int ds_var_field_init(struct ds_var_field *dsvf, const char *filename) {
if (0 > ds_var_field_free(dsvf))
return -1;
if (0 > file_mapper_init(&dsvf->data, filename))
return -1;
size_t file_size = file_mapper_size(&dsvf->data);
struct ds_var_field_header *header;
if (file_size < sizeof(struct ds_var_field_header) ||
(header = file_mapper_data(&dsvf->data))->ofs_table >= file_size)
return LOGGER_ERROR("wrong size: %s", filename), file_mapper_free(&dsvf->data), -1;
size_t ofs_table_size = file_size - header->ofs_table;
if ((ofs_table_size & 7) > 0 ||
ofs_table_size < 8)
return LOGGER_ERROR_FUNC("%s: corrupted data detected", filename), file_mapper_free(&dsvf->data), -1;
dsvf->num_elements = (ofs_table_size / sizeof(size_t)) - 1;
dsvf->ofs_table = file_mapper_data(&dsvf->data) + header->ofs_table;
size_t ofs_table = dsvf->ofs_table[dsvf->num_elements] + (size_t)7;
ofs_table &= ~((size_t)7);
if (ofs_table != header->ofs_table)
return LOGGER_ERROR_FUNC("%s: corrupted data detected", filename), file_mapper_free(&dsvf->data), -1;
if (ds_type_var != header->type && ds_type_array != header->type)
return LOGGER_ERROR_FUNC("%s: corrupted data detected, wrong type or unsupported", filename), file_mapper_free(&dsvf->data), -1;
dsvf->array_el_size = (ds_type_array == header->type ? ds_type_to_size(header->element_type) : 0);
return 0;
}
int file_mapper_init(struct file_mapper *fm, const char *filename) {
if (0 > file_mapper_free(fm))
return -1;
int fd = open(filename, O_RDONLY | O_CLOEXEC);
if (fd < 0)
return LOGGER_PERROR_FUNC("open: %s", filename), -1;
struct stat st;
if (0 > fstat(fd, &st))
return LOGGER_PERROR_FUNC("fstat %s", filename), close(fd), -1;
fm->size = st.st_size;
fm->mem = (char *)mmap(NULL, vmbuf_align(fm->size), PROT_READ, MAP_SHARED, fd, 0);
close(fd);
if (MAP_FAILED == fm->mem)
return LOGGER_PERROR_FUNC("mmap %s", filename), close(fd), fm->mem = NULL, -1;
return 0;
}
int ds_var_field_free(struct ds_var_field *dsvf) {
return file_mapper_free(&dsvf->data);
}
