Function config_write_atomic

src/ui/config.c:235–291

}

static bool config_write_atomic(const char *path, const char *json, size_t json_length) {
    wchar_t *wide_path = cbm_path_to_wide(path);
    if (!wide_path) {
        return false;
    }
    size_t temporary_capacity = wcslen(wide_path) + 40U;
    wchar_t *temporary = calloc(temporary_capacity, sizeof(*temporary));
    HANDLE file = INVALID_HANDLE_VALUE;
    if (temporary) {
        for (unsigned int attempt = 0; attempt < 128U; attempt++) {
            ULONG sequence = (ULONG)InterlockedIncrement(&g_config_temp_sequence);
            int written = swprintf(temporary, temporary_capacity, L"%ls.tmp.%08lX.%08lX", wide_path,
                                   (unsigned long)GetCurrentProcessId(), (unsigned long)sequence);
            if (written <= 0 || (size_t)written >= temporary_capacity) {
                break;
            }
            /* DELETE access on the temp handle is what permits the
             * rename-by-handle publish below. */
            file = CreateFileW(temporary, GENERIC_WRITE | DELETE, 0, NULL, CREATE_NEW,
                               FILE_ATTRIBUTE_NORMAL | FILE_FLAG_WRITE_THROUGH, NULL);
            if (file != INVALID_HANDLE_VALUE || GetLastError() != ERROR_FILE_EXISTS) {
                break;
            }
        }
    }
    bool ok = file != INVALID_HANDLE_VALUE;
    size_t offset = 0;
    while (ok && offset < json_length) {
        size_t remaining = json_length - offset;
        DWORD chunk = remaining > UINT32_MAX ? UINT32_MAX : (DWORD)remaining;
        DWORD written = 0;
        ok = WriteFile(file, json + offset, chunk, &written, NULL) != 0 && written > 0;
        offset += written;
    }
    if (ok) {
        ok = FlushFileBuffers(file) != 0;
    }
    bool published = ok && config_posix_rename_handle(file, wide_path);
    if (file != INVALID_HANDLE_VALUE && !CloseHandle(file)) {
        ok = false;
    }
    if (ok && !published) {
        /* Error-driven fallback, not a version probe: POSIX rename needs
         * NTFS-class filesystem support, so exFAT/SMB-homed configs land
         * here, keeping the pre-POSIX behavior (replace can fail while a
         * reader holds the destination open). */
        published = MoveFileExW(temporary, wide_path,
                                MOVEFILE_REPLACE_EXISTING | MOVEFILE_WRITE_THROUGH) != 0;
    }
    ok = ok && published;
    if (!ok && temporary) {
        (void)DeleteFileW(temporary);
    }
    free(temporary);
    free(wide_path);
    return ok;
}
#else