Add file wrapper

CMakeLists.txt

@@ -16,7 +16,7 @@ set(INCLUDES "")
 set(SOURCES "")
 set(IMGUI_SOURCES "")
 set(DEFINITIONS "")
-# imgui include because <GH ISSUE LINK HERE>
+# imgui include because https://github.com/ocornut/imgui/issues/6184#issuecomment-1439570929
 list(APPEND INCLUDES thirdparty thirdparty/imgui /usr/include/SDL2)
 list(APPEND SOURCES main.cpp event_loop.cpp logcat_thread.cpp logcat_entry.cpp log.cpp config.cpp filters.cpp misc.cpp pcre2_wrapper.cpp
     group_panel.cpp fragments/filters.cpp windows/logs.cpp windows/settings.cpp windows/main.cpp)

config.cpp

@@ -1,29 +1,13 @@
 #include <cstdlib>
-#include <cstring>
 #include <sys/stat.h>
 #include <string>
 #include <nlohmann/json.hpp>
 
 #include "log.h"
+#include "file.h"
 #include "misc.h"
 #include "config.h"
 
-static FILE* fopen_or_raise(const char* __restrict path, const char* __restrict mode, bool ignore_enoent) {
-    FILE* file = fopen(path, mode);
-    if (!file && !(ignore_enoent && errno == ENOENT)) {
-        throw_system_error(std::string("fopen(") + quote(path) + ')');
-    }
-    return file;
-}
-
-static void fclose_and_log(FILE* file) {
-    if (!fclose(file)) {
-        return;
-    }
-    log(std::string("Failed to close a file: fclose(): ") + strerror(errno));
-}
-
-
 std::string get_config_folder() {
     const char* path;
 
@@ -76,13 +60,15 @@ void from_json(const nlohmann::json& j, Config& config) {
 
 Config load_config() {
     std::string config_file_path = get_config_file_path();
-    std::unique_ptr<FILE, decltype(&fclose_and_log)> config_file(fopen_or_raise(config_file_path.c_str(), "r", true), fclose_and_log);
-
-    if (!config_file) {
+    try {
+        File config_file(config_file_path.c_str(), "r");
+        return nlohmann::json::parse(config_file.get());
+    } catch (const std::system_error& e) {
+        if (e.code().value() != ENOENT) {
+            throw;
+        }
         return Config();
     }
-
-    return nlohmann::json::parse(config_file.get()).get<Config>();
 }
 
 
@@ -98,10 +84,11 @@ void write_config(const Config& config) {
     std::string config_file_path = get_config_file_path();
     std::string tmp_config_file_path = config_file_path + ".tmp";
 
-    std::unique_ptr<FILE, decltype(&fclose_and_log)> config_file(fopen_or_raise(tmp_config_file_path.c_str(), "w", false), fclose_and_log);
-    std::string str_config = nlohmann::json(config).dump(4);
-    fwrite(str_config.data(), sizeof(char), str_config.size(), config_file.get());
-    config_file.reset();
+    {
+        File config_file(tmp_config_file_path.c_str(), "w");
+        std::string str_config = nlohmann::json(config).dump(4);
+        config_file.write(std::move(str_config));
+    }
 
     if (!rename(tmp_config_file_path.c_str(), config_file_path.c_str())) {
         return;

file.h

@@ -0,0 +1,65 @@
+#pragma once
+
+#include <cstdio>
+#include <string>
+
+#include "../log.h"
+#include "../misc.h"
+
+static void try_close(FILE* file);
+
+// Not usable for logcat thread!
+class File {
+public:
+    // https://stackoverflow.com/a/2173764
+    File(const File&) = delete;
+    File& operator=(const File&) = delete;
+
+    inline constexpr File(File&& other) {
+        try_close(this->_file);
+        this->_file = other._file;
+        other._file = nullptr;
+    }
+    inline constexpr File& operator=(File&& other) {
+        if (this == &other) {
+            return *this;
+        }
+
+        try_close(this->_file);
+        this->_file = other._file;
+        other._file = nullptr;
+
+        return *this;
+    }
+
+    File(const char* __restrict path, const char* __restrict mode) {
+        this->_file = fopen(path, mode);
+        if (!this->_file) {
+            throw_system_error(std::string("fopen(") + quote(path) + ')');
+        }
+    }
+    ~File() {
+        try_close(this->_file);
+    }
+
+    void write(const char* data, size_t length) {
+        if (fwrite(data, 1, length, this->_file) != length) {
+            throw_system_error("fwrite()");
+        }
+    }
+    inline constexpr void write(const std::string& str) {
+        this->write(str.data(), str.size());
+    }
+    inline constexpr FILE* get() const noexcept {
+        return this->_file;
+    }
+
+protected:
+    FILE* _file = nullptr;
+};
+
+static void try_close(FILE* file) {
+    if (file && fclose(file)) {
+        log(std::string("Failed to close a file: fclose(): ") + strerror(errno));
+    }
+}