feat(storage): add sample for hierarchical namespace recursive delete

google/cloud/storagecontrol/v2/samples/storage_control_folder_samples.cc

@@ -30,15 +30,16 @@ void RemoveStaleFolders(
     google::cloud::storagecontrol_v2::StorageControlClient client,
     std::string const& bucket_name, std::string const& prefix,
     std::chrono::system_clock::time_point created_time_limit) {
-  std::regex re(prefix + R"re(-[a-z]{32})re");
   auto const parent = std::string{"projects/_/buckets/"} + bucket_name;
+  std::regex re(parent + "/folders/" + prefix +
+                R"re(-(recursive-)?[a-z]{32})re");
   for (auto folder : client.ListFolders(parent)) {
     if (!folder) throw std::move(folder).status();
     if (!std::regex_match(folder->name(), re)) continue;
     auto const create_time =
         google::cloud::internal::ToChronoTimePoint(folder->create_time());
     if (create_time > created_time_limit) continue;
-    (void)client.DeleteFolder(folder->name());
+    (void)client.DeleteFolderRecursive(folder->name()).get();
   }
 }
 
@@ -133,6 +134,27 @@ void RenameFolder(google::cloud::storagecontrol_v2::StorageControlClient client,
   (std::move(client), argv.at(0), argv.at(1), argv.at(2));
 }
 
+void DeleteFolderRecursive(
+    google::cloud::storagecontrol_v2::StorageControlClient client,
+    std::vector<std::string> const& argv) {
+  // [START storage_control_delete_folder_recursive]
+  namespace storagecontrol = google::cloud::storagecontrol_v2;
+  [](storagecontrol::StorageControlClient client,
+     std::string const& bucket_name, std::string const& folder_id) {
+    auto const name = std::string{"projects/_/buckets/"} + bucket_name +
+                      "/folders/" + folder_id;
+    // Start a delete folder recursive operation and block until it completes.
+    // Real applications may want to setup a callback, wait on a coroutine, or
+    // poll until it completes.
+    auto result = client.DeleteFolderRecursive(name).get();
+    if (!result) throw std::move(result).status();
+
+    std::cout << "Deleted folder recursively: " << folder_id << "\n";
+  }
+  // [END storage_control_delete_folder_recursive]
+  (std::move(client), argv.at(0), argv.at(1));
+}
+
 void AutoRun(std::vector<std::string> const& argv) {
   namespace examples = google::cloud::testing_util;
   namespace storagecontrol = google::cloud::storagecontrol_v2;
@@ -176,6 +198,42 @@ void AutoRun(std::vector<std::string> const& argv) {
 
   std::cout << "\nRunning DeleteFolder() example" << std::endl;
   DeleteFolder(client, {bucket_name, dest_folder_id});
+
+  auto const recursive_parent_id =
+      prefix + "-recursive-" +
+      google::cloud::internal::Sample(generator, 32,
+                                      "abcdefghijklmnopqrstuvwxyz");
+  auto const recursive_child_id = recursive_parent_id + "/child";
+
+  std::cout << "\nRunning CreateFolder() for recursive test parent"
+            << std::endl;
+  CreateFolder(client, {bucket_name, recursive_parent_id});
+
+  std::cout << "\nRunning CreateFolder() for recursive test child" << std::endl;
+  CreateFolder(client, {bucket_name, recursive_child_id});
+
+  std::cout << "\nRunning DeleteFolderRecursive() example" << std::endl;
+  DeleteFolderRecursive(client, {bucket_name, recursive_parent_id});
+
+  // Verify deletion by checking that getting the parent and child folders fail
+  // with NOT_FOUND.
+  try {
+    GetFolder(client, {bucket_name, recursive_parent_id});
+    throw std::runtime_error("Parent folder was not deleted recursively");
+  } catch (google::cloud::Status const& status) {
+    if (status.code() != google::cloud::StatusCode::kNotFound) {
+      throw;
+    }
+  }
+
+  try {
+    GetFolder(client, {bucket_name, recursive_child_id});
+    throw std::runtime_error("Child folder was not deleted recursively");
+  } catch (google::cloud::Status const& status) {
+    if (status.code() != google::cloud::StatusCode::kNotFound) {
+      throw;
+    }
+  }
 }
 
 }  // namespace
@@ -207,6 +265,8 @@ int main(int argc, char* argv[]) {  // NOLINT(bugprone-exception-escape)
   Example example({
       make_entry("create-folder", {"bucket-name", "folder-id"}, CreateFolder),
       make_entry("delete-folder", {"bucket-name", "folder-id"}, DeleteFolder),
+      make_entry("delete-folder-recursive", {"bucket-name", "folder-id"},
+                 DeleteFolderRecursive),
       make_entry("get-folder", {"bucket-name", "folder-id"}, GetFolder),
       make_entry("list-folders", {"bucket-name"}, ListFolders),
       make_entry("rename-folder",