Rework MAD cleanup handles (#817)

Mods are no longer marked as successfully installed when the process failed.
When mod downloading/extraction fails, the mod directory is removed again.

Author: Alystrasz

primedev/mods/autodownload/moddownloader.cpp

@@ -176,7 +176,7 @@ int ModDownloader::ModFetchingProgressCallback(
 	return 0;
 }
 
-std::optional<fs::path> ModDownloader::FetchModFromDistantStore(std::string_view modName, VerifiedModVersion version)
+std::tuple<fs::path, bool> ModDownloader::FetchModFromDistantStore(std::string_view modName, VerifiedModVersion version)
 {
 	std::string url = version.downloadLink;
 	std::string archiveName = fs::path(url).filename().generic_string();
@@ -190,7 +190,7 @@ std::optional<fs::path> ModDownloader::FetchModFromDistantStore(std::string_view
 	modState.state = DOWNLOADING;
 
 	// Download the actual archive
-	bool failed = false;
+	bool success = false;
 	FILE* fp = fopen(downloadPath.generic_string().c_str(), "wb");
 	CURLcode result;
 	CURL* easyhandle;
@@ -219,13 +219,14 @@ std::optional<fs::path> ModDownloader::FetchModFromDistantStore(std::string_view
 	if (result == CURLcode::CURLE_OK)
 	{
 		spdlog::info("Mod archive successfully fetched.");
-		return std::optional<fs::path>(downloadPath);
+		success = true;
 	}
 	else
 	{
 		spdlog::error("Fetching mod archive failed: {}", curl_easy_strerror(result));
-		return std::optional<fs::path>();
 	}
+
+	return {downloadPath, success};
 }
 
 bool ModDownloader::IsModLegit(fs::path modPath, std::string_view expectedChecksum)
@@ -399,11 +400,9 @@ int GetModArchiveSize(unzFile file, unz_global_info64 info)
 	return totalSize;
 }
 
-void ModDownloader::ExtractMod(fs::path modPath, VerifiedModPlatform platform)
+void ModDownloader::ExtractMod(fs::path modPath, fs::path destinationPath, VerifiedModPlatform platform)
 {
 	unzFile file;
-	std::string name;
-	fs::path modDirectory;
 
 	file = unzOpen(modPath.generic_string().c_str());
 	ScopeGuard cleanup(
@@ -445,11 +444,6 @@ void ModDownloader::ExtractMod(fs::path modPath, VerifiedModPlatform platform)
 		return;
 	}
 
-	// Mod directory name (removing the ".zip" fom the archive name)
-	name = modPath.filename().string();
-	name = name.substr(0, name.length() - 4);
-	modDirectory = GetRemoteModFolderPath() / name;
-
 	for (int i = 0; i < gi.number_entry; i++)
 	{
 		char zipFilename[256];
@@ -459,7 +453,7 @@ void ModDownloader::ExtractMod(fs::path modPath, VerifiedModPlatform platform)
 		// Extract file
 		{
 			std::error_code ec;
-			fs::path fileDestination = modDirectory / zipFilename;
+			fs::path fileDestination = destinationPath / zipFilename;
 			spdlog::info("=> {}", fileDestination.generic_string());
 
 			// Create parent directory if needed
@@ -589,6 +583,9 @@ void ModDownloader::ExtractMod(fs::path modPath, VerifiedModPlatform platform)
 			}
 		}
 	}
+
+	// Mod extraction went fine
+	modState.state = DONE;
 }
 
 void ModDownloader::DownloadMod(std::string modName, std::string modVersion)
@@ -603,11 +600,14 @@ void ModDownloader::DownloadMod(std::string modName, std::string modVersion)
 	std::thread requestThread(
 		[this, modName, modVersion]()
 		{
+			std::string name;
 			fs::path archiveLocation;
+			fs::path modDirectory;
 
 			ScopeGuard cleanup(
 				[&]
 				{
+					// Remove downloaded archive
 					try
 					{
 						remove(archiveLocation);
@@ -617,14 +617,31 @@ void ModDownloader::DownloadMod(std::string modName, std::string modVersion)
 						spdlog::error("Error while removing downloaded archive: {}", a.what());
 					}
 
+					// Remove mod if auto-download process failed
+					if (modState.state != DONE)
+					{
+						try
+						{
+							remove_all(modDirectory);
+						}
+						catch (const std::exception& e)
+						{
+							spdlog::error("Error while removing downloaded mod: {}", e.what());
+						}
+					}
+
 					spdlog::info("Done cleaning after downloading {}.", modName);
 				});
 
 			// Download mod archive
 			VerifiedModVersion fullVersion = verifiedMods[modName].versions[modVersion];
 			std::string expectedHash = fullVersion.checksum;
-			std::optional<fs::path> fetchingResult = FetchModFromDistantStore(std::string_view(modName), fullVersion);
-			if (!fetchingResult.has_value())
+
+			const std::tuple<fs::path, bool> downloadResult = FetchModFromDistantStore(std::string_view(modName), fullVersion);
+			archiveLocation = get<0>(downloadResult);
+			bool downloadSuccessful = get<1>(downloadResult);
+
+			if (!downloadSuccessful)
 			{
 				spdlog::error("Something went wrong while fetching archive, aborting.");
 				if (modState.state != ABORTED)
@@ -633,17 +650,21 @@ void ModDownloader::DownloadMod(std::string modName, std::string modVersion)
 				}
 				return;
 			}
-			archiveLocation = fetchingResult.value();
+
 			if (!IsModLegit(archiveLocation, std::string_view(expectedHash)))
 			{
 				spdlog::warn("Archive hash does not match expected checksum, aborting.");
 				modState.state = MOD_CORRUPTED;
 				return;
 			}
 
+			// Mod directory name (removing the ".zip" fom the archive name)
+			name = archiveLocation.filename().string();
+			name = name.substr(0, name.length() - 4);
+			modDirectory = GetRemoteModFolderPath() / name;
+
 			// Extract downloaded mod archive
-			ExtractMod(archiveLocation, fullVersion.platform);
-			modState.state = DONE;
+			ExtractMod(archiveLocation, modDirectory, fullVersion.platform);
 		});
 
 	requestThread.detach();

primedev/mods/autodownload/moddownloader.h

@@ -43,14 +43,12 @@ class ModDownloader
 	 * input mod name as mod dependency string if bypass flag is set up; fetched
 	 * archive is then stored in a temporary location.
 	 *
-	 * If something went wrong during archive download, this will return an empty
-	 * optional object.
 	 *
 	 * @param modName name of the mod to be downloaded
 	 * @param modVersion version of the mod to be downloaded
-	 * @returns location of the downloaded archive
+	 * @returns tuple containing location of the downloaded archive and whether download completed successfully
 	 */
-	std::optional<fs::path> FetchModFromDistantStore(std::string_view modName, VerifiedModVersion modVersion);
+	std::tuple<fs::path, bool> FetchModFromDistantStore(std::string_view modName, VerifiedModVersion modVersion);
 
 	/**
 	 * Tells if a mod archive has not been corrupted.
@@ -69,14 +67,16 @@ class ModDownloader
 	/**
 	 * Extracts a mod archive to the game folder.
 	 *
-	 * This extracts a downloaded mod archive from its original location to the
-	 * current game profile; the install folder is defined by the platform parameter.
+	 * This extracts a downloaded mod archive from its original location, `modPath`,
+	 * to the specified `destinationPath`; the way to decompress the archive is
+	 * defined by the `platform` parameter.
 	 *
 	 * @param modPath location of the downloaded archive
+	 * @param destinationPath destination of the extraction
 	 * @param platform origin of the downloaded archive
 	 * @returns nothing
 	 */
-	void ExtractMod(fs::path modPath, VerifiedModPlatform platform);
+	void ExtractMod(fs::path modPath, fs::path destinationPath, VerifiedModPlatform platform);
 
 public:
 	ModDownloader();