0004-use-glibc-strlen.patch

From c94172d2a4451368530db2186190d70be8a1d9e5 Mon Sep 17 00:00:00 2001
From: Ilya Zub <ilya@serpapi.com>
Date: Wed, 23 Dec 2020 12:45:29 +0200
Subject: Use glibc strlen to speed up xmlStrlen
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xmlStrlen (entire HTML file): 926171.936981 μs
glibc_xmlStrlen (entire HTML file): 36905.903992 μs
delta (xmlStrlen ÷ glibc_xmlStrlen): 25.094584 times

xmlStrlen (average string): 57479.204010 μs
glibc_xmlStrlen (average string): 5802.069000 μs
delta (xmlStrlen ÷ glibc_xmlStrlen): 9.905937 times

xmlStrlen (bigger string): 388056.315979 μs
glibc_xmlStrlen (bigger string): 12797.856995 μs
delta (xmlStrlen ÷ glibc_xmlStrlen): 30.318382 times

xmlStrlen (smallest string): 15870.046021 μs
glibc_xmlStrlen (smallest string): 6282.208984 μs
delta (xmlStrlen ÷ glibc_xmlStrlen): 2.527903 times

See https://gitlab.gnome.org/GNOME/libxml2/-/issues/212 for reference.
---
 xmlstring.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/xmlstring.c b/xmlstring.c
index e8a1e45d..df247dff 100644
--- a/xmlstring.c
+++ b/xmlstring.c
@@ -423,12 +423,7 @@ xmlStrsub(const xmlChar *str, int start, int len) {

 int
 xmlStrlen(const xmlChar *str) {
-    size_t len = 0;
-
     if (str == NULL) return(0);
-    while (*str != 0) { /* non input consuming */
-        str++;
-        len++;
-    }
-    return(len > INT_MAX ? 0 : len);
+
+    return strlen((const char*)str);
 }

 /**
--
2.29.2