int read(int fdesc, char * buf, int count)
{
struct iob * io;
if ((io = iob_from_fdesc(fdesc)) == NULL)
{
return (-1);
}
if ((io->i_offset + count) > (unsigned int)io->i_filesize)
{
count = io->i_filesize - io->i_offset;
}
if (count <= 0)
{
return 0; // end of file
}
bcopy(io->i_buf + io->i_offset, buf, count);
io->i_offset += count;
return count;
}
int file_size(int fdesc)
{
register struct iob *io;
if ((io = iob_from_fdesc(fdesc)) == 0) {
return (-1);
}
return io->i_ino.i_size;
}
int file_size(int fdesc)
{
struct iob * io;
if ((io = iob_from_fdesc(fdesc)) == 0)
return 0;
return io->i_filesize;
}
int tell(int fdesc)
{
struct iob * io;
if ((io = iob_from_fdesc(fdesc)) == NULL)
return 0;
return io->i_offset;
}
int b_lseek(int fdesc, int offset, int ptr)
{
struct iob * io;
if ((io = iob_from_fdesc(fdesc)) == NULL)
return (-1);
io->i_offset = offset;
return offset;
}
int close(int fdesc)
{
struct iob * io;
if ((io = iob_from_fdesc(fdesc)) == NULL)
return (-1);
io->i_flgs = 0;
return 0;
}
int writebyte(int fdesc, char value)
{
struct iob * io;
if ((io = iob_from_fdesc(fdesc)) == NULL)
return (-1);
if ((io->i_offset + 1) > (unsigned int)io->i_filesize)
return 0; // end of file
io->i_buf[io->i_offset++] = value;
return 1;
}
int writeint(int fdesc, int value)
{
struct iob * io;
if ((io = iob_from_fdesc(fdesc)) == NULL)
return (-1);
if ((io->i_offset + 4) > (unsigned int)io->i_filesize)
return 0; // end of file
bcopy(&value, io->i_buf + io->i_offset, 4);
io->i_offset += 4;
return 4;
}
static int getch(int fdesc)
{
register struct iob *io;
struct fs *fs;
char *p;
int c, lbn, off, size, diff;
if ((io = iob_from_fdesc(fdesc)) == 0) {
return (-1);
}
p = io->i_ma;
if (io->i_cc <= 0) {
if ((io->i_flgs & F_FILE) != 0) {
diff = io->i_ino.i_size - io->i_offset;
if (diff <= 0)
return (-1);
fs = io->i_fs;
lbn = lblkno(fs, io->i_offset);
io->i_bn = fsbtodb(fs, sbmap(io, lbn)) + io->i_boff;
off = blkoff(fs, io->i_offset);
size = blksize(fs, &io->i_ino, lbn);
} else {
diff = 0;
#ifndef SMALL
io->i_bn = io->i_offset / DEV_BSIZE;
off = 0;
size = DEV_BSIZE;
#endif SMALL
}
io->i_ma = io->i_buf;
io->i_cc = size;
if (devread(io) < 0) {
return (-1);
}
if ((io->i_flgs & F_FILE) != 0) {
if (io->i_offset - off + size >= io->i_ino.i_size)
io->i_cc = diff + off;
io->i_cc -= off;
}
p = &io->i_buf[off];
}
io->i_cc--;
io->i_offset++;
c = (unsigned)*p++;
io->i_ma = p;
return (c);
}
int
b_lseek(int fdesc, unsigned int addr, int ptr)
{
register struct iob *io;
#if CHECK_CAREFULLY
if (ptr != 0) {
error("Seek not from beginning of file\n");
return (-1);
}
#endif CHECK_CAREFULLY
if ((io = iob_from_fdesc(fdesc)) == 0) {
return (-1);
}
io->i_offset = addr;
io->i_bn = addr / DEV_BSIZE;
io->i_cc = 0;
return (0);
}
int write(int fdesc, const char * buf, int count)
{
struct iob * io;
if ((io = iob_from_fdesc(fdesc)) == NULL)
return (-1);
if ((io->i_offset + count) > (unsigned int)io->i_filesize)
count = io->i_filesize - io->i_offset;
if (count <= 0)
return 0; // end of file
bcopy(buf, io->i_buf + io->i_offset, count);
io->i_offset += count;
return count;
}
int
close(int fdesc)
{
register struct iob *file;
register int i;
if ((file = iob_from_fdesc(fdesc)) == 0) {
return (-1);
}
// free((char *)file->i_fs);
file->i_fs = NULL;
free(file->i_buf); file->i_buf = NULL;
for (i=0;i<NBUFS;i++)
{
if (b[i])
{ free(b[i]);
b[i] = NULL;
}
blknos[i] = 0;
}
file->i_flgs = 0;
return (0);
}
int
read(int fdesc, char *buf, int count)
{
int i, size;
register struct iob *file;
struct fs *fs;
int lbn, off;
if ((file = iob_from_fdesc(fdesc)) == 0) {
return (-1);
}
if ((file->i_flgs&F_READ) == 0) {
return (-1);
}
#ifndef SMALL
if ((file->i_flgs & F_FILE) == 0) {
file->i_cc = count;
file->i_ma = buf;
file->i_bn = file->i_boff + (file->i_offset / DEV_BSIZE);
i = devread(file);
file->i_offset += count;
return (i);
}
#endif SMALL
if (file->i_offset+count > file->i_ino.i_size)
count = file->i_ino.i_size - file->i_offset;
if ((i = count) <= 0)
return (0);
/*
* While reading full blocks, do I/O into user buffer.
* Anything else uses getc().
*/
fs = file->i_fs;
while (i) {
off = blkoff(fs, file->i_offset);
lbn = lblkno(fs, file->i_offset);
size = blksize(fs, &file->i_ino, lbn);
if (off == 0 && size <= i) {
file->i_bn = fsbtodb(fs, sbmap(file, lbn)) +
file->i_boff;
file->i_cc = size;
file->i_ma = buf;
if (devread(file) < 0) {
return (-1);
}
file->i_offset += size;
file->i_cc = 0;
buf += size;
i -= size;
} else {
size -= off;
if (size > i)
size = i;
i -= size;
do {
*buf++ = getch(fdesc);
} while (--size);
}
}
return (count);
}
