Modernize client code (#6250)

[oweals/minetest.git] / src / filesys.cpp

diff --git a/src/filesys.cpp b/src/filesys.cpp
index 9aeecf427e54b0dd7f0aaa66707bef5ee9b9c73e..bd8b94aff98ff86ebf2ca6a0a5383c4625fd8717 100644 (file)
--- a/src/filesys.cpp
+++ b/src/filesys.cpp
@@ -26,6 +26,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include <fstream>
 #include "log.h"
 #include "config.h"
+#include "porting.h"
 
 namespace fs
 {
@@ -142,7 +143,7 @@ bool RecursiveDelete(const std::string &path)
                infostream<<"RecursiveDelete: Deleting content of directory "
                                <<path<<std::endl;
                std::vector<DirListNode> content = GetDirListing(path);
-               for(int i=0; i<content.size(); i++){
+               for(size_t i=0; i<content.size(); i++){
                        const DirListNode &n = content[i];
                        std::string fullpath = path + DIR_DELIM + n.name;
                        bool did = RecursiveDelete(fullpath);
@@ -183,7 +184,7 @@ bool DeleteSingleFileOrEmptyDirectory(const std::string &path)
 
 std::string TempPath()
 {
-       DWORD bufsize = GetTempPath(0, "");
+       DWORD bufsize = GetTempPath(0, NULL);
        if(bufsize == 0){
                errorstream<<"GetTempPath failed, error = "<<GetLastError()<<std::endl;
                return "";
@@ -616,48 +617,51 @@ std::string RemoveRelativePathComponents(std::string path)
 {
        size_t pos = path.size();
        size_t dotdot_count = 0;
-       while(pos != 0){
+       while (pos != 0) {
                size_t component_with_delim_end = pos;
                // skip a dir delimiter
-               while(pos != 0 && IsDirDelimiter(path[pos-1]))
+               while (pos != 0 && IsDirDelimiter(path[pos-1]))
                        pos--;
                // strip a path component
                size_t component_end = pos;
-               while(pos != 0 && !IsDirDelimiter(path[pos-1]))
+               while (pos != 0 && !IsDirDelimiter(path[pos-1]))
                        pos--;
                size_t component_start = pos;
 
                std::string component = path.substr(component_start,
                                component_end - component_start);
                bool remove_this_component = false;
-               if(component == "."){
+               if (component == ".") {
                        remove_this_component = true;
-               }
-               else if(component == ".."){
+               } else if (component == "..") {
                        remove_this_component = true;
                        dotdot_count += 1;
-               }
-               else if(dotdot_count != 0){
+               } else if (dotdot_count != 0) {
                        remove_this_component = true;
                        dotdot_count -= 1;
                }
 
-               if(remove_this_component){
-                       while(pos != 0 && IsDirDelimiter(path[pos-1]))
+               if (remove_this_component) {
+                       while (pos != 0 && IsDirDelimiter(path[pos-1]))
                                pos--;
-                       path = path.substr(0, pos) + DIR_DELIM +
-                               path.substr(component_with_delim_end,
-                                               std::string::npos);
-                       pos++;
+                       if (component_start == 0) {
+                               // We need to remove the delemiter too
+                               path = path.substr(component_with_delim_end, std::string::npos);
+                       } else {
+                               path = path.substr(0, pos) + DIR_DELIM +
+                                       path.substr(component_with_delim_end, std::string::npos);
+                       }
+                       if (pos > 0)
+                               pos++;
                }
        }
 
-       if(dotdot_count > 0)
+       if (dotdot_count > 0)
                return "";
 
        // remove trailing dir delimiters
        pos = path.size();
-       while(pos != 0 && IsDirDelimiter(path[pos-1]))
+       while (pos != 0 && IsDirDelimiter(path[pos-1]))
                pos--;
        return path.substr(0, pos);
 }
@@ -693,18 +697,47 @@ bool safeWriteToFile(const std::string &path, const std::string &content)
        os.flush();
        os.close();
        if (os.fail()) {
+               // Remove the temporary file because writing it failed and it's useless.
                remove(tmp_file.c_str());
                return false;
        }
 
-       // Copy file
-       remove(path.c_str());
-       if(rename(tmp_file.c_str(), path.c_str())) {
+       bool rename_success = false;
+
+       // Move the finished temporary file over the real file
+#ifdef _WIN32
+       // When creating the file, it can cause Windows Search indexer, virus scanners and other apps
+       // to query the file. This can make the move file call below fail.
+       // We retry up to 5 times, with a 1ms sleep between, before we consider the whole operation failed
+       int number_attempts = 0;
+       while (number_attempts < 5) {
+               rename_success = MoveFileEx(tmp_file.c_str(), path.c_str(),
+                               MOVEFILE_REPLACE_EXISTING | MOVEFILE_WRITE_THROUGH);
+               if (rename_success)
+                       break;
+               sleep_ms(1);
+               ++number_attempts;
+       }
+#else
+       // On POSIX compliant systems rename() is specified to be able to swap the
+       // file in place of the destination file, making this a truly error-proof
+       // transaction.
+       rename_success = rename(tmp_file.c_str(), path.c_str()) == 0;
+#endif
+       if (!rename_success) {
+               warningstream << "Failed to write to file: " << path.c_str() << std::endl;
+               // Remove the temporary file because moving it over the target file
+               // failed.
                remove(tmp_file.c_str());
                return false;
-       } else {
-               return true;
        }
+
+       return true;
+}
+
+bool Rename(const std::string &from, const std::string &to)
+{
+       return rename(from.c_str(), to.c_str()) == 0;
 }
 
 } // namespace fs