From: Peter Krempa <pkrempa@redhat.com>
Date: Wed, 24 Nov 2021 16:03:07 +0000 (+0100)
Subject: internal: Add STRLIM macro for checking string length using strnlen()
X-Git-Tag: v8.0.0-rc1~436
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8eb7471eb360f627e2b80bc75bd4552785b9625c;p=thirdparty%2Flibvirt.git

internal: Add STRLIM macro for checking string length using strnlen()

As a microoprimization when checking whether length of a string fits
into a limit we don't necessarily need to calculate the full length but
can use strnlen to check only LIMIT+1 chars. Add a macro which will
simplify the expressions.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
---

diff --git a/src/internal.h b/src/internal.h
index d3809bf057..2e404cd705 100644
--- a/src/internal.h
+++ b/src/internal.h
@@ -87,6 +87,15 @@
 #define STRPREFIX(a, b) (strncmp(a, b, strlen(b)) == 0)
 #define STRCASEPREFIX(a, b) (g_ascii_strncasecmp(a, b, strlen(b)) == 0)
 #define STRSKIP(a, b) (STRPREFIX(a, b) ? (a) + strlen(b) : NULL)
+/**
+ * STRLIM
+ * @str: pointer to a string (evaluated once)
+ * @lim: length limit (evaluated twice)
+ *
+ * Evaluates as true if length of @str doesn't exceed the limit @lim. Note
+ * that @lim + 1 characters may be accessed.
+ */
+#define STRLIM(str, lim) (strnlen((str), (lim) + 1) <= (lim))
 
 #define STREQ_NULLABLE(a, b) (g_strcmp0(a, b) == 0)
 #define STRNEQ_NULLABLE(a, b) (g_strcmp0(a, b) != 0)