sys/src/cmd/hgfs/revlog.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include <thread.h>
   4 #include "dat.h"
   5 #include "fns.h"
   6
   7 int
   8 fmktemp(void)
   9 {
  10         char temp[MAXPATH];
  11
  12         snprint(temp, sizeof(temp), "/tmp/hgXXXXXXXXXXX");
  13         return create(mktemp(temp), OTRUNC|ORCLOSE|ORDWR, 0666);
  14 }
  15
  16 void
  17 revlogupdate(Revlog *r)
  18 {
  19         uchar buf[64];
  20         Revmap *m;
  21         int rev;
  22
  23         if(seek(r->ifd, r->ioff, 0) < 0)
  24                 return;
  25         for(rev=r->nmap;;rev++){
  26                 if(readn(r->ifd, buf, sizeof(buf)) != sizeof(buf))
  27                         break;
  28                 if((rev % 16) == 0)
  29                         r->map = realloc(r->map, sizeof(r->map[0])*(rev+16));
  30                 m = &r->map[rev];
  31                 memset(m, 0, sizeof(*m));
  32                 m->hoff = (vlong)buf[0]<<40 |
  33                         (vlong)buf[1]<<32 |
  34                         (vlong)buf[2]<<24 |
  35                         (vlong)buf[3]<<16 |
  36                         (vlong)buf[4]<<8 |
  37                         (vlong)buf[5];
  38                 if(rev == 0)
  39                         m->hoff &= 0xFFFF;
  40                 m->rev = rev;
  41                 m->flags = buf[6]<<8 | buf[7];
  42                 m->hlen = buf[8]<<24 | buf[9]<<16 | buf[10]<<8 | buf[11];
  43                 m->flen = buf[12]<<24 | buf[13]<<16 | buf[14]<<8 | buf[15];
  44                 m->baserev = buf[16]<<24 | buf[17]<<16 | buf[18]<<8 | buf[19];
  45                 m->linkrev = buf[20]<<24 | buf[21]<<16 | buf[22]<<8 | buf[23];
  46                 m->p1rev = buf[24]<<24 | buf[25]<<16 | buf[26]<<8 | buf[27];
  47                 m->p2rev = buf[28]<<24 | buf[29]<<16 | buf[30]<<8 | buf[31];
  48                 memmove(m->hash, buf+32, HASHSZ);
  49
  50                 if(r->dfd < 0){
  51                         m->hoff = seek(r->ifd, 0, 1);
  52                         r->ioff = seek(r->ifd, m->hlen, 1);
  53                 } else
  54                         r->ioff = seek(r->ifd, 0, 1);
  55         }
  56         r->nmap = rev;
  57 }
  58
  59 int
  60 revlogopen(Revlog *r, char *path, int mode)
  61 {
  62         r->ifd = -1;
  63         r->dfd = -1;
  64         path = smprint("%s.i", path);
  65         if((r->ifd = open(path, mode)) < 0){
  66                 free(path);
  67                 return -1;
  68         }
  69         path[strlen(path)-1] = 'd';
  70         r->dfd = open(path, mode);
  71         free(path);
  72         r->ioff = 0;
  73         r->nmap = 0;
  74         r->map = nil;
  75         revlogupdate(r);
  76         return 0;
  77 }
  78
  79 void
  80 revlogclose(Revlog *r)
  81 {
  82         if(r->ifd >= 0){
  83                 close(r->ifd);
  84                 r->ifd = -1;
  85         }
  86         if(r->dfd >= 0){
  87                 close(r->dfd);
  88                 r->dfd = -1;
  89         }
  90         free(r->map);
  91         r->map = nil;
  92         r->nmap = 0;
  93 }
  94
  95 uchar*
  96 revhash(Revlog *r, int rev)
  97 {
  98         static uchar nullid[HASHSZ];
  99         if(rev < 0 || rev >= r->nmap)
 100                 return nullid;
 101         return r->map[rev].hash;
 102 }
 103
 104 int
 105 hashrev(Revlog *r, uchar hash[])
 106 {
 107         int rev;
 108
 109         for(rev=0; rev<r->nmap; rev++)
 110                 if(memcmp(r->map[rev].hash, hash, HASHSZ) == 0)
 111                         return rev;
 112         return -1;
 113 }
 114
 115 static int
 116 prevlogrev(Revlog *r, int rev)
 117 {
 118         if(r->map[rev].baserev == rev)
 119                 return -1;
 120         return rev-1;
 121 }
 122
 123 static int
 124 prevbundlerev(Revlog *r, int rev)
 125 {
 126         if(r->map[rev].baserev == rev)
 127                 return -1;
 128         return r->map[rev].p1rev;
 129 }
 130
 131 static Revmap**
 132 getchain1(Revlog *r, int rev, int *count, int (*next)(Revlog *, int))
 133 {
 134         Revmap **chain;
 135
 136         if(rev < 0 || rev >= r->nmap){
 137                 if(*count <= 0)
 138                         return nil;
 139                 chain = malloc(sizeof(chain[0]) * ((*count)+1));
 140                 chain[*count] = nil;
 141                 *count = 0;
 142         }else{
 143                 (*count)++;
 144                 if(chain = getchain1(r, (*next)(r, rev), count, next))
 145                         chain[(*count)++] = &r->map[rev];
 146         }
 147         return chain;
 148 }
 149
 150 static Revmap**
 151 getchain(Revlog *r, int rev, int (*next)(Revlog *, int))
 152 {
 153         int count = 0;
 154         return getchain1(r, rev, &count, next);
 155 }
 156
 157 int
 158 revlogextract(Revlog *r, int rev, int ofd)
 159 {
 160         int err, hfd, pfd, bfd;
 161         uchar hash[HASHSZ];
 162         Revmap **chain, *m;
 163         char buf[32];
 164         vlong off;
 165         int i;
 166
 167         err = -1;
 168         bfd = -1;
 169         pfd = -1;
 170
 171         if((chain = getchain(r, rev, prevlogrev)) == nil){
 172                 werrstr("bad patch chain");
 173                 goto errout;
 174         }
 175
 176         off = seek(ofd, 0, 1);
 177         if(off < 0){
 178                 werrstr("seek outfile: %r");
 179                 goto errout;
 180         }
 181         hfd = r->dfd < 0 ? r->ifd : r->dfd;
 182         for(i=0; m = chain[i]; i++){
 183                 if(seek(hfd, m->hoff, 0) < 0){
 184                         werrstr("seek index: %r");
 185                         goto errout;
 186                 }
 187                 if(m == chain[0] && m->baserev == m->rev){
 188                         if(chain[1]){
 189                                 if(bfd >= 0 && bfd != ofd)
 190                                         close(bfd);
 191                                 if((bfd = fmktemp()) < 0){
 192                                         werrstr("create basefile: %r");
 193                                         goto errout;
 194                                 }
 195                         } else
 196                                 bfd = ofd;
 197                         if(funzip(bfd, hfd, m->hlen) < 0){
 198                                 werrstr("unzip basefile: %r");
 199                                 goto errout;
 200                         }
 201                 } else {
 202                         if(pfd < 0){
 203                                 if((pfd = fmktemp()) < 0){
 204                                         werrstr("create patchfile: %r");
 205                                         goto errout;
 206                                 }
 207                         }
 208
 209                         /* put a mark before the patch data */
 210                         snprint(buf, sizeof(buf), "%H", m->hash);
 211                         if(fpatchmark(pfd, buf) < 0){
 212                                 werrstr("patchmark: %r");
 213                                 goto errout;
 214                         }
 215
 216                         if(funzip(pfd, hfd, m->hlen) < 0){
 217                                 werrstr("unzip patchfile: %r");
 218                                 goto errout;
 219                         }
 220                 }
 221         }
 222         m = chain[i-1];
 223
 224         if(pfd >= 0 && bfd >= 0 && bfd != ofd){
 225                 if(seek(pfd, 0, 0) < 0){
 226                         werrstr("seek patchfile: %r");
 227                         goto errout;
 228                 }
 229                 if(fpatch(ofd, bfd, pfd) < 0){
 230                         werrstr("patch: %r");
 231                         goto errout;
 232                 }
 233         }
 234
 235         if(seek(ofd, off, 0) < 0){
 236                 werrstr("seek outfile: %r");
 237                 goto errout;
 238         }
 239         if(fhash(ofd, revhash(r, m->p1rev), revhash(r, m->p2rev), hash) < 0){
 240                 werrstr("hash outfile: %r");
 241                 goto errout;
 242         }
 243         if(memcmp(m->hash, hash, HASHSZ)){
 244                 werrstr("got bad hash");
 245                 goto errout;
 246         }
 247         err = 0;
 248
 249 errout:
 250         if(pfd >= 0)
 251                 close(pfd);
 252         if(bfd >= 0 && bfd != ofd)
 253                 close(bfd);
 254         free(chain);
 255
 256         return err;
 257 }
 258
 259 int
 260 revlogopentemp(Revlog *r, int rev)
 261 {
 262         int fd;
 263
 264         if((fd = fmktemp()) < 0)
 265                 return -1;
 266         if(revlogextract(r, rev, fd) < 0){
 267                 close(fd);
 268                 return -1;
 269         }
 270         if(seek(fd, 0, 0) < 0){
 271                 close(fd);
 272                 return -1;
 273         }
 274         return fd;
 275 }