ref: 440ccbc06007422f04943378260f250f9efa5331
dir: /sys/src/cmd/git/save.c/
#include <u.h>
#include <libc.h>
#include "git.h"
typedef struct Objbuf Objbuf;
struct Objbuf {
int off;
char *hdr;
int nhdr;
char *dat;
int ndat;
};
enum {
Maxparents = 16,
};
char *authorname;
char *authoremail;
char *committername;
char *committeremail;
char *commitmsg;
Hash parents[Maxparents];
int nparents;
int
gitmode(Dirent *e)
{
if(e->islink)
return 0120000;
else if(e->ismod)
return 0160000;
else if(e->mode & DMDIR)
return 0040000;
else if(e->mode & 0111)
return 0100755;
else
return 0100644;
}
int
entcmp(void *pa, void *pb)
{
char abuf[256], bbuf[256], *ae, *be;
Dirent *a, *b;
a = pa;
b = pb;
/*
* If the files have the same name, they're equal.
* Otherwise, If they're trees, they sort as thoug
* there was a trailing slash.
*
* Wat.
*/
if(strcmp(a->name, b->name) == 0)
return 0;
ae = seprint(abuf, abuf + sizeof(abuf) - 1, a->name);
be = seprint(bbuf, bbuf + sizeof(bbuf) - 1, b->name);
if(a->mode & DMDIR)
*ae = '/';
if(b->mode & DMDIR)
*be = '/';
return strcmp(abuf, bbuf);
}
static int
bwrite(void *p, void *buf, int nbuf)
{
return Bwrite(p, buf, nbuf);
}
static int
objbytes(void *p, void *buf, int nbuf)
{
Objbuf *b;
int r, n, o;
char *s;
b = p;
n = 0;
if(b->off < b->nhdr){
r = b->nhdr - b->off;
r = (nbuf < r) ? nbuf : r;
memcpy(buf, b->hdr, r);
b->off += r;
nbuf -= r;
n += r;
}
if(b->off < b->ndat + b->nhdr){
s = buf;
o = b->off - b->nhdr;
r = b->ndat - o;
r = (nbuf < r) ? nbuf : r;
memcpy(s + n, b->dat + o, r);
b->off += r;
n += r;
}
return n;
}
void
writeobj(Hash *h, char *hdr, int nhdr, char *dat, int ndat)
{
Objbuf b = {.off=0, .hdr=hdr, .nhdr=nhdr, .dat=dat, .ndat=ndat};
char s[64], o[256];
SHA1state *st;
Biobuf *f;
int fd;
st = sha1((uchar*)hdr, nhdr, nil, nil);
st = sha1((uchar*)dat, ndat, nil, st);
sha1(nil, 0, h->h, st);
snprint(s, sizeof(s), "%H", *h);
fd = create(".git/objects", OREAD, DMDIR|0755);
close(fd);
snprint(o, sizeof(o), ".git/objects/%c%c", s[0], s[1]);
fd = create(o, OREAD, DMDIR | 0755);
close(fd);
snprint(o, sizeof(o), ".git/objects/%c%c/%s", s[0], s[1], s + 2);
if(readobject(*h) == nil){
if((f = Bopen(o, OWRITE)) == nil)
sysfatal("could not open %s: %r", o);
if(deflatezlib(f, bwrite, &b, objbytes, 9, 0) == -1)
sysfatal("could not write %s: %r", o);
Bterm(f);
}
}
int
writetree(Dirent *ent, int nent, Hash *h)
{
char *t, *txt, *etxt, hdr[128];
int nhdr, n;
Dirent *d, *p;
t = emalloc((16+256+20) * nent);
txt = t;
etxt = t + (16+256+20) * nent;
/* sqeeze out deleted entries */
n = 0;
p = ent;
for(d = ent; d != ent + nent; d++)
if(d->name)
p[n++] = *d;
nent = n;
qsort(ent, nent, sizeof(Dirent), entcmp);
for(d = ent; d != ent + nent; d++){
if(strlen(d->name) >= 255)
sysfatal("overly long filename: %s", d->name);
t = seprint(t, etxt, "%o %s", gitmode(d), d->name) + 1;
memcpy(t, d->h.h, sizeof(d->h.h));
t += sizeof(d->h.h);
}
nhdr = snprint(hdr, sizeof(hdr), "%T %lld", GTree, (vlong)(t - txt)) + 1;
writeobj(h, hdr, nhdr, txt, t - txt);
free(txt);
return nent;
}
void
blobify(Dir *d, char *path, int *mode, Hash *bh)
{
char h[64], *buf;
int f, nh;
if((d->mode & DMDIR) != 0)
sysfatal("not file: %s", path);
*mode = d->mode;
nh = snprint(h, sizeof(h), "%T %lld", GBlob, d->length) + 1;
if((f = open(path, OREAD)) == -1)
sysfatal("could not open %s: %r", path);
buf = emalloc(d->length);
if(readn(f, buf, d->length) != d->length)
sysfatal("could not read blob %s: %r", path);
writeobj(bh, h, nh, buf, d->length);
free(buf);
close(f);
}
int
tracked(char *path)
{
char ipath[256];
Dir *d;
/* Explicitly removed. */
snprint(ipath, sizeof(ipath), ".git/index9/removed/%s", path);
if(strstr(cleanname(ipath), ".git/index9/removed") != ipath)
sysfatal("path %s leaves index", ipath);
d = dirstat(ipath);
if(d != nil && d->qid.type != QTDIR){
free(d);
return 0;
}
/* Explicitly added. */
snprint(ipath, sizeof(ipath), ".git/index9/tracked/%s", path);
if(strstr(cleanname(ipath), ".git/index9/tracked") != ipath)
sysfatal("path %s leaves index", ipath);
if(access(ipath, AEXIST) == 0)
return 1;
return 0;
}
int
pathelt(char *buf, int nbuf, char *p, int *isdir)
{
char *b;
b = buf;
if(*p == '/')
p++;
while(*p && *p != '/' && b != buf + nbuf)
*b++ = *p++;
*b = '\0';
*isdir = (*p == '/');
return b - buf;
}
Dirent*
dirent(Dirent **ent, int *nent, char *name)
{
Dirent *d;
for(d = *ent; d != *ent + *nent; d++)
if(d->name && strcmp(d->name, name) == 0)
return d;
*nent += 1;
*ent = erealloc(*ent, *nent * sizeof(Dirent));
d = *ent + (*nent - 1);
memset(d, 0, sizeof(*d));
d->name = estrdup(name);
return d;
}
int
treeify(Object *t, char **path, char **epath, int off, Hash *h)
{
int r, n, ne, nsub, nent, isdir;
char **p, **ep;
char elt[256];
Object **sub;
Dirent *e, *ent;
Dir *d;
r = -1;
nsub = 0;
nent = t->tree->nent;
ent = eamalloc(nent, sizeof(*ent));
sub = eamalloc((epath - path), sizeof(Object*));
memcpy(ent, t->tree->ent, nent*sizeof(*ent));
for(p = path; p != epath; p = ep){
ne = pathelt(elt, sizeof(elt), *p + off, &isdir);
for(ep = p; ep != epath; ep++){
if(strncmp(elt, *ep + off, ne) != 0)
break;
if((*ep)[off+ne] != '\0' && (*ep)[off+ne] != '/')
break;
}
e = dirent(&ent, &nent, elt);
if(e->islink)
sysfatal("symlinks may not be modified: %s", *path);
if(e->ismod)
sysfatal("submodules may not be modified: %s", *path);
if(isdir){
e->mode = DMDIR | 0755;
sub[nsub] = readobject(e->h);
if(sub[nsub] == nil || sub[nsub]->type != GTree)
sub[nsub] = emptydir();
/*
* if after processing deletions, a tree is empty,
* mark it for removal from the parent.
*
* Note, it is still written to the object store,
* but this is fine -- and ensures that an empty
* repository will continue to work.
*/
n = treeify(sub[nsub], p, ep, off + ne + 1, &e->h);
if(n == 0)
e->name = nil;
else if(n == -1)
goto err;
}else{
d = dirstat(*p);
if(d != nil && tracked(*p))
blobify(d, *p, &e->mode, &e->h);
else
e->name = nil;
free(d);
}
}
if(nent == 0){
werrstr("%.*s: empty directory", off, *path);
goto err;
}
r = writetree(ent, nent, h);
err:
free(sub);
return r;
}
void
mkcommit(Hash *c, vlong date, Hash tree)
{
char *s, h[64];
int ns, nh, i;
Fmt f;
fmtstrinit(&f);
fmtprint(&f, "tree %H\n", tree);
for(i = 0; i < nparents; i++)
fmtprint(&f, "parent %H\n", parents[i]);
fmtprint(&f, "author %s <%s> %lld +0000\n", authorname, authoremail, date);
fmtprint(&f, "committer %s <%s> %lld +0000\n", committername, committeremail, date);
fmtprint(&f, "\n");
fmtprint(&f, "%s", commitmsg);
s = fmtstrflush(&f);
ns = strlen(s);
nh = snprint(h, sizeof(h), "%T %d", GCommit, ns) + 1;
writeobj(c, h, nh, s, ns);
free(s);
}
Object*
findroot(void)
{
Object *t, *c;
Hash h;
if(resolveref(&h, "HEAD") == -1)
return emptydir();
if((c = readobject(h)) == nil || c->type != GCommit)
sysfatal("could not read HEAD %H", h);
if((t = readobject(c->commit->tree)) == nil)
sysfatal("could not read tree for commit %H", h);
return t;
}
void
usage(void)
{
fprint(2, "usage: %s -n name -e email -m message -d date [files...]\n", argv0);
exits("usage");
}
void
main(int argc, char **argv)
{
Hash th, ch;
char *dstr, cwd[1024];
int i, r, ncwd;
vlong date;
Object *t;
gitinit();
if(access(".git", AEXIST) != 0)
sysfatal("could not find git repo: %r");
if(getwd(cwd, sizeof(cwd)) == nil)
sysfatal("getcwd: %r");
dstr = nil;
date = time(nil);
ncwd = strlen(cwd);
ARGBEGIN{
case 'm':
commitmsg = EARGF(usage());
break;
case 'n':
authorname = EARGF(usage());
break;
case 'e':
authoremail = EARGF(usage());
break;
case 'N':
committername = EARGF(usage());
break;
case 'E':
committeremail = EARGF(usage());
break;
case 'd':
dstr = EARGF(usage());
break;
case 'p':
if(nparents >= Maxparents)
sysfatal("too many parents");
if(resolveref(&parents[nparents++], EARGF(usage())) == -1)
sysfatal("invalid parent: %r");
break;
default:
usage();
break;
}ARGEND;
if(commitmsg == nil)
sysfatal("missing message");
if(authorname == nil)
sysfatal("missing name");
if(authoremail == nil)
sysfatal("missing email");
if((committername == nil) != (committeremail == nil))
sysfatal("partially specified committer");
if(committername == nil && committeremail == nil){
committername = authorname;
committeremail = authoremail;
}
if(dstr){
date=strtoll(dstr, &dstr, 10);
if(strlen(dstr) != 0)
sysfatal("could not parse date %s", dstr);
}
for(i = 0; i < argc; i++){
cleanname(argv[i]);
if(*argv[i] == '/' && strncmp(argv[i], cwd, ncwd) == 0)
argv[i] += ncwd;
while(*argv[i] == '/')
argv[i]++;
}
t = findroot();
r = treeify(t, argv, argv + argc, 0, &th);
if(r == -1)
sysfatal("could not commit: %r\n");
mkcommit(&ch, date, th);
print("%H\n", ch);
exits(nil);
}