ref: e4c57f3ea9cb88c50b47ca3c99b2adf85ab1a984
dir: /sys/src/cmd/git/get.c/
#include <u.h>
#include <libc.h>
#include "git.h"
enum{
Spintime = 10,
};
char *fetchbranch;
char *upstream = "origin";
int listonly;
/*
* Checks the rules for a refname at
* git/Documentation/protocol-common.txt
*/
int
okrefname(char *s)
{
if(strcmp(s, "HEAD") == 0)
return 1;
if(strncmp(s, "refs/", 5) == 0)
return okref(s);
return 0;
}
int
resolveremote(Hash *h, char *ref)
{
char buf[128], *s;
int r, f;
ref = strip(ref);
if((r = hparse(h, ref)) != -1)
return r;
/* Slightly special handling: translate remote refs to local ones. */
if(strcmp(ref, "HEAD") == 0){
snprint(buf, sizeof(buf), ".git/HEAD");
}else if(strstr(ref, "refs/heads") == ref){
ref += strlen("refs/heads");
snprint(buf, sizeof(buf), ".git/refs/remotes/%s/%s", upstream, ref);
}else if(strstr(ref, "refs/tags") == ref){
ref += strlen("refs/tags");
snprint(buf, sizeof(buf), ".git/refs/tags/%s/%s", upstream, ref);
}else{
return -1;
}
r = -1;
s = strip(buf);
if((f = open(s, OREAD)) == -1)
return -1;
if(readn(f, buf, sizeof(buf)) >= 40)
r = hparse(h, buf);
close(f);
if(r == -1 && strstr(buf, "ref:") == buf)
return resolveremote(h, buf + strlen("ref:"));
return r;
}
int
rename(char *pack, char *idx, Hash h)
{
char name[128];
Dir st;
nulldir(&st);
st.name = name;
snprint(name, sizeof(name), "%H.pack", h);
if(access(name, AEXIST) == 0)
fprint(2, "warning, pack %s already fetched\n", name);
else if(dirwstat(pack, &st) == -1)
return -1;
snprint(name, sizeof(name), "%H.idx", h);
if(access(name, AEXIST) == 0)
fprint(2, "warning, pack %s already indexed\n", name);
else if(dirwstat(idx, &st) == -1)
return -1;
return 0;
}
int
checkhash(int fd, vlong sz, Hash *hcomp)
{
DigestState *st;
Hash hexpect;
char buf[Pktmax];
vlong n, r;
int nr;
if(sz < 28){
werrstr("undersize packfile");
return -1;
}
st = nil;
n = 0;
while(n != sz - 20){
nr = sizeof(buf);
if(sz - n - 20 < sizeof(buf))
nr = sz - n - 20;
r = readn(fd, buf, nr);
if(r != nr)
return -1;
st = sha1((uchar*)buf, nr, nil, st);
n += r;
}
sha1(nil, 0, hcomp->h, st);
if(readn(fd, hexpect.h, sizeof(hexpect.h)) != sizeof(hexpect.h))
sysfatal("truncated packfile");
if(!hasheq(hcomp, &hexpect)){
werrstr("bad hash: %H != %H", *hcomp, hexpect);
return -1;
}
return 0;
}
int
mkoutpath(char *path)
{
char s[128];
char *p;
int fd;
snprint(s, sizeof(s), "%s", path);
for(p=strchr(s+1, '/'); p; p=strchr(p+1, '/')){
*p = 0;
if(access(s, AEXIST) != 0){
fd = create(s, OREAD, DMDIR | 0775);
if(fd == -1)
return -1;
close(fd);
}
*p = '/';
}
return 0;
}
int
branchmatch(char *br, char *pat)
{
char name[128];
if(strstr(pat, "refs/heads") == pat)
snprint(name, sizeof(name), "%s", pat);
else if(strstr(pat, "heads"))
snprint(name, sizeof(name), "refs/%s", pat);
else
snprint(name, sizeof(name), "refs/heads/%s", pat);
return strcmp(br, name) == 0;
}
void
fail(char *pack, char *idx, char *msg, ...)
{
char buf[ERRMAX];
va_list ap;
va_start(ap, msg);
snprint(buf, sizeof(buf), msg, ap);
va_end(ap);
remove(pack);
remove(idx);
fprint(2, "%s", buf);
exits(buf);
}
void
enqueueparent(Objq *q, Object *o)
{
Object *p;
int i;
if(o->type != GCommit)
return;
for(i = 0; i < o->commit->nparent; i++){
if((p = readobject(o->commit->parent[i])) == nil)
continue;
qput(q, p, 0);
unref(p);
}
}
void
fmtcaps(Conn *c, char *caps, int ncaps)
{
char *p, *e;
p = caps;
e = caps + ncaps;
*p = 0;
if(c->multiack)
p = seprint(p, e, " multi_ack");
if(c->sideband64k)
p = seprint(p, e, " side-band-64k");
else if(c->sideband)
p = seprint(p, e, " side-band");
assert(p != e);
}
int
sbread(Conn *c, char *buf, int nbuf, char **pbuf)
{
int n;
assert(nbuf >= Pktmax);
if(!c->sideband && !c->sideband64k){
*pbuf = buf;
return readn(c->rfd, buf, nbuf);
}else{
*pbuf = buf+1;
while(1){
n = readpkt(c, buf, nbuf);
if(n <= 0)
return n;
else if(buf[0] == 1 && n > 1)
return n - 1;
else if(buf[0] == 3)
fprint(2, "error: %s\n", buf+1);
else if(buf[0] < 1 || buf[0] > 3)
fprint(2, "unknown sideband(%c:%d) data: %s\n", buf[0], buf[0], buf+1);
}
}
}
int
fetchpack(Conn *c)
{
Rune spinner[] = {' ', L'🚅', L'🚃', L'🚃', L'🚃', L'💨', ' ', ' ', L'🏃', ' '};
char buf[Pktmax], caps[512], *sp[3], *ep;
char *packtmp, *idxtmp, **ref, *rp;
Hash h, *have, *want;
int nref, refsz, first, nsent;
int i, j, l, n, spin, req, pfd;
vlong packsz;
Objset hadobj;
Object *o;
Objq haveq;
Qelt e;
nref = 0;
refsz = 16;
first = 1;
have = eamalloc(refsz, sizeof(have[0]));
want = eamalloc(refsz, sizeof(want[0]));
ref = eamalloc(refsz, sizeof(ref[0]));
while(1){
n = readpkt(c, buf, sizeof(buf));
if(n == -1)
return -1;
if(n == 0)
break;
if(first && n > strlen(buf)){
parsecaps(buf + strlen(buf) + 1, c);
if(c->symfrom[0] != 0)
print("symref %s %s\n", c->symfrom, c->symto);
}
first = 0;
getfields(buf, sp, nelem(sp), 1, " \t\n\r");
if(strstr(sp[1], "^{}"))
continue;
if(!okrefname(sp[1]))
sysfatal("remote side sent invalid ref: %s", sp[1]);
if(fetchbranch && !branchmatch(sp[1], fetchbranch))
continue;
if(refsz == nref + 1){
refsz *= 2;
have = earealloc(have, refsz, sizeof(have[0]));
want = earealloc(want, refsz, sizeof(want[0]));
ref = earealloc(ref, refsz, sizeof(ref[0]));
}
if(hparse(&want[nref], sp[0]) == -1)
sysfatal("invalid hash %s", sp[0]);
if (resolveremote(&have[nref], sp[1]) == -1)
memset(&have[nref], 0, sizeof(have[nref]));
ref[nref] = estrdup(sp[1]);
nref++;
}
if(listonly){
flushpkt(c);
goto showrefs;
}
if(writephase(c) == -1)
sysfatal("write: %r");
req = 0;
fmtcaps(c, caps, sizeof(caps));
for(i = 0; i < nref; i++){
if(hasheq(&have[i], &want[i]))
continue;
for(j = 0; j < i; j++)
if(hasheq(&want[i], &want[j]))
goto Next;
if((o = readobject(want[i])) != nil){
unref(o);
continue;
}
if(fmtpkt(c, "want %H%s\n", want[i], caps) == -1)
sysfatal("could not send want for %H", want[i]);
caps[0] = 0;
req = 1;
Next: continue;
}
flushpkt(c);
nsent = 0;
qinit(&haveq);
osinit(&hadobj);
/*
* We know we have these objects, and we want to make sure that
* they end up at the front of the queue. Send the 'have lines'
* first, and then enqueue their parents for a second round of
* sends.
*/
for(i = 0; i < nref; i++){
if(hasheq(&have[i], &Zhash) || oshas(&hadobj, have[i]))
continue;
if((o = readobject(have[i])) == nil)
sysfatal("missing exected object: %H", have[i]);
if(fmtpkt(c, "have %H", o->hash) == -1)
sysfatal("write: %r");
enqueueparent(&haveq, o);
osadd(&hadobj, o);
unref(o);
nsent++;
}
/*
* While we could short circuit this and check if upstream has
* acked our objects, for the first 256 haves, this is simple
* enough.
*
* Also, doing multiple rounds of reference discovery breaks
* when using smart http.
*/
while(req && qpop(&haveq, &e) && nsent < 256){
if(oshas(&hadobj, e.o->hash))
continue;
if((o = readobject(e.o->hash)) == nil)
sysfatal("missing object we should have: %H", e.o->hash);
if(fmtpkt(c, "have %H", o->hash) == -1)
sysfatal("write: %r");
enqueueparent(&haveq, o);
osadd(&hadobj, o);
unref(o);
nsent++;
}
osclear(&hadobj);
qclear(&haveq);
if(!req)
flushpkt(c);
if(fmtpkt(c, "done\n") == -1)
sysfatal("write: %r");
if(!req)
goto showrefs;
if(readphase(c) == -1)
sysfatal("read: %r");
if((packtmp = smprint(".git/objects/pack/fetch.%d.pack", getpid())) == nil)
sysfatal("smprint: %r");
if((idxtmp = smprint(".git/objects/pack/fetch.%d.idx", getpid())) == nil)
sysfatal("smprint: %r");
if(mkoutpath(packtmp) == -1)
sysfatal("could not create %s: %r", packtmp);
if((pfd = create(packtmp, ORDWR, 0664)) == -1)
sysfatal("could not create %s: %r", packtmp);
fprint(2, "fetching... ");
packsz = 0;
if(c->multiack){
for(i = 0; i < nsent; i++){
if(readpkt(c, buf, sizeof(buf)) == -1)
sysfatal("read: %r");
if(strncmp(buf, "NAK\n", 4) == 0)
break;
if(strncmp(buf, "ACK ", 4) != 0)
sysfatal("bad response: '%s'", buf);
}
}
if(readpkt(c, buf, sizeof(buf)) == -1)
sysfatal("read: %r");
if(!c->sideband && !c->sideband64k && !c->multiack){
/*
* Work around torvalds git bug: we get duplicate have lines
* somtimes, even though the protocol is supposed to start the
* pack file immediately.
*
* Skip ahead until we read 'PACK' off the wire
*/
while(1){
if(readn(c->rfd, buf, 4) != 4)
sysfatal("fetch packfile: short read");
if(strncmp(buf, "PACK", 4) == 0)
break;
buf[4] = 0;
l = strtol(buf, &ep, 16);
if(ep != buf + 4)
sysfatal("fetch packfile: junk pktline");
if(readn(c->rfd, buf, l-4) != l-4)
sysfatal("fetch packfile: short read");
}
if(write(pfd, "PACK", 4) != 4)
sysfatal("write pack header: %r");
packsz = 4;
}
spin = 0;
while(1){
n = sbread(c, buf, sizeof buf, &rp);
if(n == 0)
break;
if(n == -1 || write(pfd, rp, n) != n)
sysfatal("fetch packfile: %r");
if(interactive && spin++ % (Spintime * nelem(spinner)) == 0){
i = spin / (Spintime * nelem(spinner)) % nelem(spinner);
j = i + 1 == nelem(spinner) ? 0 : i + 1;
fprint(2, "\b\b%C%C", spinner[i], spinner[j]);
}
packsz += n;
}
if(interactive && spin > 0)
fprint(2, "\b\b");
fprint(2, "\n");
closeconn(c);
if(seek(pfd, 0, 0) == -1)
fail(packtmp, idxtmp, "packfile seek: %r");
if(checkhash(pfd, packsz, &h) == -1)
fail(packtmp, idxtmp, "corrupt packfile: %r");
close(pfd);
if(indexpack(packtmp, idxtmp, h) == -1)
fail(packtmp, idxtmp, "could not index fetched pack: %r");
if(rename(packtmp, idxtmp, h) == -1)
fail(packtmp, idxtmp, "could not rename indexed pack: %r");
showrefs:
for(i = 0; i < nref; i++){
print("remote %s %H local %H\n", ref[i], want[i], have[i]);
free(ref[i]);
}
free(ref);
free(want);
free(have);
return 0;
}
void
usage(void)
{
fprint(2, "usage: %s [-dl] [-b br] [-u upstream] remote\n", argv0);
fprint(2, "\t-b br: only fetch matching branch 'br'\n");
fprint(2, "remote: fetch from this repository\n");
exits("usage");
}
void
main(int argc, char **argv)
{
Conn c;
ARGBEGIN{
case 'b': fetchbranch=EARGF(usage()); break;
case 'u': upstream=EARGF(usage()); break;
case 'd': chattygit++; break;
case 'l': listonly++; break;
default: usage(); break;
}ARGEND;
gitinit();
if(argc != 1)
usage();
if(gitconnect(&c, argv[0], "upload") == -1)
sysfatal("could not dial %s: %r", argv[0]);
if(fetchpack(&c) == -1)
sysfatal("fetch failed: %r");
closeconn(&c);
exits(nil);
}