From 8937e9addfe15dfe34ea241884aa10cfb3dc54fb Mon Sep 17 00:00:00 2001
From: Olivier Matz <zer0@droids-corp.org>
Date: Tue, 24 Jul 2018 21:36:42 +0200
Subject: [PATCH] get node children and refs in the same function

---
 lib/ecoli_node.c        | 69 ++++++++++++++++++++++++-----------------
 lib/ecoli_node.h        | 14 +++------
 lib/ecoli_node_cmd.c    | 11 ++++---
 lib/ecoli_node_expr.c   | 11 ++++---
 lib/ecoli_node_many.c   | 11 ++++---
 lib/ecoli_node_once.c   | 11 ++++---
 lib/ecoli_node_option.c | 11 ++++---
 lib/ecoli_node_or.c     | 11 ++++---
 lib/ecoli_node_re_lex.c | 11 ++++---
 lib/ecoli_node_seq.c    | 21 +++++--------
 lib/ecoli_node_sh_lex.c | 11 ++++---
 lib/ecoli_node_subset.c | 11 ++++---
 12 files changed, 116 insertions(+), 87 deletions(-)

diff --git a/lib/ecoli_node.c b/lib/ecoli_node.c
index a1b10dd..1ebbcf1 100644
--- a/lib/ecoli_node.c
+++ b/lib/ecoli_node.c
@@ -129,6 +129,7 @@ static void count_references(struct ec_node *node, unsigned int refs)
 {
 	struct ec_node *child;
 	size_t i, n;
+	int ret;
 
 	if (node->free.state == EC_NODE_FREE_STATE_TRAVERSED) {
 		node->free.refcnt += refs;
@@ -138,8 +139,8 @@ static void count_references(struct ec_node *node, unsigned int refs)
 	node->free.state = EC_NODE_FREE_STATE_TRAVERSED;
 	n = ec_node_get_children_count(node);
 	for (i = 0; i < n; i++) {
-		child = ec_node_get_child(node, i);
-		refs = ec_node_get_child_refs(node, i);
+		ret = ec_node_get_child(node, i, &child, &refs);
+		assert(ret == 0);
 		count_references(child, refs);
 	}
 }
@@ -147,7 +148,9 @@ static void count_references(struct ec_node *node, unsigned int refs)
 static void mark_freeable(struct ec_node *node, enum ec_node_free_state mark)
 {
 	struct ec_node *child;
+	unsigned int refs;
 	size_t i, n;
+	int ret;
 
 	if (mark == node->free.state)
 		return;
@@ -159,7 +162,8 @@ static void mark_freeable(struct ec_node *node, enum ec_node_free_state mark)
 
 	n = ec_node_get_children_count(node);
 	for (i = 0; i < n; i++) {
-		child = ec_node_get_child(node, i);
+		ret = ec_node_get_child(node, i, &child, &refs);
+		assert(ret == 0);
 		mark_freeable(child, mark);
 	}
 }
@@ -167,7 +171,9 @@ static void mark_freeable(struct ec_node *node, enum ec_node_free_state mark)
 static void reset_mark(struct ec_node *node)
 {
 	struct ec_node *child;
+	unsigned int refs;
 	size_t i, n;
+	int ret;
 
 	if (node->free.state == EC_NODE_FREE_STATE_NONE)
 		return;
@@ -177,7 +183,8 @@ static void reset_mark(struct ec_node *node)
 
 	n = ec_node_get_children_count(node);
 	for (i = 0; i < n; i++) {
-		child = ec_node_get_child(node, i);
+		ret = ec_node_get_child(node, i, &child, &refs);
+		assert(ret == 0);
 		reset_mark(child);
 	}
 }
@@ -250,20 +257,15 @@ size_t ec_node_get_children_count(const struct ec_node *node)
 	return node->type->get_children_count(node);
 }
 
-struct ec_node *
-ec_node_get_child(const struct ec_node *node, size_t i)
+int
+ec_node_get_child(const struct ec_node *node, size_t i,
+	struct ec_node **child, unsigned int *refs)
 {
+	*child = NULL;
+	*refs = 0;
 	if (node->type->get_child == NULL)
-		return NULL;
-	return node->type->get_child(node, i);
-}
-
-unsigned int
-ec_node_get_child_refs(const struct ec_node *node, size_t i)
-{
-	if (node->type->get_child_refs == NULL)
-		return 1;
-	return node->type->get_child_refs(node, i);
+		return -1;
+	return node->type->get_child(node, i, child, refs);
 }
 
 int
@@ -298,19 +300,22 @@ const struct ec_config *ec_node_get_config(struct ec_node *node)
 
 struct ec_node *ec_node_find(struct ec_node *node, const char *id)
 {
-	struct ec_node *child, *ret;
+	struct ec_node *child, *retnode;
 	const char *node_id = ec_node_id(node);
+	unsigned int refs;
 	size_t i, n;
+	int ret;
 
 	if (id != NULL && node_id != NULL && !strcmp(node_id, id))
 		return node;
 
 	n = ec_node_get_children_count(node);
 	for (i = 0; i < n; i++) {
-		child = ec_node_get_child(node, i);
-		ret = ec_node_find(child, id);
-		if (ret != NULL)
-			return ret;
+		ret = ec_node_get_child(node, i, &child, &refs);
+		assert(ret == 0);
+		retnode = ec_node_find(child, id);
+		if (retnode != NULL)
+			return retnode;
 	}
 
 	return NULL;
@@ -336,8 +341,10 @@ static void __ec_node_dump(FILE *out,
 {
 	const char *id, *typename;
 	struct ec_node *child;
+	unsigned int refs;
 	char buf[32];
 	size_t i, n;
+	int ret;
 
 	id = ec_node_id(node);
 	typename = node->type->name;
@@ -356,7 +363,8 @@ static void __ec_node_dump(FILE *out,
 
 	n = ec_node_get_children_count(node);
 	for (i = 0; i < n; i++) {
-		child = ec_node_get_child(node, i);
+		ret = ec_node_get_child(node, i, &child, &refs);
+		assert(ret == 0);
 		__ec_node_dump(out, child, indent + 1, dict);
 	}
 }
@@ -410,8 +418,9 @@ static int ec_node_testcase(void)
 {
 	struct ec_node *node = NULL, *expr = NULL;
 	struct ec_node *expr2 = NULL, *val = NULL, *op = NULL, *seq = NULL;
-	const struct ec_node *child;
 	const struct ec_node_type *type;
+	struct ec_node *child;
+	unsigned int refs;
 	FILE *f = NULL;
 	char *buf = NULL;
 	size_t buflen = 0;
@@ -455,17 +464,21 @@ static int ec_node_testcase(void)
 	testres |= EC_TEST_CHECK(
 		ec_node_get_children_count(node) == 2,
 		"bad children count\n");
-	child = ec_node_get_child(node, 0);
-	testres |= EC_TEST_CHECK(child != NULL &&
+	ret = ec_node_get_child(node, 0, &child, &refs);
+	testres |= EC_TEST_CHECK(ret == 0 &&
+		child != NULL &&
 		!strcmp(ec_node_type(child)->name, "str") &&
 		!strcmp(ec_node_id(child), "id_x"),
 		"bad child 0");
-	child = ec_node_get_child(node, 1);
-	testres |= EC_TEST_CHECK(child != NULL &&
+	ret = ec_node_get_child(node, 1, &child, &refs);
+	testres |= EC_TEST_CHECK(ret == 0 &&
+		child != NULL &&
 		!strcmp(ec_node_type(child)->name, "str") &&
 		!strcmp(ec_node_id(child), "id_y"),
 		"bad child 1");
-	child = ec_node_get_child(node, 2);
+	ret = ec_node_get_child(node, 2, &child, &refs);
+	testres |= EC_TEST_CHECK(ret != 0,
+		"ret should be != 0");
 	testres |= EC_TEST_CHECK(child == NULL,
 		"child 2 should be NULL");
 
diff --git a/lib/ecoli_node.h b/lib/ecoli_node.h
index 67652ab..f66fa3d 100644
--- a/lib/ecoli_node.h
+++ b/lib/ecoli_node.h
@@ -83,10 +83,8 @@ typedef const char * (*ec_node_desc_t)(const struct ec_node *);
 typedef int (*ec_node_init_priv_t)(struct ec_node *);
 typedef void (*ec_node_free_priv_t)(struct ec_node *);
 typedef size_t (*ec_node_get_children_count_t)(const struct ec_node *);
-typedef struct ec_node * (*ec_node_get_child_t)(const struct ec_node *,
-						size_t i);
-typedef unsigned int (*ec_node_get_child_refs_t)(const struct ec_node *,
-						size_t i);
+typedef int (*ec_node_get_child_t)(const struct ec_node *,
+	size_t i, struct ec_node **child, unsigned int *refs);
 
 /**
  * A structure describing a node type.
@@ -106,7 +104,6 @@ struct ec_node_type {
 	ec_node_free_priv_t free_priv;
 	ec_node_get_children_count_t get_children_count;
 	ec_node_get_child_t get_child;
-	ec_node_get_child_refs_t get_child_refs;
 };
 
 /**
@@ -177,10 +174,9 @@ int ec_node_set_config(struct ec_node *node, struct ec_config *config);
 const struct ec_config *ec_node_get_config(struct ec_node *node);
 
 size_t ec_node_get_children_count(const struct ec_node *node);
-struct ec_node *
-ec_node_get_child(const struct ec_node *node, size_t i);
-unsigned int
-ec_node_get_child_refs(const struct ec_node *node, size_t i);
+int
+ec_node_get_child(const struct ec_node *node, size_t i,
+	struct ec_node **child, unsigned int *refs);
 
 /* XXX add more accessors */
 const struct ec_node_type *ec_node_type(const struct ec_node *node);
diff --git a/lib/ecoli_node_cmd.c b/lib/ecoli_node_cmd.c
index 5b0d459..4ab13bd 100644
--- a/lib/ecoli_node_cmd.c
+++ b/lib/ecoli_node_cmd.c
@@ -528,15 +528,18 @@ ec_node_cmd_get_children_count(const struct ec_node *gen_node)
 	return 1;
 }
 
-static struct ec_node *
-ec_node_cmd_get_child(const struct ec_node *gen_node, size_t i)
+static int
+ec_node_cmd_get_child(const struct ec_node *gen_node, size_t i,
+		struct ec_node **child, unsigned int *refs)
 {
 	struct ec_node_cmd *node = (struct ec_node_cmd *)gen_node;
 
 	if (i > 0)
-		return NULL;
+		return -1;
 
-	return node->cmd;
+	*child = node->cmd;
+	*refs = 1;
+	return 0;
 }
 
 static struct ec_node_type ec_node_cmd_type = {
diff --git a/lib/ecoli_node_expr.c b/lib/ecoli_node_expr.c
index eb7bff3..3b47d8c 100644
--- a/lib/ecoli_node_expr.c
+++ b/lib/ecoli_node_expr.c
@@ -237,15 +237,18 @@ ec_node_expr_get_children_count(const struct ec_node *gen_node)
 	return 0;
 }
 
-static struct ec_node *
-ec_node_expr_get_child(const struct ec_node *gen_node, size_t i)
+static int
+ec_node_expr_get_child(const struct ec_node *gen_node, size_t i,
+		struct ec_node **child, unsigned int *refs)
 {
 	struct ec_node_expr *node = (struct ec_node_expr *)gen_node;
 
 	if (i >= 1)
-		return NULL;
+		return -1;
 
-	return node->child;
+	*child = node->child;
+	*refs = 1;
+	return 0;
 }
 
 static struct ec_node_type ec_node_expr_type = {
diff --git a/lib/ecoli_node_many.c b/lib/ecoli_node_many.c
index 6a5f676..32e7ad5 100644
--- a/lib/ecoli_node_many.c
+++ b/lib/ecoli_node_many.c
@@ -171,15 +171,18 @@ ec_node_many_get_children_count(const struct ec_node *gen_node)
 	return 0;
 }
 
-static struct ec_node *
-ec_node_many_get_child(const struct ec_node *gen_node, size_t i)
+static int
+ec_node_many_get_child(const struct ec_node *gen_node, size_t i,
+		struct ec_node **child, unsigned int *refs)
 {
 	struct ec_node_many *node = (struct ec_node_many *)gen_node;
 
 	if (i >= 1)
-		return NULL;
+		return -1;
 
-	return node->child;
+	*child = node->child;
+	*refs = 1;
+	return 0;
 }
 
 static struct ec_node_type ec_node_many_type = {
diff --git a/lib/ecoli_node_once.c b/lib/ecoli_node_once.c
index 5248d13..3d4b038 100644
--- a/lib/ecoli_node_once.c
+++ b/lib/ecoli_node_once.c
@@ -105,15 +105,18 @@ ec_node_once_get_children_count(const struct ec_node *gen_node)
 	return 0;
 }
 
-static struct ec_node *
-ec_node_once_get_child(const struct ec_node *gen_node, size_t i)
+static int
+ec_node_once_get_child(const struct ec_node *gen_node, size_t i,
+		struct ec_node **child, unsigned int *refs)
 {
 	struct ec_node_once *node = (struct ec_node_once *)gen_node;
 
 	if (i >= 1)
-		return NULL;
+		return -1;
 
-	return node->child;
+	*child = node->child;
+	*refs = 1;
+	return 0;
 }
 
 static struct ec_node_type ec_node_once_type = {
diff --git a/lib/ecoli_node_option.c b/lib/ecoli_node_option.c
index befbb2e..06cca69 100644
--- a/lib/ecoli_node_option.c
+++ b/lib/ecoli_node_option.c
@@ -71,15 +71,18 @@ ec_node_option_get_children_count(const struct ec_node *gen_node)
 	return 0;
 }
 
-static struct ec_node *
-ec_node_option_get_child(const struct ec_node *gen_node, size_t i)
+static int
+ec_node_option_get_child(const struct ec_node *gen_node, size_t i,
+	struct ec_node **child, unsigned int *refs)
 {
 	struct ec_node_option *node = (struct ec_node_option *)gen_node;
 
 	if (i >= 1)
-		return NULL;
+		return -1;
 
-	return node->child;
+	*child = node->child;
+	*refs = 1;
+	return 0;
 }
 
 static struct ec_node_type ec_node_option_type = {
diff --git a/lib/ecoli_node_or.c b/lib/ecoli_node_or.c
index b36cbd7..aeac206 100644
--- a/lib/ecoli_node_or.c
+++ b/lib/ecoli_node_or.c
@@ -82,15 +82,18 @@ ec_node_or_get_children_count(const struct ec_node *gen_node)
 	return node->len;
 }
 
-static struct ec_node *
-ec_node_or_get_child(const struct ec_node *gen_node, size_t i)
+static int
+ec_node_or_get_child(const struct ec_node *gen_node, size_t i,
+		struct ec_node **child, unsigned int *refs)
 {
 	struct ec_node_or *node = (struct ec_node_or *)gen_node;
 
 	if (i >= node->len)
-		return NULL;
+		return -1;
 
-	return node->table[i];
+	*child = node->table[i];
+	*refs = 1;
+	return 0;
 }
 
 static struct ec_node_type ec_node_or_type = {
diff --git a/lib/ecoli_node_re_lex.c b/lib/ecoli_node_re_lex.c
index 4f0f8d3..0120367 100644
--- a/lib/ecoli_node_re_lex.c
+++ b/lib/ecoli_node_re_lex.c
@@ -162,15 +162,18 @@ ec_node_re_lex_get_children_count(const struct ec_node *gen_node)
 	return 0;
 }
 
-static struct ec_node *
-ec_node_re_lex_get_child(const struct ec_node *gen_node, size_t i)
+static int
+ec_node_re_lex_get_child(const struct ec_node *gen_node, size_t i,
+			struct ec_node **child, unsigned int *refs)
 {
 	struct ec_node_re_lex *node = (struct ec_node_re_lex *)gen_node;
 
 	if (i >= 1)
-		return NULL;
+		return -1;
 
-	return node->child;
+	*child = node->child;
+	*refs = 1;
+	return 0;
 }
 
 static struct ec_node_type ec_node_re_lex_type = {
diff --git a/lib/ecoli_node_seq.c b/lib/ecoli_node_seq.c
index be03f31..ae0bb60 100644
--- a/lib/ecoli_node_seq.c
+++ b/lib/ecoli_node_seq.c
@@ -234,26 +234,20 @@ ec_node_seq_get_children_count(const struct ec_node *gen_node)
 	return node->len;
 }
 
-static struct ec_node *
-ec_node_seq_get_child(const struct ec_node *gen_node, size_t i)
+static int
+ec_node_seq_get_child(const struct ec_node *gen_node, size_t i,
+		struct ec_node **child, unsigned int *refs)
 {
 	struct ec_node_seq *node = (struct ec_node_seq *)gen_node;
 
 	if (i >= node->len)
-		return NULL;
-
-	return node->table[i];
-}
-
-static unsigned int
-ec_node_seq_get_child_refs(const struct ec_node *gen_node, size_t i)
-{
-	(void)gen_node;
-	(void)i;
+		return -1;
 
+	*child = node->table[i];
 	/* each child node is referenced twice: once in the config and
 	 * once in the node->table[] */
-	return 2;
+	*refs = 2;
+	return 0;
 }
 
 static struct ec_node_type ec_node_seq_type = {
@@ -267,7 +261,6 @@ static struct ec_node_type ec_node_seq_type = {
 	.free_priv = ec_node_seq_free_priv,
 	.get_children_count = ec_node_seq_get_children_count,
 	.get_child = ec_node_seq_get_child,
-	.get_child_refs = ec_node_seq_get_child_refs,
 };
 
 EC_NODE_TYPE_REGISTER(ec_node_seq_type);
diff --git a/lib/ecoli_node_sh_lex.c b/lib/ecoli_node_sh_lex.c
index b39ce21..a632f97 100644
--- a/lib/ecoli_node_sh_lex.c
+++ b/lib/ecoli_node_sh_lex.c
@@ -353,15 +353,18 @@ ec_node_sh_lex_get_children_count(const struct ec_node *gen_node)
 	return 0;
 }
 
-static struct ec_node *
-ec_node_sh_lex_get_child(const struct ec_node *gen_node, size_t i)
+static int
+ec_node_sh_lex_get_child(const struct ec_node *gen_node, size_t i,
+	struct ec_node **child, unsigned int *refs)
 {
 	struct ec_node_sh_lex *node = (struct ec_node_sh_lex *)gen_node;
 
 	if (i >= 1)
-		return NULL;
+		return -1;
 
-	return node->child;
+	*refs = 1;
+	*child = node->child;
+	return 0;
 }
 
 static struct ec_node_type ec_node_sh_lex_type = {
diff --git a/lib/ecoli_node_subset.c b/lib/ecoli_node_subset.c
index 059b7b9..bfd7e71 100644
--- a/lib/ecoli_node_subset.c
+++ b/lib/ecoli_node_subset.c
@@ -248,15 +248,18 @@ ec_node_subset_get_children_count(const struct ec_node *gen_node)
 	return node->len;
 }
 
-static struct ec_node *
-ec_node_subset_get_child(const struct ec_node *gen_node, size_t i)
+static int
+ec_node_subset_get_child(const struct ec_node *gen_node, size_t i,
+			struct ec_node **child, unsigned int *refs)
 {
 	struct ec_node_subset *node = (struct ec_node_subset *)gen_node;
 
 	if (i >= node->len)
-		return NULL;
+		return -1;
 
-	return node->table[i];
+	*child = node->table[i];
+	*refs = 1;
+	return 0;
 }
 
 static struct ec_node_type ec_node_subset_type = {
-- 
2.20.1