From d99e02dc8ae052b044ac255b1ec9ac76655a73c7 Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Sun, 26 Jun 2022 15:12:33 +0930
Subject: [PATCH] strmap: add strmap_getn for non-terminated string search.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 ccan/strmap/strmap.c | 17 +++++++++++------
 ccan/strmap/strmap.h | 19 ++++++++++++++++++-
 2 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/ccan/strmap/strmap.c b/ccan/strmap/strmap.c
index 9fa51d0d..16a30e03 100644
--- a/ccan/strmap/strmap.c
+++ b/ccan/strmap/strmap.c
@@ -17,9 +17,8 @@ struct node {
 };
 
 /* Closest member to this in a non-empty map. */
-static struct strmap *closest(struct strmap *n, const char *member)
+static struct strmap *closest(struct strmap *n, const char *member, size_t len)
 {
-	size_t len = strlen(member);
 	const u8 *bytes = (const u8 *)member;
 
 	/* Anything with NULL value is a node. */
@@ -35,20 +34,26 @@ static struct strmap *closest(struct strmap *n, const char *member)
 	return n;
 }
 
-void *strmap_get_(const struct strmap *map, const char *member)
+void *strmap_getn_(const struct strmap *map,
+		   const char *member, size_t memberlen)
 {
 	struct strmap *n;
 
 	/* Not empty map? */
 	if (map->u.n) {
-		n = closest((struct strmap *)map, member);
-		if (streq(member, n->u.s))
+		n = closest((struct strmap *)map, member, memberlen);
+		if (!strncmp(member, n->u.s, memberlen) && !n->u.s[memberlen])
 			return n->v;
 	}
 	errno = ENOENT;
 	return NULL;
 }
 
+void *strmap_get_(const struct strmap *map, const char *member)
+{
+	return strmap_getn_(map, member, strlen(member));
+}
+
 bool strmap_add_(struct strmap *map, const char *member, const void *value)
 {
 	size_t len = strlen(member);
@@ -68,7 +73,7 @@ bool strmap_add_(struct strmap *map, const char *member, const void *value)
 	}
 
 	/* Find closest existing member. */
-	n = closest(map, member);
+	n = closest(map, member, len);
 
 	/* Find where they differ. */
 	for (byte_num = 0; n->u.s[byte_num] == member[byte_num]; byte_num++) {
diff --git a/ccan/strmap/strmap.h b/ccan/strmap/strmap.h
index 0b32e6be..8724c31d 100644
--- a/ccan/strmap/strmap.h
+++ b/ccan/strmap/strmap.h
@@ -72,7 +72,7 @@ static inline bool strmap_empty_(const struct strmap *map)
 /**
  * strmap_get - get a value from a string map
  * @map: the typed strmap to search.
- * @member: the string to search for.
+ * @member: the string to search for (nul terminated)
  *
  * Returns the value, or NULL if it isn't in the map (and sets errno = ENOENT).
  *
@@ -85,6 +85,23 @@ static inline bool strmap_empty_(const struct strmap *map)
 	tcon_cast((map), canary, strmap_get_(tcon_unwrap(map), (member)))
 void *strmap_get_(const struct strmap *map, const char *member);
 
+/**
+ * strmap_getn - get a value from a string map
+ * @map: the typed strmap to search.
+ * @member: the string to search for.
+ * @memberlen: the length of @member.
+ *
+ * Returns the value, or NULL if it isn't in the map (and sets errno = ENOENT).
+ *
+ * Example:
+ *	val = strmap_getn(&map, "hello", 5);
+ *	if (val)
+ *		printf("hello => %i\n", *val);
+ */
+#define strmap_getn(map, member, n)					\
+	tcon_cast((map), canary, strmap_getn_(tcon_unwrap(map), (member), (n)))
+void *strmap_getn_(const struct strmap *map, const char *member, size_t n);
+
 /**
  * strmap_add - place a member in the string map.
  * @map: the typed strmap to add to.
-- 
2.39.2