stream = Stream{ .writeFn = writeFn },
};
}
fn writeFn(out_stream: *Stream, bytes: []const u8) Error!void {
const self = @fieldParentPtr(COutStream, "stream", out_stream);
const amt_written = std.c.fwrite(bytes.ptr, 1, bytes.len, self.c_file);
if (amt_written == bytes.len) return;
switch (std.c._errno().*) {
0 => unreachable,
os.EINVAL => unreachable,
os.EFAULT => unreachable,
os.EAGAIN => unreachable, // this is a blocking API
os.EBADF => unreachable, // always a race condition
os.EDESTADDRREQ => unreachable, // connect was never called
os.EDQUOT => return error.DiskQuota,
os.EFBIG => return error.FileTooBig,
os.EIO => return error.InputOutput,
os.ENOSPC => return error.NoSpaceLeft,
os.EPERM => return error.AccessDenied,
os.EPIPE => return error.BrokenPipe,
else => |err| return os.unexpectedErrno(@intCast(usize, err)),
}
}
};