From c1db97f057e8f20aa26a2342da94eeff1d7a7725 Mon Sep 17 00:00:00 2001
From: dec05eba <dec05eba@protonmail.com>
Date: Tue, 20 Apr 2021 13:11:59 +0200
Subject: Proper atomic rename? also do not generate mipmap for manga

---
 src/Storage.cpp | 62 +++++++++++++++++----------------------------------------
 1 file changed, 18 insertions(+), 44 deletions(-)

(limited to 'src/Storage.cpp')

diff --git a/src/Storage.cpp b/src/Storage.cpp
index 1e9f206..6a98267 100644
--- a/src/Storage.cpp
+++ b/src/Storage.cpp
@@ -1,5 +1,4 @@
 #include "../include/Storage.hpp"
-#include "../include/env.hpp"
 #include "../include/StringUtils.hpp"
 #include <stdio.h>
 #include <assert.h>
@@ -10,13 +9,11 @@
 #include <rapidjson/stringbuffer.h>
 #include <unordered_set>
 
-#if OS_FAMILY == OS_FAMILY_POSIX
 #include <pwd.h>
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <fcntl.h>
-#endif
 
 static int makedir(const char *path) {
     return mkdir(path, S_IRWXU);
@@ -25,7 +22,6 @@ static int makedir(const char *path) {
 namespace QuickMedia {
     Path get_home_dir()
     {
-    #if OS_FAMILY == OS_FAMILY_POSIX
         const char *homeDir = getenv("HOME");
         if(!homeDir)
         {
@@ -37,26 +33,6 @@ namespace QuickMedia {
             abort();
         }
         return homeDir;
-    #elif OS_FAMILY == OS_FAMILY_WINDOWS
-        BOOL ret;
-        HANDLE hToken;
-        std::wstring homeDir;
-        DWORD homeDirLen = MAX_PATH;
-        homeDir.resize(homeDirLen);
-
-        if (!OpenProcessToken(GetCurrentProcess(), TOKEN_READ, &hToken))
-            throw std::runtime_error("Failed to open process token");
-
-        if (!GetUserProfileDirectory(hToken, &homeDir[0], &homeDirLen))
-        {
-            CloseHandle(hToken);
-            throw std::runtime_error("Failed to get home directory");
-        }
-
-        CloseHandle(hToken);
-        homeDir.resize(wcslen(homeDir.c_str()));
-        return boost::filesystem::path(homeDir);
-    #endif
     }
 
     Path get_storage_dir() {
@@ -167,7 +143,7 @@ namespace QuickMedia {
         int res = file_overwrite(tmp_path, data.c_str(), data.size());
         if(res != 0)
             return res;
-        return rename(tmp_path.data.c_str(), path.data.c_str());
+        return rename_atomic(tmp_path.data.c_str(), path.data.c_str());
     }
 
     void for_files_in_dir(const Path &path, FileIteratorCallback callback) {
@@ -230,20 +206,8 @@ namespace QuickMedia {
     }
 
     bool save_json_to_file_atomic(const Path &path, const Json::Value &json) {
-        Path tmp_path = path;
-        tmp_path.append(".tmp");
-
         Json::StreamWriterBuilder json_builder;
-        if(file_overwrite(tmp_path, Json::writeString(json_builder, json)) != 0)
-            return false;
-
-        // Rename is atomic under posix!
-        if(rename(tmp_path.data.c_str(), path.data.c_str()) != 0) {
-            perror("save_json_to_file_atomic rename");
-            return false;
-        }
-
-        return true;
+        return file_overwrite_atomic(path, Json::writeString(json_builder, json)) == 0;
     }
 
     bool save_json_to_file_atomic(const Path &path, const rapidjson::Value &json) {
@@ -254,17 +218,27 @@ namespace QuickMedia {
         rapidjson::Writer<rapidjson::StringBuffer> writer(buffer);
         json.Accept(writer);
 
-        Json::StreamWriterBuilder json_builder;
         if(file_overwrite(tmp_path, buffer.GetString(), buffer.GetSize()) != 0)
             return false;
 
-        // Rename is atomic under posix!
-        if(rename(tmp_path.data.c_str(), path.data.c_str()) != 0) {
-            perror("save_json_to_file_atomic rename");
-            return false;
+        return rename_atomic(tmp_path.data.c_str(), path.data.c_str()) == 0;
+    }
+
+    int rename_atomic(const char *oldpath, const char *newpath) {
+        int fd = open(oldpath, O_RDONLY);
+        if(fd == -1) {
+            perror(oldpath);
+            return -1;
         }
 
-        return true;
+        if(fsync(fd) == -1) {
+            perror(oldpath);
+            close(fd);
+            return -1;
+        }
+
+        close(fd);
+        return rename(oldpath, newpath);
     }
 
     bool is_program_executable_by_name(const char *name) {
-- 
cgit v1.2.3