X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/c627d61324e9dcd5df833ee6236dd10415f5bac4..27d3cdbc943a57d64f4f2a35a4f1e1b15d9ca41f:/checksum.c

diff --git a/checksum.c b/checksum.c
index cdd554fd..2262728c 100644
--- a/checksum.c
+++ b/checksum.c
@@ -19,60 +19,177 @@
 
 #include "rsync.h"
 
+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);
 }
 
 
+static void sum_put(MDstruct *md,char *sum)
+{
+  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]);
+}
+
+
 void get_checksum2(char *buf,int len,char *sum)
 {
-  char buf2[64];
   int i;
   MDstruct MD;
+  static char *buf1;
+  static int len1;
+
+  if (len > len1) {
+    if (buf1) free(buf1);
+    buf1 = (char *)malloc(len+4);
+    len1 = len;
+    if (!buf1) out_of_memory("get_checksum2");
+  }
 
   MDbegin(&MD);
-  for(i = 0; i + 64 <= len; i += 64) {
-    bcopy(buf+i,buf2,64);
-    MDupdate(&MD, buf2, 512);
+
+  memcpy(buf1,buf,len);
+  if (checksum_seed) {
+    SIVAL(buf1,len,checksum_seed);
+    len += 4;
   }
-  bcopy(buf+i,buf2,len-i);
-  MDupdate(&MD, buf2, (len-i)*8);
-  SIVAL(sum,0,MD.buffer[0]);
-  SIVAL(sum,4,MD.buffer[1]);
-  SIVAL(sum,8,MD.buffer[2]);
-  SIVAL(sum,12,MD.buffer[3]);
+
+  for(i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
+    MDupdate(&MD, buf1+i, CSUM_CHUNK*8);
+  }
+  if (len - i > 0)
+    MDupdate(&MD, buf1+i, (len-i)*8);
+
+  sum_put(&MD,sum);
 }
 
-void file_checksum(char *fname,char *sum,off_t size)
+
+void file_checksum(char *fname,char *sum,OFF_T size)
 {
-  char *buf;
+  OFF_T i;
+  MDstruct MD;
+  struct map_struct *buf;
   int fd;
-  bzero(sum,SUM_LENGTH);
+  OFF_T len = size;
+  char tmpchunk[CSUM_CHUNK];
+
+  memset(sum,0,csum_length);
 
   fd = open(fname,O_RDONLY);
   if (fd == -1) return;
 
   buf = map_file(fd,size);
-  if (!buf) {
-    close(fd);
-    return;
+
+  MDbegin(&MD);
+
+  for(i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
+    memcpy(tmpchunk, map_ptr(buf,i,CSUM_CHUNK), CSUM_CHUNK);
+    MDupdate(&MD, tmpchunk, CSUM_CHUNK*8);
   }
 
-  get_checksum2(buf,size,sum);
+  if (len - i > 0) {
+    memcpy(tmpchunk, map_ptr(buf,i,len-i), len-i);
+    MDupdate(&MD, tmpchunk, (len-i)*8);
+  }
+
+  sum_put(&MD,sum);
+
   close(fd);
-  unmap_file(buf,size);
+  unmap_file(buf);
 }
+
+
+void checksum_init(void)
+{
+  if (remote_version >= 14)
+    csum_length = 2; /* adaptive */
+  else
+    csum_length = SUM_LENGTH;
+}
+
+
+
+static MDstruct sumMD;
+static int sumresidue;
+static char sumrbuf[CSUM_CHUNK];
+
+void sum_init(void)
+{
+  char s[4];
+  MDbegin(&sumMD);  
+  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);
+    MDupdate(&sumMD, sumrbuf, (i+sumresidue)*8);
+    len -= i;
+    p += i;
+  }
+
+  for(i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
+    memcpy(sumrbuf,p+i,CSUM_CHUNK);
+    MDupdate(&sumMD, sumrbuf, CSUM_CHUNK*8);
+  }
+
+  if (len - i > 0) {
+    sumresidue = len-i;
+    memcpy(sumrbuf,p+i,sumresidue);
+  } else {
+    sumresidue = 0;    
+  }
+}
+
+void sum_end(char *sum)
+{
+  if (sumresidue)
+    MDupdate(&sumMD, sumrbuf, sumresidue*8);
+
+  SIVAL(sum,0,sumMD.buffer[0]);
+  SIVAL(sum,4,sumMD.buffer[1]);
+  SIVAL(sum,8,sumMD.buffer[2]);
+  SIVAL(sum,12,sumMD.buffer[3]);  
+}
+
+