universal7885: aidl-support: Mark unstable and fix errors

universal7885-common/apps/aidl-support/libfileio/Android.bp

@@ -0,0 +1,9 @@
+cc_library_shared {
+   name: "libfileio",
+   srcs: ["FileIO.cpp"],
+   cppflags: ["-fexceptions"],
+   local_include_dirs: ["include"],
+   export_include_dirs: ["include"],
+   shared_libs: ["liblog"],
+}
+   

universal7885-common/apps/aidl-support/libfileio/FileIO.cpp

@@ -0,0 +1,50 @@
+#define LOG_TAG "libFileIO"
+
+#include <log/log.h>
+
+#include <fstream>
+#include <string>
+
+namespace FileIO {
+
+constexpr const int EXIT_ERR = -1;
+
+int readline(const char *path) {
+  std::ifstream file;
+  std::string value;
+  file.open(path);
+  ALOGD("%s: Opening %s", __func__, path);
+  if (file.is_open()) {
+    getline(file, value);
+    file.close();
+  } else {
+    ALOGE("%s: Failed to open %s", __func__, path);
+    return EXIT_ERR;
+  }
+  try {
+    return stoi(value);
+  } catch (std::invalid_argument const &ex) {
+    ALOGE("%s: stoi(): invalid argument: for %s", __func__, value.c_str());
+  } catch (std::out_of_range const &ex) {
+    ALOGE("%s: stoi(): out of range: for %s", __func__, value.c_str());
+  }
+  return EXIT_ERR;
+}
+
+void writeline(const char *path, const std::string& data) {
+  std::ofstream file;
+  file.open(path);
+  ALOGD("%s: Opening %s", __func__, path);
+  if (file.is_open()) {
+    file << data;
+    file.close();
+    return;
+  }
+  ALOGE("%s: Failed to open %s", __func__, path);
+}
+
+void writeline(const char *path, const int data) {
+  writeline(path, std::to_string(data));
+}
+
+} // namespace FileIO

universal7885-common/apps/aidl-support/libfileio/include/FileIO.h

@@ -0,0 +1,6 @@
+namespace FileIO {
+  int readline(const char *path);
+
+  void writeline(const char *path, const std::string& data);
+  void writeline(const char *path, const int data);
+} // namespace FileIO