Binder file module

Test: mma
Bug: 302723053
Change-Id: Ie27f8a36ab56069c928079da8a0cf3d8bfb49813

1 files changed, 57 insertions, 0 deletions

diff --git a/libs/binder/file.cpp b/libs/binder/file.cpp
new file mode 100644
index 0000000000..bac667e4e5
--- /dev/null
+++ b/libs/binder/file.cpp
@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "file.h"
+
+#ifdef BINDER_NO_LIBBASE
+
+#include <stdint.h>
+
+// clang-format off
+
+namespace android::binder {
+
+bool ReadFully(borrowed_fd fd, void* data, size_t byte_count) {
+  uint8_t* p = reinterpret_cast<uint8_t*>(data);
+  size_t remaining = byte_count;
+  while (remaining > 0) {
+    ssize_t n = TEMP_FAILURE_RETRY(read(fd.get(), p, remaining));
+    if (n == 0) {  // EOF
+      errno = ENODATA;
+      return false;
+    }
+    if (n == -1) return false;
+    p += n;
+    remaining -= n;
+  }
+  return true;
+}
+
+bool WriteFully(borrowed_fd fd, const void* data, size_t byte_count) {
+  const uint8_t* p = reinterpret_cast<const uint8_t*>(data);
+  size_t remaining = byte_count;
+  while (remaining > 0) {
+    ssize_t n = TEMP_FAILURE_RETRY(write(fd.get(), p, remaining));
+    if (n == -1) return false;
+    p += n;
+    remaining -= n;
+  }
+  return true;
+}
+
+}  // namespace android::binder
+
+#endif // BINDER_NO_LIBBASE