ref: f28cb3a880a38864884e8c5e791c191dd477cd97
dir: /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;
char *path;
vlong mtime;
/* The best delta we picked */
Meta *head;
Meta *prev;
Object *base;
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 {
int refs;
Biobuf *pack;
char *idx;
vlong nidx;
};
static int readpacked(Biobuf *, Object *, int);
static Object *readidxobject(Biobuf *, Hash, int);
Objset objcache;
Object *lruhead;
Object *lrutail;
int ncache;
int cachemax = 4096;
Packf *packf;
int npackf;
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)
o->prev->next = o->next;
if(o->next)
o->next->prev = o->prev;
if(lrutail == o){
lrutail = o->prev;
lrutail->next = nil;
}else if(!lrutail)
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++;
}
while(ncache > cachemax){
p = lrutail;
lrutail = p->prev;
lrutail->next = nil;
p->flag &= ~Ccache;
p->prev = nil;
p->next = nil;
unref(p);
ncache--;
}
}
static int
openpack(Packf *pf, char *name)
{
char buf[128];
int ifd;
Dir *d;
memset(pf, 0, sizeof(Packf));
snprint(buf, sizeof(buf), ".git/objects/pack/%s.pack", name);
pf->pack = Bopen(buf, OREAD);
snprint(buf, sizeof(buf), ".git/objects/pack/%s.idx", name);
ifd = open(buf, OREAD);
if(pf->pack == nil || ifd == -1)
goto errorf;
if((d = dirfstat(ifd)) == nil)
goto errorf;
pf->nidx = d->length;
pf->idx = emalloc(pf->nidx);
if(readn(ifd, pf->idx, pf->nidx) != pf->nidx)
goto errori;
free(d);
return 0;
errori:
free(d);
free(pf->idx);
errorf:
if(pf->pack == nil) Bterm(pf->pack);
if(ifd != -1) close(ifd);
return -1;
}
static void
refreshpacks(void)
{
Packf *pf;
int i, n, l;
Dir *d;
for(i = 0; i < npackf; i++){
pf = &packf[i];
free(pf->idx);
Bterm(pf->pack);
}
free(packf);
if((n = slurpdir(".git/objects/pack", &d)) == -1)
return;
npackf = 0;
packf = 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(openpack(&packf[npackf], d[i].name) != -1)
npackf++;
}
free(d);
}
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", c);
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];
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[2].ep - m[2].sp;
memcpy(buf, m[2].sp, nm);
buf[nm] = 0;
*time = atoll(buf);
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)
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, 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++;
t->mode = m & 0777;
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, 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++){
if((o = searchindex(packf[i].idx, packf[i].nidx, h)) != -1){
f = packf[i].pack;
if(Bseek(f, o, 0) == -1)
goto errorf;
if(readpacked(f, obj, flag) == -1)
goto errorf;
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;
o = readidxobject(nil, h, 0);
if(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);
goto error;
}
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);
hwrite(f, buf, 4, &st);
}
for(i = 0; i < nobj; i++){
o = obj[i];
hwrite(f, o->hash.h, sizeof(o->hash.h), &st);
}
for(i = 0; i < nobj; i++){
PUTBE32(buf, obj[i]->crc);
hwrite(f, buf, 4, &st);
}
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++;
}
hwrite(f, buf, 4, &st);
}
for(i = 0; i < nobj; i++){
if(obj[i]->off >= (1ull<<31)){
PUTBE64(buf, obj[i]->off);
hwrite(f, buf, 8, &st);
}
}
hwrite(f, ph.h, sizeof(ph.h), &st);
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;
int cmp;
a = *(Meta**)pa;
b = *(Meta**)pb;
if(a->obj->type != b->obj->type)
return a->obj->type - b->obj->type;
cmp = strcmp(a->path, b->path);
if(cmp != 0)
return cmp;
if(a->mtime != b->mtime)
return a->mtime - b->mtime;
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, char *path, 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 = estrdup(path);
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->path);
free(m);
}
static int
loadtree(Metavec *v, Objset *has, Hash tree, char *dpath, vlong mtime)
{
Object *t, *o;
Dirent *e;
char *p;
int i, k;
if(oshas(has, tree))
return 0;
if((t = readobject(tree)) == nil)
return -1;
addmeta(v, has, t, dpath, 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);
p = smprint("%s/%s", dpath, e->name);
if(k == GBlob)
addmeta(v, has, o, p, mtime);
else if(loadtree(v, has, e->h, p, mtime) == -1){
free(p);
return -1;
}
free(p);
}
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;
addmeta(v, has, c, "", 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(*m);
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");
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->base = nil;
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);
best = o->size;
dtinit(&m->dtab, o->data, o->size);
if(i >= 11)
dtclear(&meta[i-11]->dtab);
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->data, o->size, &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;
if((m->base = readobject(p->obj->hash)) == nil)
sysfatal("readobject %H: %r", p->obj->hash);
unref(m->base);
}else
free(d);
}
unref(o);
}
for(i = max(0, nmeta - 10); i < nmeta; i++)
dtclear(&meta[i]->dtab);
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;
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++){
m = meta[i];
pct = showprogress((i*100)/nmeta, pct);
if((o = readobject(m->obj->hash)) == nil)
return -1;
if(m->delta == nil){
nh = packhdr(buf, o->type, o->size);
hwrite(bfd, buf, nh, &st);
if(hcompress(bfd, o->data, o->size, &st) == -1)
goto error;
}else{
m->off = Boffset(bfd);
nd = encodedelta(m, o, m->base, &p);
if(odelta && m->prev->off != 0){
nh = 0;
nh += packhdr(buf, GOdelta, nd);
nh += packoff(buf+nh, m->off - m->prev->off);
hwrite(bfd, buf, nh, &st);
}else{
nh = packhdr(buf, GRdelta, nd);
hwrite(bfd, buf, nh, &st);
hwrite(bfd, m->base->hash.h, sizeof(m->base->hash.h), &st);
}
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;
}