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JMA: Fixed some bugs in decompression. Improved performance. Lower memory requirements. Support for JMA v1 files.

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This commit is contained in:
n-a-c-h
2005-03-08 10:59:22 +00:00
parent 0ba0f5608c
commit 68d1fde4e1
2 changed files with 126 additions and 30 deletions
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150
zsnes/src/jma/jma.cpp
View File

@@ -1,5 +1,5 @@
/*
Copyright (C) 2004 NSRT Team ( http://nsrt.edgeemu.com )
Copyright (C) 2005 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
@@ -17,6 +17,7 @@ along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <sstream>
#include "jma.h"
using namespace std;
@@ -28,7 +29,7 @@ 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_version = 1;
const unsigned int jma_version_length = 1;
const unsigned int jma_total_header_length = jma_header_length + jma_version_length + UINT_SIZE;
@@ -72,9 +73,46 @@ namespace JMA
//Seek to before file block so we can read the file block
stream.seekg(-((int)file_block_size+UINT_SIZE),ios::end);
//This is needed if the file block is compressed
stringstream decompressed_file_block;
//Pointer to where to read file block from (file or decompressed buffer)
istream *file_block_stream;
//Setup file info buffer and byte to read with
jma_file_info file_info;
char byte;
stream.get(byte);
if (!byte) //If file block is compressed
{
//Compressed size isn't counting the byte we just read or the UINT for compressed size
size_t compressed_size = file_block_size - (1+UINT_SIZE);
//Read decompressed size / true file block size
stream.read((char *)uint_buffer, UINT_SIZE);
file_block_size = charp_to_uint(uint_buffer);
//Setup access methods for decompression
ISequentialInStream_Istream compressed_data(stream);
ISequentialOutStream_Ostream decompressed_data(decompressed_file_block);
//Decompress the data
if (!decompress_lzma_7z(compressed_data, compressed_size, decompressed_data, file_block_size))
{
throw(JMA_DECOMPRESS_FAILED);
}
//Go to beginning, setup pointer to buffer
decompressed_file_block.seekg(0, ios::beg);
file_block_stream = &decompressed_file_block;
}
else
{
stream.putback(byte); //Putback byte, byte is part of filename, not compressed indicator
file_block_stream = &stream;
}
//Minimum file name length is 2 bytes, a char and a null
//Minimum comment length is 1 byte, a null
//There are currently 2 UINTs and 2 USHORTs per file
@@ -83,11 +121,11 @@ namespace JMA
//First stored in the file block is the file name null terminated
file_info.name = "";
stream.get(byte);
file_block_stream->get(byte);
while (byte)
{
file_info.name += byte;
stream.get(byte);
file_block_stream->get(byte);
}
//There must be a file name or the file is bad
@@ -99,27 +137,27 @@ namespace JMA
//Same trick as above for the comment
file_info.comment = "";
stream.get(byte);
file_block_stream->get(byte);
while (byte)
{
file_info.comment += byte;
stream.get(byte);
file_block_stream->get(byte);
}
//Next is a UINT representing the file's size
stream.read((char *)uint_buffer, UINT_SIZE);
file_block_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_block_stream->read((char *)uint_buffer, UINT_SIZE);
file_info.crc32 = charp_to_uint(uint_buffer);
//Special USHORT representation of file's date
stream.read((char *)ushort_buffer, USHORT_SIZE);
file_block_stream->read((char *)ushort_buffer, USHORT_SIZE);
file_info.date = charp_to_ushort(ushort_buffer);
//Special USHORT representation of file's time
stream.read((char *)ushort_buffer, USHORT_SIZE);
file_block_stream->read((char *)ushort_buffer, USHORT_SIZE);
file_info.time = charp_to_ushort(ushort_buffer);
file_info.buffer = 0; //Pointing to null till we decompress files
@@ -131,7 +169,6 @@ namespace JMA
}
}
//Constructor for opening JMA files for reading
jma_open::jma_open(const char *compressed_file_name) throw (jma_errors)
{
@@ -139,7 +176,7 @@ namespace JMA
compressed_buffer = 0;
stream.open(compressed_file_name, ios::in | ios::binary);
if (!stream)
if (!stream.is_open())
{
throw(JMA_NO_OPEN);
}
@@ -154,7 +191,7 @@ namespace JMA
//Not the cleanest code but logical
stream.read((char *)header, 5);
if (*header == 0) //Version 0
if (*header <= jma_version)
{
chunk_size = charp_to_uint(header+1); //Chunk size is a UINT that follows version #
retrieve_file_block();
@@ -168,7 +205,7 @@ namespace JMA
//Destructor only has to close the stream if neccesary
jma_open::~jma_open()
{
if (stream)
if (stream.is_open())
{
stream.close();
}
@@ -197,11 +234,14 @@ namespace JMA
void jma_open::chunk_seek(unsigned int chunk_num) throw(jma_errors)
{
//Check the stream is open
if (!stream)
if (!stream.is_open())
{
throw(JMA_NO_OPEN);
}
//Clear possible errors so the seek will work
stream.clear();
//Move forward over header
stream.seekg(jma_total_header_length, ios::beg);
@@ -222,7 +262,7 @@ namespace JMA
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)
if (!stream.is_open())
{
throw(JMA_NO_OPEN);
}
@@ -279,16 +319,35 @@ namespace JMA
throw(JMA_DECOMPRESS_FAILED);
}
delete[] compressed_buffer;
if (remaining_size <= chunk_size) //If we just decompressed the remainder
{
break;
}
}
}
else //Solidly compressed JMA
{
unsigned char int4_buffer[UINT_SIZE];
//read the size of the compressed data
//Read the size of the compressed data
stream.read((char *)int4_buffer, UINT_SIZE);
size_t compressed_size = charp_to_uint(int4_buffer);
//Get decompressed size
size_t size = get_total_size(files);
//Setup access methods for decompression
ISequentialInStream_Istream compressed_data(stream);
ISequentialOutStream_Array decompressed_data(reinterpret_cast<char*>(decompressed_buffer), size);
//Decompress the data
if (!decompress_lzma_7z(compressed_data, compressed_size, decompressed_data, size))
{
throw(JMA_DECOMPRESS_FAILED);
}
/*
//Allocate memory of the right size to hold the compressed data in the JMA
try
{
@@ -313,13 +372,14 @@ namespace JMA
throw(JMA_BAD_FILE);
}
//decompress the data
//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;
@@ -340,7 +400,7 @@ namespace JMA
//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)
if (!stream.is_open())
{
throw(JMA_NO_OPEN);
}
@@ -400,7 +460,7 @@ namespace JMA
for (size_t i = 0; i < our_file_size;)
{
//Get size
stream.read((char *) int4_buffer, UINT_SIZE);
stream.read((char *)int4_buffer, UINT_SIZE);
size_t compressed_size = charp_to_uint(int4_buffer);
//Read all the compressed data in
@@ -422,14 +482,12 @@ namespace JMA
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;
}
size_t copy_amount = our_file_size-i > chunk_size-first_chunk_offset ? chunk_size-first_chunk_offset : our_file_size-i;
memcpy(buffer+i, decomp_buffer+first_chunk_offset, copy_amount);
first_chunk_offset = 0; //Set to zero since this is only for the first iteration
i += copy_amount;
}
delete[] comp_buffer;
}
@@ -453,6 +511,42 @@ namespace JMA
}
}
bool jma_open::is_solid()
{
return(chunk_size ? false : true);
}
const char *jma_error_text(jma_errors error)
{
switch (error)
{
case JMA_NO_CREATE:
return("JMA could not be created");
case JMA_NO_MEM_ALLOC:
return("Memory for JMA could be allocated");
case JMA_NO_OPEN:
return("JMA could not be opened");
case JMA_BAD_FILE:
return("Invalid/Corrupt JMA");
case JMA_UNSUPPORTED_VERSION:
return("JMA version not supported");
case JMA_COMPRESS_FAILED:
return("JMA compression failed");
case JMA_DECOMPRESS_FAILED:
return("JMA decompression failed");
case JMA_FILE_NOT_FOUND:
return("File not found in JMA");
}
return("Unknown error");
}
}

4
zsnes/src/jma/jma.h
View File

@@ -1,5 +1,5 @@
/*
Copyright (C) 2004 NSRT Team ( http://nsrt.edgeemu.com )
Copyright (C) 2005 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
@@ -72,6 +72,7 @@ namespace JMA
std::vector<jma_public_file_info> get_files_info();
std::vector<unsigned char *> get_all_files(unsigned char *) throw(jma_errors);
void extract_file(std::string& name, unsigned char *) throw(jma_errors);
bool is_solid();
private:
std::ifstream stream;
@@ -84,5 +85,6 @@ namespace JMA
void retrieve_file_block() throw(jma_errors);
};
const char *jma_error_text(jma_errors);
}
#endif