From: Willy Tarreau <w@1wt.eu>
Date: Tue, 24 Jun 2025 15:14:47 +0000 (+0200)
Subject: MINOR: tools: add support for ist to the word fingerprinting functions
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=a4d78dd4f5882176e4259baa6f973f3abe6ffe1f;p=thirdparty%2Fhaproxy.git

MINOR: tools: add support for ist to the word fingerprinting functions

The word fingerprinting functions are used to compare similar words to
suggest a correctly spelled one that looks like what the user proposed.
Currently the functions only support const char*, but there's no reason
for this, and it would be convenient to support substrings extracted
from random pieces of configurations. Here we're adding new variants
"_with_len" that take these ISTs and which are in fact a slight change
of the original ones that the old ones now rely on.
---

diff --git a/include/haproxy/tools.h b/include/haproxy/tools.h
index 160d5f3ac..931f71506 100644
--- a/include/haproxy/tools.h
+++ b/include/haproxy/tools.h
@@ -1028,7 +1028,9 @@ int is_dir_present(const char *path_fmt, ...);
 uint32_t parse_line(char *in, char *out, size_t *outlen, char **args, int *nbargs, uint32_t opts, const char **errptr);
 ssize_t read_line_to_trash(const char *path_fmt, ...);
 size_t sanitize_for_printing(char *line, size_t pos, size_t width);
+void update_word_fingerprint_with_len(uint8_t *fp, struct ist word);
 void update_word_fingerprint(uint8_t *fp, const char *word);
+void make_word_fingerprint_with_len(uint8_t *fp, struct ist word);
 void make_word_fingerprint(uint8_t *fp, const char *word);
 int word_fingerprint_distance(const uint8_t *fp1, const uint8_t *fp2);
 
diff --git a/src/tools.c b/src/tools.c
index 7f29e807b..093e691b9 100644
--- a/src/tools.c
+++ b/src/tools.c
@@ -6627,20 +6627,20 @@ size_t sanitize_for_printing(char *line, size_t pos, size_t width)
 	return pos - shift;
 }
 
-/* Update array <fp> with the fingerprint of word <word> by counting the
- * transitions between characters. <fp> is a 1024-entries array indexed as
- * 32*from+to. Positions for 'from' and 'to' are:
+/* Update array <fp> with the fingerprint of word <word> for up to <len> chars
+ * by counting the transitions between characters. <fp> is a 1024-entries array
+ * indexed as 32*from+to. Positions for 'from' and 'to' are:
  *   1..26=letter, 27=digit, 28=other/begin/end.
  * Row "from=0" is used to mark the character's presence. Others unused.
  */
-void update_word_fingerprint(uint8_t *fp, const char *word)
+void update_word_fingerprint_with_len(uint8_t *fp, struct ist word)
 {
 	const char *p;
 	int from, to;
 	int c;
 
 	from = 28; // begin
-	for (p = word; *p; p++) {
+	for (p = word.ptr; p < word.ptr + word.len; p++) {
 		c = tolower((unsigned char)*p);
 		switch(c) {
 		case 'a'...'z': to = c - 'a' + 1; break;
@@ -6656,6 +6656,17 @@ void update_word_fingerprint(uint8_t *fp, const char *word)
 	fp[32 * from + to]++;
 }
 
+/* Update array <fp> with the fingerprint of word <word> by counting the
+ * transitions between characters. <fp> is a 1024-entries array indexed as
+ * 32*from+to. Positions for 'from' and 'to' are:
+ *   1..26=letter, 27=digit, 28=other/begin/end.
+ * Row "from=0" is used to mark the character's presence. Others unused.
+ */
+void update_word_fingerprint(uint8_t *fp, const char *word)
+{
+	return update_word_fingerprint_with_len(fp, ist(word));
+}
+
 /* This function hashes a word, scramble is the anonymizing key, returns
  * the hashed word when the key (scramble) != 0, else returns the word.
  * This function can be called NB_L_HASH_WORD times in a row, don't call
@@ -6785,6 +6796,17 @@ void make_word_fingerprint(uint8_t *fp, const char *word)
 	update_word_fingerprint(fp, word);
 }
 
+/* Initialize array <fp> with the fingerprint of word <word> by counting the
+ * transitions between characters. <fp> is a 1024-entries array indexed as
+ * 32*from+to. Positions for 'from' and 'to' are:
+ *   0..25=letter, 26=digit, 27=other, 28=begin, 29=end, others unused.
+ */
+void make_word_fingerprint_with_len(uint8_t *fp, struct ist word)
+{
+	memset(fp, 0, 1024);
+	update_word_fingerprint_with_len(fp, word);
+}
+
 /* Return the distance between two word fingerprints created by function
  * make_word_fingerprint(). It's a positive integer calculated as the sum of
  * the differences between each location.