plan9fox/sys/src/cmd/git/ols.c
Ori Bernstein 1ee1bfaa8c git: got git?
Add a snapshot of git9 to 9front.
2021-05-16 18:49:45 -07:00

171 lines
2.8 KiB
C

#include <u.h>
#include <libc.h>
#include <ctype.h>
#include "git.h"
enum {
Sinit,
Siter,
};
static int
crackidx(char *path, int *np)
{
int fd;
char buf[4];
if((fd = open(path, OREAD)) == -1)
return -1;
if(seek(fd, 8 + 255*4, 0) == -1)
return -1;
if(readn(fd, buf, sizeof(buf)) != sizeof(buf))
return -1;
*np = GETBE32(buf);
return fd;
}
int
isloosedir(char *s)
{
return strlen(s) == 2 && isxdigit(s[0]) && isxdigit(s[1]);
}
int
endswith(char *n, char *s)
{
int nn, ns;
nn = strlen(n);
ns = strlen(s);
return nn > ns && strcmp(n + nn - ns, s) == 0;
}
int
olsreadpacked(Objlist *ols, Hash *h)
{
char *p;
int i, j;
i = ols->packidx;
j = ols->entidx;
if(ols->state == Siter)
goto step;
for(i = 0; i < ols->npack; i++){
if(!endswith(ols->pack[i].name, ".idx"))
continue;
if((p = smprint(".git/objects/pack/%s", ols->pack[i].name)) == nil)
sysfatal("smprint: %r");
ols->fd = crackidx(p, &ols->nent);
free(p);
if(ols->fd == -1)
continue;
j = 0;
while(j < ols->nent){
if(readn(ols->fd, h->h, sizeof(h->h)) != sizeof(h->h))
continue;
ols->state = Siter;
ols->packidx = i;
ols->entidx = j;
return 0;
step:
j++;
}
close(ols->fd);
}
ols->state = Sinit;
return -1;
}
int
olsreadloose(Objlist *ols, Hash *h)
{
char buf[64], *p;
int i, j, n;
i = ols->topidx;
j = ols->looseidx;
if(ols->state == Siter)
goto step;
for(i = 0; i < ols->ntop; i++){
if(!isloosedir(ols->top[i].name))
continue;
if((p = smprint(".git/objects/%s", ols->top[i].name)) == nil)
sysfatal("smprint: %r");
ols->fd = open(p, OREAD);
free(p);
if(ols->fd == -1)
continue;
while((ols->nloose = dirread(ols->fd, &ols->loose)) > 0){
j = 0;
while(j < ols->nloose){
n = snprint(buf, sizeof(buf), "%s%s", ols->top[i].name, ols->loose[j].name);
if(n >= sizeof(buf))
goto step;
if(hparse(h, buf) == -1)
goto step;
ols->state = Siter;
ols->topidx = i;
ols->looseidx = j;
return 0;
step:
j++;
}
free(ols->loose);
ols->loose = nil;
}
close(ols->fd);
ols->fd = -1;
}
ols->state = Sinit;
return -1;
}
Objlist*
mkols(void)
{
Objlist *ols;
ols = emalloc(sizeof(Objlist));
if((ols->ntop = slurpdir(".git/objects", &ols->top)) == -1)
sysfatal("read top level: %r");
if((ols->npack = slurpdir(".git/objects/pack", &ols->pack)) == -1)
ols->pack = nil;
ols->fd = -1;
return ols;
}
void
olsfree(Objlist *ols)
{
if(ols == nil)
return;
if(ols->fd != -1)
close(ols->fd);
free(ols->top);
free(ols->loose);
free(ols->pack);
free(ols);
}
int
olsnext(Objlist *ols, Hash *h)
{
if(ols->stage == 0){
if(olsreadloose(ols, h) != -1){
ols->idx++;
return 0;
}
ols->stage++;
}
if(ols->stage == 1){
if(olsreadpacked(ols, h) != -1){
ols->idx++;
return 0;
}
ols->stage++;
}
return -1;
}