Implement windows native function for getting file size.

 * This is required when UNC paths (e.g. \\?\Volume{guid}) are used,
 otherwise the stat() will fail

Author: Rosen Nedyalkov

src/ds3.c

@@ -21623,11 +21623,99 @@ size_t ds3_read_from_fd(void* buffer, size_t size, size_t nmemb, void* user_data
     return read(*(int*)user_data, buffer, size * nmemb);
 }
 
+static void get_file_size_windows(const char* file_path, uint64_t* file_size) {
+    BY_HANDLE_FILE_INFORMATION info;
+    HANDLE file_handle;
+    char * file_path_windows;
+    gunichar2 * file_path_windows_wide;
+    BOOL res;
+
+    file_path_windows = g_strdup(file_path);
+
+    /* Convert the path slashes to windows */
+    for (char * ch = file_path_windows; *ch != '\0'; ++ch) {
+        switch(*ch) {
+        case '/': *ch = '\\'; break;
+        }
+    }
+
+    *file_size = 0;
+
+    /* Convert the path to UTF16 to use in windows native function */
+    file_path_windows_wide = g_utf8_to_utf16(file_path_windows, -1, NULL, NULL, NULL);
+    if (file_path_windows_wide == NULL) {
+        fprintf(stderr, "error converting file name to wide char '%s'\n", file_path_windows);
+        g_free(file_path_windows);
+        return;
+    }
+
+
+    /* Open the file for attributes read only */
+    file_handle = CreateFileW(
+        (wchar_t*)file_path_windows_wide,
+        FILE_READ_ATTRIBUTES,
+        FILE_SHARE_READ|FILE_SHARE_WRITE|FILE_SHARE_DELETE,
+        NULL,
+        OPEN_EXISTING,
+        FILE_ATTRIBUTE_NORMAL,
+        NULL);
+    g_free(file_path_windows_wide);
+
+    if (file_handle == INVALID_HANDLE_VALUE) {
+        g_free(file_path_windows);
+        fprintf(stderr, "error opening file '%s'\n", file_path_windows);
+        return;
+    }
+
+    res = GetFileInformationByHandle(file_handle, &info);
+    CloseHandle(file_handle);
+
+    if (!res) {
+        fprintf(stderr, "error getting file attributes\n");
+        g_free(file_path_windows);
+        return;
+    }
+
+    /* If entry is file get the file size */
+    if (!(info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)) {
+        ULARGE_INTEGER size;
+        size.LowPart = info.nFileSizeLow;
+        size.HighPart = info.nFileSizeHigh;
+
+        *file_size =  size.QuadPart;
+    } else {
+        *file_size = 0;
+    }
+
+    g_free(file_path_windows);
+
+    return;
+}
+
+static void get_file_size_posix(const char* file_path, uint64_t* file_size) {
+    struct stat file_info;
+    int result;
+
+    result = stat(file_path, &file_info);
+    if (result != 0) {
+        fprintf(stderr, "Failed to get file info for '%s' res=%d errno=%d\n", file_path, result, errno);
+        *file_size = 0;
+        return;
+    }
+
+    if (S_ISDIR(file_info.st_mode)) {
+        *file_size = 0;
+    } else {
+        *file_size = file_info.st_size;
+    }
+}
+
 static ds3_bulk_object_response* _ds3_bulk_object_from_file(const char* file_name, const char* base_path) {
     struct stat file_info;
     int result;
     ds3_bulk_object_response* obj = g_new0(ds3_bulk_object_response, 1);
     char* file_to_stat;
+
     memset(&file_info, 0, sizeof(struct stat));
 
     if (base_path != NULL) {
@@ -21636,18 +21724,13 @@ static ds3_bulk_object_response* _ds3_bulk_object_from_file(const char* file_nam
         file_to_stat = g_strdup(file_name);
     }
 
-    result = stat(file_to_stat, &file_info);
-    if (result != 0) {
-        fprintf(stderr, "Failed to get file info for %s\n", file_name);
-    }
-
     obj->name = ds3_str_init(file_name);
 
-    if (S_ISDIR(file_info.st_mode)) {
-        obj->length = 0;
-    } else {
-        obj->length = file_info.st_size;
-    }
+#ifdef _MSC_VER
+    get_file_size_windows(file_to_stat, &obj->length);
+#else
+    get_file_size_posix(file_to_stat, &obj->length);
+#endif
 
     g_free(file_to_stat);