summaryrefslogtreecommitdiffstats
path: root/applypatch/bsdiff.c
diff options
context:
space:
mode:
Diffstat (limited to 'applypatch/bsdiff.c')
-rw-r--r--applypatch/bsdiff.c410
1 files changed, 410 insertions, 0 deletions
diff --git a/applypatch/bsdiff.c b/applypatch/bsdiff.c
new file mode 100644
index 000000000..b6d342b7a
--- /dev/null
+++ b/applypatch/bsdiff.c
@@ -0,0 +1,410 @@
+/*
+ * Copyright (C) 2009 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * Most of this code comes from bsdiff.c from the bsdiff-4.3
+ * distribution, which is:
+ */
+
+/*-
+ * 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.
+ */
+
+#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;
+}
+
+// This is main() from bsdiff.c, with the following changes:
+//
+// - old, oldsize, new, newsize are arguments; we don't load this
+// data from files. old and new are owned by the caller; we
+// don't free them at the end.
+//
+// - the "I" block of memory is owned by the caller, who passes a
+// pointer to *I, which can be NULL. This way if we call
+// bsdiff() multiple times with the same 'old' data, we only do
+// the qsufsort() step the first time.
+//
+int bsdiff(u_char* old, off_t oldsize, off_t** IP, u_char* new, off_t newsize,
+ const char* patch_filename)
+{
+ int fd;
+ off_t *I;
+ 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 (*IP == NULL) {
+ off_t* V;
+ *IP = malloc((oldsize+1) * sizeof(off_t));
+ V = malloc((oldsize+1) * sizeof(off_t));
+ qsufsort(*IP, V, old, oldsize);
+ free(V);
+ }
+ I = *IP;
+
+ 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(patch_filename, "w")) == NULL)
+ err(1, "%s", patch_filename);
+
+ /* 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)", patch_filename);
+
+ /* 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)", patch_filename);
+ if (fclose(pf))
+ err(1, "fclose");
+
+ /* Free the memory we used */
+ free(db);
+ free(eb);
+
+ return 0;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-05 18:59:58 +0100