Wrap std::filesystem calls.

PiperOrigin-RevId: 620315145

sharing/common/BUILD

@@ -61,3 +61,10 @@ cc_library(
     hdrs = ["compatible_u8_string.h"],
     visibility = ["//sharing:__subpackages__"],
 )
+
+cc_library(
+    name = "files",
+    srcs = ["files.cc"],
+    hdrs = ["files.h"],
+    visibility = ["//visibility:public"],
+)

sharing/common/files.cc

@@ -0,0 +1,63 @@
+// Copyright 2024 Google LLC
+//
+// 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
+//
+//     https://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 "sharing/common/files.h"
+
+#include <cstdint>
+#include <filesystem>  // NOLINT(build/c++17)
+#include <optional>
+#include <system_error>  // NOLINT(build/c++11)
+
+namespace nearby::sharing {
+
+bool FileExists(const std::filesystem::path& path) {
+  std::error_code error_code;
+  if (std::filesystem::exists(path, error_code) &&
+      !std::filesystem::is_directory(path, error_code)) {
+    // is_directory returns false on error.
+    return (!error_code);
+  }
+  return false;
+}
+
+std::optional<uintmax_t> GetFileSize(const std::filesystem::path& path) {
+  if (!FileExists(path)) {
+    return std::nullopt;
+  }
+  std::error_code error_code;
+  uintmax_t size = std::filesystem::file_size(path, error_code);
+  if (size == static_cast<uintmax_t>(-1)) {
+    return std::nullopt;
+  }
+  return size;
+}
+
+bool DirectoryExists(const std::filesystem::path& path) {
+  std::error_code error_code;
+  if (std::filesystem::exists(path, error_code) &&
+      std::filesystem::is_directory(path, error_code)) {
+    return true;
+  }
+  return false;
+}
+
+bool RemoveFile(const std::filesystem::path& path) {
+  if (!FileExists(path)) {
+    return false;
+  }
+  std::error_code error_code;
+  return std::filesystem::remove(path, error_code);
+}
+
+}  // namespace nearby::sharing

sharing/common/files.h

@@ -0,0 +1,41 @@
+// Copyright 2024 Google LLC
+//
+// 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
+//
+//     https://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.
+
+#ifndef THIRD_PARTY_NEARBY_SHARING_COMMON_FILES_H_
+#define THIRD_PARTY_NEARBY_SHARING_COMMON_FILES_H_
+
+#include <cstdint>
+#include <filesystem>  // NOLINT(build/c++17)
+#include <optional>
+
+// This file contains exception safe wrappers to access common std::filesystem
+// functions.
+namespace nearby::sharing {
+
+// Returns true if path exists and is not a directory.
+bool FileExists(const std::filesystem::path& path);
+
+// Returns the size of the file at path, or nullopt if not found or not a file.
+std::optional<uintmax_t> GetFileSize(const std::filesystem::path& path);
+
+// Returns true if path exists and is a directory.
+bool DirectoryExists(const std::filesystem::path& path);
+
+// Removes the file at path and returns true.
+// Returns false if path does not exist, is not a file or cannot be removed.
+bool RemoveFile(const std::filesystem::path& path);
+
+}  // namespace nearby::sharing
+
+#endif  // THIRD_PARTY_NEARBY_SHARING_COMMON_FILES_H_