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SASC
DVBSoftCAM
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SASC
DVBSoftCAM
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#include <sys/types.h>#include <bzlib.h>#include <err.h>#include <fcntl.h>#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>Go to the source code of this file.
Defines | |
| #define | MIN(x, y) (((x)<(y)) ? (x) : (y)) |
Functions | |
| static void | split (off_t *I, off_t *V, off_t start, off_t len, off_t h) |
| static void | qsufsort (off_t *I, off_t *V, u_char *old, off_t oldsize) |
| static off_t | matchlen (u_char *old, off_t oldsize, u_char *new, off_t newsize) |
| static off_t | search (off_t *I, u_char *old, off_t oldsize, u_char *new, off_t newsize, off_t st, off_t en, off_t *pos) |
| static void | offtout (off_t x, u_char *buf) |
| int | main (int argc, char *argv[]) |
| #define MIN | ( | x, | |
| y | |||
| ) | (((x)<(y)) ? (x) : (y)) |
| int main | ( | int | argc, |
| char * | argv[] | ||
| ) |
Definition at line 196 of file bsdiff.c.
References db, fd, free, header, i, NULL, offtout(), open(), qsufsort(), and search().
{
int fd;
u_char *old,*new;
off_t oldsize,newsize;
off_t *I,*V;
off_t scan,pos,len;
off_t lastscan,lastpos,lastoffset;
off_t oldscore,scsc;
off_t s,Sf,lenf,Sb,lenb;
off_t overlap,Ss,lens;
off_t i;
off_t dblen,eblen;
u_char *db,*eb;
u_char buf[8];
u_char header[32];
FILE * pf;
BZFILE * pfbz2;
int bz2err;
if(argc!=4) errx(1,"usage: %s oldfile newfile patchfile\n",argv[0]);
/* Allocate oldsize+1 bytes instead of oldsize bytes to ensure
that we never try to malloc(0) and get a NULL pointer */
if(((fd=open(argv[1],O_RDONLY,0))<0) ||
((oldsize=lseek(fd,0,SEEK_END))==-1) ||
((old=malloc(oldsize+1))==NULL) ||
(lseek(fd,0,SEEK_SET)!=0) ||
(read(fd,old,oldsize)!=oldsize) ||
(close(fd)==-1)) err(1,"%s",argv[1]);
if(((I=malloc((oldsize+1)*sizeof(off_t)))==NULL) ||
((V=malloc((oldsize+1)*sizeof(off_t)))==NULL)) err(1,NULL);
qsufsort(I,V,old,oldsize);
free(V);
/* Allocate newsize+1 bytes instead of newsize bytes to ensure
that we never try to malloc(0) and get a NULL pointer */
if(((fd=open(argv[2],O_RDONLY,0))<0) ||
((newsize=lseek(fd,0,SEEK_END))==-1) ||
((new=malloc(newsize+1))==NULL) ||
(lseek(fd,0,SEEK_SET)!=0) ||
(read(fd,new,newsize)!=newsize) ||
(close(fd)==-1)) err(1,"%s",argv[2]);
if(((db=malloc(newsize+1))==NULL) ||
((eb=malloc(newsize+1))==NULL)) err(1,NULL);
dblen=0;
eblen=0;
/* Create the patch file */
if ((pf = fopen(argv[3], "w")) == NULL)
err(1, "%s", argv[3]);
/* Header is
0 8 "BSDIFF40"
8 8 length of bzip2ed ctrl block
16 8 length of bzip2ed diff block
24 8 length of new file */
/* File is
0 32 Header
32 ?? Bzip2ed ctrl block
?? ?? Bzip2ed diff block
?? ?? Bzip2ed extra block */
memcpy(header,"BSDIFF40",8);
offtout(0, header + 8);
offtout(0, header + 16);
offtout(newsize, header + 24);
if (fwrite(header, 32, 1, pf) != 1)
err(1, "fwrite(%s)", argv[3]);
/* Compute the differences, writing ctrl as we go */
if ((pfbz2 = BZ2_bzWriteOpen(&bz2err, pf, 9, 0, 0)) == NULL)
errx(1, "BZ2_bzWriteOpen, bz2err = %d", bz2err);
scan=0;len=0;
lastscan=0;lastpos=0;lastoffset=0;
while(scan<newsize) {
oldscore=0;
for(scsc=scan+=len;scan<newsize;scan++) {
len=search(I,old,oldsize,new+scan,newsize-scan,
0,oldsize,&pos);
for(;scsc<scan+len;scsc++)
if((scsc+lastoffset<oldsize) &&
(old[scsc+lastoffset] == new[scsc]))
oldscore++;
if(((len==oldscore) && (len!=0)) ||
(len>oldscore+8)) break;
if((scan+lastoffset<oldsize) &&
(old[scan+lastoffset] == new[scan]))
oldscore--;
};
if((len!=oldscore) || (scan==newsize)) {
s=0;Sf=0;lenf=0;
for(i=0;(lastscan+i<scan)&&(lastpos+i<oldsize);) {
if(old[lastpos+i]==new[lastscan+i]) s++;
i++;
if(s*2-i>Sf*2-lenf) { Sf=s; lenf=i; };
};
lenb=0;
if(scan<newsize) {
s=0;Sb=0;
for(i=1;(scan>=lastscan+i)&&(pos>=i);i++) {
if(old[pos-i]==new[scan-i]) s++;
if(s*2-i>Sb*2-lenb) { Sb=s; lenb=i; };
};
};
if(lastscan+lenf>scan-lenb) {
overlap=(lastscan+lenf)-(scan-lenb);
s=0;Ss=0;lens=0;
for(i=0;i<overlap;i++) {
if(new[lastscan+lenf-overlap+i]==
old[lastpos+lenf-overlap+i]) s++;
if(new[scan-lenb+i]==
old[pos-lenb+i]) s--;
if(s>Ss) { Ss=s; lens=i+1; };
};
lenf+=lens-overlap;
lenb-=lens;
};
for(i=0;i<lenf;i++)
db[dblen+i]=new[lastscan+i]-old[lastpos+i];
for(i=0;i<(scan-lenb)-(lastscan+lenf);i++)
eb[eblen+i]=new[lastscan+lenf+i];
dblen+=lenf;
eblen+=(scan-lenb)-(lastscan+lenf);
offtout(lenf,buf);
BZ2_bzWrite(&bz2err, pfbz2, buf, 8);
if (bz2err != BZ_OK)
errx(1, "BZ2_bzWrite, bz2err = %d", bz2err);
offtout((scan-lenb)-(lastscan+lenf),buf);
BZ2_bzWrite(&bz2err, pfbz2, buf, 8);
if (bz2err != BZ_OK)
errx(1, "BZ2_bzWrite, bz2err = %d", bz2err);
offtout((pos-lenb)-(lastpos+lenf),buf);
BZ2_bzWrite(&bz2err, pfbz2, buf, 8);
if (bz2err != BZ_OK)
errx(1, "BZ2_bzWrite, bz2err = %d", bz2err);
lastscan=scan-lenb;
lastpos=pos-lenb;
lastoffset=pos-scan;
};
};
BZ2_bzWriteClose(&bz2err, pfbz2, 0, NULL, NULL);
if (bz2err != BZ_OK)
errx(1, "BZ2_bzWriteClose, bz2err = %d", bz2err);
/* Compute size of compressed ctrl data */
if ((len = ftello(pf)) == -1)
err(1, "ftello");
offtout(len-32, header + 8);
/* Write compressed diff data */
if ((pfbz2 = BZ2_bzWriteOpen(&bz2err, pf, 9, 0, 0)) == NULL)
errx(1, "BZ2_bzWriteOpen, bz2err = %d", bz2err);
BZ2_bzWrite(&bz2err, pfbz2, db, dblen);
if (bz2err != BZ_OK)
errx(1, "BZ2_bzWrite, bz2err = %d", bz2err);
BZ2_bzWriteClose(&bz2err, pfbz2, 0, NULL, NULL);
if (bz2err != BZ_OK)
errx(1, "BZ2_bzWriteClose, bz2err = %d", bz2err);
/* Compute size of compressed diff data */
if ((newsize = ftello(pf)) == -1)
err(1, "ftello");
offtout(newsize - len, header + 16);
/* Write compressed extra data */
if ((pfbz2 = BZ2_bzWriteOpen(&bz2err, pf, 9, 0, 0)) == NULL)
errx(1, "BZ2_bzWriteOpen, bz2err = %d", bz2err);
BZ2_bzWrite(&bz2err, pfbz2, eb, eblen);
if (bz2err != BZ_OK)
errx(1, "BZ2_bzWrite, bz2err = %d", bz2err);
BZ2_bzWriteClose(&bz2err, pfbz2, 0, NULL, NULL);
if (bz2err != BZ_OK)
errx(1, "BZ2_bzWriteClose, bz2err = %d", bz2err);
/* Seek to the beginning, write the header, and close the file */
if (fseeko(pf, 0, SEEK_SET))
err(1, "fseeko");
if (fwrite(header, 32, 1, pf) != 1)
err(1, "fwrite(%s)", argv[3]);
if (fclose(pf))
err(1, "fclose");
/* Free the memory we used */
free(db);
free(eb);
free(I);
free(old);
free(new);
return 0;
}
| static off_t matchlen | ( | u_char * | old, |
| off_t | oldsize, | ||
| u_char * | new, | ||
| off_t | newsize | ||
| ) | [static] |
| static void offtout | ( | off_t | x, |
| u_char * | buf | ||
| ) | [static] |
Definition at line 178 of file bsdiff.c.
Referenced by main().
{
off_t y;
if(x<0) y=-x; else y=x;
buf[0]=y%256;y-=buf[0];
y=y/256;buf[1]=y%256;y-=buf[1];
y=y/256;buf[2]=y%256;y-=buf[2];
y=y/256;buf[3]=y%256;y-=buf[3];
y=y/256;buf[4]=y%256;y-=buf[4];
y=y/256;buf[5]=y%256;y-=buf[5];
y=y/256;buf[6]=y%256;y-=buf[6];
y=y/256;buf[7]=y%256;
if(x<0) buf[7]|=0x80;
}
| static void qsufsort | ( | off_t * | I, |
| off_t * | V, | ||
| u_char * | old, | ||
| off_t | oldsize | ||
| ) | [static] |
Definition at line 104 of file bsdiff.c.
Referenced by main().
{
off_t buckets[256];
off_t i,h,len;
for(i=0;i<256;i++) buckets[i]=0;
for(i=0;i<oldsize;i++) buckets[old[i]]++;
for(i=1;i<256;i++) buckets[i]+=buckets[i-1];
for(i=255;i>0;i--) buckets[i]=buckets[i-1];
buckets[0]=0;
for(i=0;i<oldsize;i++) I[++buckets[old[i]]]=i;
I[0]=oldsize;
for(i=0;i<oldsize;i++) V[i]=buckets[old[i]];
V[oldsize]=0;
for(i=1;i<256;i++) if(buckets[i]==buckets[i-1]+1) I[buckets[i]]=-1;
I[0]=-1;
for(h=1;I[0]!=-(oldsize+1);h+=h) {
len=0;
for(i=0;i<oldsize+1;) {
if(I[i]<0) {
len-=I[i];
i-=I[i];
} else {
if(len) I[i-len]=-len;
len=V[I[i]]+1-i;
split(I,V,i,len,h);
i+=len;
len=0;
};
};
if(len) I[i-len]=-len;
};
for(i=0;i<oldsize+1;i++) I[V[i]]=i;
}
| static off_t search | ( | off_t * | I, |
| u_char * | old, | ||
| off_t | oldsize, | ||
| u_char * | new, | ||
| off_t | newsize, | ||
| off_t | st, | ||
| off_t | en, | ||
| off_t * | pos | ||
| ) | [static] |
Definition at line 152 of file bsdiff.c.
References matchlen(), and MIN.
Referenced by main().
{
off_t x,y;
if(en-st<2) {
x=matchlen(old+I[st],oldsize-I[st],new,newsize);
y=matchlen(old+I[en],oldsize-I[en],new,newsize);
if(x>y) {
*pos=I[st];
return x;
} else {
*pos=I[en];
return y;
}
};
x=st+(en-st)/2;
if(memcmp(old+I[x],new,MIN(oldsize-I[x],newsize))<0) {
return search(I,old,oldsize,new,newsize,x,en,pos);
} else {
return search(I,old,oldsize,new,newsize,st,x,pos);
};
}
| static void split | ( | off_t * | I, |
| off_t * | V, | ||
| off_t | start, | ||
| off_t | len, | ||
| off_t | h | ||
| ) | [static] |
Definition at line 43 of file bsdiff.c.
References i, j, k, and start().
Referenced by qsufsort().
{
off_t i,j,k,x,tmp,jj,kk;
if(len<16) {
for(k=start;k<start+len;k+=j) {
j=1;x=V[I[k]+h];
for(i=1;k+i<start+len;i++) {
if(V[I[k+i]+h]<x) {
x=V[I[k+i]+h];
j=0;
};
if(V[I[k+i]+h]==x) {
tmp=I[k+j];I[k+j]=I[k+i];I[k+i]=tmp;
j++;
};
};
for(i=0;i<j;i++) V[I[k+i]]=k+j-1;
if(j==1) I[k]=-1;
};
return;
};
x=V[I[start+len/2]+h];
jj=0;kk=0;
for(i=start;i<start+len;i++) {
if(V[I[i]+h]<x) jj++;
if(V[I[i]+h]==x) kk++;
};
jj+=start;kk+=jj;
i=start;j=0;k=0;
while(i<jj) {
if(V[I[i]+h]<x) {
i++;
} else if(V[I[i]+h]==x) {
tmp=I[i];I[i]=I[jj+j];I[jj+j]=tmp;
j++;
} else {
tmp=I[i];I[i]=I[kk+k];I[kk+k]=tmp;
k++;
};
};
while(jj+j<kk) {
if(V[I[jj+j]+h]==x) {
j++;
} else {
tmp=I[jj+j];I[jj+j]=I[kk+k];I[kk+k]=tmp;
k++;
};
};
if(jj>start) split(I,V,start,jj-start,h);
for(i=0;i<kk-jj;i++) V[I[jj+i]]=kk-1;
if(jj==kk-1) I[jj]=-1;
if(start+len>kk) split(I,V,kk,start+len-kk,h);
}
1.7.3