added hashmatch

[tridge/junkcode.git] / hashmatch / blockhash.c

diff --git a/hashmatch/blockhash.c b/hashmatch/blockhash.c
new file mode 100644 (file)
index 0000000..eec0a8a
--- /dev/null
+++ b/hashmatch/blockhash.c
@@ -0,0 +1,151 @@
+/*****************************************************************************
+a tokenised block hashing algorithm designed to find common pieces
+of source code between two trees
+
+Idea:
+
+- tokenise input
+- collect groups of N tokens, overlapping my M tokens
+- hash each group
+
+Copyright Andrew Tridgell <tridge@samba.org> July 2003
+
+ * 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.,
+ * 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
+
+******************************************************************************/
+#include "includes.h"
+
+static int token_width=7, token_skip=5;
+static int annotate;
+static const char *filename_pattern = "*";
+
+struct hash_info {
+       const char *fname;
+       FILE *in, *out;
+};
+
+/*
+  write the hash to a file
+*/
+static void hash_write(const char *buf, const uint8 *md4, void *private, int line, struct char_range *ranges)
+{
+       struct hash_info *h = private;
+
+       hash_print(h->out, md4);
+       if (annotate) {
+               fprintf(h->out," %s(%d:%ld:%ld)\n", 
+                       h->fname, line, ranges[0].start, 
+                       ranges[token_width-1].end - ranges[0].start);
+       } else {
+               fprintf(h->out,"\n");
+       }
+}
+
+
+/* 
+   form groups of token_width tokens, with a skip of token_skip, and write hashes
+   to hashfile
+*/
+static void blockhash(FILE *infile, FILE *hashfile, struct hash_info *h)
+{
+       gen_hashblocks(infile, token_width, token_skip, hash_write, h);
+}
+
+
+/*
+  show help
+*/
+static void usage(void)
+{
+       printf("Blockhash version %s - Copyright Andrew Tridgell 2003\n", VERSION);
+       printf("released under the GNU GPL v2 or later\n\n");
+       printf("Usage: blockhash [options] <dir>\n");
+       printf("\nOptions: \n");
+       printf("\t-w token_width (default %d)\n", token_width);
+       printf("\t-s token_skip (default %d)\n", token_skip);
+       printf("\t-a                  source filename enable annotation\n");
+       printf("\t-p PATTERN          set filename wildcard pattern\n");
+}
+
+/*
+  hash one file
+*/
+static void scan_fn(const char *fname)
+{
+       struct hash_info h;
+       FILE *f = fopen(fname, "r");
+       if (!f) {
+               perror(fname);
+               return;
+       }
+       h.in = f;
+       h.fname = fname;
+       h.out = stdout;
+       blockhash(f, stdout, &h);
+       fclose(f);
+}
+
+int main(int argc, char *argv[])
+{
+       int c;
+
+       while ((c = getopt(argc, argv, "hw:s:ap:")) != -1) {
+               switch (c) {
+               case 'w':
+                       token_width = atoi(optarg);
+                       break;
+               case 's':
+                       token_skip = atoi(optarg);
+                       break;
+               case 'a':
+                       annotate = 1;
+                       break;
+               case 'p':
+                       filename_pattern = strdup(optarg);
+                       break;
+               case 'h':
+               default:
+                       usage();
+                       exit(0);
+               }
+               
+       }
+       
+       if (token_width < token_skip || token_skip <= 0) {
+               printf("Invalid width/skip parameters\n");
+               usage();
+               exit(1);
+       }
+
+       argv += optind;
+       argc -= optind;
+
+       if (argc != 1) {
+               usage();
+               exit(1);
+       }
+
+       /* deliberately arrange things so that 'sort -r' will leave
+          the format intact while removing the hash ordering
+          information from the file */
+       printf("version %s of blockhash\n", VERSION);
+       printf("token_width %d\n", token_width);
+       printf("token_skip %d\n", token_skip);
+
+       traverse_dir(argv[0], scan_fn, filename_pattern);
+
+       return 0;
+}
+