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#include "stdinc.h"
#include "dat.h"
#include "fns.h"
static char vcmagic[] = "venti config\n";
enum {
Maxconfig = 8 * 1024,
Maglen = sizeof vcmagic - 1,
};
int
readifile(IFile *f, char *name)
{
Part *p;
ZBlock *b;
u8int *z;
p = initpart(name, OREAD);
if(p == nil)
return -1;
b = alloczblock(Maxconfig+1, 1, 0);
if(b == nil){
seterr(EOk, "can't alloc for %s: %R", name);
return -1;
}
if(p->size > PartBlank){
/*
* this is likely a real venti partition, in which case we're
* looking for the config file stored as 8k at end of PartBlank.
*/
if(readpart(p, PartBlank-Maxconfig, b->data, Maxconfig) < 0){
seterr(EOk, "can't read %s: %r", name);
freezblock(b);
freepart(p);
return -1;
}
b->data[Maxconfig] = '\0';
if(memcmp(b->data, vcmagic, Maglen) != 0){
seterr(EOk, "bad venti config magic in %s", name);
freezblock(b);
freepart(p);
return -1;
}
/*
* if we change b->data+b->_size, freezblock
* will blow an assertion, so don't.
*/
b->data += Maglen;
b->_size -= Maglen;
b->len -= Maglen;
z = memchr(b->data, '\0', b->len);
if(z)
b->len = z - b->data;
}else if(p->size > Maxconfig){
seterr(EOk, "config file is too large");
freepart(p);
freezblock(b);
return -1;
}else{
freezblock(b);
b = readfile(name);
if(b == nil){
freepart(p);
return -1;
}
}
freepart(p);
f->name = name;
f->b = b;
f->pos = 0;
return 0;
}
void
freeifile(IFile *f)
{
freezblock(f->b);
f->b = nil;
f->pos = 0;
}
int
partifile(IFile *f, Part *part, u64int start, u32int size)
{
ZBlock *b;
b = alloczblock(size, 0, part->blocksize);
if(b == nil)
return -1;
if(readpart(part, start, b->data, size) < 0){
seterr(EAdmin, "can't read %s: %r", part->name);
freezblock(b);
return -1;
}
f->name = part->name;
f->b = b;
f->pos = 0;
return 0;
}
/*
* return the next non-blank input line,
* stripped of leading white space and with # comments eliminated
*/
char*
ifileline(IFile *f)
{
char *s, *e, *t;
int c;
for(;;){
s = (char*)&f->b->data[f->pos];
e = memchr(s, '\n', f->b->len - f->pos);
if(e == nil)
return nil;
*e++ = '\0';
f->pos = e - (char*)f->b->data;
t = strchr(s, '#');
if(t != nil)
*t = '\0';
for(; c = *s; s++)
if(c != ' ' && c != '\t' && c != '\r')
return s;
}
}
int
ifilename(IFile *f, char *dst)
{
char *s;
s = ifileline(f);
if(s == nil || strlen(s) >= ANameSize)
return -1;
namecp(dst, s);
return 0;
}
int
ifileu32int(IFile *f, u32int *r)
{
char *s;
s = ifileline(f);
if(s == nil)
return -1;
return stru32int(s, r);
}
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