ref: 733c5d6645b133b60d304c38fcb1398f94d0618c
dir: /sys/src/cmd/git/pack.c/
#include <u.h> #include <libc.h> #include <ctype.h> #include "git.h" typedef struct Buf Buf; typedef struct Metavec Metavec; typedef struct Meta Meta; typedef struct Compout Compout; typedef struct Packf Packf; #define max(x, y) ((x) > (y) ? (x) : (y)) struct Metavec { Meta **meta; int nmeta; int metasz; }; struct Meta { Object *obj; vlong path; vlong mtime; /* The best delta we picked */ Meta *head; Meta *prev; Delta *delta; int ndelta; int nchain; /* Only used for delta window */ Dtab dtab; /* Only used for writing offset deltas */ vlong off; }; struct Compout { Biobuf *bfd; DigestState *st; }; struct Buf { int len; int sz; int off; char *data; }; struct Packf { char path[128]; char *idx; vlong nidx; int refs; Biobuf *pack; vlong opentm; }; static int readpacked(Biobuf *, Object *, int); static Object *readidxobject(Biobuf *, Hash, int); Objset objcache; Object *lruhead; Object *lrutail; vlong ncache; vlong cachemax = 128*MiB; Packf *packf; int npackf; int openpacks; int gitdirmode = -1; static void clear(Object *o) { if(!o) return; assert(o->refs == 0); assert((o->flag & Ccache) == 0); assert(o->flag & Cloaded); switch(o->type){ case GCommit: if(!o->commit) break; free(o->commit->parent); free(o->commit->author); free(o->commit->committer); free(o->commit); o->commit = nil; break; case GTree: if(!o->tree) break; free(o->tree->ent); free(o->tree); o->tree = nil; break; default: break; } free(o->all); o->all = nil; o->data = nil; o->flag &= ~(Cloaded|Cparsed); } void unref(Object *o) { if(!o) return; o->refs--; if(o->refs == 0) clear(o); } Object* ref(Object *o) { o->refs++; return o; } void cache(Object *o) { Object *p; if(o == lruhead) return; if(o == lrutail) lrutail = lrutail->prev; if(!(o->flag & Cexist)){ osadd(&objcache, o); o->id = objcache.nobj; o->flag |= Cexist; } if(o->prev != nil) o->prev->next = o->next; if(o->next != nil) o->next->prev = o->prev; if(lrutail == o){ lrutail = o->prev; if(lrutail != nil) lrutail->next = nil; }else if(lrutail == nil) lrutail = o; if(lruhead) lruhead->prev = o; o->next = lruhead; o->prev = nil; lruhead = o; if(!(o->flag & Ccache)){ o->flag |= Ccache; ref(o); ncache += o->size; } while(ncache > cachemax && lrutail != lruhead){ p = lrutail; lrutail = p->prev; if(lrutail != nil) lrutail->next = nil; p->flag &= ~Ccache; p->prev = nil; p->next = nil; ncache -= p->size; unref(p); } } static int loadpack(Packf *pf, char *name) { char buf[128]; int i, ifd; Dir *d; memset(pf, 0, sizeof(Packf)); snprint(buf, sizeof(buf), ".git/objects/pack/%s.idx", name); snprint(pf->path, sizeof(pf->path), ".git/objects/pack/%s.pack", name); /* * if we already have the pack open, just * steal the loaded info */ for(i = 0; i < npackf; i++){ if(strcmp(pf->path, packf[i].path) == 0){ pf->pack = packf[i].pack; pf->idx = packf[i].idx; pf->nidx = packf[i].nidx; packf[i].idx = nil; packf[i].pack = nil; return 0; } } if((ifd = open(buf, OREAD)) == -1) return -1; if((d = dirfstat(ifd)) == nil){ close(ifd); return -1; } pf->nidx = d->length; pf->idx = emalloc(pf->nidx); if(readn(ifd, pf->idx, pf->nidx) != pf->nidx){ close(ifd); free(pf->idx); free(d); return -1; } close(ifd); free(d); return 0; } static void refreshpacks(void) { Packf *pf, *new; int i, n, l, nnew; Dir *d; if((n = slurpdir(".git/objects/pack", &d)) == -1) return; nnew = 0; new = eamalloc(n, sizeof(Packf)); for(i = 0; i < n; i++){ l = strlen(d[i].name); if(l > 4 && strcmp(d[i].name + l - 4, ".idx") != 0) continue; d[i].name[l - 4] = 0; if(loadpack(&new[nnew], d[i].name) != -1) nnew++; } for(i = 0; i < npackf; i++){ pf = &packf[i]; free(pf->idx); if(pf->pack != nil) Bterm(pf->pack); } free(packf); packf = new; npackf = nnew; free(d); } static Biobuf* openpack(Packf *pf) { vlong t; int i, best; if(pf->pack != nil){ pf->refs++; return pf->pack; } /* * If we've got more packs open * than we want cached, try to * free up the oldest ones. * * If we can't find a slot, this * isn't fatal; we can just use * another fd. */ while(openpacks >= Npackcache){ t = (1ull<<62)-1; best = -1; for(i = 0; i < npackf; i++){ if(&packf[i] != pf && packf[i].pack != nil && packf[i].opentm < t && packf[i].refs == 0){ t = packf[i].opentm; best = i; } } if(best == -1){ fprint(2, "no available pack slots\n"); break; } Bterm(packf[best].pack); packf[best].pack = nil; openpacks--; } openpacks++; pf->opentm = nsec(); pf->refs++; if((pf->pack = Bopen(pf->path, OREAD)) == nil) return nil; return pf->pack; } static void closepack(Packf *pf) { pf->refs--; } static u32int crc32(u32int crc, char *b, int nb) { static u32int crctab[256] = { 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d }; int i; crc ^= 0xFFFFFFFF; for(i = 0; i < nb; i++) crc = (crc >> 8) ^ crctab[(crc ^ b[i]) & 0xFF]; return crc ^ 0xFFFFFFFF; } int bappend(void *p, void *src, int len) { Buf *b = p; char *n; while(b->len + len >= b->sz){ b->sz = b->sz*2 + 64; n = realloc(b->data, b->sz); if(n == nil) return -1; b->data = n; } memmove(b->data + b->len, src, len); b->len += len; return len; } int breadc(void *p) { return Bgetc(p); } int bdecompress(Buf *d, Biobuf *b, vlong *csz) { vlong o; o = Boffset(b); if(inflatezlib(d, bappend, b, breadc) == -1 || d->data == nil){ free(d->data); return -1; } if (csz) *csz = Boffset(b) - o; return d->len; } int decompress(void **p, Biobuf *b, vlong *csz) { Buf d = {.len=0, .data=nil, .sz=0}; if(bdecompress(&d, b, csz) == -1){ free(d.data); return -1; } *p = d.data; return d.len; } static vlong readvint(char *p, char **pp) { int s, c; vlong n; s = 0; n = 0; do { c = *p++; n |= (c & 0x7f) << s; s += 7; } while (c & 0x80 && s < 63); *pp = p; return n; } static int applydelta(Object *dst, Object *base, char *d, int nd) { char *r, *b, *ed, *er; int n, nr, c; vlong o, l; ed = d + nd; b = base->data; n = readvint(d, &d); if(n != base->size){ werrstr("mismatched source size"); return -1; } nr = readvint(d, &d); r = emalloc(nr + 64); n = snprint(r, 64, "%T %d", base->type, nr) + 1; dst->all = r; dst->type = base->type; dst->data = r + n; dst->size = nr; er = dst->data + nr; r = dst->data; while(d != ed){ c = *d++; /* copy from base */ if(c & 0x80){ o = 0; l = 0; /* Offset in base */ if(d != ed && (c & 0x01)) o |= (*d++ << 0) & 0x000000ff; if(d != ed && (c & 0x02)) o |= (*d++ << 8) & 0x0000ff00; if(d != ed && (c & 0x04)) o |= (*d++ << 16) & 0x00ff0000; if(d != ed && (c & 0x08)) o |= (*d++ << 24) & 0xff000000; /* Length to copy */ if(d != ed && (c & 0x10)) l |= (*d++ << 0) & 0x0000ff; if(d != ed && (c & 0x20)) l |= (*d++ << 8) & 0x00ff00; if(d != ed && (c & 0x40)) l |= (*d++ << 16) & 0xff0000; if(l == 0) l = 0x10000; if(o + l > base->size){ werrstr("garbled delta: out of bounds copy"); return -1; } memmove(r, b + o, l); r += l; /* inline data */ }else{ if(c > ed - d){ werrstr("garbled delta: write past object"); return -1; } memmove(r, d, c); d += c; r += c; } } if(r != er){ werrstr("truncated delta"); return -1; } return nr; } static int readrdelta(Biobuf *f, Object *o, int nd, int flag) { Object *b; Hash h; char *d; int n; d = nil; if(Bread(f, h.h, sizeof(h.h)) != sizeof(h.h)) goto error; if(hasheq(&o->hash, &h)) goto error; if((n = decompress(&d, f, nil)) == -1) goto error; o->len = Boffset(f) - o->off; if(d == nil || n != nd) goto error; if((b = readidxobject(f, h, flag|Cthin)) == nil) goto error; if(applydelta(o, b, d, n) == -1) goto error; free(d); return 0; error: free(d); return -1; } static int readodelta(Biobuf *f, Object *o, vlong nd, vlong p, int flag) { Object b; char *d; vlong r; int c, n; d = nil; if((c = Bgetc(f)) == -1) return -1; r = c & 0x7f; while(c & 0x80 && r < (1ULL<<56)){ if((c = Bgetc(f)) == -1) return -1; r = ((r + 1)<<7) | (c & 0x7f); } if(r > p || r >= (1ULL<<56)){ werrstr("junk offset -%lld (from %lld)", r, p); goto error; } if((n = decompress(&d, f, nil)) == -1) goto error; o->len = Boffset(f) - o->off; if(d == nil || n != nd) goto error; if(Bseek(f, p - r, 0) == -1) goto error; memset(&b, 0, sizeof(Object)); if(readpacked(f, &b, flag) == -1) goto error; if(applydelta(o, &b, d, nd) == -1) goto error; clear(&b); free(d); return 0; error: free(d); return -1; } static int readpacked(Biobuf *f, Object *o, int flag) { int c, s, n; vlong l, p; int t; Buf b; p = Boffset(f); c = Bgetc(f); if(c == -1) return -1; l = c & 0xf; s = 4; t = (c >> 4) & 0x7; if(!t){ werrstr("unknown type for byte %x at %lld", c, p); return -1; } while(c & 0x80){ if((c = Bgetc(f)) == -1) return -1; l |= (c & 0x7f) << s; s += 7; } if(l >= (1ULL << 32)){ werrstr("object too big"); return -1; } switch(t){ default: werrstr("invalid object at %lld", Boffset(f)); return -1; case GCommit: case GTree: case GTag: case GBlob: b.sz = 64 + l; b.data = emalloc(b.sz); n = snprint(b.data, 64, "%T %lld", t, l) + 1; b.len = n; if(bdecompress(&b, f, nil) == -1){ free(b.data); return -1; } o->len = Boffset(f) - o->off; o->type = t; o->all = b.data; o->data = b.data + n; o->size = b.len - n; break; case GOdelta: if(readodelta(f, o, l, p, flag) == -1) return -1; break; case GRdelta: if(readrdelta(f, o, l, flag) == -1) return -1; break; } o->flag |= Cloaded|flag; return 0; } static int readloose(Biobuf *f, Object *o, int flag) { struct { char *tag; int type; } *p, types[] = { {"blob", GBlob}, {"tree", GTree}, {"commit", GCommit}, {"tag", GTag}, {nil}, }; char *d, *s, *e; vlong sz, n; int l; n = decompress(&d, f, nil); if(n == -1) return -1; s = d; o->type = GNone; for(p = types; p->tag; p++){ l = strlen(p->tag); if(strncmp(s, p->tag, l) == 0){ s += l; o->type = p->type; while(!isspace(*s)) s++; break; } } if(o->type == GNone){ free(o->data); return -1; } sz = strtol(s, &e, 0); if(e == s || *e++ != 0){ werrstr("malformed object header"); goto error; } if(sz != n - (e - d)){ werrstr("mismatched sizes"); goto error; } o->size = sz; o->data = e; o->all = d; o->flag |= Cloaded|flag; return 0; error: free(d); return -1; } vlong searchindex(char *idx, int nidx, Hash h) { int lo, hi, hidx, i, r, nent; vlong o, oo; void *s; o = 8; if(nidx < 8 + 256*4) return -1; /* * Read the fanout table. The fanout table * contains 256 entries, corresponsding to * the first byte of the hash. Each entry * is a 4 byte big endian integer, containing * the total number of entries with a leading * byte <= the table index, allowing us to * rapidly do a binary search on them. */ if (h.h[0] == 0){ lo = 0; hi = GETBE32(idx + o); } else { o += h.h[0]*4 - 4; lo = GETBE32(idx + o); hi = GETBE32(idx + o + 4); } if(hi == lo) goto notfound; nent=GETBE32(idx + 8 + 255*4); /* * Now that we know the range of hashes that the * entry may exist in, search them */ r = -1; hidx = -1; o = 8 + 256*4; while(lo < hi){ hidx = (hi + lo)/2; s = idx + o + hidx*sizeof(h.h); r = memcmp(h.h, s, sizeof(h.h)); if(r < 0) hi = hidx; else if(r > 0) lo = hidx + 1; else break; } if(r != 0) goto notfound; /* * We found the entry. If it's 32 bits, then we * can just return the oset, otherwise the 32 * bit entry contains the oset to the 64 bit * entry. */ oo = 8; /* Header */ oo += 256*4; /* Fanout table */ oo += Hashsz*nent; /* Hashes */ oo += 4*nent; /* Checksums */ oo += 4*hidx; /* Offset offset */ if(oo < 0 || oo + 4 > nidx) goto err; i = GETBE32(idx + oo); o = i & 0xffffffffULL; /* * Large offsets (i.e. 64-bit) are encoded as an index * into the next table with the MSB bit set. */ if(o & (1ull << 31)){ o &= 0x7fffffffULL; oo = 8; /* Header */ oo += 256*4; /* Fanout table */ oo += Hashsz*nent; /* Hashes */ oo += 4*nent; /* Checksums */ oo += 4*nent; /* 32-bit Offsets */ oo += 8*o; /* 64-bit Offset offset */ if(oo < 0 || oo + 8 >= nidx) goto err; o = GETBE64(idx + oo); } return o; err: werrstr("out of bounds read"); return -1; notfound: werrstr("not present"); return -1; } /* * Scans for non-empty word, copying it into buf. * Strips off word, leading, and trailing space * from input. * * Returns -1 on empty string or error, leaving * input unmodified. */ static int scanword(char **str, int *nstr, char *buf, int nbuf) { char *p; int n, r; r = -1; p = *str; n = *nstr; while(n && isblank(*p)){ n--; p++; } for(; n && *p && !isspace(*p); p++, n--){ r = 0; *buf++ = *p; nbuf--; if(nbuf == 0) return -1; } while(n && isblank(*p)){ n--; p++; } *buf = 0; *str = p; *nstr = n; return r; } static void nextline(char **str, int *nstr) { char *s; if((s = strchr(*str, '\n')) != nil){ *nstr -= s - *str + 1; *str = s + 1; } } static int parseauthor(char **str, int *nstr, char **name, vlong *time) { char buf[128]; Resub m[4]; vlong tz; char *p; int n, nm; if((p = strchr(*str, '\n')) == nil) sysfatal("malformed author line"); n = p - *str; if(n >= sizeof(buf)) sysfatal("overlong author line"); memset(m, 0, sizeof(m)); snprint(buf, n + 1, *str); *str = p; *nstr -= n; if(!regexec(authorpat, buf, m, nelem(m))) sysfatal("invalid author line %s", buf); nm = m[1].ep - m[1].sp; *name = emalloc(nm + 1); memcpy(*name, m[1].sp, nm); buf[nm] = 0; nm = m[3].ep - m[3].sp; memcpy(buf, m[3].sp, nm); buf[nm] = 0; tz = atoll(buf); nm = m[2].ep - m[2].sp; memcpy(buf, m[2].sp, nm); buf[nm] = 0; *time = atoll(buf) + 3600*(tz/100) + 60*(tz%100); return 0; } static void parsecommit(Object *o) { char *p, *t, buf[128]; int np; p = o->data; np = o->size; o->commit = emalloc(sizeof(Cinfo)); while(1){ if(scanword(&p, &np, buf, sizeof(buf)) == -1) break; if(strcmp(buf, "tree") == 0){ if(scanword(&p, &np, buf, sizeof(buf)) == -1) sysfatal("invalid commit: tree missing"); if(hparse(&o->commit->tree, buf) == -1) sysfatal("invalid commit: garbled tree"); }else if(strcmp(buf, "parent") == 0){ if(scanword(&p, &np, buf, sizeof(buf)) == -1) sysfatal("invalid commit: missing parent"); o->commit->parent = realloc(o->commit->parent, ++o->commit->nparent * sizeof(Hash)); if(!o->commit->parent) sysfatal("unable to malloc: %r"); if(hparse(&o->commit->parent[o->commit->nparent - 1], buf) == -1) sysfatal("invalid commit: garbled parent"); }else if(strcmp(buf, "author") == 0){ parseauthor(&p, &np, &o->commit->author, &o->commit->mtime); }else if(strcmp(buf, "committer") == 0){ parseauthor(&p, &np, &o->commit->committer, &o->commit->ctime); }else if(strcmp(buf, "gpgsig") == 0){ /* just drop it */ if((t = strstr(p, "-----END PGP SIGNATURE-----")) == nil) if((t = strstr(p, "-----END SSH SIGNATURE-----")) == nil) if((t = strstr(p, "-----END SIGNED MESSAGE-----")) == nil) sysfatal("malformed gpg signature"); np -= t - p; p = t; } nextline(&p, &np); } while (np && isspace(*p)) { p++; np--; } o->commit->msg = p; o->commit->nmsg = np; } static void parsetree(Object *o) { int m, a, entsz, nent; Dirent *t, *ent; char *p, *ep; p = o->data; ep = p + o->size; nent = 0; entsz = 16; ent = eamalloc(entsz, sizeof(Dirent)); o->tree = emalloc(sizeof(Tinfo)); while(p != ep){ if(nent == entsz){ entsz *= 2; ent = earealloc(ent, entsz, sizeof(Dirent)); } t = &ent[nent++]; m = strtol(p, &p, 8); if(*p != ' ') sysfatal("malformed tree %H: *p=(%d) %c\n", o->hash, *p, *p); p++; /* * only the stored permissions for the user * are relevant; git fills group and world * bits with whatever -- so to serve with * useful permissions, replicate the mode * of the git repo dir. */ a = (m & 0777)>>6; t->mode = ((a<<6)|(a<<3)|a) & gitdirmode; t->ismod = 0; t->islink = 0; if(m == 0160000){ t->mode |= DMDIR; t->ismod = 1; }else if(m == 0120000){ t->mode = 0; t->islink = 1; } if(m & 0040000) t->mode |= DMDIR; t->name = p; p = memchr(p, 0, ep - p); if(*p++ != 0 || ep - p < sizeof(t->h.h)) sysfatal("malformed tree %H, remaining %d (%s)", o->hash, (int)(ep - p), p); memcpy(t->h.h, p, sizeof(t->h.h)); p += sizeof(t->h.h); } o->tree->ent = ent; o->tree->nent = nent; } static void parsetag(Object *) { } void parseobject(Object *o) { if(o->flag & Cparsed) return; switch(o->type){ case GTree: parsetree(o); break; case GCommit: parsecommit(o); break; case GTag: parsetag(o); break; default: break; } o->flag |= Cparsed; } static Object* readidxobject(Biobuf *idx, Hash h, int flag) { char path[Pathmax], hbuf[41]; Object *obj, *new; int i, r, retried; Biobuf *f; vlong o; if((obj = osfind(&objcache, h)) != nil){ if(flag & Cidx){ /* * If we're indexing, we need to be careful * to only return objects within this pack, * so if the objects exist outside the pack, * we don't index the wrong copy. */ if(!(obj->flag & Cidx)) return nil; if(obj->flag & Cloaded) return obj; o = Boffset(idx); if(Bseek(idx, obj->off, 0) == -1) return nil; if(readpacked(idx, obj, flag) == -1) return nil; if(Bseek(idx, o, 0) == -1) sysfatal("could not restore offset"); cache(obj); return obj; } if(obj->flag & Cloaded) return obj; } if(flag & Cthin) flag &= ~Cidx; if(flag & Cidx) return nil; new = nil; if(obj == nil){ new = emalloc(sizeof(Object)); new->id = objcache.nobj + 1; new->hash = h; obj = new; } o = -1; retried = 0; retry: for(i = 0; i < npackf; i++){ o = searchindex(packf[i].idx, packf[i].nidx, h); if(o != -1){ if((f = openpack(&packf[i])) == nil) goto error; if((r = Bseek(f, o, 0)) != -1) r = readpacked(f, obj, flag); closepack(&packf[i]); if(r == -1) goto error; parseobject(obj); cache(obj); return obj; } } snprint(hbuf, sizeof(hbuf), "%H", h); snprint(path, sizeof(path), ".git/objects/%c%c/%s", hbuf[0], hbuf[1], hbuf + 2); if((f = Bopen(path, OREAD)) != nil){ if(readloose(f, obj, flag) == -1) goto errorf; Bterm(f); parseobject(obj); cache(obj); return obj; } if(o == -1){ if(retried) goto error; retried = 1; refreshpacks(); goto retry; } errorf: Bterm(f); error: free(new); return nil; } /* * Loads and returns a cached object. */ Object* readobject(Hash h) { Object *o; Dir *d; if(gitdirmode == -1){ if((d = dirstat(".git")) == nil) sysfatal("stat .git: %r"); gitdirmode = d->mode & 0777; free(d); } if((o = readidxobject(nil, h, 0)) == nil) return nil; parseobject(o); ref(o); return o; } /* * Creates and returns a cached, cleared object * that will get loaded some other time. Useful * for performance if need to mark that a blob * exists, but we don't care about its contents. * * The refcount of the returned object is 0, so * it doesn't need to be unrefed. */ Object* clearedobject(Hash h, int type) { Object *o; if((o = osfind(&objcache, h)) != nil) return o; o = emalloc(sizeof(Object)); o->hash = h; o->type = type; osadd(&objcache, o); o->id = objcache.nobj; o->flag |= Cexist; return o; } int objcmp(void *pa, void *pb) { Object *a, *b; a = *(Object**)pa; b = *(Object**)pb; return memcmp(a->hash.h, b->hash.h, sizeof(a->hash.h)); } static int hwrite(Biobuf *b, void *buf, int len, DigestState **st) { *st = sha1(buf, len, nil, *st); return Bwrite(b, buf, len); } static u32int objectcrc(Biobuf *f, Object *o) { char buf[8096]; int n, r; o->crc = 0; Bseek(f, o->off, 0); for(n = o->len; n > 0; n -= r){ r = Bread(f, buf, n > sizeof(buf) ? sizeof(buf) : n); if(r == -1) return -1; if(r == 0) return 0; o->crc = crc32(o->crc, buf, r); } return 0; } int indexpack(char *pack, char *idx, Hash ph) { char hdr[4*3], buf[8]; int nobj, npct, nvalid, nbig; int i, n, pct; Object *o, **obj; DigestState *st; char *valid; Biobuf *f; Hash h; int c; if((f = Bopen(pack, OREAD)) == nil) return -1; if(Bread(f, hdr, sizeof(hdr)) != sizeof(hdr)){ werrstr("short read on header"); return -1; } if(memcmp(hdr, "PACK\0\0\0\2", 8) != 0){ werrstr("invalid header"); return -1; } pct = 0; npct = 0; nvalid = 0; nobj = GETBE32(hdr + 8); obj = eamalloc(nobj, sizeof(Object*)); valid = eamalloc(nobj, sizeof(char)); if(interactive) fprint(2, "indexing %d objects: 0%%", nobj); while(nvalid != nobj){ n = 0; for(i = 0; i < nobj; i++){ if(valid[i]){ n++; continue; } pct = showprogress((npct*100)/nobj, pct); if(obj[i] == nil){ o = emalloc(sizeof(Object)); o->off = Boffset(f); obj[i] = o; } o = obj[i]; /* * We can seek around when packing delta chains. * Be extra careful while we don't know where all * the objects start. */ Bseek(f, o->off, 0); if(readpacked(f, o, Cidx) == -1) continue; sha1((uchar*)o->all, o->size + strlen(o->all) + 1, o->hash.h, nil); valid[i] = 1; cache(o); npct++; n++; if(objectcrc(f, o) == -1) return -1; } if(n == nvalid) sysfatal("fix point reached too early: %d/%d: %r", nvalid, nobj); nvalid = n; } if(interactive) fprint(2, "\b\b\b\b100%%\n"); Bterm(f); st = nil; qsort(obj, nobj, sizeof(Object*), objcmp); if((f = Bopen(idx, OWRITE)) == nil) return -1; if(hwrite(f, "\xfftOc\x00\x00\x00\x02", 8, &st) != 8) goto error; /* fanout table */ c = 0; for(i = 0; i < 256; i++){ while(c < nobj && (obj[c]->hash.h[0] & 0xff) <= i) c++; PUTBE32(buf, c); if(hwrite(f, buf, 4, &st) == -1) goto error; } for(i = 0; i < nobj; i++){ o = obj[i]; if(hwrite(f, o->hash.h, sizeof(o->hash.h), &st) == -1) goto error; } for(i = 0; i < nobj; i++){ PUTBE32(buf, obj[i]->crc); if(hwrite(f, buf, 4, &st) == -1) goto error; } nbig = 0; for(i = 0; i < nobj; i++){ if(obj[i]->off < (1ull<<31)) PUTBE32(buf, obj[i]->off); else{ PUTBE32(buf, (1ull << 31) | nbig); nbig++; } if(hwrite(f, buf, 4, &st) == -1) goto error; } for(i = 0; i < nobj; i++){ if(obj[i]->off >= (1ull<<31)){ PUTBE64(buf, obj[i]->off); if(hwrite(f, buf, 8, &st) == -1) goto error; } } if(hwrite(f, ph.h, sizeof(ph.h), &st) == -1) goto error; sha1(nil, 0, h.h, st); Bwrite(f, h.h, sizeof(h.h)); free(obj); free(valid); Bterm(f); return 0; error: free(obj); free(valid); Bterm(f); return -1; } static int deltaordercmp(void *pa, void *pb) { Meta *a, *b; vlong cmp; a = *(Meta**)pa; b = *(Meta**)pb; if(a->obj->type != b->obj->type) return a->obj->type - b->obj->type; cmp = (b->path - a->path); if(cmp != 0) return (cmp < 0) ? -1 : 1; cmp = a->mtime - b->mtime; if(cmp != 0) return (cmp < 0) ? -1 : 1; return memcmp(a->obj->hash.h, b->obj->hash.h, sizeof(a->obj->hash.h)); } static int writeordercmp(void *pa, void *pb) { Meta *a, *b, *ahd, *bhd; a = *(Meta**)pa; b = *(Meta**)pb; ahd = (a->head == nil) ? a : a->head; bhd = (b->head == nil) ? b : b->head; if(ahd->mtime != bhd->mtime) return bhd->mtime - ahd->mtime; if(ahd != bhd) return (uintptr)bhd - (uintptr)ahd; if(a->nchain != b->nchain) return a->nchain - b->nchain; return a->mtime - b->mtime; } static void addmeta(Metavec *v, Objset *has, Object *o, vlong pathid, vlong mtime) { Meta *m; if(oshas(has, o->hash)) return; osadd(has, o); if(v == nil) return; m = emalloc(sizeof(Meta)); m->obj = o; m->path = pathid; m->mtime = mtime; if(v->nmeta == v->metasz){ v->metasz = 2*v->metasz; v->meta = earealloc(v->meta, v->metasz, sizeof(Meta*)); } v->meta[v->nmeta++] = m; } static void freemeta(Meta *m) { free(m->delta); free(m); } static int loadtree(Metavec *v, Objset *has, Hash tree, char *dpath, vlong mtime) { Object *t, *o; Dirent *e; vlong dh, eh; int i, k, r; char *p; if(oshas(has, tree)) return 0; if((t = readobject(tree)) == nil) return -1; if(t->type != GTree){ fprint(2, "load: %H: not tree\n", t->hash); unref(t); return 0; } dh = murmurhash2(dpath, strlen(dpath)); addmeta(v, has, t, dh, mtime); for(i = 0; i < t->tree->nent; i++){ e = &t->tree->ent[i]; if(oshas(has, e->h)) continue; if(e->ismod) continue; k = (e->mode & DMDIR) ? GTree : GBlob; o = clearedobject(e->h, k); if(k == GTree){ p = smprint("%s/%s", dpath, e->name); r = loadtree(v, has, e->h, p, mtime); free(p); if(r == -1) return -1; }else{ eh = murmurhash2(e->name, strlen(e->name)); addmeta(v, has, o, dh^eh, mtime); } } unref(t); return 0; } static int loadcommit(Metavec *v, Objset *has, Hash h) { Object *c; int r; if(osfind(has, h)) return 0; if((c = readobject(h)) == nil) return -1; if(c->type != GCommit){ fprint(2, "load: %H: not commit\n", c->hash); unref(c); return 0; } addmeta(v, has, c, 0, c->commit->ctime); r = loadtree(v, has, c->commit->tree, "", c->commit->ctime); unref(c); return r; } static int readmeta(Hash *theirs, int ntheirs, Hash *ours, int nours, Meta ***m) { Object **obj; Objset has; int i, nobj; Metavec v; *m = nil; osinit(&has); v.nmeta = 0; v.metasz = 64; v.meta = eamalloc(v.metasz, sizeof(Meta*)); if(findtwixt(theirs, ntheirs, ours, nours, &obj, &nobj) == -1) sysfatal("load twixt: %r"); if(nobj == 0) return 0; for(i = 0; i < nours; i++) if(!hasheq(&ours[i], &Zhash)) if(loadcommit(nil, &has, ours[i]) == -1) goto out; for(i = 0; i < nobj; i++) if(loadcommit(&v, &has, obj[i]->hash) == -1) goto out; osclear(&has); *m = v.meta; return v.nmeta; out: osclear(&has); free(v.meta); return -1; } static int deltasz(Delta *d, int nd) { int i, sz; sz = 32; for(i = 0; i < nd; i++) sz += d[i].cpy ? 7 : d[i].len + 1; return sz; } static void pickdeltas(Meta **meta, int nmeta) { Meta *m, *p; Object *o; Delta *d; int i, j, nd, sz, pct, best; pct = 0; dprint(1, "picking deltas\n"); if(interactive) fprint(2, "deltifying %d objects: 0%%", nmeta); qsort(meta, nmeta, sizeof(Meta*), deltaordercmp); for(i = 0; i < nmeta; i++){ m = meta[i]; pct = showprogress((i*100) / nmeta, pct); m->delta = nil; m->ndelta = 0; if(m->obj->type == GCommit || m->obj->type == GTag) continue; if((o = readobject(m->obj->hash)) == nil) sysfatal("readobject %H: %r", m->obj->hash); dtinit(&m->dtab, o); if(i >= 11) dtclear(&meta[i-11]->dtab); best = o->size; for(j = max(0, i - 10); j < i; j++){ p = meta[j]; /* long chains make unpacking slow */ if(p->nchain >= 128 || p->obj->type != o->type) continue; d = deltify(o, &p->dtab, &nd); sz = deltasz(d, nd); if(sz + 32 < best){ /* * if we already picked a best delta, * replace it. */ free(m->delta); best = sz; m->delta = d; m->ndelta = nd; m->nchain = p->nchain + 1; m->prev = p; m->head = p->head; if(m->head == nil) m->head = p; }else free(d); } unref(o); } for(i = max(0, nmeta - 10); i < nmeta; i++) dtclear(&meta[i]->dtab); if(interactive) fprint(2, "\b\b\b\b100%%\n"); } static int compread(void *p, void *dst, int n) { Buf *b; b = p; if(n > b->sz - b->off) n = b->sz - b->off; memcpy(dst, b->data + b->off, n); b->off += n; return n; } static int compwrite(void *p, void *buf, int n) { return hwrite(((Compout *)p)->bfd, buf, n, &((Compout*)p)->st); } static int hcompress(Biobuf *bfd, void *buf, int sz, DigestState **st) { int r; Buf b ={ .off=0, .data=buf, .sz=sz, }; Compout o = { .bfd = bfd, .st = *st, }; r = deflatezlib(&o, compwrite, &b, compread, 6, 0); *st = o.st; return r; } static void append(char **p, int *len, int *sz, void *seg, int nseg) { if(*len + nseg >= *sz){ while(*len + nseg >= *sz) *sz += *sz/2; *p = erealloc(*p, *sz); } memcpy(*p + *len, seg, nseg); *len += nseg; } static int encodedelta(Meta *m, Object *o, Object *b, void **pp) { char *p, *bp, buf[16]; int len, sz, n, i, j; Delta *d; sz = 128; len = 0; p = emalloc(sz); /* base object size */ buf[0] = b->size & 0x7f; n = b->size >> 7; for(i = 1; n > 0; i++){ buf[i - 1] |= 0x80; buf[i] = n & 0x7f; n >>= 7; } append(&p, &len, &sz, buf, i); /* target object size */ buf[0] = o->size & 0x7f; n = o->size >> 7; for(i = 1; n > 0; i++){ buf[i - 1] |= 0x80; buf[i] = n & 0x7f; n >>= 7; } append(&p, &len, &sz, buf, i); for(j = 0; j < m->ndelta; j++){ d = &m->delta[j]; if(d->cpy){ n = d->off; bp = buf + 1; buf[0] = 0x81; buf[1] = 0x00; for(i = 0; i < sizeof(buf); i++) { buf[0] |= 1<<i; *bp++ = n & 0xff; n >>= 8; if(n == 0) break; } n = d->len; if(n != 0x10000) { buf[0] |= 0x1<<4; for(i = 0; i < sizeof(buf)-4 && n > 0; i++){ buf[0] |= 1<<(i + 4); *bp++ = n & 0xff; n >>= 8; } } append(&p, &len, &sz, buf, bp - buf); }else{ n = 0; while(n != d->len){ buf[0] = (d->len - n < 127) ? d->len - n : 127; append(&p, &len, &sz, buf, 1); append(&p, &len, &sz, o->data + d->off + n, buf[0]); n += buf[0]; } } } *pp = p; return len; } static int packhdr(char *hdr, int ty, int len) { int i; hdr[0] = ty << 4; hdr[0] |= len & 0xf; len >>= 4; for(i = 1; len != 0; i++){ hdr[i-1] |= 0x80; hdr[i] = len & 0x7f; len >>= 7; } return i; } static int packoff(char *hdr, vlong off) { int i, j; char rbuf[8]; rbuf[0] = off & 0x7f; for(i = 1; (off >>= 7) != 0; i++) rbuf[i] = (--off & 0x7f)|0x80; j = 0; while(i > 0) hdr[j++] = rbuf[--i]; return j; } static int genpack(int fd, Meta **meta, int nmeta, Hash *h, int odelta) { int i, nh, nd, res, pct, ret; DigestState *st; Biobuf *bfd; Meta *m; Object *o, *po, *b; char *p, buf[32]; st = nil; ret = -1; pct = 0; dprint(1, "generating pack\n"); if((fd = dup(fd, -1)) == -1) return -1; if((bfd = Bfdopen(fd, OWRITE)) == nil) return -1; if(hwrite(bfd, "PACK", 4, &st) == -1) return -1; PUTBE32(buf, 2); if(hwrite(bfd, buf, 4, &st) == -1) return -1; PUTBE32(buf, nmeta); if(hwrite(bfd, buf, 4, &st) == -1) return -1; qsort(meta, nmeta, sizeof(Meta*), writeordercmp); if(interactive) fprint(2, "writing %d objects: 0%%", nmeta); for(i = 0; i < nmeta; i++){ pct = showprogress((i*100)/nmeta, pct); m = meta[i]; m->off = Boffset(bfd); if(m->off == -1) goto error; if((o = readobject(m->obj->hash)) == nil) return -1; if(m->delta == nil){ nh = packhdr(buf, o->type, o->size); if(hwrite(bfd, buf, nh, &st) == -1) goto error; if(hcompress(bfd, o->data, o->size, &st) == -1) goto error; }else{ if((b = readobject(m->prev->obj->hash)) == nil) goto error; nd = encodedelta(m, o, b, &p); unref(b); if(odelta && m->prev->off != 0){ nh = 0; nh += packhdr(buf, GOdelta, nd); nh += packoff(buf+nh, m->off - m->prev->off); if(hwrite(bfd, buf, nh, &st) == -1) goto error; }else{ nh = packhdr(buf, GRdelta, nd); po = m->prev->obj; if(hwrite(bfd, buf, nh, &st) == -1) goto error; if(hwrite(bfd, po->hash.h, sizeof(po->hash.h), &st) == -1) goto error; } res = hcompress(bfd, p, nd, &st); free(p); if(res == -1) goto error; } unref(o); } if(interactive) fprint(2, "\b\b\b\b100%%\n"); sha1(nil, 0, h->h, st); if(Bwrite(bfd, h->h, sizeof(h->h)) == -1) goto error; ret = 0; error: if(Bterm(bfd) == -1) return -1; return ret; } int writepack(int fd, Hash *theirs, int ntheirs, Hash *ours, int nours, Hash *h) { Meta **meta; int i, r, nmeta; if((nmeta = readmeta(theirs, ntheirs, ours, nours, &meta)) == -1) return -1; pickdeltas(meta, nmeta); r = genpack(fd, meta, nmeta, h, 0); for(i = 0; i < nmeta; i++) freemeta(meta[i]); free(meta); return r; }