From: Maxime Henrion <mhenrion@haproxy.com>
Date: Thu, 18 Dec 2025 04:37:44 +0000 (-0500)
Subject: MEDIUM: patterns: reorganize pattern reference elements
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=545cf59b6fdccf68c4368a9157ef3fbd1a58a8b9;p=thirdparty%2Fhaproxy.git

MEDIUM: patterns: reorganize pattern reference elements

Instead of a global list (and tree) of pattern reference elements, we
now have an intermediate pat_ref_gen structure and store the elements in
those. This simplifies the logic of some operations such as commit and
clear, and improves performance in some cases - numbers to be provided
in a subsequent commit after one important optimization is added.

A lot of the changes are due to adding an extra level of indirection,
changing many cases where we iterate over all elements to an outer loop
iterating over the generation and an inner one iterating over the
elements of the current generation. It is therefore easier to read this
patch using 'git diff -w'.
---

diff --git a/include/haproxy/pattern-t.h b/include/haproxy/pattern-t.h
index 42da6ed33..8325cec2c 100644
--- a/include/haproxy/pattern-t.h
+++ b/include/haproxy/pattern-t.h
@@ -108,8 +108,6 @@ struct pat_ref {
 	char *reference; /* The reference name. */
 	char *display; /* String displayed to identify the pattern origin. */
 	struct ceb_root *gen_root; /* The tree mapping generation IDs to pattern reference elements */
-	struct list head; /* The head of the list of struct pat_ref_elt. */
-	struct ceb_root *ceb_root; /* The tree where pattern reference elements are attached. */
 	struct list pat; /* The head of the list of struct pattern_expr. */
 	unsigned int flags; /* flags PAT_REF_*. */
 	unsigned int curr_gen; /* current generation number (anything below can be removed) */
@@ -144,7 +142,7 @@ struct pat_ref_elt {
 	char *sample;
 	unsigned int gen_id; /* generation of pat_ref this was made for */
 	int line;
-	struct ceb_node node; /* Node to attach this element to its <pat_ref> ebtree. */
+	struct ceb_node node; /* Node to attach this element to its <pat_ref_gen> cebtree. */
 	const char pattern[0]; // const only to make sure nobody tries to free it.
 };
 
diff --git a/include/haproxy/pattern.h b/include/haproxy/pattern.h
index 73245096b..e92f3612e 100644
--- a/include/haproxy/pattern.h
+++ b/include/haproxy/pattern.h
@@ -189,7 +189,7 @@ struct pat_ref *pat_ref_new(const char *reference, const char *display, unsigned
 struct pat_ref *pat_ref_newid(int unique_id, const char *display, unsigned int flags);
 struct pat_ref_elt *pat_ref_find_elt(struct pat_ref *ref, const char *key);
 struct pat_ref_elt *pat_ref_gen_find_elt(struct pat_ref *ref, unsigned int gen_id, const char *key);
-struct pat_ref_elt *pat_ref_append(struct pat_ref *ref, const char *pattern, const char *sample, int line);
+struct pat_ref_elt *pat_ref_append(struct pat_ref *ref, unsigned int gen, const char *pattern, const char *sample, int line);
 struct pat_ref_elt *pat_ref_load(struct pat_ref *ref, unsigned int gen, const char *pattern, const char *sample, int line, char **err);
 struct pat_ref_gen *pat_ref_gen_new(struct pat_ref *ref, unsigned int gen_id);
 struct pat_ref_gen *pat_ref_gen_get(struct pat_ref *ref, unsigned int gen_id);
diff --git a/src/hlua_fcn.c b/src/hlua_fcn.c
index 6be8723b0..b30f37319 100644
--- a/src/hlua_fcn.c
+++ b/src/hlua_fcn.c
@@ -3063,18 +3063,18 @@ static int _hlua_listable_patref_pairs_iterator(lua_State *L, int status, lua_KC
 
 	if (LIST_ISEMPTY(&hctx->bref.users)) {
 		/* first iteration */
-		hctx->bref.ref = hctx->ref->ptr->head.n;
+		hctx->gen = pat_ref_gen_get(hctx->ref->ptr, curr_gen);
+		if (!hctx->gen)
+			goto done;
+		hctx->bref.ref = hctx->gen->head.n;
 	}
 	else
 		LIST_DEL_INIT(&hctx->bref.users); // drop back ref from previous iteration
 
  next:
 	/* reached end of list? */
-	if (hctx->bref.ref == &hctx->ref->ptr->head) {
-		HA_RWLOCK_WRUNLOCK(PATREF_LOCK, &hctx->ref->ptr->lock);
-		lua_pushnil(L);
-		return 1;
-	}
+	if (hctx->bref.ref == &hctx->gen->head)
+		goto done;
 
 	elt = LIST_ELEM(hctx->bref.ref, struct pat_ref_elt *, list);
 
@@ -3107,6 +3107,11 @@ static int _hlua_listable_patref_pairs_iterator(lua_State *L, int status, lua_KC
 		return 1;
 	return 2;
 
+done:
+	HA_RWLOCK_WRUNLOCK(PATREF_LOCK, &hctx->ref->ptr->lock);
+	lua_pushnil(L);
+	return 1;
+
 }
 /* iterator must return key as string and value as patref
  * element value (as string), if we reach end of list, it
diff --git a/src/map.c b/src/map.c
index b02224d8d..cd9d7a350 100644
--- a/src/map.c
+++ b/src/map.c
@@ -388,10 +388,16 @@ static int cli_io_handler_pat_list(struct appctx *appctx)
 			LIST_DELETE(&ctx->bref.users);
 			LIST_INIT(&ctx->bref.users);
 		} else {
-			ctx->bref.ref = ctx->ref->head.n;
+			ctx->gen = pat_ref_gen_get(ctx->ref, ctx->curr_gen);
+			if (!ctx->gen) {
+				HA_RWLOCK_WRUNLOCK(PATREF_LOCK, &ctx->ref->lock);
+				ctx->state = STATE_DONE;
+				return 1;
+			}
+			ctx->bref.ref = ctx->gen->head.n;
 		}
 
-		while (ctx->bref.ref != &ctx->ref->head) {
+		while (ctx->bref.ref != &ctx->gen->head) {
 			chunk_reset(&trash);
 
 			elt = LIST_ELEM(ctx->bref.ref, struct pat_ref_elt *, list);
diff --git a/src/pattern.c b/src/pattern.c
index 8270d3640..5276521c5 100644
--- a/src/pattern.c
+++ b/src/pattern.c
@@ -1581,9 +1581,13 @@ struct pat_ref *pat_ref_lookupid(int unique_id)
  */
 void pat_ref_delete_by_ptr(struct pat_ref *ref, struct pat_ref_elt *elt)
 {
+	struct pat_ref_gen *gen;
 	struct pattern_expr *expr;
 	struct bref *bref, *back;
 
+	gen = pat_ref_gen_get(ref, elt->gen_id);
+	BUG_ON(!gen);
+
 	/*
 	 * we have to unlink all watchers from this reference pattern. We must
 	 * not relink them if this elt was the last one in the list.
@@ -1591,7 +1595,7 @@ void pat_ref_delete_by_ptr(struct pat_ref *ref, struct pat_ref_elt *elt)
 	list_for_each_entry_safe(bref, back, &elt->back_refs, users) {
 		LIST_DELETE(&bref->users);
 		LIST_INIT(&bref->users);
-		if (elt->list.n != &ref->head)
+		if (elt->list.n != &gen->head)
 			LIST_APPEND(&LIST_ELEM(elt->list.n, typeof(elt), list)->back_refs, &bref->users);
 		bref->ref = elt->list.n;
 	}
@@ -1606,7 +1610,7 @@ void pat_ref_delete_by_ptr(struct pat_ref *ref, struct pat_ref_elt *elt)
 		HA_RWLOCK_WRUNLOCK(PATEXP_LOCK, &expr->lock);
 
 	LIST_DELETE(&elt->list);
-	cebs_item_delete(&ref->ceb_root, node, pattern, elt);
+	cebs_item_delete(&gen->elt_root, node, pattern, elt);
 	free(elt->sample);
 	free(elt);
 	HA_ATOMIC_INC(&patterns_freed);
@@ -1621,14 +1625,17 @@ void pat_ref_delete_by_ptr(struct pat_ref *ref, struct pat_ref_elt *elt)
  */
 int pat_ref_delete_by_id(struct pat_ref *ref, struct pat_ref_elt *refelt)
 {
+	struct pat_ref_gen *gen;
 	struct pat_ref_elt *elt, *safe;
 
 	/* delete pattern from reference */
-	list_for_each_entry_safe(elt, safe, &ref->head, list) {
-		if (elt == refelt) {
-			event_hdl_publish(&ref->e_subs, EVENT_HDL_SUB_PAT_REF_DEL, NULL);
-			pat_ref_delete_by_ptr(ref, elt);
-			return 1;
+	pat_ref_gen_foreach(gen, ref) {
+		list_for_each_entry_safe(elt, safe, &gen->head, list) {
+			if (elt == refelt) {
+				event_hdl_publish(&ref->e_subs, EVENT_HDL_SUB_PAT_REF_DEL, NULL);
+				pat_ref_delete_by_ptr(ref, elt);
+				return 1;
+			}
 		}
 	}
 	return 0;
@@ -1642,7 +1649,7 @@ struct pat_ref_gen *pat_ref_gen_new(struct pat_ref *ref, unsigned int gen_id)
 {
 	struct pat_ref_gen *gen, *old;
 
-	gen = calloc(1, sizeof(struct pat_ref_gen));
+	gen = malloc(sizeof(struct pat_ref_gen));
 	if (!gen)
 		return NULL;
 
@@ -1672,24 +1679,21 @@ struct pat_ref_gen *pat_ref_gen_get(struct pat_ref *ref, unsigned int gen_id)
  */
 int pat_ref_gen_delete(struct pat_ref *ref, unsigned int gen_id, const char *key)
 {
-	struct pat_ref_elt *elt, *elt2;
-	int found = 0;
+	struct pat_ref_gen *gen;
+	struct pat_ref_elt *elt;
 
-	/* delete pattern from reference */
-	elt = cebs_item_lookup(&ref->ceb_root, node, pattern, key, struct pat_ref_elt);
-	while (elt) {
-		elt2 = cebs_item_next_dup(&ref->ceb_root, node, pattern, elt);
-		if (elt->gen_id == gen_id) {
-			pat_ref_delete_by_ptr(ref, elt);
-			found = 1;
-		}
-		elt = elt2;
-	}
+	gen = pat_ref_gen_get(ref, gen_id);
+	if (!gen)
+		return 0;
 
-	if (found)
-		event_hdl_publish(&ref->e_subs, EVENT_HDL_SUB_PAT_REF_DEL, NULL);
+	/* delete pattern from reference */
+	elt = cebs_item_lookup(&gen->elt_root, node, pattern, key, struct pat_ref_elt);
+	if (!elt)
+		return 0;
 
-	return found;
+	pat_ref_delete_by_ptr(ref, elt);
+	event_hdl_publish(&ref->e_subs, EVENT_HDL_SUB_PAT_REF_DEL, NULL);
+	return 1;
 }
 
 /* This function removes all patterns matching <key> from the reference
@@ -1707,15 +1711,12 @@ int pat_ref_delete(struct pat_ref *ref, const char *key)
  */
 struct pat_ref_elt *pat_ref_gen_find_elt(struct pat_ref *ref, unsigned int gen_id, const char *key)
 {
-	struct pat_ref_elt *elt;
+	struct pat_ref_gen *gen;
 
-	elt = cebs_item_lookup(&ref->ceb_root, node, pattern, key, struct pat_ref_elt);
-	while (elt) {
-		if (elt->gen_id == gen_id)
-			break;
-		elt = cebs_item_next_dup(&ref->ceb_root, node, pattern, elt);
-	}
-	return elt;
+	gen = pat_ref_gen_get(ref, gen_id);
+	if (!gen)
+		return NULL;
+	return cebs_item_lookup(&gen->elt_root, node, pattern, key, struct pat_ref_elt);
 }
 
 /*
@@ -1815,14 +1816,17 @@ static inline int pat_ref_set_elt(struct pat_ref *ref, struct pat_ref_elt *elt,
  */
 int pat_ref_set_by_id(struct pat_ref *ref, struct pat_ref_elt *refelt, const char *value, char **err)
 {
+	struct pat_ref_gen *gen;
 	struct pat_ref_elt *elt;
 
 	/* Look for pattern in the reference. */
-	list_for_each_entry(elt, &ref->head, list) {
-		if (elt == refelt) {
-			if (!pat_ref_set_elt(ref, elt, value, err))
-				return 0;
-			return 1;
+	pat_ref_gen_foreach(gen, ref) {
+		list_for_each_entry(elt, &gen->head, list) {
+			if (elt == refelt) {
+				if (!pat_ref_set_elt(ref, elt, value, err))
+					return 0;
+				return 1;
+			}
 		}
 	}
 
@@ -1832,31 +1836,30 @@ int pat_ref_set_by_id(struct pat_ref *ref, struct pat_ref_elt *refelt, const cha
 
 static int pat_ref_set_from_elt(struct pat_ref *ref, struct pat_ref_elt *elt, const char *value, char **err)
 {
-	unsigned int gen;
+	struct pat_ref_gen *gen;
 	struct pat_ref_elt *elt2;
-	int first = 1;
-	int found = 0;
+	int found = 0, publish = 0;
 
-	for (; elt; elt = elt2) {
-		char *tmp_err = NULL;
+	if (elt) {
+		if (elt->gen_id == ref->curr_gen)
+			publish = 1;
+		gen = pat_ref_gen_get(ref, elt->gen_id);
+		BUG_ON(!gen);
 
-		elt2 = cebs_item_next_dup(&ref->ceb_root, node, pattern, elt);
-		if (first)
-			gen = elt->gen_id;
-		else if (elt->gen_id != gen) {
-			/* only consider duplicate elements from the same gen! */
-			continue;
-		}
+		for (; elt; elt = elt2) {
+			char *tmp_err = NULL;
 
-		if (!pat_ref_set_elt(ref, elt, value, &tmp_err)) {
-			if (err)
-				*err = tmp_err;
-			else
-				ha_free(&tmp_err);
-			return 0;
+			elt2 = cebs_item_next_dup(&gen->elt_root, node, pattern, elt);
+
+			if (!pat_ref_set_elt(ref, elt, value, &tmp_err)) {
+				if (err)
+					*err = tmp_err;
+				else
+					ha_free(&tmp_err);
+				return 0;
+			}
+			found = 1;
 		}
-		found = 1;
-		first = 0;
 	}
 
 	if (!found) {
@@ -1864,7 +1867,7 @@ static int pat_ref_set_from_elt(struct pat_ref *ref, struct pat_ref_elt *elt, co
 		return 0;
 	}
 
-	if (gen == ref->curr_gen) // gen cannot be uninitialized here
+	if (publish)
 		event_hdl_publish(&ref->e_subs, EVENT_HDL_SUB_PAT_REF_SET, NULL);
 
 	return 1;
@@ -1883,15 +1886,15 @@ int pat_ref_set_elt_duplicate(struct pat_ref *ref, struct pat_ref_elt *elt, cons
 int pat_ref_gen_set(struct pat_ref *ref, unsigned int gen_id,
                     const char *key, const char *value, char **err)
 {
+	struct pat_ref_gen *gen;
 	struct pat_ref_elt *elt;
 
 	/* Look for pattern in the reference. */
-	elt = cebs_item_lookup(&ref->ceb_root, node, pattern, key, struct pat_ref_elt);
-	while (elt) {
-		if (elt->gen_id == gen_id)
-			break;
-		elt = cebs_item_next_dup(&ref->ceb_root, node, pattern, elt);
-	}
+	gen = pat_ref_gen_get(ref, gen_id);
+	if (gen)
+		elt = cebs_item_lookup(&gen->elt_root, node, pattern, key, struct pat_ref_elt);
+	else
+		elt = NULL;
 	return pat_ref_set_from_elt(ref, elt, value, err);
 }
 
@@ -1933,8 +1936,7 @@ static struct pat_ref *_pat_ref_new(const char *display, unsigned int flags)
 	ref->unique_id = -1;
 	ref->revision = 0;
 	ref->entry_cnt = 0;
-	LIST_INIT(&ref->head);
-	ref->ceb_root = NULL;
+	ceb_init_root(&ref->gen_root);
 	LIST_INIT(&ref->pat);
 	HA_RWLOCK_INIT(&ref->lock);
 	event_hdl_sub_list_init(&ref->e_subs);
@@ -2016,8 +2018,10 @@ struct pat_ref *pat_ref_newid(int unique_id, const char *display, unsigned int f
  * <ref> must be held. It sets the newly created pattern's generation number
  * to the same value as the reference's.
  */
-struct pat_ref_elt *pat_ref_append(struct pat_ref *ref, const char *pattern, const char *sample, int line)
+struct pat_ref_elt *pat_ref_append(struct pat_ref *ref, unsigned int gen_id,
+                                   const char *pattern, const char *sample, int line)
 {
+	struct pat_ref_gen *gen;
 	struct pat_ref_elt *elt;
 	int len = strlen(pattern);
 
@@ -2025,6 +2029,13 @@ struct pat_ref_elt *pat_ref_append(struct pat_ref *ref, const char *pattern, con
 	if (!elt)
 		goto fail;
 
+	gen = pat_ref_gen_get(ref, gen_id);
+	if (!gen) {
+		gen = pat_ref_gen_new(ref, gen_id);
+		if (!gen)
+			goto fail;
+	}
+
 	elt->gen_id = ref->curr_gen;
 	elt->line = line;
 
@@ -2039,8 +2050,8 @@ struct pat_ref_elt *pat_ref_append(struct pat_ref *ref, const char *pattern, con
 	LIST_INIT(&elt->back_refs);
 	elt->list_head = NULL;
 	elt->tree_head = NULL;
-	LIST_APPEND(&ref->head, &elt->list);
-	cebs_item_insert(&ref->ceb_root, node, pattern, elt);
+	LIST_APPEND(&gen->head, &elt->list);
+	cebs_item_insert(&gen->elt_root, node, pattern, elt);
 	HA_ATOMIC_INC(&patterns_added);
 	return elt;
  fail:
@@ -2138,9 +2149,8 @@ struct pat_ref_elt *pat_ref_load(struct pat_ref *ref, unsigned int gen,
 {
 	struct pat_ref_elt *elt;
 
-	elt = pat_ref_append(ref, pattern, sample, line);
+	elt = pat_ref_append(ref, gen, pattern, sample, line);
 	if (elt) {
-		elt->gen_id = gen;
 		if (!pat_ref_commit_elt(ref, elt, err))
 			elt = NULL;
 	} else
@@ -2177,6 +2187,7 @@ int pat_ref_add(struct pat_ref *ref,
  */
 int pat_ref_purge_range(struct pat_ref *ref, uint from, uint to, int budget)
 {
+	struct pat_ref_gen *gen, *gen2;
 	struct pat_ref_elt *elt, *elt_bck;
 	struct bref *bref, *bref_bck;
 	struct pattern_expr *expr;
@@ -2189,35 +2200,51 @@ int pat_ref_purge_range(struct pat_ref *ref, uint from, uint to, int budget)
 
 	/* assume completion for e.g. empty lists */
 	done = 1;
-	list_for_each_entry_safe(elt, elt_bck, &ref->head, list) {
-		if (elt->gen_id - from > to - from)
+	pat_ref_gen_foreach_safe(gen, gen2, ref) {
+		if (gen->gen_id - from > to - from) {
+			if (from <= to) {
+				break;
+			}
 			continue;
-
-		if (budget >= 0 && !budget--) {
-			done = 0;
-			break;
 		}
 
-		/*
-		 * we have to unlink all watchers from this reference pattern. We must
-		 * not relink them if this elt was the last one in the list.
-		 */
-		list_for_each_entry_safe(bref, bref_bck, &elt->back_refs, users) {
-			LIST_DELETE(&bref->users);
-			LIST_INIT(&bref->users);
-			if (elt->list.n != &ref->head)
-				LIST_APPEND(&LIST_ELEM(elt->list.n, typeof(elt), list)->back_refs, &bref->users);
-			bref->ref = elt->list.n;
+		list_for_each_entry_safe(elt, elt_bck, &gen->head, list) {
+			if (budget >= 0 && !budget--) {
+				done = 0;
+				break;
+			}
+
+			BUG_ON(elt->gen_id != gen->gen_id);
+
+			/*
+			 * we have to unlink all watchers from this reference pattern. We must
+			 * not relink them if this elt was the last one in the list.
+			 */
+			list_for_each_entry_safe(bref, bref_bck, &elt->back_refs, users) {
+				LIST_DELETE(&bref->users);
+				LIST_INIT(&bref->users);
+				if (elt->list.n != &gen->head)
+					LIST_APPEND(&LIST_ELEM(elt->list.n, typeof(elt), list)->back_refs, &bref->users);
+				bref->ref = elt->list.n;
+			}
+
+			/* delete the storage for all representations of this pattern. */
+			pat_delete_gen(ref, elt);
+
+			LIST_DELETE(&elt->list);
+			cebs_item_delete(&gen->elt_root, node, pattern, elt);
+			free(elt->sample);
+			free(elt);
+			HA_ATOMIC_INC(&patterns_freed);
 		}
 
-		/* delete the storage for all representations of this pattern. */
-		pat_delete_gen(ref, elt);
+		if (!done)
+			break;
 
-		LIST_DELETE(&elt->list);
-		cebs_item_delete(&ref->ceb_root, node, pattern, elt);
-		free(elt->sample);
-		free(elt);
-		HA_ATOMIC_INC(&patterns_freed);
+		BUG_ON(!LIST_ISEMPTY(&gen->head));
+		BUG_ON(!ceb_isempty(&gen->elt_root));
+		cebu32_item_delete(&ref->gen_root, gen_node, gen_id, gen);
+		free(gen);
 	}
 
 	list_for_each_entry(expr, &ref->pat, list)
@@ -2432,7 +2459,7 @@ int pat_ref_read_from_file_smp(struct pat_ref *ref, char **err)
 		*value_end = '\0';
 
 		/* insert values */
-		if (!pat_ref_append(ref, key_beg, value_beg, line)) {
+		if (!pat_ref_append(ref, ref->curr_gen, key_beg, value_beg, line)) {
 			memprintf(err, "out of memory");
 			goto out_close;
 		}
@@ -2499,7 +2526,7 @@ int pat_ref_read_from_file(struct pat_ref *ref, char **err)
 		if (c == arg)
 			continue;
 
-		if (!pat_ref_append(ref, arg, NULL, line)) {
+		if (!pat_ref_append(ref, ref->curr_gen, arg, NULL, line)) {
 			memprintf(err, "out of memory when loading patterns from file <%s>", ref->reference);
 			goto out_close;
 		}
@@ -2523,6 +2550,7 @@ int pattern_read_from_file(struct pattern_head *head, unsigned int refflags,
 {
 	struct pat_ref *ref;
 	struct pattern_expr *expr;
+	struct pat_ref_gen *gen;
 	struct pat_ref_elt *elt;
 	int reuse = 0;
 
@@ -2623,12 +2651,14 @@ int pattern_read_from_file(struct pattern_head *head, unsigned int refflags,
 	 * content-based in case of duplicated keys we only want the first key
 	 * in the file to be considered.
 	 */
-	list_for_each_entry(elt, &ref->head, list) {
-		if (!pat_ref_push(elt, expr, patflags, err)) {
-			if (elt->line > 0)
-				memprintf(err, "%s at line %d of file '%s'",
-				          *err, elt->line, filename);
-			return 0;
+	pat_ref_gen_foreach(gen, ref) {
+		list_for_each_entry(elt, &gen->head, list) {
+			if (!pat_ref_push(elt, expr, patflags, err)) {
+				if (elt->line > 0)
+					memprintf(err, "%s at line %d of file '%s'",
+						*err, elt->line, filename);
+				return 0;
+			}
 		}
 	}