struct Stream [src]

Fields

handle: posix.socket_tUnderlying platform-defined type which may or may not be interchangeable with a file system file descriptor.
Members

close (Function)
read (Function)
readAll (Function)
readAtLeast (Function)
reader (Function)
Reader (Type)
ReadError (Error Set)
readv (Function)
write (Function)
writeAll (Function)
WriteError (Error Set)
writer (Function)
Writer (Type)
writev (Function)
writevAll (Function)
Source

  pub const Stream = struct {
    /// Underlying platform-defined type which may or may not be
    /// interchangeable with a file system file descriptor.
    handle: posix.socket_t,

    pub fn close(s: Stream) void {
        switch (native_os) {
            .windows => windows.closesocket(s.handle) catch unreachable,
            else => posix.close(s.handle),
        }
    }

    pub const ReadError = posix.ReadError;
    pub const WriteError = posix.WriteError;

    pub const Reader = io.Reader(Stream, ReadError, read);
    pub const Writer = io.Writer(Stream, WriteError, write);

    pub fn reader(self: Stream) Reader {
        return .{ .context = self };
    }

    pub fn writer(self: Stream) Writer {
        return .{ .context = self };
    }

    pub fn read(self: Stream, buffer: []u8) ReadError!usize {
        if (native_os == .windows) {
            return windows.ReadFile(self.handle, buffer, null);
        }

        return posix.read(self.handle, buffer);
    }

    pub fn readv(s: Stream, iovecs: []const posix.iovec) ReadError!usize {
        if (native_os == .windows) {
            // TODO improve this to use ReadFileScatter
            if (iovecs.len == 0) return @as(usize, 0);
            const first = iovecs[0];
            return windows.ReadFile(s.handle, first.base[0..first.len], null);
        }

        return posix.readv(s.handle, iovecs);
    }

    /// Returns the number of bytes read. If the number read is smaller than
    /// `buffer.len`, it means the stream reached the end. Reaching the end of
    /// a stream is not an error condition.
    pub fn readAll(s: Stream, buffer: []u8) ReadError!usize {
        return readAtLeast(s, buffer, buffer.len);
    }

    /// Returns the number of bytes read, calling the underlying read function
    /// the minimal number of times until the buffer has at least `len` bytes
    /// filled. If the number read is less than `len` it means the stream
    /// reached the end. Reaching the end of the stream is not an error
    /// condition.
    pub fn readAtLeast(s: Stream, buffer: []u8, len: usize) ReadError!usize {
        assert(len <= buffer.len);
        var index: usize = 0;
        while (index < len) {
            const amt = try s.read(buffer[index..]);
            if (amt == 0) break;
            index += amt;
        }
        return index;
    }

    /// TODO in evented I/O mode, this implementation incorrectly uses the event loop's
    /// file system thread instead of non-blocking. It needs to be reworked to properly
    /// use non-blocking I/O.
    pub fn write(self: Stream, buffer: []const u8) WriteError!usize {
        if (native_os == .windows) {
            return windows.WriteFile(self.handle, buffer, null);
        }

        return posix.write(self.handle, buffer);
    }

    pub fn writeAll(self: Stream, bytes: []const u8) WriteError!void {
        var index: usize = 0;
        while (index < bytes.len) {
            index += try self.write(bytes[index..]);
        }
    }

    /// See https://github.com/ziglang/zig/issues/7699
    /// See equivalent function: `std.fs.File.writev`.
    pub fn writev(self: Stream, iovecs: []const posix.iovec_const) WriteError!usize {
        return posix.writev(self.handle, iovecs);
    }

    /// The `iovecs` parameter is mutable because this function needs to mutate the fields in
    /// order to handle partial writes from the underlying OS layer.
    /// See https://github.com/ziglang/zig/issues/7699
    /// See equivalent function: `std.fs.File.writevAll`.
    pub fn writevAll(self: Stream, iovecs: []posix.iovec_const) WriteError!void {
        if (iovecs.len == 0) return;

        var i: usize = 0;
        while (true) {
            var amt = try self.writev(iovecs[i..]);
            while (amt >= iovecs[i].len) {
                amt -= iovecs[i].len;
                i += 1;
                if (i >= iovecs.len) return;
            }
            iovecs[i].base += amt;
            iovecs[i].len -= amt;
        }
    }
}  