shill: Add File IO wrapper
Add a layer of indirection over basic system file IO calls like
write/read so that this behavior can be mocked out in tests. This is
especially needed because we register Ready/InputIO handlers with the
event loop based on the raw file descriptors. We must later use those
raw descriptors to do I/O since higher order abstractions seem to have
blocking semantics.
BUG=chromium-os:39055
TEST=Unit tests still pass.
Change-Id: Ic653436b39ecbe21b275b8f3bceb4b14f162e903
Reviewed-on: https://gerrit.chromium.org/gerrit/44127
Tested-by: Christopher Wiley <wiley@chromium.org>
Reviewed-by: Paul Stewart <pstew@chromium.org>
Reviewed-by: Darin Petkov <petkov@chromium.org>
Commit-Queue: Wade Guthrie <wdg@chromium.org>
diff --git a/file_io.cc b/file_io.cc
new file mode 100644
index 0000000..5bab442
--- /dev/null
+++ b/file_io.cc
@@ -0,0 +1,47 @@
+// Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "shill/file_io.h"
+
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <base/posix/eintr_wrapper.h>
+
+namespace shill {
+
+namespace {
+
+static base::LazyInstance<FileIO> g_file_io =
+ LAZY_INSTANCE_INITIALIZER;
+
+} // namespace
+
+FileIO::FileIO() {}
+
+FileIO::~FileIO() {}
+
+// static
+FileIO *FileIO::GetInstance() {
+ return g_file_io.Pointer();
+}
+
+ssize_t FileIO::Write(int fd, const void *buf, size_t count) {
+ return HANDLE_EINTR(write(fd, buf, count));
+}
+
+ssize_t FileIO::Read(int fd, void *buf, size_t count) {
+ return HANDLE_EINTR(read(fd, buf, count));
+}
+
+int FileIO::Close(int fd) {
+ return HANDLE_EINTR(close(fd));
+}
+
+int FileIO::SetFdNonBlocking(int fd) {
+ const int flags = HANDLE_EINTR(fcntl(fd, F_GETFL)) | O_NONBLOCK;
+ return HANDLE_EINTR(fcntl(fd, F_SETFL, flags));
+}
+
+} // namespace shill