ObjFW  Diff

#define MAX_BITS    15

struct huffman_tree {
	struct huffman_tree *leafs[2];
	uint16_t value;
};

static uint8_t lengthCodes[29] = {
	/* indices are -257, values -3 */
	0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, 20, 24, 28, 32, 40, 48, 56,
	64, 80, 96, 112, 128, 160, 192, 224, 255
};
static uint8_t lengthExtraBits[29] = {
	0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4,
	5, 5, 5, 5, 0
};
static uint16_t distanceCodes[30] = {
	1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 257, 385,
	513, 769, 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577
};
static uint8_t distanceExtraBits[30] = {
	0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10,
	10, 11, 11, 12, 12, 13, 13
};
static uint8_t codeLengthsOrder[19] = {
	16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
};
static struct huffman_tree *fixedLitLenTree, *fixedDistTree;

static bool
tryReadBits(OFDeflateStream *stream, uint_fast16_t *bits, uint_fast8_t count)
{

	tree->value = value;
}

static struct huffman_tree*
constructTree(uint8_t lengths[], uint_fast16_t count)
{
	struct huffman_tree *tree;
	uint8_t lengthCount[MAX_BITS + 1] = { 0 };
	uint16_t code, maxCode, nextCode[MAX_BITS + 1];
	uint_fast16_t i;

	for (i = 0; i < count; i++) {
		uint8_t length = lengths[i];

		if OF_UNLIKELY (length > MAX_BITS)

static bool
walkTree(OFDeflateStream *stream, struct huffman_tree **tree, uint16_t *value)
{
	struct huffman_tree *iter = *tree;
	uint_fast16_t bits;

	for (;;) {
		if OF_UNLIKELY (iter->leafs[0] == NULL &&
		    iter->leafs[1] == NULL)
			break;

		if OF_UNLIKELY (!tryReadBits(stream, &bits, 1)) {
			*tree = iter;
			return false;
		}

		if OF_UNLIKELY (iter->leafs[bits] == NULL)
			break;

		iter = iter->leafs[bits];
	}

	if OF_UNLIKELY (iter->value == 0xFFFF)
		@throw [OFInvalidFormatException exception];

	*value = iter->value;
	return true;
}

static void
releaseTree(struct huffman_tree *tree)
{