double ZopfliCalculateBlockSize(const ZopfliLZ77Store* lz77,
size_t lstart, size_t lend, int btype) {
unsigned ll_lengths[ZOPFLI_NUM_LL];
unsigned d_lengths[ZOPFLI_NUM_D];
double result = 3; /* bfinal and btype bits */
if (btype == 0) {
size_t length = ZopfliLZ77GetByteRange(lz77, lstart, lend);
size_t rem = length % 65535;
size_t blocks = length / 65535 + (rem ? 1 : 0);
/* An uncompressed block must actually be split into multiple blocks if it's
larger than 65535 bytes long. Eeach block header is 5 bytes: 3 bits,
padding, LEN and NLEN (potential less padding for first one ignored). */
return blocks * 5 * 8 + length * 8;
} if (btype == 1) {
GetFixedTree(ll_lengths, d_lengths);
} else {
GetDynamicLengths(lz77, lstart, lend, ll_lengths, d_lengths);
result += CalculateTreeSize(ll_lengths, d_lengths);
}
result += CalculateBlockSymbolSize(
ll_lengths, d_lengths, lz77, lstart, lend);
return result;
}
double ZopfliCalculateBlockSize(const unsigned short* litlens,
const unsigned short* dists,
size_t lstart, size_t lend, int btype) {
unsigned ll_lengths[288];
unsigned d_lengths[32];
double result = 3; /* bfinal and btype bits */
assert(btype == 1 || btype == 2); /* This is not for uncompressed blocks. */
if(btype == 1) {
GetFixedTree(ll_lengths, d_lengths);
} else {
GetDynamicLengths(litlens, dists, lstart, lend, ll_lengths, d_lengths);
result += CalculateTreeSize(ll_lengths, d_lengths);
}
result += CalculateBlockSymbolSize(
ll_lengths, d_lengths, litlens, dists, lstart, lend);
return result;
}
