Add package io

core/io/multi.odin

@@ -0,0 +1,115 @@
+package io
+
+import "core:runtime"
+
+@(private)
+Multi_Reader :: struct {
+	using stream: Stream,
+	readers: [dynamic]Reader,
+}
+
+@(private)
+_multi_reader_vtable := &Stream_VTable{
+	impl_read = proc(s: Stream, p: []byte) -> (n: int, err: Error) {
+		mr := (^Multi_Reader)(s.data);
+		for len(mr.readers) > 0 {
+			r := mr.readers[0];
+			n, err = read(r, p);
+			if err == .EOF {
+				ordered_remove(&mr.readers, 0);
+			}
+			if n > 0 || err != .EOF {
+				if err == .EOF && len(mr.readers) > 0 {
+					// Don't return EOF yet, more readers remain
+					err = nil;
+				}
+				return;
+			}
+		}
+		return 0, .EOF;
+	},
+	impl_destroy = proc(s: Stream) -> Error {
+		mr := (^Multi_Reader)(s.data);
+		context.allocator = mr.readers.allocator;
+		delete(mr.readers);
+		free(mr);
+		return .None;
+	},
+};
+
+mutlti_reader :: proc(readers: ..Reader, allocator := context.allocator) -> Reader {
+	context.allocator = allocator;
+	mr := new(Multi_Reader);
+	mr.vtable = _multi_reader_vtable;
+	mr.data = mr;
+	all_readers := make([dynamic]Reader, 0, len(readers));
+
+	for w in readers {
+		if w.vtable == _multi_reader_vtable {
+			other := (^Multi_Reader)(w.data);
+			append(&all_readers, ..other.readers[:]);
+		} else {
+			append(&all_readers, w);
+		}
+	}
+
+	mr.readers = all_readers;
+	res, _ := to_reader(mr^);
+	return res;
+}
+
+
+@(private)
+Multi_Writer :: struct {
+	using stream: Stream,
+	writers:      []Writer,
+	allocator:    runtime.Allocator,
+}
+
+@(private)
+_multi_writer_vtable := &Stream_VTable{
+	impl_write = proc(s: Stream, p: []byte) -> (n: int, err: Error) {
+		mw := (^Multi_Writer)(s.data);
+		for w in mw.writers {
+			n, err = write(w, p);
+			if err != nil {
+				return;
+			}
+			if n != len(p) {
+				err = .Short_Write;
+				return;
+			}
+		}
+
+		return len(p), nil;
+	},
+	impl_destroy = proc(s: Stream) -> Error {
+		mw := (^Multi_Writer)(s.data);
+		context.allocator = mw.allocator;
+		delete(mw.writers);
+		free(mw);
+		return .None;
+	},
+};
+
+mutlti_writer :: proc(writers: ..Writer, allocator := context.allocator) -> Writer {
+	context.allocator = allocator;
+	mw := new(Multi_Writer);
+	mw.vtable = _multi_writer_vtable;
+	mw.data = mw;
+	mw.allocator = allocator;
+	all_writers := make([dynamic]Writer, 0, len(writers));
+
+	for w in writers {
+		if w.vtable == _multi_writer_vtable {
+			other := (^Multi_Writer)(w.data);
+			append(&all_writers, ..other.writers);
+		} else {
+			append(&all_writers, w);
+		}
+	}
+
+	mw.writers = all_writers[:];
+	res, _ := to_writer(mw^);
+	return res;
+}