X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/900cfcb584e878c9600827b7e0ad7160e1018b48..f57ab2f71889ca2e0f3f6c2c784e7ff76db20db0:/match.c

diff --git a/match.c b/match.c
index ee49a0ef..8367d158 100644
--- a/match.c
+++ b/match.c
@@ -1,21 +1,23 @@
 /*
-   Copyright (C) Andrew Tridgell 1996
-   Copyright (C) Paul Mackerras 1996
-
-   This program is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2 of the License, or
-   (at your option) any later version.
-
-   This program is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU General Public License for more details.
-
-   You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-*/
+ * Block matching used by the file-transfer code.
+ *
+ * Copyright (C) 1996 Andrew Tridgell
+ * Copyright (C) 1996 Paul Mackerras
+ * Copyright (C) 2003-2007 Wayne Davison
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, visit the http://fsf.org website.
+ */
 
 #include "rsync.h"
 
@@ -37,35 +39,29 @@ static int total_matches;
 
 extern struct stats stats;
 
-static uint32 tablesize;
-static int32 *sum_table;
+#define TABLESIZE (1<<16)
+
+static int32 *hash_table;
 
-#define GETTAG(sum) ((sum)%tablesize)
+#define SUM2HASH2(s1,s2) (((s1) + (s2)) & 0xFFFF)
+#define SUM2HASH(sum) SUM2HASH2((sum)&0xFFFF,(sum)>>16)
 
 static void build_hash_table(struct sum_struct *s)
 {
 	int32 i;
-	uint32 prior_size = tablesize;
-
-	/* Dynamically calculate the hash table size so that the hash load
-	 * for big files is about 80%.  This number must be odd or s2 will
-	 * not be able to span the entire set. */
-	tablesize = (uint32)(s->count/8) * 10 + 11;
-	if (tablesize < 65537)
-		tablesize = 65537; /* a prime number */
-	if (tablesize != prior_size) {
-		free(sum_table);
-		sum_table = new_array(int32, tablesize);
-		if (!sum_table)
+
+	if (!hash_table) {
+		hash_table = new_array(int32, TABLESIZE);
+		if (!hash_table)
 			out_of_memory("build_hash_table");
 	}
 
-	memset(sum_table, 0xFF, tablesize * sizeof sum_table[0]);
+	memset(hash_table, 0xFF, TABLESIZE * sizeof hash_table[0]);
 
 	for (i = 0; i < s->count; i++) {
-		uint32 t = GETTAG(s->sums[i].sum1);
-		s->sums[i].chain = sum_table[t];
-		sum_table[t] = i;
+		uint32 t = SUM2HASH(s->sums[i].sum1);
+		s->sums[i].chain = hash_table[t];
+		hash_table[t] = i;
 	}
 }
 
@@ -88,7 +84,7 @@ static OFF_T last_match;
 static void matched(int f, struct sum_struct *s, struct map_struct *buf,
 		    OFF_T offset, int32 i)
 {
-	int32 n = offset - last_match; /* max value: block_size (int32) */
+	int32 n = (int32)(offset - last_match); /* max value: block_size (int32) */
 	int32 j;
 
 	if (verbose > 2 && i >= 0) {
@@ -124,8 +120,8 @@ static void matched(int f, struct sum_struct *s, struct map_struct *buf,
 static void hash_search(int f,struct sum_struct *s,
 			struct map_struct *buf, OFF_T len)
 {
-	OFF_T offset, end, backup;
-	int32 k, want_i;
+	OFF_T offset, end;
+	int32 k, want_i, backup;
 	char sum2[SUM_LENGTH];
 	uint32 s1, s2, sum;
 	int more;
@@ -162,16 +158,17 @@ static void hash_search(int f,struct sum_struct *s,
 	do {
 		int done_csum2 = 0;
 		int32 i;
-		uint32 t;
 
-		if (verbose > 4)
-			rprintf(FINFO,"offset=%.0f sum=%08x\n",(double)offset,sum);
+		if (verbose > 4) {
+			rprintf(FINFO, "offset=%.0f sum=%04x%04x\n",
+				(double)offset, s2 & 0xFFFF, s1 & 0xFFFF);
+		}
 
-		t = GETTAG(sum);
-		i = sum_table[t];
+		i = hash_table[SUM2HASH2(s1,s2)];
 		if (i < 0)
 			goto null_hash;
 
+		sum = (s1 & 0xffff) | (s2 << 16);
 		hash_hits++;
 		do {
 			int32 l;
@@ -256,7 +253,7 @@ static void hash_search(int f,struct sum_struct *s,
 		} while ((i = s->sums[i].chain) >= 0);
 
 	  null_hash:
-		backup = offset - last_match;
+		backup = (int32)(offset - last_match);
 		/* We sometimes read 1 byte prior to last_match... */
 		if (backup < 0)
 			backup = 0;
@@ -274,7 +271,6 @@ static void hash_search(int f,struct sum_struct *s,
 			s2 += s1;
 		} else
 			--k;
-		sum = (s1 & 0xffff) | (s2 << 16);
 
 		/* By matching early we avoid re-reading the
 		   data 3 times in the case where a token
@@ -307,7 +303,8 @@ static void hash_search(int f,struct sum_struct *s,
  **/
 void match_sums(int f, struct sum_struct *s, struct map_struct *buf, OFF_T len)
 {
-	char file_sum[MD4_SUM_LENGTH];
+	char file_sum[MAX_DIGEST_LEN];
+	int sum_len;
 
 	last_match = 0;
 	false_alarms = 0;
@@ -317,22 +314,24 @@ void match_sums(int f, struct sum_struct *s, struct map_struct *buf, OFF_T len)
 
 	sum_init(checksum_seed);
 
-	if (append_mode) {
-		OFF_T j = 0;
-		for (j = CHUNK_SIZE; j < s->flength; j += CHUNK_SIZE) {
-			if (buf && do_progress)
-				show_progress(last_match, buf->file_size);
-			sum_update(map_ptr(buf, last_match, CHUNK_SIZE),
-				   CHUNK_SIZE);
-			last_match = j;
-		}
-		if (last_match < s->flength) {
-			int32 len = s->flength - last_match;
-			if (buf && do_progress)
-				show_progress(last_match, buf->file_size);
-			sum_update(map_ptr(buf, last_match, len), len);
-			last_match = s->flength;
+	if (append_mode > 0) {
+		if (append_mode == 2) {
+			OFF_T j = 0;
+			for (j = CHUNK_SIZE; j < s->flength; j += CHUNK_SIZE) {
+				if (buf && do_progress)
+					show_progress(last_match, buf->file_size);
+				sum_update(map_ptr(buf, last_match, CHUNK_SIZE),
+					   CHUNK_SIZE);
+				last_match = j;
+			}
+			if (last_match < s->flength) {
+				int32 n = (int32)(s->flength - last_match);
+				if (buf && do_progress)
+					show_progress(last_match, buf->file_size);
+				sum_update(map_ptr(buf, last_match, n), n);
+			}
 		}
+		last_match = s->flength;
 		s->count = 0;
 	}
 
@@ -342,7 +341,7 @@ void match_sums(int f, struct sum_struct *s, struct map_struct *buf, OFF_T len)
 		if (verbose > 2)
 			rprintf(FINFO,"built hash table\n");
 
-		hash_search(f,s,buf,len);
+		hash_search(f, s, buf, len);
 
 		if (verbose > 2)
 			rprintf(FINFO,"done hash search\n");
@@ -354,14 +353,14 @@ void match_sums(int f, struct sum_struct *s, struct map_struct *buf, OFF_T len)
 		matched(f, s, buf, len, -1);
 	}
 
-	sum_end(file_sum);
+	sum_len = sum_end(file_sum);
 	/* If we had a read error, send a bad checksum. */
 	if (buf && buf->status != 0)
 		file_sum[0]++;
 
 	if (verbose > 2)
 		rprintf(FINFO,"sending file_sum\n");
-	write_buf(f,file_sum,MD4_SUM_LENGTH);
+	write_buf(f, file_sum, sum_len);
 
 	if (verbose > 2)
 		rprintf(FINFO, "false_alarms=%d hash_hits=%d matches=%d\n",