void read_pchk
( char *pchk_file
)
{
FILE *f;
f = open_file_std(pchk_file,"rb");
if (f==NULL)
{ fprintf(stderr,"Can't open parity check file: %s\n",pchk_file);
exit(1);
}
if (intio_read(f)!=('P'<<8)+0x80)
{ fprintf(stderr,"File %s doesn't contain a parity check matrix\n",pchk_file);
exit(1);
}
H = mod2sparse_read(f);
if (H==0)
{ fprintf(stderr,"Error reading parity check matrix from %s\n",pchk_file);
exit(1);
}
M = mod2sparse_rows(H);
N = mod2sparse_cols(H);
fclose(f);
}
mod2sparse *mod2sparse_read
( FILE *f
)
{
int n_rows, n_cols;
mod2sparse *m;
int v, row, col;
n_rows = intio_read(f);
if (feof(f) || ferror(f) || n_rows<=0) return 0;
n_cols = intio_read(f);
if (feof(f) || ferror(f) || n_cols<=0) return 0;
m = mod2sparse_allocate(n_rows,n_cols);
row = -1;
for (;;)
{
v = intio_read(f);
if (feof(f) || ferror(f)) break;
if (v==0)
{ return m;
}
else if (v<0)
{ row = -v-1;
if (row>=n_rows) break;
}
else
{ col = v-1;
if (col>=n_cols) break;
if (row==-1) break;
mod2sparse_insert(m,row,col);
}
}
/* Error if we get here. */
mod2sparse_free(m);
return 0;
}
void read_gen
( char *gen_file, /* Name of generator matrix file */
int cols_only, /* Read only column ordering? */
int no_pchk_file /* No parity check file used? */
)
{
int M2, N2;
FILE *f;
int i;
f = open_file_std(gen_file,"rb");
if (f==NULL)
{ fprintf(stderr,"Can't open generator matrix file: %s\n",gen_file);
exit(1);
}
if (intio_read(f)!=('G'<<8)+0x80)
{ fprintf(stderr,"File %s doesn't contain a generator matrix\n",gen_file);
exit(1);
}
if (fread (&type, 1, 1, f) != 1) goto error;
M2 = intio_read(f);
N2 = intio_read(f);
if (feof(f) || ferror(f)) goto error;
if (no_pchk_file)
{ M = M2;
N = N2;
}
else
{ if (M2!=M || N2!=N)
{ fprintf(stderr,
"Generator matrix and parity-check matrix are incompatible\n");
exit(1);
}
}
cols = chk_alloc (N, sizeof *cols);
rows = chk_alloc (M, sizeof *rows);
for (i = 0; i<N; i++)
{ cols[i] = intio_read(f);
if (feof(f) || ferror(f)) goto error;
}
if (!cols_only)
{
switch (type)
{
case 's':
{
for (i = 0; i<M; i++)
{ rows[i] = intio_read(f);
if (feof(f) || ferror(f)) goto error;
}
if ((L = mod2sparse_read(f)) == 0) goto error;
if ((U = mod2sparse_read(f)) == 0) goto error;
if (mod2sparse_rows(L)!=M || mod2sparse_cols(L)!=M) goto garbled;
if (mod2sparse_rows(U)!=M || mod2sparse_cols(U)<M) goto garbled;
break;
}
case 'd':
{
if ((G = mod2dense_read(f)) == 0) goto error;
if (mod2dense_rows(G)!=M || mod2dense_cols(G)!=N-M) goto garbled;
break;
}
case 'm':
{
if ((G = mod2dense_read(f)) == 0) goto error;
if (mod2dense_rows(G)!=M || mod2dense_cols(G)!=M) goto garbled;
break;
}
default:
{ fprintf(stderr,
"Unknown type of generator matrix in file %s\n",gen_file);
exit(1);
}
}
}
fclose(f);
return;
error:
fprintf(stderr,"Error reading generator matrix from file %s\n",gen_file);
exit(1);
garbled:
fprintf(stderr,"Garbled generator matrix in file %s\n",gen_file);
exit(1);
}
