ref: ec628c4dfbf62891e311567034936a0b2cb584c4
dir: /sys/src/cmd/git/fs.c/
#include <u.h> #include <libc.h> #include <ctype.h> #include <fcall.h> #include <thread.h> #include <9p.h> #include "git.h" enum { Qroot, Qhead, Qbranch, Qcommit, Qmsg, Qparent, Qtree, Qcdata, Qhash, Qauthor, Qcommitter, Qobject, Qctl, Qmax, Internal=1<<7, }; typedef struct Gitaux Gitaux; typedef struct Crumb Crumb; typedef struct Cache Cache; typedef struct Uqid Uqid; struct Crumb { char *name; Object *obj; Qid qid; int mode; vlong mtime; }; struct Gitaux { int ncrumb; Crumb *crumb; char *refpath; int qdir; /* For listing object dir */ Objlist *ols; Object *olslast; }; struct Uqid { vlong uqid; vlong ppath; vlong oid; int t; int idx; }; struct Cache { Uqid *cache; int n; int max; }; char *qroot[] = { "HEAD", "branch", "object", "ctl", }; #define Eperm "permission denied" #define Eexist "file does not exist" #define E2long "path too long" #define Enodir "not a directory" #define Erepo "unable to read repo" #define Eobject "invalid object" #define Egreg "wat" #define Ebadobj "invalid object" char gitdir[512]; char *username; char *groupname; char *mntpt = ".git/fs"; char **branches = nil; Cache uqidcache[512]; vlong nextqid = Qmax; static Object* walklink(Gitaux *, char *, int, int, int*); vlong qpath(Crumb *p, int idx, vlong id, vlong t) { int h, i; vlong pp; Cache *c; Uqid *u; pp = p ? p->qid.path : 0; h = (pp*333 + id*7 + t) & (nelem(uqidcache) - 1); c = &uqidcache[h]; u = c->cache; for(i=0; i <c->n ; i++){ if(u->ppath == pp && u->oid == id && u->t == t && u->idx == idx) return (u->uqid << 8) | t; u++; } if(c->n == c->max){ c->max += c->max/2 + 1; c->cache = erealloc(c->cache, c->max*sizeof(Uqid)); } nextqid++; c->cache[c->n] = (Uqid){nextqid, pp, id, t, idx}; c->n++; return (nextqid << 8) | t; } static Crumb* crumb(Gitaux *aux, int n) { if(n < aux->ncrumb) return &aux->crumb[aux->ncrumb - n - 1]; return nil; } static void popcrumb(Gitaux *aux) { Crumb *c; if(aux->ncrumb > 1){ c = crumb(aux, 0); free(c->name); unref(c->obj); aux->ncrumb--; } } static vlong branchid(Gitaux *aux, char *path) { int i; for(i = 0; branches[i]; i++) if(strcmp(path, branches[i]) == 0) goto found; branches = realloc(branches, sizeof(char *)*(i + 2)); branches[i] = estrdup(path); branches[i + 1] = nil; found: if(aux){ if(aux->refpath) free(aux->refpath); aux->refpath = estrdup(branches[i]); } return i; } static void obj2dir(Dir *d, Crumb *c, Object *o, char *name) { d->qid = c->qid; d->atime = c->mtime; d->mtime = c->mtime; d->mode = c->mode; d->name = estrdup9p(name); d->uid = estrdup9p(username); d->gid = estrdup9p(groupname); d->muid = estrdup9p(username); if(o->type == GBlob || o->type == GTag){ d->qid.type = 0; d->mode &= 0777; d->length = o->size; } } static int rootgen(int i, Dir *d, void *p) { Crumb *c; c = crumb(p, 0); if (i >= nelem(qroot)) return -1; d->mode = 0555 | DMDIR; d->name = estrdup9p(qroot[i]); d->qid.vers = 0; d->qid.type = strcmp(qroot[i], "ctl") == 0 ? 0 : QTDIR; d->qid.path = qpath(nil, i, i, Qroot); d->uid = estrdup9p(username); d->gid = estrdup9p(groupname); d->muid = estrdup9p(username); d->mtime = c->mtime; return 0; } static int branchgen(int i, Dir *d, void *p) { Gitaux *aux; Dir *refs; Crumb *c; int n; aux = p; c = crumb(aux, 0); refs = nil; d->qid.vers = 0; d->qid.type = QTDIR; d->qid.path = qpath(c, i, branchid(aux, aux->refpath), Qbranch | Internal); d->mode = 0555 | DMDIR; d->uid = estrdup9p(username); d->gid = estrdup9p(groupname); d->muid = estrdup9p(username); d->mtime = c->mtime; d->atime = c->mtime; if((n = slurpdir(aux->refpath, &refs)) < 0) return -1; if(i < n){ d->name = estrdup9p(refs[i].name); free(refs); return 0; }else{ free(refs); return -1; } } static int gtreegen(int i, Dir *d, void *p) { Object *o, *l, *e; Gitaux *aux; Crumb *c; int m; aux = p; c = crumb(aux, 0); e = c->obj; if(i >= e->tree->nent) return -1; m = e->tree->ent[i].mode; if(e->tree->ent[i].ismod) o = emptydir(); else if((o = readobject(e->tree->ent[i].h)) == nil) sysfatal("could not read object %H: %r", e->tree->ent[i].h); if(e->tree->ent[i].islink) if((l = walklink(aux, o->data, o->size, 0, &m)) != nil) o = l; d->qid.vers = 0; d->qid.type = o->type == GTree ? QTDIR : 0; d->qid.path = qpath(c, i, o->id, aux->qdir); d->mode = m; d->atime = c->mtime; d->mtime = c->mtime; d->uid = estrdup9p(username); d->gid = estrdup9p(groupname); d->muid = estrdup9p(username); d->name = estrdup9p(e->tree->ent[i].name); d->length = o->size; return 0; } static int gcommitgen(int i, Dir *d, void *p) { Object *o; Crumb *c; c = crumb(p, 0); o = c->obj; d->uid = estrdup9p(username); d->gid = estrdup9p(groupname); d->muid = estrdup9p(username); d->mode = 0444; d->atime = o->commit->ctime; d->mtime = o->commit->ctime; d->qid.type = 0; d->qid.vers = 0; switch(i){ case 0: d->mode = 0755 | DMDIR; d->name = estrdup9p("tree"); d->qid.type = QTDIR; d->qid.path = qpath(c, i, o->id, Qtree); break; case 1: d->name = estrdup9p("parent"); d->qid.path = qpath(c, i, o->id, Qparent); break; case 2: d->name = estrdup9p("msg"); d->qid.path = qpath(c, i, o->id, Qmsg); break; case 3: d->name = estrdup9p("hash"); d->qid.path = qpath(c, i, o->id, Qhash); break; case 4: d->name = estrdup9p("author"); d->qid.path = qpath(c, i, o->id, Qauthor); break; default: return -1; } return 0; } static int objgen(int i, Dir *d, void *p) { Gitaux *aux; Object *o; Crumb *c; char name[64]; Objlist *ols; Hash h; aux = p; c = crumb(aux, 0); if(!aux->ols) aux->ols = mkols(); ols = aux->ols; o = nil; /* We tried to sent it, but it didn't fit */ if(aux->olslast && ols->idx == i + 1){ snprint(name, sizeof(name), "%H", aux->olslast->hash); obj2dir(d, c, aux->olslast, name); return 0; } while(ols->idx <= i){ if(olsnext(ols, &h) == -1) return -1; if((o = readobject(h)) == nil){ fprint(2, "corrupt object %H\n", h); return -1; } } if(o != nil){ snprint(name, sizeof(name), "%H", o->hash); obj2dir(d, c, o, name); unref(aux->olslast); aux->olslast = ref(o); return 0; } return -1; } static void objread(Req *r, Gitaux *aux) { Object *o; o = crumb(aux, 0)->obj; switch(o->type){ case GBlob: readbuf(r, o->data, o->size); break; case GTag: readbuf(r, o->data, o->size); break; case GTree: dirread9p(r, gtreegen, aux); break; case GCommit: dirread9p(r, gcommitgen, aux); break; default: sysfatal("invalid object type %d", o->type); } } static void readcommitparent(Req *r, Object *o) { char *buf, *p, *e; int i, n; /* 40 bytes per hash, 1 per nl, 1 for terminator */ n = o->commit->nparent * (40 + 1) + 1; buf = emalloc(n); p = buf; e = buf + n; for (i = 0; i < o->commit->nparent; i++) p = seprint(p, e, "%H\n", o->commit->parent[i]); readbuf(r, buf, p - buf); free(buf); } static void gitattach(Req *r) { Gitaux *aux; Dir *d; if((d = dirstat(".git")) == nil) sysfatal("git/fs: %r"); if(getwd(gitdir, sizeof(gitdir)) == nil) sysfatal("getwd: %r"); aux = emalloc(sizeof(Gitaux)); aux->crumb = emalloc(sizeof(Crumb)); aux->crumb[0].qid = (Qid){Qroot, 0, QTDIR}; aux->crumb[0].obj = nil; aux->crumb[0].mode = DMDIR | 0555; aux->crumb[0].mtime = d->mtime; aux->crumb[0].name = estrdup("/"); aux->ncrumb = 1; r->ofcall.qid = (Qid){Qroot, 0, QTDIR}; r->fid->qid = r->ofcall.qid; r->fid->aux = aux; respond(r, nil); } static Object* walklink(Gitaux *aux, char *link, int nlink, int ndotdot, int *mode) { char *p, *e, *path; Object *o, *n; int i; path = emalloc(nlink + 1); memcpy(path, link, nlink); cleanname(path); o = crumb(aux, ndotdot)->obj; assert(o->type == GTree); for(p = path; *p; p = e){ n = nil; e = p + strcspn(p, "/"); if(*e == '/') *e++ = '\0'; /* * cleanname guarantees these show up at the start of the name, * which allows trimming them from the end of the trail of crumbs * instead of needing to keep track of full parentage. */ if(strcmp(p, "..") == 0) n = crumb(aux, ++ndotdot)->obj; else if(o->type == GTree) for(i = 0; i < o->tree->nent; i++) if(strcmp(o->tree->ent[i].name, p) == 0){ *mode = o->tree->ent[i].mode; n = readobject(o->tree->ent[i].h); break; } o = n; if(o == nil) break; } free(path); for(i = 0; o != nil && i < aux->ncrumb; i++) if(crumb(aux, i)->obj == o) return nil; return o; } static char * objwalk1(Qid *q, Object *o, Crumb *p, Crumb *c, char *name, vlong qdir, Gitaux *aux) { Object *w, *l; char *e; int i, m; w = nil; e = nil; if(!o) return Eexist; if(o->type == GTree){ q->type = 0; for(i = 0; i < o->tree->nent; i++){ if(strcmp(o->tree->ent[i].name, name) != 0) continue; m = o->tree->ent[i].mode; w = readobject(o->tree->ent[i].h); if(!w && o->tree->ent[i].ismod) w = emptydir(); if(w && o->tree->ent[i].islink) if((l = walklink(aux, w->data, w->size, 1, &m)) != nil) w = l; if(!w) return Ebadobj; q->type = (w->type == GTree) ? QTDIR : 0; q->path = qpath(c, i, w->id, qdir); c->mode = m; c->mode |= (w->type == GTree) ? DMDIR|0755 : 0644; c->obj = w; break; } if(!w) e = Eexist; }else if(o->type == GCommit){ q->type = 0; c->mtime = o->commit->mtime; c->mode = 0644; assert(qdir == Qcommit || qdir == Qobject || qdir == Qtree || qdir == Qhead || qdir == Qcommitter); if(strcmp(name, "msg") == 0) q->path = qpath(p, 0, o->id, Qmsg); else if(strcmp(name, "parent") == 0) q->path = qpath(p, 1, o->id, Qparent); else if(strcmp(name, "hash") == 0) q->path = qpath(p, 2, o->id, Qhash); else if(strcmp(name, "author") == 0) q->path = qpath(p, 3, o->id, Qauthor); else if(strcmp(name, "committer") == 0) q->path = qpath(p, 3, o->id, Qcommitter); else if(strcmp(name, "tree") == 0){ q->type = QTDIR; q->path = qpath(p, 4, o->id, Qtree); unref(c->obj); c->mode = DMDIR | 0755; c->obj = readobject(o->commit->tree); if(c->obj == nil) sysfatal("could not read object %H: %r", o->commit->tree); } else e = Eexist; }else if(o->type == GTag){ e = "tag walk unimplemented"; } return e; } static Object * readref(char *pathstr) { char buf[128], path[128], *p, *e; Hash h; int n, f; snprint(path, sizeof(path), "%s", pathstr); while(1){ if((f = open(path, OREAD)) == -1) return nil; if((n = readn(f, buf, sizeof(buf) - 1)) == -1) return nil; close(f); buf[n] = 0; if(strncmp(buf, "ref:", 4) != 0) break; p = buf + 4; while(isspace(*p)) p++; if((e = strchr(p, '\n')) != nil) *e = 0; snprint(path, sizeof(path), ".git/%s", p); } if(hparse(&h, buf) == -1) return nil; return readobject(h); } static char* gitwalk1(Fid *fid, char *name, Qid *q) { char path[128]; Gitaux *aux; Crumb *c, *o; char *e; Dir *d; Hash h; e = nil; aux = fid->aux; q->vers = 0; if(strcmp(name, "..") == 0){ popcrumb(aux); c = crumb(aux, 0); *q = c->qid; fid->qid = *q; return nil; } aux->crumb = realloc(aux->crumb, (aux->ncrumb + 1) * sizeof(Crumb)); aux->ncrumb++; c = crumb(aux, 0); o = crumb(aux, 1); memset(c, 0, sizeof(Crumb)); c->mode = o->mode; c->mtime = o->mtime; c->obj = o->obj ? ref(o->obj) : nil; switch(QDIR(&fid->qid)){ case Qroot: if(strcmp(name, "HEAD") == 0){ *q = (Qid){Qhead, 0, QTDIR}; c->mode = DMDIR | 0555; c->obj = readref(".git/HEAD"); }else if(strcmp(name, "object") == 0){ *q = (Qid){Qobject, 0, QTDIR}; c->mode = DMDIR | 0555; }else if(strcmp(name, "branch") == 0){ *q = (Qid){Qbranch, 0, QTDIR}; aux->refpath = estrdup(".git/refs/"); c->mode = DMDIR | 0555; }else if(strcmp(name, "ctl") == 0){ *q = (Qid){Qctl, 0, 0}; c->mode = 0644; }else{ e = Eexist; } break; case Qbranch: if(strcmp(aux->refpath, ".git/refs/heads") == 0 && strcmp(name, "HEAD") == 0) snprint(path, sizeof(path), ".git/HEAD"); else snprint(path, sizeof(path), "%s/%s", aux->refpath, name); q->type = QTDIR; d = dirstat(path); if(d && d->qid.type == QTDIR) q->path = qpath(o, Qbranch, branchid(aux, path), Qbranch); else if(d && (c->obj = readref(path)) != nil) q->path = qpath(o, Qbranch, c->obj->id, Qcommit); else e = Eexist; free(d); break; case Qobject: if(c->obj){ e = objwalk1(q, o->obj, o, c, name, Qobject, aux); }else{ if(hparse(&h, name) == -1) return Eobject; if((c->obj = readobject(h)) == nil) return Eobject; if(c->obj->type == GBlob || c->obj->type == GTag){ c->mode = 0644; q->type = 0; }else{ c->mode = DMDIR | 0755; q->type = QTDIR; } q->path = qpath(o, Qobject, c->obj->id, Qobject); q->vers = 0; } break; case Qhead: e = objwalk1(q, o->obj, o, c, name, Qhead, aux); break; case Qcommit: e = objwalk1(q, o->obj, o, c, name, Qcommit, aux); break; case Qtree: e = objwalk1(q, o->obj, o, c, name, Qtree, aux); break; case Qparent: case Qmsg: case Qcdata: case Qhash: case Qauthor: case Qcommitter: case Qctl: return Enodir; default: return Egreg; } c->name = estrdup(name); c->qid = *q; fid->qid = *q; return e; } static char* gitclone(Fid *o, Fid *n) { Gitaux *aux, *oaux; int i; oaux = o->aux; aux = emalloc(sizeof(Gitaux)); aux->ncrumb = oaux->ncrumb; aux->crumb = eamalloc(oaux->ncrumb, sizeof(Crumb)); for(i = 0; i < aux->ncrumb; i++){ aux->crumb[i] = oaux->crumb[i]; aux->crumb[i].name = estrdup(oaux->crumb[i].name); if(aux->crumb[i].obj) aux->crumb[i].obj = ref(oaux->crumb[i].obj); } if(oaux->refpath) aux->refpath = strdup(oaux->refpath); aux->qdir = oaux->qdir; n->aux = aux; return nil; } static void gitdestroyfid(Fid *f) { Gitaux *aux; int i; if((aux = f->aux) == nil) return; for(i = 0; i < aux->ncrumb; i++){ if(aux->crumb[i].obj) unref(aux->crumb[i].obj); free(aux->crumb[i].name); } olsfree(aux->ols); free(aux->refpath); free(aux->crumb); free(aux); } static char * readctl(Req *r) { char data[1024], ref[512], *s, *e; int fd, n; if((fd = open(".git/HEAD", OREAD)) == -1) return Erepo; /* empty HEAD is invalid */ if((n = readn(fd, ref, sizeof(ref) - 1)) <= 0) return Erepo; close(fd); s = ref; ref[n] = 0; if(strncmp(s, "ref:", 4) == 0) s += 4; while(*s == ' ' || *s == '\t') s++; if((e = strchr(s, '\n')) != nil) *e = 0; if(strstr(s, "refs/") == s) s += strlen("refs/"); snprint(data, sizeof(data), "branch %s\nrepo %s\n", s, gitdir); readstr(r, data); return nil; } static void gitread(Req *r) { char buf[256], *e; Gitaux *aux; Object *o; Qid *q; aux = r->fid->aux; q = &r->fid->qid; o = crumb(aux, 0)->obj; e = nil; switch(QDIR(q)){ case Qroot: dirread9p(r, rootgen, aux); break; case Qbranch: if(o) objread(r, aux); else dirread9p(r, branchgen, aux); break; case Qobject: if(o) objread(r, aux); else dirread9p(r, objgen, aux); break; case Qmsg: readbuf(r, o->commit->msg, o->commit->nmsg); break; case Qparent: readcommitparent(r, o); break; case Qhash: snprint(buf, sizeof(buf), "%H\n", o->hash); readstr(r, buf); break; case Qauthor: snprint(buf, sizeof(buf), "%s\n", o->commit->author); readstr(r, buf); break; case Qcommitter: snprint(buf, sizeof(buf), "%s\n", o->commit->committer); readstr(r, buf); break; case Qctl: e = readctl(r); break; case Qhead: /* Empty repositories have no HEAD */ if(o == nil) r->ofcall.count = 0; else objread(r, aux); break; case Qcommit: case Qtree: case Qcdata: objread(r, aux); break; default: e = Egreg; } respond(r, e); } static void gitopen(Req *r) { Gitaux *aux; Crumb *c; aux = r->fid->aux; c = crumb(aux, 0); switch(r->ifcall.mode&3){ default: respond(r, "botched mode"); break; case OWRITE: respond(r, Eperm); break; case OREAD: case ORDWR: respond(r, nil); break; case OEXEC: if((c->mode & 0111) == 0) respond(r, Eperm); else respond(r, nil); break; } } static void gitstat(Req *r) { Gitaux *aux; Crumb *c; aux = r->fid->aux; c = crumb(aux, 0); r->d.uid = estrdup9p(username); r->d.gid = estrdup9p(groupname); r->d.muid = estrdup9p(username); r->d.qid = r->fid->qid; r->d.mtime = c->mtime; r->d.atime = c->mtime; r->d.mode = c->mode; if(c->obj) obj2dir(&r->d, c, c->obj, c->name); else r->d.name = estrdup9p(c->name); respond(r, nil); } Srv gitsrv = { .attach=gitattach, .walk1=gitwalk1, .clone=gitclone, .open=gitopen, .read=gitread, .stat=gitstat, .destroyfid=gitdestroyfid, }; void usage(void) { fprint(2, "usage: %s [-d]\n", argv0); fprint(2, "\t-d: debug\n"); exits("usage"); } void main(int argc, char **argv) { Dir *d; gitinit(); ARGBEGIN{ case 'd': chatty9p++; break; case 'm': mntpt = EARGF(usage()); break; default: usage(); break; }ARGEND; if(argc != 0) usage(); if((d = dirstat(".git")) == nil) sysfatal("dirstat .git: %r"); username = strdup(d->uid); groupname = strdup(d->gid); free(d); branches = emalloc(sizeof(char*)); branches[0] = nil; postmountsrv(&gitsrv, nil, mntpt, MCREATE); exits(nil); }