bsnes/snespurify/nall/gzip.hpp

88 lines
1.7 KiB
C++
Executable File

#ifndef NALL_GZIP_HPP
#define NALL_GZIP_HPP
#include <nall/file.hpp>
#include <nall/inflate.hpp>
namespace nall {
struct gzip {
string filename;
uint8_t *data;
unsigned size;
bool decompress(const string &filename);
bool decompress(const uint8_t *data, unsigned size);
gzip();
~gzip();
};
bool gzip::decompress(const string &filename) {
uint8_t *data;
unsigned size;
if(file::read(filename, data, size) == false) return false;
bool result = decompress(data, size);
delete[] data;
return result;
}
bool gzip::decompress(const uint8_t *data, unsigned size) {
if(size < 18) return false;
if(data[0] != 0x1f) return false;
if(data[1] != 0x8b) return false;
unsigned cm = data[2];
unsigned flg = data[3];
unsigned mtime = data[4];
mtime |= data[5] << 8;
mtime |= data[6] << 16;
mtime |= data[7] << 24;
unsigned xfl = data[8];
unsigned os = data[9];
unsigned p = 10;
unsigned isize = data[size - 4];
isize |= data[size - 3] << 8;
isize |= data[size - 2] << 16;
isize |= data[size - 1] << 24;
filename = "";
if(flg & 0x04) { //FEXTRA
unsigned xlen = data[p + 0];
xlen |= data[p + 1] << 8;
p += 2 + xlen;
}
if(flg & 0x08) { //FNAME
char buffer[PATH_MAX];
for(unsigned 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);
}
gzip::gzip() : data(0) {
}
gzip::~gzip() {
if(data) delete[] data;
}
}
#endif