Replace _fsopen on Windows to allow the opened file to be used by logrotate (supporting move and delete operations)

loguru.cpp

@@ -156,6 +156,83 @@ namespace loguru
 	typedef FILE* FileAbs;
 #endif
 
+
+#if defined(_WIN32) && LOGURU_WITH_FILEABS
+    #include <stdio.h>
+    #include <fcntl.h>
+    #include <io.h>
+    #define NOMINMAX
+    #include <windows.h>
+
+    /**
+    * Opens the file whose name is the string pointed to by file and associates
+    * a stream with it.
+    * Credit to Xavier Roche http://blog.httrack.com/blog/2013/10/05/creating-deletable-and-movable-files-on-windows
+    **/
+    FILE* fopen_unixlike(const char* file, const char* mode) {
+        DWORD dwDesiredAccess = 0;
+        DWORD dwCreationDisposition = 0;
+        const DWORD dwFlagsAndAttributes = FILE_ATTRIBUTE_NORMAL;
+        const DWORD dwShareMode = FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE;
+        size_t i = 0;
+
+        HANDLE handle = NULL;
+        int fd = 0;
+
+    #if defined(_WIN32) && !defined(__CYGWIN__)
+        if (strcmp(file, "/dev/null") == 0)
+            file = "NUL";
+    #endif
+
+        /* Infer flags. */
+        for (i = 0; mode[i] != '\0'; i++) {
+            switch (mode[i]) {
+                case 'r':
+                    dwDesiredAccess |= GENERIC_READ;
+                    dwCreationDisposition = OPEN_EXISTING;
+                    break;
+                case 'a':
+                    dwDesiredAccess |= FILE_APPEND_DATA;
+                    dwCreationDisposition = OPEN_ALWAYS;
+                    break;
+                case 'w':
+                    dwDesiredAccess |= GENERIC_WRITE;
+                    dwCreationDisposition = CREATE_ALWAYS;
+                    break;
+                case '+':
+                    dwDesiredAccess |= GENERIC_READ;
+                    dwDesiredAccess |= GENERIC_WRITE;
+                    break;
+            }
+        }
+
+        /* Create the file. */
+        handle = CreateFileA(file,
+                             dwDesiredAccess,
+                             dwShareMode,
+                             NULL,
+                             dwCreationDisposition,
+                             dwFlagsAndAttributes,
+                             NULL);
+        if (handle == INVALID_HANDLE_VALUE) {
+            return NULL;
+        }
+
+        /* Associates a C run-time file descriptor with a file HANDLE. */
+        fd = _open_osfhandle((intptr_t)handle, _O_BINARY);
+        if (fd == -1) {
+            CloseHandle(handle);
+            return NULL;
+        }
+
+        /* Associates a stream with a C run-time file descriptor. */
+        return _fdopen(fd, mode);
+    }
+
+    #define _fsopen(file, mode, ...) fopen_unixlike(file, mode) // replace _fsopen
+                                                                // for files created by it is not movable and deletable
+#endif
+
 	struct Callback
 	{
 		std::string     id;
@@ -358,7 +435,11 @@ namespace loguru
 			if (!create_directories(file_abs->path)) {
 				LOG_F(ERROR, "Failed to create directories to '" LOGURU_FMT(s) "'", file_abs->path);
 			}
-			file_abs->fp = fopen(file_abs->path, file_abs->mode_str);
+#ifdef _WIN32
+            file_abs->fp = _fsopen(file_abs->path, file_abs->mode_str, _SH_DENYNO);
+#else
+            file_abs->fp = fopen(file_abs->path, file_abs->mode_str);
+#endif
 			if (!file_abs->fp) {
 				LOG_F(ERROR, "Failed to open '" LOGURU_FMT(s) "'", file_abs->path);
 			} else {
@@ -537,6 +618,7 @@ namespace loguru
 	{
 		VLOG_F(g_internal_verbosity, "atexit");
 		flush();
+        remove_all_callbacks();
 	}
 
 	static void install_signal_handlers(const SignalOptions& signal_options);