first commit

Author: deminy

.gitignore

@@ -0,0 +1,42 @@
+*.dep
+*.lo
+*.la
+.libs
+acinclude.m4
+aclocal.m4
+autom4te.cache
+build
+config.guess
+config.h
+config.h.in
+config.log
+config.nice
+config.status
+config.sub
+configure
+configure.ac
+configure.in
+include
+install-sh
+libtool
+ltmain.sh
+Makefile
+Makefile.fragments
+Makefile.global
+Makefile.objects
+missing
+mkinstalldirs
+modules
+php_test_results_*.txt
+phpt.*
+run-test-info.php
+run-tests.php
+tests/**/*.diff
+tests/**/*.out
+tests/**/*.php
+tests/**/*.exp
+tests/**/*.log
+tests/**/*.sh
+tests/**/*.db
+tests/**/*.mem
+tmp-php.ini

bsdiff.c

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+/*-
+ * Copyright 2003-2005 Colin Percival
+ * Copyright 2012 Matthew Endsley
+ * 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 "bsdiff.h"
+
+#include <limits.h>
+#include <string.h>
+
+#define MIN(x,y) (((x)<(y)) ? (x) : (y))
+
+static void split(int64_t *I,int64_t *V,int64_t start,int64_t len,int64_t h)
+{
+	int64_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(int64_t *I,int64_t *V,const uint8_t *old,int64_t oldsize)
+{
+	int64_t buckets[256];
+	int64_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 int64_t matchlen(const uint8_t *old,int64_t oldsize,const uint8_t *new,int64_t newsize)
+{
+	int64_t i;
+
+	for(i=0;(i<oldsize)&&(i<newsize);i++)
+		if(old[i]!=new[i]) break;
+
+	return i;
+}
+
+static int64_t search(const int64_t *I,const uint8_t *old,int64_t oldsize,
+		const uint8_t *new,int64_t newsize,int64_t st,int64_t en,int64_t *pos)
+{
+	int64_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);
+	};
+}
+
+void offtout(int64_t x,uint8_t *buf)
+{
+	int64_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 int64_t writedata(struct bsdiff_stream* stream, const void* buffer, int64_t length)
+{
+	int64_t result = 0;
+
+	while (length > 0)
+	{
+		const int smallsize = (int)MIN(length, INT_MAX);
+		const int writeresult = stream->write(stream, buffer, smallsize);
+		if (writeresult == -1)
+		{
+			return -1;
+		}
+
+		result += writeresult;
+		length -= smallsize;
+		buffer = (uint8_t*)buffer + smallsize;
+	}
+
+	return result;
+}
+
+struct bsdiff_request
+{
+	const uint8_t* old;
+	int64_t oldsize;
+	const uint8_t* new;
+	int64_t newsize;
+	struct bsdiff_stream* stream;
+	int64_t *I;
+	uint8_t *buffer;
+};
+
+static int bsdiff_internal(const struct bsdiff_request req)
+{
+	int64_t *I,*V;
+	int64_t scan,pos,len;
+	int64_t lastscan,lastpos,lastoffset;
+	int64_t oldscore,scsc;
+	int64_t s,Sf,lenf,Sb,lenb;
+	int64_t overlap,Ss,lens;
+	int64_t i;
+	uint8_t *buffer;
+	uint8_t buf[8 * 3];
+
+	if((V=req.stream->malloc((req.oldsize+1)*sizeof(int64_t)))==NULL) return -1;
+	I = req.I;
+
+	qsufsort(I,V,req.old,req.oldsize);
+	req.stream->free(V);
+
+	buffer = req.buffer;
+
+	/* Compute the differences, writing ctrl as we go */
+	scan=0;len=0;pos=0;
+	lastscan=0;lastpos=0;lastoffset=0;
+	while(scan<req.newsize) {
+		oldscore=0;
+
+		for(scsc=scan+=len;scan<req.newsize;scan++) {
+			len=search(I,req.old,req.oldsize,req.new+scan,req.newsize-scan,
+					0,req.oldsize,&pos);
+
+			for(;scsc<scan+len;scsc++)
+			if((scsc+lastoffset<req.oldsize) &&
+				(req.old[scsc+lastoffset] == req.new[scsc]))
+				oldscore++;
+
+			if(((len==oldscore) && (len!=0)) || 
+				(len>oldscore+8)) break;
+
+			if((scan+lastoffset<req.oldsize) &&
+				(req.old[scan+lastoffset] == req.new[scan]))
+				oldscore--;
+		};
+
+		if((len!=oldscore) || (scan==req.newsize)) {
+			s=0;Sf=0;lenf=0;
+			for(i=0;(lastscan+i<scan)&&(lastpos+i<req.oldsize);) {
+				if(req.old[lastpos+i]==req.new[lastscan+i]) s++;
+				i++;
+				if(s*2-i>Sf*2-lenf) { Sf=s; lenf=i; };
+			};
+
+			lenb=0;
+			if(scan<req.newsize) {
+				s=0;Sb=0;
+				for(i=1;(scan>=lastscan+i)&&(pos>=i);i++) {
+					if(req.old[pos-i]==req.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(req.new[lastscan+lenf-overlap+i]==
+					   req.old[lastpos+lenf-overlap+i]) s++;
+					if(req.new[scan-lenb+i]==
+					   req.old[pos-lenb+i]) s--;
+					if(s>Ss) { Ss=s; lens=i+1; };
+				};
+
+				lenf+=lens-overlap;
+				lenb-=lens;
+			};
+
+			offtout(lenf,buf);
+			offtout((scan-lenb)-(lastscan+lenf),buf+8);
+			offtout((pos-lenb)-(lastpos+lenf),buf+16);
+
+			/* Write control data */
+			if (writedata(req.stream, buf, sizeof(buf)))
+				return -1;
+
+			/* Write diff data */
+			for(i=0;i<lenf;i++)
+				buffer[i]=req.new[lastscan+i]-req.old[lastpos+i];
+			if (writedata(req.stream, buffer, lenf))
+				return -1;
+
+			/* Write extra data */
+			for(i=0;i<(scan-lenb)-(lastscan+lenf);i++)
+				buffer[i]=req.new[lastscan+lenf+i];
+			if (writedata(req.stream, buffer, (scan-lenb)-(lastscan+lenf)))
+				return -1;
+
+			lastscan=scan-lenb;
+			lastpos=pos-lenb;
+			lastoffset=pos-scan;
+		};
+	};
+
+	return 0;
+}
+
+int bsdiff(const uint8_t* old, int64_t oldsize, const uint8_t* new, int64_t newsize, struct bsdiff_stream* stream)
+{
+	int result;
+	struct bsdiff_request req;
+
+	if((req.I=stream->malloc((oldsize+1)*sizeof(int64_t)))==NULL)
+		return -1;
+
+	if((req.buffer=stream->malloc(newsize+1))==NULL)
+	{
+		stream->free(req.I);
+		return -1;
+	}
+
+	req.old = old;
+	req.oldsize = oldsize;
+	req.new = new;
+	req.newsize = newsize;
+	req.stream = stream;
+
+	result = bsdiff_internal(req);
+
+	stream->free(req.buffer);
+	stream->free(req.I);
+
+	return result;
+}