X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/43a481dc5586a16af249fbae611b36442bed6a8c..7ae359c331afedbab7a9d572cf78495b2bf92dbf:/checksum.c

diff --git a/checksum.c b/checksum.c
index b656ef90..edc844f2 100644
--- a/checksum.c
+++ b/checksum.c
@@ -19,21 +19,31 @@
 
 #include "rsync.h"
 
-extern int csum_length;
+int csum_length=2; /* initial value */
+
+#define CSUM_CHUNK 64
+
+int checksum_seed = 0;
+extern int remote_version;
 
 /*
   a simple 32 bit checksum that can be upadted from either end
   (inspired by Mark Adler's Adler-32 checksum)
   */
-uint32 get_checksum1(char *buf,int len)
+uint32 get_checksum1(char *buf1,int len)
 {
     int i;
     uint32 s1, s2;
+    schar *buf = (schar *)buf1;
 
     s1 = s2 = 0;
-    for (i = 0; i < len; i++) {
-	s1 += buf[i];
-	s2 += s1;
+    for (i = 0; i < (len-4); i+=4) {
+	s2 += 4*(s1 + buf[i]) + 3*buf[i+1] + 2*buf[i+2] + buf[i+3] + 
+	  10*CHAR_OFFSET;
+	s1 += (buf[i+0] + buf[i+1] + buf[i+2] + buf[i+3] + 4*CHAR_OFFSET); 
+    }
+    for (; i < len; i++) {
+	s1 += (buf[i]+CHAR_OFFSET); s2 += s1;
     }
     return (s1 & 0xffff) + (s2 << 16);
 }
@@ -41,42 +51,130 @@ uint32 get_checksum1(char *buf,int len)
 
 void get_checksum2(char *buf,int len,char *sum)
 {
-  char buf2[64];
-  int i;
-  MDstruct MD;
-
-  MDbegin(&MD);
-  for(i = 0; i + 64 <= len; i += 64) {
-    bcopy(buf+i,buf2,64);
-    MDupdate(&MD, buf2, 512);
-  }
-  bcopy(buf+i,buf2,len-i);
-  MDupdate(&MD, buf2, (len-i)*8);
-  SIVAL(sum,0,MD.buffer[0]);
-  if (csum_length <= 4) return;
-  SIVAL(sum,4,MD.buffer[1]);
-  if (csum_length <= 8) return;
-  SIVAL(sum,8,MD.buffer[2]);
-  if (csum_length <= 12) return;
-  SIVAL(sum,12,MD.buffer[3]);
+	int i;
+	static char *buf1;
+	static int len1;
+	struct mdfour m;
+
+	if (len > len1) {
+		if (buf1) free(buf1);
+		buf1 = (char *)malloc(len+4);
+		len1 = len;
+		if (!buf1) out_of_memory("get_checksum2");
+	}
+	
+	mdfour_begin(&m);
+	
+	memcpy(buf1,buf,len);
+	if (checksum_seed) {
+		SIVAL(buf1,len,checksum_seed);
+		len += 4;
+	}
+	
+	for(i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
+		mdfour_update(&m, (uchar *)(buf1+i), CSUM_CHUNK);
+	}
+	if (len - i > 0) {
+		mdfour_update(&m, (uchar *)(buf1+i), (len-i));
+	}
+	
+	mdfour_result(&m, (uchar *)sum);
 }
 
-void file_checksum(char *fname,char *sum,off_t size)
+
+void file_checksum(char *fname,char *sum,OFF_T size)
 {
-  char *buf;
-  int fd;
-  bzero(sum,csum_length);
-
-  fd = open(fname,O_RDONLY);
-  if (fd == -1) return;
-
-  buf = map_file(fd,size);
-  if (!buf) {
-    close(fd);
-    return;
-  }
-
-  get_checksum2(buf,size,sum);
-  close(fd);
-  unmap_file(buf,size);
+	OFF_T i;
+	struct map_struct *buf;
+	int fd;
+	OFF_T len = size;
+	char tmpchunk[CSUM_CHUNK];
+	struct mdfour m;
+	
+	memset(sum,0,csum_length);
+	
+	fd = open(fname,O_RDONLY);
+	if (fd == -1) return;
+	
+	buf = map_file(fd,size);
+	
+	mdfour_begin(&m);
+
+	for(i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
+		memcpy(tmpchunk, map_ptr(buf,i,CSUM_CHUNK), CSUM_CHUNK);
+		mdfour_update(&m, (uchar *)tmpchunk, CSUM_CHUNK);
+	}
+
+	if (len - i > 0) {
+		memcpy(tmpchunk, map_ptr(buf,i,len-i), len-i);
+		mdfour_update(&m, (uchar *)tmpchunk, (len-i));
+	}
+
+	mdfour_result(&m, (uchar *)sum);
+
+	close(fd);
+	unmap_file(buf);
+}
+
+
+void checksum_init(void)
+{
+  if (remote_version >= 14)
+    csum_length = 2; /* adaptive */
+  else
+    csum_length = SUM_LENGTH;
+}
+
+
+
+static int sumresidue;
+static char sumrbuf[CSUM_CHUNK];
+static struct mdfour md;
+
+void sum_init(void)
+{
+	char s[4];
+	mdfour_begin(&md);
+	sumresidue=0;
+	SIVAL(s,0,checksum_seed);
+	sum_update(s,4);
+}
+
+void sum_update(char *p,int len)
+{
+	int i;
+	if (len + sumresidue < CSUM_CHUNK) {
+		memcpy(sumrbuf+sumresidue, p, len);
+		sumresidue += len;
+		return;
+	}
+
+	if (sumresidue) {
+		i = MIN(CSUM_CHUNK-sumresidue,len);
+		memcpy(sumrbuf+sumresidue,p,i);
+		mdfour_update(&md, (uchar *)sumrbuf, (i+sumresidue));
+		len -= i;
+		p += i;
+	}
+
+	for(i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
+		memcpy(sumrbuf,p+i,CSUM_CHUNK);
+		mdfour_update(&md, (uchar *)sumrbuf, CSUM_CHUNK);
+	}
+
+	if (len - i > 0) {
+		sumresidue = len-i;
+		memcpy(sumrbuf,p+i,sumresidue);
+	} else {
+		sumresidue = 0;    
+	}
+}
+
+void sum_end(char *sum)
+{
+	if (sumresidue) {
+		mdfour_update(&md, (uchar *)sumrbuf, sumresidue);
+	}
+
+	mdfour_result(&md, (uchar *)sum);
 }