bsnes/nall/decode/gzip.hpp

79 lines
1.6 KiB
C++

#pragma once
#include <nall/file.hpp>
#include <nall/decode/inflate.hpp>
namespace nall { namespace Decode {
struct GZIP {
inline ~GZIP();
inline auto decompress(const string& filename) -> bool;
inline auto decompress(const uint8* data, uint size) -> bool;
string filename;
uint8* data = nullptr;
uint size = 0;
};
GZIP::~GZIP() {
if(data) delete[] data;
}
auto GZIP::decompress(const string& filename) -> bool {
if(auto memory = file::read(filename)) {
return decompress(memory.data(), memory.size());
}
return false;
}
auto GZIP::decompress(const uint8* data, uint size) -> bool {
if(size < 18) return false;
if(data[0] != 0x1f) return false;
if(data[1] != 0x8b) return false;
uint cm = data[2];
uint flg = data[3];
uint mtime = data[4];
mtime |= data[5] << 8;
mtime |= data[6] << 16;
mtime |= data[7] << 24;
uint xfl = data[8];
uint os = data[9];
uint p = 10;
uint isize = data[size - 4];
isize |= data[size - 3] << 8;
isize |= data[size - 2] << 16;
isize |= data[size - 1] << 24;
filename = "";
if(flg & 0x04) { //FEXTRA
uint xlen = data[p + 0];
xlen |= data[p + 1] << 8;
p += 2 + xlen;
}
if(flg & 0x08) { //FNAME
char buffer[PATH_MAX];
for(uint n = 0; n < PATH_MAX; n++, p++) {
buffer[n] = data[p];
if(data[p] == 0) break;
}
if(data[p++]) return false;
filename = buffer;
}
if(flg & 0x10) { //FCOMMENT
while(data[p++]);
}
if(flg & 0x02) { //FHCRC
p += 2;
}
this->size = isize;
this->data = new uint8_t[this->size];
return inflate(this->data, this->size, data + p, size - p - 8);
}
}}