bsnes/nall/ups.hpp

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#ifndef NALL_UPS_HPP
#define NALL_UPS_HPP
#include <nall/crc32.hpp>
#include <nall/file.hpp>
#include <nall/function.hpp>
#include <nall/stdint.hpp>
namespace nall {
struct ups {
enum class result : unsigned {
unknown,
success,
patch_unwritable,
patch_invalid,
source_invalid,
target_invalid,
target_too_small,
patch_checksum_invalid,
source_checksum_invalid,
target_checksum_invalid,
};
function<void (unsigned offset, unsigned length)> progress;
result create(
const uint8_t* sourcedata, unsigned sourcelength,
const uint8_t* targetdata, unsigned targetlength,
const char* patchfilename
) {
source_data = (uint8_t*)sourcedata, target_data = (uint8_t*)targetdata;
source_length = sourcelength, target_length = targetlength;
source_offset = target_offset = 0;
source_checksum = target_checksum = patch_checksum = ~0;
if(patch_file.open(patchfilename, file::mode::write) == false) return result::patch_unwritable;
patch_write('U');
patch_write('P');
patch_write('S');
patch_write('1');
encode(source_length);
encode(target_length);
unsigned output_length = source_length > target_length ? source_length : target_length;
unsigned relative = 0;
for(unsigned offset = 0; offset < output_length;) {
uint8_t x = source_read();
uint8_t y = target_read();
if(x == y) {
offset++;
continue;
}
encode(offset++ - relative);
patch_write(x ^ y);
while(true) {
if(offset >= output_length) {
patch_write(0x00);
break;
}
x = source_read();
y = target_read();
offset++;
patch_write(x ^ y);
if(x == y) break;
}
relative = offset;
}
source_checksum = ~source_checksum;
target_checksum = ~target_checksum;
for(unsigned i = 0; i < 4; i++) patch_write(source_checksum >> (i * 8));
for(unsigned i = 0; i < 4; i++) patch_write(target_checksum >> (i * 8));
uint32_t patch_result_checksum = ~patch_checksum;
for(unsigned i = 0; i < 4; i++) patch_write(patch_result_checksum >> (i * 8));
patch_file.close();
return result::success;
}
result apply(
const uint8_t* patchdata, unsigned patchlength,
const uint8_t* sourcedata, unsigned sourcelength,
uint8_t* targetdata, unsigned& targetlength
) {
patch_data = (uint8_t*)patchdata, source_data = (uint8_t*)sourcedata, target_data = targetdata;
patch_length = patchlength, source_length = sourcelength, target_length = targetlength;
patch_offset = source_offset = target_offset = 0;
patch_checksum = source_checksum = target_checksum = ~0;
if(patch_length < 18) return result::patch_invalid;
if(patch_read() != 'U') return result::patch_invalid;
if(patch_read() != 'P') return result::patch_invalid;
if(patch_read() != 'S') return result::patch_invalid;
if(patch_read() != '1') return result::patch_invalid;
unsigned source_read_length = decode();
unsigned target_read_length = decode();
if(source_length != source_read_length && source_length != target_read_length) return result::source_invalid;
targetlength = (source_length == source_read_length ? target_read_length : source_read_length);
if(target_length < targetlength) return result::target_too_small;
target_length = targetlength;
while(patch_offset < patch_length - 12) {
unsigned length = decode();
while(length--) target_write(source_read());
while(true) {
uint8_t patch_xor = patch_read();
target_write(patch_xor ^ source_read());
if(patch_xor == 0) break;
}
}
while(source_offset < source_length) target_write(source_read());
while(target_offset < target_length) target_write(source_read());
uint32_t patch_read_checksum = 0, source_read_checksum = 0, target_read_checksum = 0;
for(unsigned i = 0; i < 4; i++) source_read_checksum |= patch_read() << (i * 8);
for(unsigned i = 0; i < 4; i++) target_read_checksum |= patch_read() << (i * 8);
uint32_t patch_result_checksum = ~patch_checksum;
source_checksum = ~source_checksum;
target_checksum = ~target_checksum;
for(unsigned i = 0; i < 4; i++) patch_read_checksum |= patch_read() << (i * 8);
if(patch_result_checksum != patch_read_checksum) return result::patch_invalid;
if(source_checksum == source_read_checksum && source_length == source_read_length) {
if(target_checksum == target_read_checksum && target_length == target_read_length) return result::success;
return result::target_invalid;
} else if(source_checksum == target_read_checksum && source_length == target_read_length) {
if(target_checksum == source_read_checksum && target_length == source_read_length) return result::success;
return result::target_invalid;
} else {
return result::source_invalid;
}
}
private:
uint8_t* patch_data = nullptr;
uint8_t* source_data = nullptr;
uint8_t* target_data = nullptr;
unsigned patch_length, source_length, target_length;
unsigned patch_offset, source_offset, target_offset;
unsigned patch_checksum, source_checksum, target_checksum;
file patch_file;
uint8_t patch_read() {
if(patch_offset < patch_length) {
uint8_t n = patch_data[patch_offset++];
patch_checksum = crc32_adjust(patch_checksum, n);
return n;
}
return 0x00;
}
uint8_t source_read() {
if(source_offset < source_length) {
uint8_t n = source_data[source_offset++];
source_checksum = crc32_adjust(source_checksum, n);
return n;
}
return 0x00;
}
uint8_t target_read() {
uint8_t result = 0x00;
if(target_offset < target_length) {
result = target_data[target_offset];
target_checksum = crc32_adjust(target_checksum, result);
}
if(((target_offset++ & 255) == 0) && progress) {
progress(target_offset, source_length > target_length ? source_length : target_length);
}
return result;
}
void patch_write(uint8_t n) {
patch_file.write(n);
patch_checksum = crc32_adjust(patch_checksum, n);
}
void target_write(uint8_t n) {
if(target_offset < target_length) {
target_data[target_offset] = n;
target_checksum = crc32_adjust(target_checksum, n);
}
if(((target_offset++ & 255) == 0) && progress) {
progress(target_offset, source_length > target_length ? source_length : target_length);
}
}
void encode(uint64_t offset) {
while(true) {
uint64_t x = offset & 0x7f;
offset >>= 7;
if(offset == 0) {
patch_write(0x80 | x);
break;
}
patch_write(x);
offset--;
}
}
uint64_t decode() {
uint64_t offset = 0, shift = 1;
while(true) {
uint8_t x = patch_read();
offset += (x & 0x7f) * shift;
if(x & 0x80) break;
shift <<= 7;
offset += shift;
}
return offset;
}
};
}
#endif