xref: /openbsd-src/lib/libcbor/src/cbor/bytestrings.c (revision 4dcc46c4d04180142eda526ce521dfb137776d05)

/*
 * Copyright (c) 2014-2020 Pavel Kalvoda <me@pavelkalvoda.com>
 *
 * libcbor is free software; you can redistribute it and/or modify
 * it under the terms of the MIT license. See LICENSE for details.
 */

#include "bytestrings.h"
#include <string.h>
#include "internal/memory_utils.h"

size_t cbor_bytestring_length(const cbor_item_t *item) {
  CBOR_ASSERT(cbor_isa_bytestring(item));
  return item->metadata.bytestring_metadata.length;
}

unsigned char *cbor_bytestring_handle(const cbor_item_t *item) {
  CBOR_ASSERT(cbor_isa_bytestring(item));
  return item->data;
}

bool cbor_bytestring_is_definite(const cbor_item_t *item) {
  CBOR_ASSERT(cbor_isa_bytestring(item));
  return item->metadata.bytestring_metadata.type == _CBOR_METADATA_DEFINITE;
}

bool cbor_bytestring_is_indefinite(const cbor_item_t *item) {
  return !cbor_bytestring_is_definite(item);
}

cbor_item_t *cbor_new_definite_bytestring(void) {
  cbor_item_t *item = _cbor_malloc(sizeof(cbor_item_t));
  _CBOR_NOTNULL(item);
  *item = (cbor_item_t){
      .refcount = 1,
      .type = CBOR_TYPE_BYTESTRING,
      .metadata = {.bytestring_metadata = {.type = _CBOR_METADATA_DEFINITE,
                                           .length = 0}}};
  return item;
}

cbor_item_t *cbor_new_indefinite_bytestring(void) {
  cbor_item_t *item = _cbor_malloc(sizeof(cbor_item_t));
  _CBOR_NOTNULL(item);
  *item = (cbor_item_t){
      .refcount = 1,
      .type = CBOR_TYPE_BYTESTRING,
      .metadata = {.bytestring_metadata = {.type = _CBOR_METADATA_INDEFINITE,
                                           .length = 0}},
      .data = _cbor_malloc(sizeof(struct cbor_indefinite_string_data))};
  _CBOR_DEPENDENT_NOTNULL(item, item->data);
  *((struct cbor_indefinite_string_data *)item->data) =
      (struct cbor_indefinite_string_data){
          .chunk_count = 0,
          .chunk_capacity = 0,
          .chunks = NULL,
      };
  return item;
}

cbor_item_t *cbor_build_bytestring(cbor_data handle, size_t length) {
  cbor_item_t *item = cbor_new_definite_bytestring();
  _CBOR_NOTNULL(item);
  void *content = _cbor_malloc(length);
  _CBOR_DEPENDENT_NOTNULL(item, content);
  memcpy(content, handle, length);
  cbor_bytestring_set_handle(item, content, length);
  return item;
}

void cbor_bytestring_set_handle(cbor_item_t *item,
                                cbor_mutable_data CBOR_RESTRICT_POINTER data,
                                size_t length) {
  CBOR_ASSERT(cbor_isa_bytestring(item));
  CBOR_ASSERT(cbor_bytestring_is_definite(item));
  item->data = data;
  item->metadata.bytestring_metadata.length = length;
}

cbor_item_t **cbor_bytestring_chunks_handle(const cbor_item_t *item) {
  CBOR_ASSERT(cbor_isa_bytestring(item));
  CBOR_ASSERT(cbor_bytestring_is_indefinite(item));
  return ((struct cbor_indefinite_string_data *)item->data)->chunks;
}

size_t cbor_bytestring_chunk_count(const cbor_item_t *item) {
  CBOR_ASSERT(cbor_isa_bytestring(item));
  CBOR_ASSERT(cbor_bytestring_is_indefinite(item));
  return ((struct cbor_indefinite_string_data *)item->data)->chunk_count;
}

bool cbor_bytestring_add_chunk(cbor_item_t *item, cbor_item_t *chunk) {
  CBOR_ASSERT(cbor_isa_bytestring(item));
  CBOR_ASSERT(cbor_bytestring_is_indefinite(item));
  CBOR_ASSERT(cbor_isa_bytestring(chunk));
  CBOR_ASSERT(cbor_bytestring_is_definite(chunk));
  struct cbor_indefinite_string_data *data =
      (struct cbor_indefinite_string_data *)item->data;
  if (data->chunk_count == data->chunk_capacity) {
    if (!_cbor_safe_to_multiply(CBOR_BUFFER_GROWTH, data->chunk_capacity)) {
      return false;
    }

    size_t new_chunk_capacity =
        data->chunk_capacity == 0 ? 1
                                  : CBOR_BUFFER_GROWTH * (data->chunk_capacity);

    cbor_item_t **new_chunks_data = _cbor_realloc_multiple(
        data->chunks, sizeof(cbor_item_t *), new_chunk_capacity);

    if (new_chunks_data == NULL) {
      return false;
    }
    data->chunk_capacity = new_chunk_capacity;
    data->chunks = new_chunks_data;
  }
  data->chunks[data->chunk_count++] = cbor_incref(chunk);
  return true;
}