ref: 52cacba37c6f3a125ef931afa4b9c2cdb7438fef
dir: /sys/src/cmd/disk/sacfs/mksacfs.c/
#include <u.h>
#include <libc.h>
#include "sac.h"
#include "sacfs.h"
enum {
NCACHE = 1024, /* must be power of two */
OffsetSize = 4, /* size of block offset */
};
int warn(char *);
int seen(Dir *);
void usage(void);
void outwrite(void *buf, int n, long off);
void putl(void *p, uint v);
void *emalloc(int size);
void sacfs(char *root);
void sacfile(char *name, Dir *dir, SacDir *sd);
void sacdir(char *name, Dir *dir, SacDir *sd);
int uflag=0;
int fflag=0;
long blocksize = 4*1024;
struct Out
{
int fd;
long size;
} out;
typedef struct Cache Cache;
struct Cache
{
Dir* cache;
int n;
int max;
} cache[NCACHE];
void
main(int argc, char *argv[])
{
char *s, *ss;
char *outfile = nil;
ARGBEGIN {
case 'u':
uflag=1;
break;
case 'o':
outfile = ARGF();
break;
case 'b':
s = ARGF();
if(s) {
blocksize = strtoul(s, &ss, 0);
if(s == ss)
usage();
if(*ss == 'k')
blocksize *= 1024;
}
if(blocksize < sizeof(SacDir))
sysfatal("blocksize too small");
break;
} ARGEND
if(outfile == nil) {
sysfatal("still to do: need to create temp file");
} else {
out.fd = create(outfile, OWRITE|OTRUNC, 0664);
if(out.fd < 0)
sysfatal("could not create file: %s: %r", outfile);
}
if(argc==0)
sacfs(".");
else
sacfs(argv[0]);
close(out.fd);
exits(0);
}
void
usage(void)
{
fprint(2, "usage: %s [-u] [-b blocksize] -o output [root]\n", argv0);
exits("usage");
}
void
sacfs(char *root)
{
Dir *dir;
long offset;
SacHeader hdr;
SacDir sd;
dir = dirstat(root);
if(dir == nil)
sysfatal("could not stat root: %s: %r", root);
offset = out.size;
out.size += sizeof(SacHeader) + sizeof(SacDir);
memset(&hdr, 0, sizeof(hdr));
putl(hdr.magic, Magic);
putl(hdr.blocksize, blocksize);
if(dir->mode & DMDIR)
sacdir(root, dir, &sd);
else
sacfile(root, dir, &sd);
putl(hdr.length, out.size);
outwrite(&hdr, sizeof(hdr), offset);
outwrite(&sd, sizeof(sd), offset+sizeof(SacHeader));
free(dir);
}
void
setsd(SacDir *sd, Dir *dir, long length, long blocks)
{
static qid = 1;
memset(sd, 0, sizeof(SacDir));
strncpy(sd->name, dir->name, NAMELEN);
strncpy(sd->uid, dir->uid, NAMELEN);
strncpy(sd->gid, dir->gid, NAMELEN);
putl(sd->qid, qid++|(dir->mode&DMDIR));
putl(sd->mode, dir->mode);
putl(sd->atime, dir->atime);
putl(sd->mtime, dir->mtime);
putl(sd->length, length);
putl(sd->blocks, blocks);
}
void
sacfile(char *name, Dir *dir, SacDir *sd)
{
int fd, i, n, nn;
long nblock;
uchar *blocks;
uchar *buf, *cbuf;
long offset;
long block;
fd = open(name, OREAD);
if(fd < 0)
sysfatal("could not open file: %s: %r", name);
nblock = (dir->length + blocksize-1)/blocksize;
blocks = emalloc((nblock+1)*OffsetSize);
buf = emalloc(blocksize);
cbuf = emalloc(blocksize);
offset = out.size;
out.size += (nblock+1)*OffsetSize;
for(i=0; i<nblock; i++) {
n = read(fd, buf, blocksize);
if(n < 0)
sysfatal("read failed: %s: %r", name);
if(n == 0)
sysfatal("unexpected eof: %s", name);
if(n < blocksize && i != nblock-1)
sysfatal("short read: %s: got %d", name, n);
block = out.size;
nn = sac(cbuf, buf, n);
if(nn < 0 || uflag) {
outwrite(buf, n, out.size);
out.size += n;
} else {
block = -block;
outwrite(cbuf, nn, out.size);
out.size += nn;
}
putl(blocks+i*OffsetSize, block);
}
putl(blocks+i*OffsetSize, out.size);
outwrite(blocks, (nblock+1)*OffsetSize, offset);
setsd(sd, dir, dir->length, offset);
close(fd);
free(buf);
free(cbuf);
free(blocks);
}
void
sacdir(char *name, Dir *dir, SacDir *sd)
{
Dir *dirs, *p;
int i, n, nn, per;
SacDir *sds;
int ndir, fd, nblock;
long offset, block;
uchar *blocks, *cbuf;
char file[512];
fd = open(name, OREAD);
if(fd < 0)
sysfatal("could not open directory: %s: %r", name);
ndir = dirreadall(fd, &dirs);
if(ndir < 0)
sysfatal("could not read directory: %s: %r", name);
close(fd);
per = blocksize/sizeof(SacDir);
nblock = (ndir+per-1)/per;
sds = emalloc(nblock*per*sizeof(SacDir));
p = dirs;
for(i=0; i<ndir; i++,p++) {
sprint(file, "%s/%s", name, p->name);
if(p->mode & DMDIR)
sacdir(file, p, sds+i);
else
sacfile(file, p, sds+i);
}
free(dirs);
blocks = emalloc((nblock+1)*OffsetSize);
offset = out.size;
out.size += (nblock+1)*OffsetSize;
n = per*sizeof(SacDir);
cbuf = emalloc(n);
for(i=0; i<nblock; i++) {
block = out.size;
if(n > (ndir-i*per)*sizeof(SacDir))
n = (ndir-i*per)*sizeof(SacDir);
nn = sac(cbuf, (uchar*)(sds+i*per), n);
if(nn < 0 || uflag) {
outwrite(sds+i*per, n, out.size);
out.size += n;
} else {
block = -block;
outwrite(cbuf, nn, out.size);
out.size += nn;
}
putl(blocks+i*OffsetSize, block);
}
free(cbuf);
putl(blocks+i*OffsetSize, out.size);
outwrite(blocks, (nblock+1)*OffsetSize, offset);
setsd(sd, dir, ndir, offset);
free(sds);
free(blocks);
}
int
seen(Dir *dir)
{
Dir *dp;
int i;
Cache *c;
c = &cache[dir->qid.path&(NCACHE-1)];
dp = c->cache;
for(i=0; i<c->n; i++, dp++)
if(dir->qid.path == dp->qid.path &&
dir->type == dp->type &&
dir->dev == dp->dev)
return 1;
if(c->n == c->max){
c->cache = realloc(c->cache, (c->max+=20)*sizeof(Dir));
if(cache == 0)
sysfatal("malloc failure");
}
c->cache[c->n++] = *dir;
return 0;
}
void
outwrite(void *buf, int n, long offset)
{
if(seek(out.fd, offset, 0) < 0)
sysfatal("seek failed: %r");
if(write(out.fd, buf, n) < n)
sysfatal("write failed: %r");
}
void
putl(void *p, uint v)
{
uchar *a;
a = p;
a[0] = v>>24;
a[1] = v>>16;
a[2] = v>>8;
a[3] = v;
}
void *
emalloc(int size)
{
void *p;
p = malloc(size);
if(p == nil)
sysfatal("malloc failed");
memset(p, 0, size);
return p;
}