X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/1f86fcf5dc1eb6a7077b0f6b52cc855409ddf881..5dd14f0c3388f69932d521915e039e32b9e6d970:/match.c

diff --git a/match.c b/match.c
index 77b3a53c..80619a49 100644
--- a/match.c
+++ b/match.c
@@ -1,89 +1,90 @@
 /*
-   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) 2003-2008 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"
+#include "inums.h"
 
-extern int verbose;
-extern int am_server;
-extern int do_progress;
 extern int checksum_seed;
 extern int append_mode;
+extern int checksum_len;
 
 int updating_basis_file;
-
-typedef unsigned short tag;
-
-#define TABLESIZE (1<<16)
-#define NULL_TAG (-1)
+char sender_file_sum[MAX_DIGEST_LEN];
 
 static int false_alarms;
-static int tag_hits;
+static int hash_hits;
 static int matches;
 static int64 data_transfer;
 
 static int total_false_alarms;
-static int total_tag_hits;
+static int total_hash_hits;
 static int total_matches;
 
 extern struct stats stats;
 
-struct target {
-	tag t;
-	int32 i;
-};
-
-static struct target *targets;
-
-static int32 *tag_table;
+#define TRADITIONAL_TABLESIZE (1<<16)
 
-#define gettag2(s1,s2) (((s1) + (s2)) & 0xFFFF)
-#define gettag(sum) gettag2((sum)&0xFFFF,(sum)>>16)
+static uint32 tablesize;
+static int32 *hash_table;
 
-static int compare_targets(struct target *t1,struct target *t2)
-{
-	return (int)t1->t - (int)t2->t;
-}
+#define SUM2HASH2(s1,s2) (((s1) + (s2)) & 0xFFFF)
+#define SUM2HASH(sum) SUM2HASH2((sum)&0xFFFF,(sum)>>16)
 
+#define BIG_SUM2HASH(sum) ((sum)%tablesize)
 
 static void build_hash_table(struct sum_struct *s)
 {
+	static uint32 alloc_size;
 	int32 i;
 
-	if (!tag_table)
-		tag_table = new_array(int32, TABLESIZE);
-
-	targets = new_array(struct target, s->count);
-	if (!tag_table || !targets)
-		out_of_memory("build_hash_table");
-
-	for (i = 0; i < s->count; i++) {
-		targets[i].i = i;
-		targets[i].t = gettag(s->sums[i].sum1);
+	/* Dynamically calculate the hash table size so that the hash load
+	 * for big files is about 80%.  A number greater than the traditional
+	 * size must be odd or s2 will not be able to span the entire set. */
+	tablesize = (uint32)(s->count/8) * 10 + 11;
+	if (tablesize < TRADITIONAL_TABLESIZE)
+		tablesize = TRADITIONAL_TABLESIZE;
+	if (tablesize > alloc_size || tablesize < alloc_size - 16*1024) {
+		if (hash_table)
+			free(hash_table);
+		hash_table = new_array(int32, tablesize);
+		if (!hash_table)
+			out_of_memory("build_hash_table");
+		alloc_size = tablesize;
 	}
 
-	qsort(targets,s->count,sizeof(targets[0]),(int (*)())compare_targets);
+	memset(hash_table, 0xFF, tablesize * sizeof hash_table[0]);
 
-	for (i = 0; i < TABLESIZE; i++)
-		tag_table[i] = NULL_TAG;
-
-	for (i = s->count; i-- > 0; )
-		tag_table[targets[i].t] = i;
+	if (tablesize == TRADITIONAL_TABLESIZE) {
+		for (i = 0; i < s->count; i++) {
+			uint32 t = SUM2HASH(s->sums[i].sum1);
+			s->sums[i].chain = hash_table[t];
+			hash_table[t] = i;
+		}
+	} else {
+		for (i = 0; i < s->count; i++) {
+			uint32 t = BIG_SUM2HASH(s->sums[i].sum1);
+			s->sums[i].chain = hash_table[t];
+			hash_table[t] = i;
+		}
+	}
 }
 
 
@@ -105,13 +106,13 @@ 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) {
+	if (DEBUG_GTE(DELTASUM, 2) && i >= 0) {
 		rprintf(FINFO,
-			"match at %.0f last_match=%.0f j=%d len=%ld n=%ld\n",
-			(double)offset, (double)last_match, i,
+			"match at %s last_match=%s j=%d len=%ld n=%ld\n",
+			big_num(offset), big_num(last_match), i,
 			(long)s->sums[i].len, (long)n);
 	}
 
@@ -128,13 +129,12 @@ static void matched(int f, struct sum_struct *s, struct map_struct *buf,
 		sum_update(map_ptr(buf, last_match + j, n1), n1);
 	}
 
-
 	if (i >= 0)
 		last_match = offset + s->sums[i].len;
 	else
 		last_match = offset;
 
-	if (buf && do_progress)
+	if (buf && INFO_GTE(PROGRESS, 1))
 		show_progress(last_match, buf->file_size);
 }
 
@@ -142,8 +142,8 @@ 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;
@@ -153,9 +153,9 @@ static void hash_search(int f,struct sum_struct *s,
 	 * coding of the output to work more efficiently. */
 	want_i = 0;
 
-	if (verbose > 2) {
-		rprintf(FINFO, "hash search b=%ld len=%.0f\n",
-			(long)s->blength, (double)len);
+	if (DEBUG_GTE(DELTASUM, 2)) {
+		rprintf(FINFO, "hash search b=%ld len=%s\n",
+			(long)s->blength, big_num(len));
 	}
 
 	k = (int32)MIN(len, (OFF_T)s->blength);
@@ -165,33 +165,40 @@ static void hash_search(int f,struct sum_struct *s,
 	sum = get_checksum1((char *)map, k);
 	s1 = sum & 0xFFFF;
 	s2 = sum >> 16;
-	if (verbose > 3)
+	if (DEBUG_GTE(DELTASUM, 3))
 		rprintf(FINFO, "sum=%.8x k=%ld\n", sum, (long)k);
 
 	offset = 0;
 
 	end = len + 1 - s->sums[s->count-1].len;
 
-	if (verbose > 3) {
-		rprintf(FINFO, "hash search s->blength=%ld len=%.0f count=%.0f\n",
-			(long)s->blength, (double)len, (double)s->count);
+	if (DEBUG_GTE(DELTASUM, 3)) {
+		rprintf(FINFO, "hash search s->blength=%ld len=%s count=%s\n",
+			(long)s->blength, big_num(len), big_num(s->count));
 	}
 
 	do {
-		tag t = gettag2(s1,s2);
 		int done_csum2 = 0;
-		int32 j = tag_table[t];
+		int32 i;
 
-		if (verbose > 4)
-			rprintf(FINFO,"offset=%.0f sum=%08x\n",(double)offset,sum);
+		if (DEBUG_GTE(DELTASUM, 4)) {
+			rprintf(FINFO, "offset=%s sum=%04x%04x\n",
+				big_num(offset), s2 & 0xFFFF, s1 & 0xFFFF);
+		}
 
-		if (j == NULL_TAG)
-			goto null_tag;
+		if (tablesize == TRADITIONAL_TABLESIZE) {
+			if ((i = hash_table[SUM2HASH2(s1,s2)]) < 0)
+				goto null_hash;
+			sum = (s1 & 0xffff) | (s2 << 16);
+		} else {
+			sum = (s1 & 0xffff) | (s2 << 16);
+			if ((i = hash_table[BIG_SUM2HASH(sum)]) < 0)
+				goto null_hash;
+		}
 
-		sum = (s1 & 0xffff) | (s2 << 16);
-		tag_hits++;
+		hash_hits++;
 		do {
-			int32 l, i = targets[j].i;
+			int32 l;
 
 			if (sum != s->sums[i].sum1)
 				continue;
@@ -207,9 +214,11 @@ static void hash_search(int f,struct sum_struct *s,
 			    && !(s->sums[i].flags & SUMFLG_SAME_OFFSET))
 				continue;
 
-			if (verbose > 3)
-				rprintf(FINFO,"potential match at %.0f target=%.0f %.0f sum=%08x\n",
-					(double)offset,(double)j,(double)i,sum);
+			if (DEBUG_GTE(DELTASUM, 3)) {
+				rprintf(FINFO,
+					"potential match at %s i=%ld sum=%08x\n",
+					big_num(offset), (long)i, sum);
+			}
 
 			if (!done_csum2) {
 				map = (schar *)map_ptr(buf,offset,l);
@@ -226,8 +235,8 @@ static void hash_search(int f,struct sum_struct *s,
 			 * one with an identical offset, so we prefer that over
 			 * the following want_i optimization. */
 			if (updating_basis_file) {
-				do {
-					int32 i2 = targets[j].i;
+				int32 i2;
+				for (i2 = i; i2 >= 0; i2 = s->sums[i2].chain) {
 					if (s->sums[i2].offset != offset)
 						continue;
 					if (i2 != i) {
@@ -242,7 +251,7 @@ static void hash_search(int f,struct sum_struct *s,
 					 * both the sender and the receiver. */
 					s->sums[i].flags |= SUMFLG_SAME_OFFSET;
 					goto set_want_i;
-				} while (++j < s->count && targets[j].t == t);
+				}
 			}
 
 			/* we've found a match, but now check to see
@@ -268,10 +277,10 @@ static void hash_search(int f,struct sum_struct *s,
 			s2 = sum >> 16;
 			matches++;
 			break;
-		} while (++j < s->count && targets[j].t == t);
+		} while ((i = s->sums[i].chain) >= 0);
 
-	null_tag:
-		backup = offset - last_match;
+	  null_hash:
+		backup = (int32)(offset - last_match);
 		/* We sometimes read 1 byte prior to last_match... */
 		if (backup < 0)
 			backup = 0;
@@ -321,44 +330,44 @@ 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];
-
 	last_match = 0;
 	false_alarms = 0;
-	tag_hits = 0;
+	hash_hits = 0;
 	matches = 0;
 	data_transfer = 0;
 
 	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 && INFO_GTE(PROGRESS, 1))
+					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 && INFO_GTE(PROGRESS, 1))
+					show_progress(last_match, buf->file_size);
+				sum_update(map_ptr(buf, last_match, n), n);
+			}
 		}
+		last_match = s->flength;
 		s->count = 0;
 	}
 
 	if (len > 0 && s->count > 0) {
 		build_hash_table(s);
 
-		if (verbose > 2)
+		if (DEBUG_GTE(DELTASUM, 2))
 			rprintf(FINFO,"built hash table\n");
 
-		hash_search(f,s,buf,len);
+		hash_search(f, s, buf, len);
 
-		if (verbose > 2)
+		if (DEBUG_GTE(DELTASUM, 2))
 			rprintf(FINFO,"done hash search\n");
 	} else {
 		OFF_T j;
@@ -368,25 +377,30 @@ 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);
-	/* If we had a read error, send a bad checksum. */
-	if (buf && buf->status != 0)
-		file_sum[0]++;
+	if (sum_end(sender_file_sum) != checksum_len)
+		overflow_exit("checksum_len"); /* Impossible... */
+
+	/* If we had a read error, send a bad checksum.  We use all bits
+	 * off as long as the checksum doesn't happen to be that, in
+	 * which case we turn the last 0 bit into a 1. */
+	if (buf && buf->status != 0) {
+		int i;
+		for (i = 0; i < checksum_len && sender_file_sum[i] == 0; i++) {}
+		memset(sender_file_sum, 0, checksum_len);
+		if (i == checksum_len)
+			sender_file_sum[i-1]++;
+	}
 
-	if (verbose > 2)
+	if (DEBUG_GTE(DELTASUM, 2))
 		rprintf(FINFO,"sending file_sum\n");
-	write_buf(f,file_sum,MD4_SUM_LENGTH);
+	write_buf(f, sender_file_sum, checksum_len);
 
-	if (targets) {
-		free(targets);
-		targets=NULL;
+	if (DEBUG_GTE(DELTASUM, 2)) {
+		rprintf(FINFO, "false_alarms=%d hash_hits=%d matches=%d\n",
+			false_alarms, hash_hits, matches);
 	}
 
-	if (verbose > 2)
-		rprintf(FINFO, "false_alarms=%d tag_hits=%d matches=%d\n",
-			false_alarms, tag_hits, matches);
-
-	total_tag_hits += tag_hits;
+	total_hash_hits += hash_hits;
 	total_false_alarms += false_alarms;
 	total_matches += matches;
 	stats.literal_data += data_transfer;
@@ -394,12 +408,11 @@ void match_sums(int f, struct sum_struct *s, struct map_struct *buf, OFF_T len)
 
 void match_report(void)
 {
-	if (verbose <= 1)
+	if (!DEBUG_GTE(DELTASUM, 1))
 		return;
 
 	rprintf(FINFO,
-		"total: matches=%d  tag_hits=%d  false_alarms=%d data=%.0f\n",
-		total_matches,total_tag_hits,
-		total_false_alarms,
-		(double)stats.literal_data);
+		"total: matches=%d  hash_hits=%d  false_alarms=%d data=%s\n",
+		total_matches, total_hash_hits, total_false_alarms,
+		big_num(stats.literal_data));
 }