Now support dynamic per-file checksum2 size.

This pushes protocol version to 27

generator.c

@@ -116,13 +116,21 @@ static int adapt_block_size(struct file_struct *file, int bsize)
 
 
 /*
-  send a header that says "we have no checksums" down the f_out fd
+ * 	NULL sum_struct means we have no checksums
   */
-static void send_null_sums(int f_out)
+
+void write_sum_head(int f, struct sum_struct *sum)
 {
-	write_int(f_out, 0);
-	write_int(f_out, block_size);
-	write_int(f_out, 0);
+	static struct sum_struct null_sum;
+
+	if (sum == (struct sum_struct *)NULL)
+		sum = &null_sum;
+
+	write_int(f, sum->count);
+	write_int(f, sum->blength);
+	if (remote_version >= 27)
+		write_int(f, sum->s2length);
+	write_int(f, sum->remainder);
 }
 
 
@@ -164,19 +172,18 @@ static void generate_and_send_sums(struct map_struct *buf, OFF_T len,
 
 	sum.count = (len + (block_len - 1)) / block_len;
 	sum.remainder = (len % block_len);
-	sum.n = block_len;
+	sum.blength	= block_len;
 	sum.flength = len;
+	sum.s2length	= csum_length;
 	/* not needed here  sum.sums = NULL; */
 
 	if (sum.count && verbose > 3) {
 		rprintf(FINFO, "count=%ld rem=%ld n=%ld flength=%.0f\n",
 			(long) sum.count, (long) sum.remainder,
-			(long) sum.n, (double) sum.flength);
+			(long) sum.blength, (double) sum.flength);
 	}
 
-	write_int(f_out, sum.count);
-	write_int(f_out, sum.n);
-	write_int(f_out, sum.remainder);
+	write_sum_head(f_out, &sum);
 
 	for (i = 0; i < sum.count; i++) {
 		int n1 = MIN(len, block_len);
@@ -192,7 +199,7 @@ static void generate_and_send_sums(struct map_struct *buf, OFF_T len,
 				i, (double) offset, n1, (unsigned long) sum1);
 		}
 		write_int(f_out, sum1);
-		write_buf(f_out, sum2, csum_length);
+		write_buf(f_out, sum2, sum.s2length);
 		len -= n1;
 		offset += n1;
 	}
@@ -384,7 +391,7 @@ void recv_generator(char *fname, struct file_list *flist, int i, int f_out)
 	if (statret == -1) {
 		if (errno == ENOENT) {
 			write_int(f_out,i);
-			if (!dry_run) send_null_sums(f_out);
+			if (!dry_run) write_sum_head(f_out, NULL);
 		} else {
 			if (verbose > 1)
 				rprintf(FERROR, RSYNC_NAME
@@ -401,7 +408,7 @@ void recv_generator(char *fname, struct file_list *flist, int i, int f_out)
 
 		/* now pretend the file didn't exist */
 		write_int(f_out,i);
-		if (!dry_run) send_null_sums(f_out);
+		if (!dry_run) write_sum_head(f_out, NULL);
 		return;
 	}
 
@@ -430,7 +437,7 @@ void recv_generator(char *fname, struct file_list *flist, int i, int f_out)
 
 	if (disable_deltas_p()) {
 		write_int(f_out,i);
-		send_null_sums(f_out);
+		write_sum_head(f_out, NULL);
 		return;
 	}
 
@@ -441,7 +448,7 @@ void recv_generator(char *fname, struct file_list *flist, int i, int f_out)
 		rprintf(FERROR,RSYNC_NAME": failed to open \"%s\", continuing : %s\n",fnamecmp,strerror(errno));
 		/* pretend the file didn't exist */
 		write_int(f_out,i);
-		send_null_sums(f_out);
+		write_sum_head(f_out, NULL);
 		return;
 	}
 

match.c

@@ -19,8 +19,6 @@
 
 #include "rsync.h"
 
-extern int csum_length;
-
 extern int verbose;
 extern int am_server;
 
@@ -152,11 +150,11 @@ static void hash_search(int f,struct sum_struct *s,
 
 	if (verbose > 2)
 		rprintf(FINFO,"hash search b=%ld len=%.0f\n",
-			(long) s->n, (double)len);
+			(long) s->blength, (double)len);
 
-	/* cast is to make s->n signed; it should always be reasonably
+	/* cast is to make s->blength signed; it should always be reasonably
 	 * small */
-	k = MIN(len, (OFF_T) s->n);
+	k = MIN(len, (OFF_T) s->blength);
 	
 	map = (schar *)map_ptr(buf,0,k);
 	
@@ -171,8 +169,8 @@ static void hash_search(int f,struct sum_struct *s,
 	end = len + 1 - s->sums[s->count-1].len;
 	
 	if (verbose > 3)
-		rprintf(FINFO, "hash search s->n=%ld len=%.0f count=%ld\n",
-			(long) s->n, (double) len, (long) s->count);
+		rprintf(FINFO, "hash search s->blength=%ld len=%.0f count=%ld\n",
+			(long) s->blength, (double) len, (long) s->count);
 	
 	do {
 		tag t = gettag2(s1,s2);
@@ -194,7 +192,7 @@ static void hash_search(int f,struct sum_struct *s,
 			if (sum != s->sums[i].sum1) continue;
 			
 			/* also make sure the two blocks are the same length */
-			l = MIN(s->n,len-offset);
+			l = MIN(s->blength,len-offset);
 			if (l != s->sums[i].len) continue;			
 
 			if (verbose > 3)
@@ -207,7 +205,7 @@ static void hash_search(int f,struct sum_struct *s,
 				done_csum2 = 1;
 			}
 			
-			if (memcmp(sum2,s->sums[i].sum2,csum_length) != 0) {
+			if (memcmp(sum2,s->sums[i].sum2,s->s2length) != 0) {
 				false_alarms++;
 				continue;
 			}
@@ -218,7 +216,7 @@ static void hash_search(int f,struct sum_struct *s,
 				int i2 = targets[j].i;
 				if (i2 == last_i + 1) {
 					if (sum != s->sums[i2].sum1) break;
-					if (memcmp(sum2,s->sums[i2].sum2,csum_length) != 0) break;
+					if (memcmp(sum2,s->sums[i2].sum2,s->s2length) != 0) break;
 					/* we've found an adjacent match - the RLL coder 
 					   will be happy */
 					i = i2;
@@ -230,7 +228,7 @@ static void hash_search(int f,struct sum_struct *s,
 			
 			matched(f,s,buf,offset,i);
 			offset += s->sums[i].len - 1;
-			k = MIN((len-offset), s->n);
+			k = MIN((len-offset), s->blength);
 			map = (schar *)map_ptr(buf,offset,k);
 			sum = get_checksum1((char *)map, k);
 			s1 = sum & 0xFFFF;
@@ -260,9 +258,9 @@ static void hash_search(int f,struct sum_struct *s,
 		   running match, the checksum update and the
 		   literal send. */
 		if (offset > last_match &&
-		    offset-last_match >= CHUNK_SIZE+s->n && 
+		    offset-last_match >= CHUNK_SIZE+s->blength && 
 		    (end-offset > CHUNK_SIZE)) {
-			matched(f,s,buf,offset - s->n, -2);
+			matched(f,s,buf,offset - s->blength, -2);
 		}
 	} while (++offset < end);
 	

receiver.c

@@ -230,7 +230,8 @@ static int receive_data(int f_in,struct map_struct *buf,int fd,char *fname,
 			OFF_T total_size)
 {
 	int i;
-	unsigned int n,remainder,len,count;
+	struct sum_struct sum;
+	unsigned int len;
 	OFF_T offset = 0;
 	OFF_T offset2;
 	char *data;
@@ -238,9 +239,7 @@ static int receive_data(int f_in,struct map_struct *buf,int fd,char *fname,
 	static char file_sum2[MD4_SUM_LENGTH];
 	char *map=NULL;
 	
-	count = read_int(f_in);
-	n = read_int(f_in);
-	remainder = read_int(f_in);
+	read_sum_head(f_in, &sum);
 	
 	sum_init();
 	
@@ -270,10 +269,10 @@ static int receive_data(int f_in,struct map_struct *buf,int fd,char *fname,
 		} 
 
 		i = -(i+1);
-		offset2 = i*(OFF_T)n;
-		len = n;
-		if (i == (int) count-1 && remainder != 0)
-			len = remainder;
+		offset2 = i*(OFF_T)sum.blength;
+		len = sum.blength;
+		if (i == (int) sum.count-1 && sum.remainder != 0)
+			len = sum.remainder;
 		
 		stats.matched_data += len;
 		

rsync.h

@@ -50,7 +50,7 @@
 #define SAME_TIME (1<<7)
 
 /* update this if you make incompatible changes */
-#define PROTOCOL_VERSION 26
+#define PROTOCOL_VERSION 27
 
 /* We refuse to interoperate with versions that are not in this range.
  * Note that we assume we'll work with later versions: the onus is on
@@ -408,7 +408,8 @@ struct sum_struct {
 	OFF_T flength;		/**< total file length */
 	size_t count;		/**< how many chunks */
 	size_t remainder;	/**< flength % block_length */
-	size_t n;		/**< block_length */
+	size_t blength;		/**< block_length */
+	size_t s2length;	/**< sum2_length */
 	struct sum_buf *sums;	/**< points to info for each chunk */
 };
 

sender.c

@@ -36,6 +36,21 @@ extern int am_server;
  **/
 
 
+void read_sum_head(int f, struct sum_struct *sum)
+{
+	extern int remote_version;
+
+	sum->count = read_int(f);
+	sum->blength = read_int(f);
+	if (remote_version < 27)
+	{
+		sum->s2length = csum_length;
+	} else {
+		sum->s2length = read_int(f);  
+	}
+	sum->remainder = read_int(f);  
+}
+
 /**
  * Receive the checksums for a buffer
  **/
@@ -48,14 +63,14 @@ static struct sum_struct *receive_sums(int f)
 	s = (struct sum_struct *)malloc(sizeof(*s));
 	if (!s) out_of_memory("receive_sums");
 
-	s->count = read_int(f);
-	s->n = read_int(f);
-	s->remainder = read_int(f);  
+	read_sum_head(f, s);
+
 	s->sums = NULL;
 
 	if (verbose > 3)
 		rprintf(FINFO,"count=%ld n=%ld rem=%ld\n",
-			(long) s->count, (long) s->n, (long) s->remainder);
+			(long) s->count, (long) s->blength,
+			(long) s->remainder);
 
 	if (s->count == 0) 
 		return(s);
@@ -65,7 +80,7 @@ static struct sum_struct *receive_sums(int f)
 
 	for (i=0; i < (int) s->count;i++) {
 		s->sums[i].sum1 = read_int(f);
-		read_buf(f,s->sums[i].sum2,csum_length);
+		read_buf(f,s->sums[i].sum2,s->s2length);
 
 		s->sums[i].offset = offset;
 		s->sums[i].i = i;
@@ -73,7 +88,7 @@ static struct sum_struct *receive_sums(int f)
 		if (i == (int) s->count-1 && s->remainder != 0) {
 			s->sums[i].len = s->remainder;
 		} else {
-			s->sums[i].len = s->n;
+			s->sums[i].len = s->blength;
 		}
 		offset += s->sums[i].len;
 
@@ -210,9 +225,7 @@ void send_files(struct file_list *flist,int f_out,int f_in)
 			if (write_batch)
 				write_batch_delta_file((char *)&i,sizeof(i));
 
-			write_int(f_out,s->count);
-			write_int(f_out,s->n);
-			write_int(f_out,s->remainder);
+			write_sum_head(f_out, s);
 		}
 	  
 		if (verbose > 2)
@@ -239,9 +252,7 @@ void send_files(struct file_list *flist,int f_out,int f_in)
                        }
                        else {
                          write_int(f_out,j);
-                         write_int(f_out,s->count);
-                         write_int(f_out,s->n);
-                         write_int(f_out,s->remainder);
+			 write_sum_head(f_out, s);
                          done=0;
                          while (!done) {
                             read_batch_delta_file( (char *) &buff_len, sizeof(int) );