Files
ZSNES/zsnes/src/jma/jma.cpp
2004-11-21 15:03:19 +00:00

454 lines
13 KiB
C++

/*
Copyright (C) 2004 NSRT Team ( http://nsrt.edgeemu.com )
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later
version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "jma.h"
using namespace std;
#include "portable.h"
#include "7z.h"
#include "crc32.h"
namespace JMA
{
const char jma_magic[] = { 'J', 'M', 'A', 0, 'N' };
const unsigned int jma_header_length = 5;
const unsigned char jma_version = 0;
const unsigned char jma_null = 0;
//Convert zip/JMA integer time to to time_t
time_t uint_to_time(unsigned int date, unsigned int time)
{
tm formatted_time;
formatted_time.tm_mday = date & 0x1F;
formatted_time.tm_mon = ((date >> 5) & 0xF) - 1;
formatted_time.tm_year = ((date >> 9) & 0x7f) + 80;
formatted_time.tm_sec = (time & 0x1F) * 2;
formatted_time.tm_min = (time >> 5) & 0x3F;
formatted_time.tm_hour = (time >> 11) & 0x1F;
return(mktime(&formatted_time));
}
//Retreive the file block, what else?
void jma_open::retrieve_file_block() throw(jma_errors)
{
unsigned char uint_buffer[UINT_SIZE];
//File block size is the last UINT in the file
stream.seekg(-UINT_SIZE,ios::end);
stream.read((char *)uint_buffer, UINT_SIZE);
size_t file_block_size = charp_to_uint(uint_buffer);
//Currently at the end of the file, so that's the file size
size_t jma_file_size = stream.tellg();
//The file block can't be larger than the JMA file.
//This if can probably be improved
if (file_block_size >= jma_file_size)
{
throw(JMA_BAD_FILE);
}
//Seek to before file block so we can read the file block
stream.seekg(-((int)file_block_size+UINT_SIZE),ios::end);
jma_file_info file_info;
char byte;
while (file_block_size)
{
//First stored in the file block is the file name null terminated
file_info.name = "";
stream.get(byte);
while (byte)
{
file_info.name += byte;
stream.get(byte);
}
//There must be a file name or the file is bad
if (!file_info.name.length())
{
throw(JMA_BAD_FILE);
}
//Same trick as above for the comment
file_info.comment = "";
stream.get(byte);
while (byte)
{
file_info.comment += byte;
stream.get(byte);
}
//Next is a UINT representing the file's size
stream.read((char *)uint_buffer, UINT_SIZE);
file_info.size = charp_to_uint(uint_buffer);
//Followed by CRC32
stream.read((char *)uint_buffer, UINT_SIZE);
file_info.crc32 = charp_to_uint(uint_buffer);
//Special UINT representation of file's date
stream.read((char *)uint_buffer, UINT_SIZE);
file_info.date = charp_to_uint(uint_buffer);
//Special UINT representation of file's time
stream.read((char *)uint_buffer, UINT_SIZE);
file_info.time = charp_to_uint(uint_buffer);
file_info.buffer = 0; //Pointing to null till we decompress files
files.push_back(file_info); //Put file info into our structure
//Subtract size of the file info we just read
file_block_size -= file_info.name.length()+file_info.comment.length()+2+UINT_SIZE*4;
}
}
//Constructor for opening JMA files for reading
jma_open::jma_open(const char *compressed_file_name) throw (jma_errors)
{
decompressed_buffer = 0;
compressed_buffer = 0;
stream.open(compressed_file_name, ios::in | ios::binary);
if (!stream)
{
throw(JMA_NO_OPEN);
}
//Header is "JMA\0N"
unsigned char header[jma_header_length];
stream.read((char *)header, jma_header_length);
if (memcmp(jma_magic, header, jma_header_length))
{
throw(JMA_BAD_FILE);
}
//Not the cleanest code but logical
stream.read((char *)header, 5);
if (*header == 0) //Version 0
{
chunk_size = charp_to_uint(header+1); //Chunk size is a UINT that follows version #
retrieve_file_block();
}
else
{
throw(JMA_UNSUPPORTED_VERSION);
}
}
//Destructor only has to close the stream if neccesary
jma_open::~jma_open()
{
if (stream)
{
stream.close();
}
}
//Return a vector containing useful info about the files in the JMA
vector<jma_public_file_info> jma_open::get_files_info()
{
vector<jma_public_file_info> file_info_vector;
jma_public_file_info file_info;
for (vector<jma_file_info>::iterator i = files.begin(); i != files.end(); i++)
{
file_info.name = i->name;
file_info.comment = i->comment;
file_info.size = i->size;
file_info.datetime = uint_to_time(i->date, i->time);
file_info.crc32 = i->crc32;
file_info_vector.push_back(file_info);
}
return(file_info_vector);
}
//Skip forward a given number of chunks
void jma_open::chunk_seek(unsigned int chunk_num) throw(jma_errors)
{
//Check the stream is open
if (!stream)
{
throw(JMA_NO_OPEN);
}
//Move forward over header
stream.seekg(10, ios::beg);
unsigned char int4_buffer[UINT_SIZE];
while (chunk_num--)
{
//Read in size of chunk
stream.read((char *)int4_buffer, UINT_SIZE);
//Skip chunk plus it's CRC32
stream.seekg(charp_to_uint(int4_buffer)+UINT_SIZE, ios::cur);
}
}
//Return a vector of pointers to each file in the JMA, the buffer to hold all the files
//must be initilized outside.
vector<unsigned char *> jma_open::get_all_files(unsigned char *buffer) throw(jma_errors)
{
//If there's no stream we can't read from it, so exit
if (!stream)
{
throw(JMA_NO_OPEN);
}
//Seek to the first chunk
chunk_seek(0);
//Set the buffer that decompressed data goes to
decompressed_buffer = buffer;
//If the JMA is not solid
if (chunk_size)
{
unsigned char int4_buffer[UINT_SIZE];
size_t size = get_total_size(files);
//For each chunk in the file...
for (size_t remaining_size = size; remaining_size; remaining_size -= chunk_size)
{
//Read the compressed size
stream.read((char *)int4_buffer, UINT_SIZE);
size_t compressed_size = charp_to_uint(int4_buffer);
//Allocate memory of the correct size to hold the compressed data in the JMA
//Throw error on failure as that is unrecoverable from
try
{
compressed_buffer = new unsigned char[compressed_size];
}
catch (bad_alloc xa)
{
throw(JMA_NO_MEM_ALLOC);
}
//Read all the compressed data in
stream.read((char *)compressed_buffer, compressed_size);
//Read the expected CRC of compressed data from the file
stream.read((char *)int4_buffer, UINT_SIZE);
//If it doesn't match, throw error and cleanup memory
if (CRC32lib::CRC32(compressed_buffer, compressed_size) != charp_to_uint(int4_buffer))
{
delete[] compressed_buffer;
throw(JMA_BAD_FILE);
}
//Decompress the data, cleanup memory on failure
if (!decompress_lzma_7z(compressed_buffer, compressed_size,
decompressed_buffer+size-remaining_size,
(remaining_size > chunk_size) ? chunk_size : remaining_size))
{
delete[] compressed_buffer;
throw(JMA_DECOMPRESS_FAILED);
}
delete[] compressed_buffer;
}
}
else //Solidly compressed JMA
{
unsigned char int4_buffer[UINT_SIZE];
//read the size of the compressed data
stream.read((char *)int4_buffer, UINT_SIZE);
size_t compressed_size = charp_to_uint(int4_buffer);
//Allocate memory of the right size to hold the compressed data in the JMA
try
{
compressed_buffer = new unsigned char[compressed_size];
}
catch (bad_alloc xa)
{
throw(JMA_NO_MEM_ALLOC);
}
//Copy the compressed data into memory
stream.read((char *)compressed_buffer, compressed_size);
size_t size = get_total_size(files);
//Read the CRC of the compressed data
stream.read((char *)int4_buffer, UINT_SIZE);
//If it doesn't match, complain
if (CRC32lib::CRC32(compressed_buffer, compressed_size) != charp_to_uint(int4_buffer))
{
delete[] compressed_buffer;
throw(JMA_BAD_FILE);
}
//decompress the data
if (!decompress_lzma_7z(compressed_buffer, compressed_size, decompressed_buffer, size))
{
delete[] compressed_buffer;
throw(JMA_DECOMPRESS_FAILED);
}
delete[] compressed_buffer;
}
vector<unsigned char *> file_pointers;
size_t size = 0;
//For each file, add it's pointer to the vector, size is pointer offset in the buffer
for (vector<jma_file_info>::iterator i = files.begin(); i != files.end(); i++)
{
i->buffer = decompressed_buffer+size;
file_pointers.push_back(decompressed_buffer+size);
size += i->size;
}
//Return the vector of pointers
return(file_pointers);
}
//Extracts the file with a given name found in the archive to the given buffer
void jma_open::extract_file(string& name, unsigned char *buffer) throw(jma_errors)
{
if (!stream)
{
throw(JMA_NO_OPEN);
}
size_t size_to_skip = 0;
size_t our_file_size = 0;
//Search through the vector of file information
for (vector<jma_file_info>::iterator i = files.begin(); i != files.end(); i++)
{
if (i->name == name)
{
//Set the variable so we can tell we found it
our_file_size = i->size;
break;
}
//Keep a running total of size
size_to_skip += i->size;
}
if (!our_file_size) //File with the specified name was not found in the archive
{
throw(JMA_FILE_NOT_FOUND);
}
//If the JMA only contains one file, we can skip a lot of overhead
if (files.size() == 1)
{
get_all_files(buffer);
return;
}
if (chunk_size) //we are using non-solid archive..
{
unsigned int chunks_to_skip = size_to_skip / chunk_size;
//skip over requisite number of chunks
chunk_seek(chunks_to_skip);
//Allocate memory for compressed and decompressed data
unsigned char *comp_buffer = 0, *decomp_buffer = 0;
try
{
//Compressed data size is <= non compressed size
unsigned char *combined_buffer = new unsigned char[chunk_size*2];
comp_buffer = combined_buffer;
decomp_buffer = combined_buffer+chunk_size;
}
catch (bad_alloc xa)
{
throw(JMA_NO_MEM_ALLOC);
}
size_t first_chunk_offset = size_to_skip % chunk_size;
unsigned char int4_buffer[UINT_SIZE];
for (size_t i = 0; i < our_file_size;)
{
//Get size
stream.read((char *) int4_buffer, UINT_SIZE);
size_t compressed_size = charp_to_uint(int4_buffer);
//Read all the compressed data in
stream.read((char *)comp_buffer, compressed_size);
//Read the CRC of the compressed data
stream.read((char *)int4_buffer, UINT_SIZE);
//If it doesn't match, complain
if (CRC32lib::CRC32(comp_buffer, compressed_size) != charp_to_uint(int4_buffer))
{
delete[] comp_buffer;
throw(JMA_BAD_FILE);
}
//Decompress chunk
if (!decompress_lzma_7z(comp_buffer, compressed_size, decomp_buffer, chunk_size))
{
delete[] comp_buffer;
throw(JMA_DECOMPRESS_FAILED);
}
else
{
size_t copy_amount = our_file_size-i > chunk_size ? chunk_size : our_file_size-i;
copy_amount -= first_chunk_offset;
memcpy(buffer+i, decomp_buffer+first_chunk_offset, copy_amount);
first_chunk_offset = 0;
i += copy_amount;
}
}
delete[] comp_buffer;
}
else //Solid JMA
{
unsigned char *decomp_buffer = 0;
try
{
decomp_buffer = new unsigned char[get_total_size(files)];
}
catch (bad_alloc xa)
{
throw(JMA_NO_MEM_ALLOC);
}
get_all_files(decomp_buffer);
memcpy(buffer, decomp_buffer+size_to_skip, our_file_size);
delete[] decomp_buffer;
}
}
}