applypatch: Use bsdiff from external/bsdiff.

external/bsdiff uses divsufsort which is much faster, and also include
some bug fixes.

Bug: 26982501
Test: ./imgdiff_test.sh

Change-Id: I089a301c291ee55d79938c7a3ca6d509895440d1
diff --git a/applypatch/Android.mk b/applypatch/Android.mk
index 9e64718..a15ac02 100644
--- a/applypatch/Android.mk
+++ b/applypatch/Android.mk
@@ -89,8 +89,13 @@
 # ===============================
 include $(CLEAR_VARS)
 LOCAL_CLANG := true
-LOCAL_SRC_FILES := imgdiff.cpp utils.cpp bsdiff.cpp
+LOCAL_SRC_FILES := imgdiff.cpp utils.cpp
 LOCAL_MODULE := imgdiff
-LOCAL_STATIC_LIBRARIES += libz libbz
+LOCAL_STATIC_LIBRARIES += \
+    libbsdiff \
+    libbz \
+    libdivsufsort64 \
+    libdivsufsort \
+    libz
 LOCAL_FORCE_STATIC_EXECUTABLE := true
 include $(BUILD_HOST_EXECUTABLE)
diff --git a/applypatch/bsdiff.cpp b/applypatch/bsdiff.cpp
deleted file mode 100644
index cca1b32..0000000
--- a/applypatch/bsdiff.cpp
+++ /dev/null
@@ -1,409 +0,0 @@
-/*
- * 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 *olddata,off_t oldsize,u_char *newdata,off_t newsize)
-{
-	off_t i;
-
-	for(i=0;(i<oldsize)&&(i<newsize);i++)
-		if(olddata[i]!=newdata[i]) break;
-
-	return i;
-}
-
-static off_t search(off_t *I,u_char *old,off_t oldsize,
-		u_char *newdata,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],newdata,newsize);
-		y=matchlen(old+I[en],oldsize-I[en],newdata,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],newdata,MIN(oldsize-I[x],newsize))<0) {
-		return search(I,old,oldsize,newdata,newsize,x,en,pos);
-	} else {
-		return search(I,old,oldsize,newdata,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, newdata, newsize are arguments; we don't load this
-//      data from files.  old and newdata 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* newdata, off_t newsize,
-           const char* patch_filename)
-{
-	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 = reinterpret_cast<off_t*>(malloc((oldsize+1) * sizeof(off_t)));
-            V = reinterpret_cast<off_t*>(malloc((oldsize+1) * sizeof(off_t)));
-            qsufsort(*IP, V, old, oldsize);
-            free(V);
-        }
-        I = *IP;
-
-	if(((db=reinterpret_cast<u_char*>(malloc(newsize+1)))==NULL) ||
-		((eb=reinterpret_cast<u_char*>(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,newdata+scan,newsize-scan,
-					0,oldsize,&pos);
-
-			for(;scsc<scan+len;scsc++)
-			if((scsc+lastoffset<oldsize) &&
-				(old[scsc+lastoffset] == newdata[scsc]))
-				oldscore++;
-
-			if(((len==oldscore) && (len!=0)) ||
-				(len>oldscore+8)) break;
-
-			if((scan+lastoffset<oldsize) &&
-				(old[scan+lastoffset] == newdata[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]==newdata[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]==newdata[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(newdata[lastscan+lenf-overlap+i]==
-					   old[lastpos+lenf-overlap+i]) s++;
-					if(newdata[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]=newdata[lastscan+i]-old[lastpos+i];
-			for(i=0;i<(scan-lenb)-(lastscan+lenf);i++)
-				eb[eblen+i]=newdata[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;
-}
diff --git a/applypatch/imgdiff.cpp b/applypatch/imgdiff.cpp
index 2aa4a68..7c5bb86 100644
--- a/applypatch/imgdiff.cpp
+++ b/applypatch/imgdiff.cpp
@@ -130,6 +130,8 @@
 #include <unistd.h>
 #include <sys/types.h>
 
+#include <bsdiff.h>
+
 #include "zlib.h"
 #include "imgdiff.h"
 #include "utils.h"
@@ -144,8 +146,6 @@
   size_t source_start;
   size_t source_len;
 
-  off_t* I;             // used by bsdiff
-
   // --- for CHUNK_DEFLATE chunks only: ---
 
   // original (compressed) deflate data
@@ -179,10 +179,6 @@
   }
 }
 
-// from bsdiff.c
-int bsdiff(u_char* old, off_t oldsize, off_t** IP, u_char* newdata, off_t newsize,
-           const char* patch_filename);
-
 unsigned char* ReadZip(const char* filename,
                        int* num_chunks, ImageChunk** chunks,
                        int include_pseudo_chunk) {
@@ -296,7 +292,6 @@
     curr->len = st.st_size;
     curr->data = img;
     curr->filename = NULL;
-    curr->I = NULL;
     ++curr;
     ++*num_chunks;
   }
@@ -311,7 +306,6 @@
       curr->deflate_len = temp_entries[nextentry].deflate_len;
       curr->deflate_data = img + pos;
       curr->filename = temp_entries[nextentry].filename;
-      curr->I = NULL;
 
       curr->len = temp_entries[nextentry].uncomp_len;
       curr->data = reinterpret_cast<unsigned char*>(malloc(curr->len));
@@ -356,7 +350,6 @@
     }
     curr->data = img + pos;
     curr->filename = NULL;
-    curr->I = NULL;
     pos += curr->len;
 
     ++*num_chunks;
@@ -424,7 +417,6 @@
       curr->type = CHUNK_NORMAL;
       curr->len = GZIP_HEADER_LEN;
       curr->data = p;
-      curr->I = NULL;
 
       pos += curr->len;
       p += curr->len;
@@ -432,7 +424,6 @@
 
       curr->type = CHUNK_DEFLATE;
       curr->filename = NULL;
-      curr->I = NULL;
 
       // We must decompress this chunk in order to discover where it
       // ends, and so we can put the uncompressed data and its length
@@ -491,7 +482,6 @@
       curr->start = pos;
       curr->len = GZIP_FOOTER_LEN;
       curr->data = img+pos;
-      curr->I = NULL;
 
       pos += curr->len;
       p += curr->len;
@@ -515,7 +505,6 @@
       *chunks = reinterpret_cast<ImageChunk*>(realloc(*chunks, *num_chunks * sizeof(ImageChunk)));
       ImageChunk* curr = *chunks + (*num_chunks-1);
       curr->start = pos;
-      curr->I = NULL;
 
       // 'pos' is not the offset of the start of a gzip chunk, so scan
       // forward until we find a gzip header.
@@ -642,7 +631,7 @@
   close(fd); // temporary file is created and we don't need its file
              // descriptor
 
-  int r = bsdiff(src->data, src->len, &(src->I), tgt->data, tgt->len, ptemp);
+  int r = bsdiff::bsdiff(src->data, src->len, tgt->data, tgt->len, ptemp);
   if (r != 0) {
     printf("bsdiff() failed: %d\n", r);
     return NULL;