snes9x/stream.cpp

472 lines
7.7 KiB
C++

/*****************************************************************************\
Snes9x - Portable Super Nintendo Entertainment System (TM) emulator.
This file is licensed under the Snes9x License.
For further information, consult the LICENSE file in the root directory.
\*****************************************************************************/
// Abstract the details of reading from zip files versus FILE *'s.
#include <string>
#ifdef UNZIP_SUPPORT
# ifdef SYSTEM_ZIP
# include <minizip/unzip.h>
# else
# include "unzip.h"
# endif
#endif
#include "snes9x.h"
#include "stream.h"
// Generic constructor/destructor
Stream::Stream (void)
{
return;
}
Stream::~Stream (void)
{
return;
}
// Generic getline function, based on gets. Reimlpement if you can do better.
char * Stream::getline (void)
{
bool eof;
std::string ret;
ret = getline(eof);
if (ret.size() == 0 && eof)
return (NULL);
return (strdup(ret.c_str()));
}
std::string Stream::getline (bool &eof)
{
char buf[1024];
std::string ret;
eof = false;
ret.clear();
do
{
if (gets(buf, sizeof(buf)) == NULL)
{
eof = true;
break;
}
ret.append(buf);
}
while (*ret.rbegin() != '\n');
return (ret);
}
size_t Stream::pos_from_origin_offset(uint8 origin, int32 offset)
{
size_t position = 0;
switch (origin)
{
case SEEK_SET:
position = offset;
break;
case SEEK_END:
position = size() + offset;
break;
case SEEK_CUR:
position = pos() + offset;
break;
}
return position;
}
// snes9x.h FSTREAM Stream
fStream::fStream (FSTREAM f)
{
fp = f;
}
fStream::~fStream (void)
{
return;
}
int fStream::get_char (void)
{
return (GETC_FSTREAM(fp));
}
char * fStream::gets (char *buf, size_t len)
{
return (GETS_FSTREAM(buf, len, fp));
}
size_t fStream::read (void *buf, size_t len)
{
return (READ_FSTREAM(buf, len, fp));
}
size_t fStream::write (void *buf, size_t len)
{
return (WRITE_FSTREAM(buf, len, fp));
}
size_t fStream::pos (void)
{
return (FIND_FSTREAM(fp));
}
size_t fStream::size (void)
{
size_t sz;
REVERT_FSTREAM(fp,0L,SEEK_END);
sz = FIND_FSTREAM(fp);
REVERT_FSTREAM(fp,0L,SEEK_SET);
return sz;
}
int fStream::revert (uint8 origin, int32 offset)
{
return (REVERT_FSTREAM(fp, offset, origin));
}
void fStream::closeStream()
{
CLOSE_FSTREAM(fp);
delete this;
}
// unzip Stream
#ifdef UNZIP_SUPPORT
unzStream::unzStream (unzFile &v)
{
file = v;
pos_in_buf = 0;
buf_pos_in_unzipped = unztell(file);
bytes_in_buf = 0;
// remember start pos for seeks
unzGetFilePos(file, &unz_file_start_pos);
}
unzStream::~unzStream (void)
{
return;
}
size_t unzStream::buffer_remaining()
{
return bytes_in_buf - pos_in_buf;
}
void unzStream::fill_buffer()
{
buf_pos_in_unzipped = unztell(file);
bytes_in_buf = unzReadCurrentFile(file, buffer, unz_BUFFSIZ);
pos_in_buf = 0;
}
int unzStream::get_char (void)
{
unsigned char c;
if (buffer_remaining() <= 0)
{
fill_buffer();
if (bytes_in_buf <= 0)
return (EOF);
}
c = *(buffer + pos_in_buf);
pos_in_buf++;
return ((int) c);
}
char * unzStream::gets (char *buf, size_t len)
{
size_t i;
int c;
for (i = 0; i < len - 1; i++)
{
c = get_char();
if (c == EOF)
{
if (i == 0)
return (NULL);
break;
}
buf[i] = (char) c;
if (buf[i] == '\n')
break;
}
buf[i] = '\0';
return (buf);
}
size_t unzStream::read (void *buf, size_t len)
{
if (len == 0)
return (len);
size_t to_read = len;
uint8 *read_to = (uint8 * )buf;
do
{
size_t in_buffer = buffer_remaining();
if (to_read <= in_buffer)
{
memcpy(read_to, buffer + pos_in_buf, to_read);
pos_in_buf += to_read;
to_read = 0;
break;
}
memcpy(read_to, buffer + pos_in_buf, in_buffer);
to_read -= in_buffer;
fill_buffer();
} while (bytes_in_buf);
return (len - to_read);
}
// not supported
size_t unzStream::write (void *buf, size_t len)
{
return (0);
}
size_t unzStream::pos (void)
{
return buf_pos_in_unzipped + pos_in_buf;
}
size_t unzStream::size (void)
{
unz_file_info info;
unzGetCurrentFileInfo(file,&info,NULL,0,NULL,0,NULL,0);
return info.uncompressed_size;
}
int unzStream::revert (uint8 origin, int32 offset)
{
size_t target_pos = pos_from_origin_offset(origin, offset);
// new pos inside buffered data
if (target_pos >= buf_pos_in_unzipped && target_pos < buf_pos_in_unzipped + bytes_in_buf)
{
pos_in_buf = target_pos - buf_pos_in_unzipped;
}
else // outside of buffer, reset file and read until pos
{
unzGoToFilePos(file, &unz_file_start_pos);
unzOpenCurrentFile(file); // necessary to reopen after seek
int times_to_read = target_pos / unz_BUFFSIZ + 1;
for( int i = 0; i < times_to_read; i++)
{
fill_buffer();
}
pos_in_buf = target_pos % unz_BUFFSIZ;
}
return 0;
}
void unzStream::closeStream()
{
unzClose(file);
delete this;
}
#endif
// memory Stream
memStream::memStream (uint8 *source, size_t sourceSize)
{
mem = head = source;
msize = remaining = sourceSize;
readonly = false;
}
memStream::memStream (const uint8 *source, size_t sourceSize)
{
mem = head = const_cast<uint8 *>(source);
msize = remaining = sourceSize;
readonly = true;
}
memStream::~memStream (void)
{
return;
}
int memStream::get_char (void)
{
if(!remaining)
return EOF;
remaining--;
return *head++;
}
char * memStream::gets (char *buf, size_t len)
{
size_t i;
int c;
for (i = 0; i < len - 1; i++)
{
c = get_char();
if (c == EOF)
{
if (i == 0)
return (NULL);
break;
}
buf[i] = (char) c;
if (buf[i] == '\n')
break;
}
buf[i] = '\0';
return (buf);
}
size_t memStream::read (void *buf, size_t len)
{
size_t bytes = len < remaining ? len : remaining;
memcpy(buf,head,bytes);
head += bytes;
remaining -= bytes;
return bytes;
}
size_t memStream::write (void *buf, size_t len)
{
if(readonly)
return 0;
size_t bytes = len < remaining ? len : remaining;
memcpy(head,buf,bytes);
head += bytes;
remaining -= bytes;
return bytes;
}
size_t memStream::pos (void)
{
return msize - remaining;
}
size_t memStream::size (void)
{
return msize;
}
int memStream::revert (uint8 origin, int32 offset)
{
size_t pos = pos_from_origin_offset(origin, offset);
if(pos > msize)
return -1;
head = mem + pos;
remaining = msize - pos;
return 0;
}
void memStream::closeStream()
{
delete [] mem;
delete this;
}
// dummy Stream
nulStream::nulStream (void)
{
bytes_written = 0;
}
nulStream::~nulStream (void)
{
return;
}
int nulStream::get_char (void)
{
return 0;
}
char * nulStream::gets (char *buf, size_t len)
{
*buf = '\0';
return NULL;
}
size_t nulStream::read (void *buf, size_t len)
{
return 0;
}
size_t nulStream::write (void *buf, size_t len)
{
bytes_written += len;
return len;
}
size_t nulStream::pos (void)
{
return 0;
}
size_t nulStream::size (void)
{
return bytes_written;
}
int nulStream::revert (uint8 origin, int32 offset)
{
size_t target_pos = pos_from_origin_offset(origin, offset);
bytes_written = target_pos;
return 0;
}
void nulStream::closeStream()
{
delete this;
}
Stream *openStreamFromFSTREAM(const char* filename, const char* mode)
{
FSTREAM f = OPEN_FSTREAM(filename,mode);
if(!f)
return NULL;
return new fStream(f);
}
Stream *reopenStreamFromFd(int fd, const char* mode)
{
FSTREAM f = REOPEN_FSTREAM(fd,mode);
if(!f)
return NULL;
return new fStream(f);
}