ref: 733c5d6645b133b60d304c38fcb1398f94d0618c
dir: /sys/src/cmd/git/get.c/
#include <u.h> #include <libc.h> #include "git.h" char *fetchbranch; char *upstream = "origin"; int listonly; 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; } char * matchcap(char *s, char *cap, int full) { if(strncmp(s, cap, strlen(cap)) == 0) if(!full || strlen(s) == strlen(cap)) return s + strlen(cap); return nil; } void handlecaps(char *caps) { char *p, *n, *c, *r; for(p = caps; p != nil; p = n){ n = strchr(p, ' '); if(n != nil) *n++ = 0; if((c = matchcap(p, "symref=", 0)) != nil){ if((r = strchr(c, ':')) != nil){ *r++ = '\0'; print("symref %s %s\n", c, r); } } } } 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); } } int fetchpack(Conn *c) { char buf[Pktmax], *sp[3], *ep; char *packtmp, *idxtmp, **ref, *caps; Hash h, *have, *want; int nref, refsz, first, nsent; int i, l, n, 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)) handlecaps(buf + strlen(buf) + 1); first = 0; getfields(buf, sp, nelem(sp), 1, " \t\n\r"); if(strstr(sp[1], "^{}")) continue; 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; caps = " multi_ack"; for(i = 0; i < nref; i++){ if(hasheq(&have[i], &want[i])) continue; 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 = ""; req = 1; } 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); } /* * 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", have[i]); 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((n = readpkt(c, buf, sizeof(buf))) == -1) sysfatal("read: %r"); buf[n] = 0; 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...\n"); /* * 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"); buf[4] = 0; if(strncmp(buf, "PACK", 4) == 0) break; 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; while(1){ n = read(c->rfd, buf, sizeof buf); if(n == 0) break; if(n == -1 || write(pfd, buf, n) != n) sysfatal("fetch packfile: %r"); packsz += 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); }