+
+
+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]);
+}
+
+