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Some JMA format and code improvements.

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This commit is contained in:
n-a-c-h
2004-11-26 01:26:50 +00:00
parent 1c7223557d
commit 760e6a53a5
3 changed files with 25 additions and 12 deletions
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24
zsnes/src/jma/jma.cpp
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@@ -29,10 +29,11 @@ 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;
const unsigned int jma_version_length = 1;
const unsigned int jma_total_header_length = jma_header_length + jma_version_length + UINT_SIZE;
//Convert zip/JMA integer time to to time_t
time_t uint_to_time(unsigned int date, unsigned int time)
time_t uint_to_time(unsigned short date, unsigned short time)
{
tm formatted_time;
@@ -47,7 +48,6 @@ namespace JMA
}
//Retreive the file block, what else?
void jma_open::retrieve_file_block() throw(jma_errors)
{
@@ -61,9 +61,9 @@ namespace JMA
//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.
//The file block can't be larger than the JMA file without it's header.
//This if can probably be improved
if (file_block_size >= jma_file_size)
if (file_block_size >= jma_file_size-jma_total_header_length)
{
throw(JMA_BAD_FILE);
}
@@ -74,7 +74,10 @@ namespace JMA
jma_file_info file_info;
char byte;
while (file_block_size)
//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
while (file_block_size > 2+1+UINT_SIZE*2+USHORT_SIZE*2) //This does allow for a gap, but that's okay
{
//First stored in the file block is the file name null terminated
file_info.name = "";
@@ -112,20 +115,21 @@ namespace JMA
//Special UINT representation of file's date
stream.read((char *)uint_buffer, UINT_SIZE);
file_info.date = charp_to_uint(uint_buffer);
file_info.date = charp_to_ushort(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.time = charp_to_ushort(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;
file_block_size -= file_info.name.length()+file_info.comment.length()+2+UINT_SIZE*2+USHORT_SIZE*2;
}
}
//Constructor for opening JMA files for reading
jma_open::jma_open(const char *compressed_file_name) throw (jma_errors)
@@ -198,7 +202,7 @@ namespace JMA
}
//Move forward over header
stream.seekg(10, ios::beg);
stream.seekg(jma_total_header_length, ios::beg);
unsigned char int4_buffer[UINT_SIZE];