Add RemoteFileCopy to be used later.

PiperOrigin-RevId: 754083880

Author: xinhaoyuan

common/remote_file.h

@@ -137,6 +137,9 @@ absl::StatusOr<std::vector<std::string>> RemoteListFiles(std::string_view path,
 // Renames a file from `from` to `to`.
 absl::Status RemoteFileRename(std::string_view from, std::string_view to);
 
+// Copies a file from `from` to `to`.
+absl::Status RemoteFileCopy(std::string_view from, std::string_view to);
+
 // Updates the last-modified time of `path` to the current time.
 absl::Status RemotePathTouchExistingFile(std::string_view path);
 

common/remote_file_oss.cc

@@ -185,6 +185,10 @@ absl::Status RemoteFileRename(std::string_view from, std::string_view to) {
   LOG(FATAL) << "Filesystem API not supported in iOS/MacOS";
 }
 
+absl::Status RemoteFileCopy(std::string_view from, std::string_view to) {
+  LOG(FATAL) << "Filesystem API not supported in iOS/MacOS";
+}
+
 absl::Status RemotePathTouchExistingFile(std::string_view path) {
   LOG(FATAL) << "Filesystem API not supported in iOS/MacOS";
 }
@@ -246,6 +250,18 @@ absl::Status RemoteFileRename(std::string_view from, std::string_view to) {
   return absl::OkStatus();
 }
 
+absl::Status RemoteFileCopy(std::string_view from, std::string_view to) {
+  std::error_code error;
+  std::filesystem::copy(
+      from, to, std::filesystem::copy_options::overwrite_existing, error);
+  if (error) {
+    return absl::UnknownError(
+        absl::StrCat("filesystem::copy() failed, from: ", std::string(from),
+                     ", to: ", std::string(to), ", error: ", error.message()));
+  }
+  return absl::OkStatus();
+}
+
 absl::Status RemotePathTouchExistingFile(std::string_view path) {
   if (!RemotePathExists(path)) {
     return absl::InvalidArgumentError(