From 46bc8ca1541d80b272e2ef0cbb499a4cb1bea659 Mon Sep 17 00:00:00 2001
From: John Mark Bell <jmb@netsurf-browser.org>
Date: Mon, 11 Jul 2005 18:10:10 +0000
Subject: [PATCH] [project @ 2005-07-11 18:10:10 by jmb] Cache previous iconv
 conversion descriptor

svn path=/import/netsurf/; revision=1792
---
 desktop/netsurf.c |  3 +++
 utils/utf8.c      | 56 +++++++++++++++++++++++++++++++++++++----------
 utils/utf8.h      |  2 ++
 3 files changed, 49 insertions(+), 12 deletions(-)

diff --git a/desktop/netsurf.c b/desktop/netsurf.c
index d0c2080ec..606774bf3 100644
--- a/desktop/netsurf.c
+++ b/desktop/netsurf.c
@@ -23,6 +23,7 @@
 #endif
 #include "netsurf/utils/log.h"
 #include "netsurf/utils/url.h"
+#include "netsurf/utils/utf8.h"
 #include "netsurf/utils/utils.h"
 
 bool netsurf_quit = false;
@@ -73,6 +74,7 @@ void netsurf_init(int argc, char** argv)
 				"machine <%s>", utsname.sysname,
 				utsname.nodename, utsname.release,
 				utsname.version, utsname.machine));
+
 	lib_init();
 	url_init();
 	gui_init(argc, argv);
@@ -103,6 +105,7 @@ void netsurf_exit(void)
 	gui_quit();
 	content_quit();
 	fetch_quit();
+	utf8_finalise();
 }
 
 
diff --git a/utils/utf8.c b/utils/utf8.c
index 801fca1a3..6c06c76f5 100644
--- a/utils/utf8.c
+++ b/utils/utf8.c
@@ -198,6 +198,26 @@ size_t utf8_next(const char *s, size_t l, size_t o)
 	return o;
 }
 
+/* Cache of previous iconv conversion descriptor used by utf8_convert */
+static struct {
+	char from[32];	/**< Encoding name to convert from */
+	char to[32];	/**< Encoding name to convert to */
+	iconv_t cd;	/**< Iconv conversion descriptor */
+} last_cd;
+
+/**
+ * Finalise the UTF-8 library
+ */
+void utf8_finalise(void)
+{
+	if (last_cd.cd != 0)
+		iconv_close(last_cd.cd);
+
+	/* paranoia follows */
+	last_cd.from[0] = '\0';
+	last_cd.to[0] = '\0';
+	last_cd.cd = 0;
+}
 
 /**
  * Convert a UTF8 string into the named encoding
@@ -262,12 +282,29 @@ utf8_convert_ret utf8_convert(const char *string, size_t len,
 
 	in = (char *)string;
 
-	cd = iconv_open(to, from);
-	if (cd == (iconv_t)-1) {
-		if (errno == EINVAL)
-			return UTF8_CONVERT_BADENC;
-		/* default to no memory */
-		return UTF8_CONVERT_NOMEM;
+	/* we cache the last used conversion descriptor,
+	 * so check if we're trying to use it here */
+	if (strncasecmp(last_cd.from, from, 32) == 0 &&
+			strncasecmp(last_cd.to, to, 32) == 0) {
+		cd = last_cd.cd;
+	}
+	else {
+		/* no match, so create a new cd */
+		cd = iconv_open(to, from);
+		if (cd == (iconv_t)-1) {
+			if (errno == EINVAL)
+				return UTF8_CONVERT_BADENC;
+			/* default to no memory */
+			return UTF8_CONVERT_NOMEM;
+		}
+
+		/* close the last cd - we don't care if this fails */
+		iconv_close(last_cd.cd);
+
+		/* and copy the to/from/cd data into last_cd */
+		strncpy(last_cd.from, from, 32);
+		strncpy(last_cd.to, to, 32);
+		last_cd.cd = cd;
 	}
 
 	slen = len ? len : strlen(string);
@@ -278,15 +315,12 @@ utf8_convert_ret utf8_convert(const char *string, size_t len,
 	rlen = slen * 4 + 4;
 
 	temp = out = malloc(rlen);
-	if (!out) {
-		iconv_close(cd);
+	if (!out)
 		return UTF8_CONVERT_NOMEM;
-	}
 
 	/* perform conversion */
 	if (iconv(cd, &in, &slen, &out, &rlen) == (size_t)-1) {
 		free(temp);
-		iconv_close(cd);
 		/** \todo handle the various cases properly
 		 * There are 3 possible error cases:
 		 * a) Insufficiently large output buffer
@@ -295,8 +329,6 @@ utf8_convert_ret utf8_convert(const char *string, size_t len,
 		return UTF8_CONVERT_NOMEM;
 	}
 
-	iconv_close(cd);
-
 	*(result) = realloc(temp, out - temp + 4);
 	if (!(*result)) {
 		free(temp);
diff --git a/utils/utf8.h b/utils/utf8.h
index a1d98685d..a77af29d0 100644
--- a/utils/utf8.h
+++ b/utils/utf8.h
@@ -31,4 +31,6 @@ utf8_convert_ret utf8_to_enc(const char *string, const char *encname,
 utf8_convert_ret utf8_from_enc(const char *string, const char *encname,
 		size_t len, char **result);
 
+void utf8_finalise(void);
+
 #endif