bsdiff.c - platform/external/bsdiff - Git at Google

 /*-
  * Copyright 2003-2005 Colin Percival
  * All rights reserved
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted providing that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */

 #if 0
 __FBSDID("$FreeBSD: src/usr.bin/bsdiff/bsdiff/bsdiff.c,v 1.1 2005/08/06 01:59:05 cperciva Exp $");
 #endif

 #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>

 #define MIN(x,y) (((x)<(y)) ? (x) : (y))

 static void split(off_t *I,off_t *V,off_t start,off_t len,off_t h)
 {
 	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);
 }

 static void qsufsort(off_t *I,off_t *V,u_char *old,off_t oldsize)
 {
 	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 matchlen(u_char *old,off_t oldsize,u_char *new,off_t newsize)
 {
 	off_t i;

 	for(i=0;(i<oldsize)&&(i<newsize);i++)
 		if(old[i]!=new[i]) break;

 	return 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)
 {
 	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 offtout(off_t x,u_char *buf)
 {
 	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;
 }

 int main(int argc,char *argv[])
 {
 	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;
 }
	/*-
	* Copyright 2003-2005 Colin Percival
	* All rights reserved
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted providing that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
	* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
	* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
	* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	* POSSIBILITY OF SUCH DAMAGE.
	*/

	#if 0
	__FBSDID("$FreeBSD: src/usr.bin/bsdiff/bsdiff/bsdiff.c,v 1.1 2005/08/06 01:59:05 cperciva Exp $");
	#endif

	#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>

	#define MIN(x,y) (((x)<(y)) ? (x) : (y))

	static void split(off_t I,off_t V,off_t start,off_t len,off_t h)
	{
	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);
	}

	static void qsufsort(off_t I,off_t V,u_char *old,off_t oldsize)
	{
	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 matchlen(u_char old,off_t oldsize,u_char new,off_t newsize)
	{
	off_t i;

	for(i=0;(i<oldsize)&&(i<newsize);i++)
	if(old[i]!=new[i]) break;

	return 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)
	{
	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 offtout(off_t x,u_char *buf)
	{
	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;
	}

	int main(int argc,char *argv[])
	{
	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(s2-i>Sf2-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(s2-i>Sb2-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;
	}