From: Andrew Tridgell <tridge@samba.org>
Date: Fri, 22 May 1998 01:53:02 +0000 (+0000)
Subject: this fixes two problems:
X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/commitdiff_plain/45f133b9769fb45a329d3d41e121109d430e307d

this fixes two problems:

1) handle 64 bit file offsets in the token code. I wonder how large
bit files worked up till now?

2) send a null token when we have passed over a large lump of data
without finding a token match. This reduces the number of IOs
considerably as it removes the need for seeks/reads on the checksum
calculation and literal send code. This is not enabled yet for the
compressed case as the deflate token code can't handle it yet.
---

diff --git a/match.c b/match.c
index bc759e24..0d8bc31b 100644
--- a/match.c
+++ b/match.c
@@ -100,7 +100,7 @@ static void matched(int f,struct sum_struct *s,struct map_struct *buf,
 		rprintf(FINFO,"match at %d last_match=%d j=%d len=%d n=%d\n",
 			(int)offset,(int)last_match,i,(int)s->sums[i].len,(int)n);
 
-	send_token(f,i,buf,last_match,n,i==-1?0:s->sums[i].len);
+	send_token(f,i,buf,last_match,n,i<0?0:s->sums[i].len);
 	data_transfer += n;
 
 	if (n > 0)
@@ -131,6 +131,7 @@ static void hash_search(int f,struct sum_struct *s,
 	char sum2[SUM_LENGTH];
 	uint32 s1, s2, sum; 
 	schar *map;
+	extern int do_compression;
 
 	if (verbose > 2)
 		rprintf(FINFO,"hash search b=%d len=%d\n",s->n,(int)len);
@@ -212,7 +213,23 @@ static void hash_search(int f,struct sum_struct *s,
 		} else {
 			--k;
 		}
-		
+
+		if (!do_compression) {
+			/* By matching early we avoid re-reading the
+			   data 3 times in the case where a token
+			   match comes a long way after last
+			   match. The 3 reads are caused by the
+			   running match, the checksum update and the
+			   literal send.
+
+			   we don't enable this for the compressed
+			   case yet as the deflated token code can't
+			   handle it. Paul is working on it */
+			if (offset-last_match >= CHUNK_SIZE+s->n && 
+			    (end-offset > CHUNK_SIZE)) {
+				matched(f,s,buf,offset - s->n, -2);
+			}
+		}
 	} while (++offset < end);
 	
 	matched(f,s,buf,len,-1);
diff --git a/token.c b/token.c
index 543031e4..318bdbc2 100644
--- a/token.c
+++ b/token.c
@@ -51,7 +51,7 @@ static int simple_recv_token(int f,char **data)
 
 /* non-compressing send token */
 static void simple_send_token(int f,int token,
-			      struct map_struct *buf,int offset,int n)
+			      struct map_struct *buf,OFF_T offset,int n)
 {
 	if (n > 0) {
 		int l = 0;
@@ -62,7 +62,10 @@ static void simple_send_token(int f,int token,
 			l += n1;
 		}
 	}
-	write_int(f,-(token+1));
+	/* a -2 token means to send data only and no token */
+	if (token != -2) {
+		write_int(f,-(token+1));
+	}
 }
 
 
@@ -103,7 +106,7 @@ static char *obuf;
 /* Send a deflated token */
 static void
 send_deflated_token(int f, int token,
-		    struct map_struct *buf, int offset, int nb, int toklen)
+		    struct map_struct *buf, OFF_T offset, int nb, int toklen)
 {
     int n, r;
     static int init_done;
@@ -350,7 +353,7 @@ see_deflate_token(char *buf, int len)
  * If token == -1 then we have reached EOF 
  * If n == 0 then don't send a buffer
  */
-void send_token(int f,int token,struct map_struct *buf,int offset,
+void send_token(int f,int token,struct map_struct *buf,OFF_T offset,
 		int n,int toklen)
 {
   if (!do_compression) {