cache manager retry refactor

2 files changed, 27 insertions, 29 deletions

diff --git a/oop2eindopdr/CacheManager.cpp b/oop2eindopdr/CacheManager.cpp
index 9324b81..6062b70 100644
--- a/oop2eindopdr/CacheManager.cpp
+++ b/oop2eindopdr/CacheManager.cpp
@@ -41,45 +41,37 @@ void CacheManager::update_cache() {
 	date.close();
 }
 
+void CacheManager::retry(std::string label, std::function<void()> action, std::function<bool()> retry_if) {
+	for (unsigned int i = 0; i < max_tries; i++) {
+		action();
+		if (retry_if() == false) return;
+	}
+	std::cout << "retry " << label << " failed after " << max_tries << " tries" << std::endl;
+}
+
 std::fstream* CacheManager::cache_get(std::string filename) { return cache_get(filename.c_str()); }
 std::fstream* CacheManager::cache_get(const char* filename) {
 	std::filesystem::path fixed_path = prefix_cache_path(filename); // fix duplicate slashes and add prefix
-	unsigned int i = 0;
-
-	i = 0;
-	while (!std::filesystem::exists(fixed_path.parent_path())) {
+	retry("mkdir", [&] {
 		std::filesystem::create_directories(fixed_path.parent_path()); // make sure folder exists
-		std::this_thread::sleep_for(std::chrono::milliseconds(1));
-		i++;
-		if (i > 100) {
-			std::cout << "folder touch doesn't succeed after 100 tries on file " << fixed_path << std::endl;
-			exit(1);
-		}
-	}
+	}, [&] {
+		return !std::filesystem::exists(fixed_path.parent_path());
+	});
 
-	i = 0;
-	while (!std::filesystem::exists(fixed_path)) {
+	retry("touch file", [&] {
 		std::fstream(fixed_path, std::ios::trunc | std::ios::out).close(); // touch file
-		std::this_thread::sleep_for(std::chrono::milliseconds(1));
-		i++;
-		if (i > 100) {
-			std::cout << "file touch doesn't succeed after 100 tries on file " << fixed_path << std::endl;
-			exit(1);
-		}
-	}
+	}, [&] {
+		return !std::filesystem::exists(fixed_path);
+	});
 
-	i = 0;
 	std::fstream* file = nullptr;
-	do {
+	retry("get file handle", [&] {
 		delete file;
 		file = new std::fstream(fixed_path.c_str(), std::ios::out | std::ios::in); // open file
-		std::this_thread::sleep_for(std::chrono::milliseconds(1));
-		i++;
-		if (i > 100) {
-			std::cout << "file open doesn't succeed after 100 tries on file " << fixed_path << std::endl;
-			exit(1);
-		}
-	} while (!file->is_open());
+	}, [&] {
+		return !file->is_open();
+	});
+
 	this->files.push_back(file); // add file pointer (for closing all files on exit)
 	return file;
 }
diff --git a/oop2eindopdr/CacheManager.h b/oop2eindopdr/CacheManager.h
index 0b15cfa..1e0a565 100644
--- a/oop2eindopdr/CacheManager.h
+++ b/oop2eindopdr/CacheManager.h
@@ -2,6 +2,8 @@
 
 #include <string>
 #include <vector>
+#include <chrono>
+#include <functional>
 
 /** @brief cache storage manager */
 class CacheManager {
@@ -10,6 +12,10 @@ private:
 	std::string cache_path;
 	/** @brief pointers to open file handles */
 	std::vector<std::fstream*> files;
+
+	const unsigned int max_tries = 100;
+
+	virtual void retry(std::string label, std::function<void()> action, std::function<bool()> retry_if);
 public:
 	/** @brief initialize CacheManager class at `cache_path` */
 	CacheManager(const char* cache_path);