int patch(AbstractFile* in, AbstractFile* out, AbstractFile* patch) {
unsigned char header[32], buf[8];
off_t oldsize, newsize;
off_t bzctrllen, bzdatalen;
off_t oldpos, newpos;
int i;
int cbz2err, dbz2err, ebz2err;
off_t ctrl[3];
size_t lenread;
BZStream* cpfbz2;
BZStream* dpfbz2;
BZStream* epfbz2;
/* Read header */
if (patch->read(patch, header, 32) < 32) {
return -1;
}
/* Check for appropriate magic */
if (memcmp(header, "BSDIFF40", 8) != 0)
return -2;
/* Read lengths from header */
bzctrllen = offtin(header + 8);
bzdatalen = offtin(header + 16);
newsize = offtin(header + 24);
if((bzctrllen < 0) || (bzdatalen < 0) || (newsize < 0))
return -3;
cpfbz2 = openBZStream(patch, 32, 1024);
dpfbz2 = openBZStream(patch, 32 + bzctrllen, 1024);
epfbz2 = openBZStream(patch, 32 + bzctrllen + bzdatalen, 1024);
oldsize = in->getLength(in);
oldpos = 0;
newpos = 0;
unsigned char* writeBuffer = (unsigned char*) malloc(BUFFERSIZE);
unsigned char* readBuffer = (unsigned char*) malloc(BUFFERSIZE);
while(newpos < newsize) {
/* Read control data */
for(i=0;i<=2;i++) {
lenread = bzRead(&cbz2err, cpfbz2, buf, 8);
if ((lenread < 8) || ((cbz2err != BZ_OK) &&
(cbz2err != BZ_STREAM_END)))
return -4;
ctrl[i] = offtin(buf);
};
/* Sanity-check */
if((newpos + ctrl[0]) > newsize)
return -5;
/* Read diff string */
unsigned int toRead;
unsigned int total = ctrl[0];
while(total > 0) {
if(total > BUFFERSIZE)
toRead = BUFFERSIZE;
else
toRead = total;
memset(writeBuffer, 0, toRead);
lenread = bzRead(&dbz2err, dpfbz2, writeBuffer, toRead);
if ((lenread < toRead) ||
((dbz2err != BZ_OK) && (dbz2err != BZ_STREAM_END)))
return -6;
/* Add old data to diff string */
in->seek(in, oldpos);
unsigned int maxRead;
if((oldpos + toRead) > oldsize)
maxRead = oldsize - oldpos;
else
maxRead = toRead;
in->read(in, readBuffer, maxRead);
for(i = 0; i < maxRead; i++) {
writeBuffer[i] += readBuffer[i];
}
out->seek(out, newpos);
out->write(out, writeBuffer, toRead);
/* Adjust pointers */
newpos += toRead;
oldpos += toRead;
total -= toRead;
}
/* Sanity-check */
if((newpos + ctrl[1]) > newsize)
return -7;
total = ctrl[1];
while(total > 0){
if(total > BUFFERSIZE)
toRead = BUFFERSIZE;
else
toRead = total;
/* Read extra string */
lenread = bzRead(&ebz2err, epfbz2, writeBuffer, toRead);
if ((lenread < toRead) ||
((ebz2err != BZ_OK) && (ebz2err != BZ_STREAM_END)))
return -8;
out->seek(out, newpos);
out->write(out, writeBuffer, toRead);
/* Adjust pointers */
newpos += toRead;
total -= toRead;
}
oldpos += ctrl[2];
};
free(writeBuffer);
free(readBuffer);
closeBZStream(cpfbz2);
closeBZStream(dpfbz2);
closeBZStream(epfbz2);
out->close(out);
in->close(in);
patch->close(patch);
return 0;
}
int patch(AbstractFile* in, AbstractFile* out, AbstractFile* patch) {
unsigned char header[32], buf[8];
off_t oldsize, newsize;
off_t bzctrllen, bzdatalen;
off_t oldpos, newpos;
unsigned char *old, *newBuffer;
int i;
int cbz2err, dbz2err, ebz2err;
off_t ctrl[3];
size_t lenread;
BZStream* cpfbz2;
BZStream* dpfbz2;
BZStream* epfbz2;
/* Read header */
if (patch->read(patch, header, 32) < 32) {
return -1;
}
/* Check for appropriate magic */
if (memcmp(header, "BSDIFF40", 8) != 0)
return -2;
/* Read lengths from header */
bzctrllen = offtin(header + 8);
bzdatalen = offtin(header + 16);
newsize = offtin(header + 24);
if((bzctrllen < 0) || (bzdatalen < 0) || (newsize < 0))
return -3;
cpfbz2 = openBZStream(patch, 32, 1024);
dpfbz2 = openBZStream(patch, 32 + bzctrllen, 1024);
epfbz2 = openBZStream(patch, 32 + bzctrllen + bzdatalen, 1024);
oldsize = in->getLength(in);
old = malloc(oldsize + 1);
in->seek(in, 0);
in->read(in, old, oldsize);
in->close(in);
newBuffer = malloc(newsize + 1);
oldpos = 0;
newpos = 0;
while(newpos < newsize) {
/* Read control data */
for(i=0;i<=2;i++) {
lenread = bzRead(&cbz2err, cpfbz2, buf, 8);
if ((lenread < 8) || ((cbz2err != BZ_OK) &&
(cbz2err != BZ_STREAM_END)))
return -4;
ctrl[i] = offtin(buf);
};
/* Sanity-check */
if((newpos + ctrl[0]) > newsize)
return -5;
/* Read diff string */
memset(newBuffer + newpos, 0, ctrl[0]);
lenread = bzRead(&dbz2err, dpfbz2, newBuffer + newpos, ctrl[0]);
if ((lenread < ctrl[0]) ||
((dbz2err != BZ_OK) && (dbz2err != BZ_STREAM_END)))
return -6;
/* Add old data to diff string */
for(i = 0; i < ctrl[0]; i++) {
if(((oldpos + i)>=0) && ((oldpos + i)<oldsize)) {
newBuffer[newpos + i] += old[oldpos + i];
}
}
/* Adjust pointers */
newpos += ctrl[0];
oldpos += ctrl[0];
/* Sanity-check */
if((newpos + ctrl[1]) > newsize)
return -7;
/* Read extra string */
lenread = bzRead(&ebz2err, epfbz2, newBuffer + newpos, ctrl[1]);
if ((lenread < ctrl[1]) ||
((ebz2err != BZ_OK) && (ebz2err != BZ_STREAM_END)))
return -8;
/* Adjust pointers */
newpos += ctrl[1];
oldpos += ctrl[2];
};
closeBZStream(cpfbz2);
closeBZStream(dpfbz2);
closeBZStream(epfbz2);
out->seek(out, 0);
if(out->write(out, newBuffer, newsize) != newsize)
return -9;
out->close(out);
free(newBuffer);
free(old);
patch->close(patch);
return 0;
}
