From 15b8a98a6c4af20558abaa82e676042245f19c72 Mon Sep 17 00:00:00 2001
From: Alon Levy <alevy@redhat.com>
Date: Sun, 29 Jan 2012 23:29:50 +0200
Subject: [PATCH 4/6] add a font cache, fix repeated reload leading to EMFILE

---
 sdltools.cpp |   41 +++++++++++++++++++++++++++++++++++++++++
 1 files changed, 41 insertions(+), 0 deletions(-)

diff --git a/sdltools.cpp b/sdltools.cpp
index 0806981..b47d4bc 100644
--- a/sdltools.cpp
+++ b/sdltools.cpp
@@ -11,6 +11,9 @@ published by the Free Software Foundation. */
 #include <stdarg.h>
 #include <unistd.h>
 
+#include <map>
+#include <string>
+
 #include <sys/types.h>
 #include <sys/stat.h>
 
@@ -246,8 +249,46 @@ TTF_Font *init_font(const char *resource_path, const char *font_file, int size)
 }
 */
 
+/*
+ * Font cache. Avoid reopening a font file. Avoid leaking fonts on reload
+ * (EMFILE after many hits of the key 'r').
+ *
+ * NB: Assume for now the font files themselves do not change
+ */
+
+using std::map;
+using std::pair;
+using std::string;
+
+class FontCache {
+private:
+    typedef pair<string, int> key_type;
+    typedef map<key_type, TTF_Font*> cache_type;
+    typedef pair<key_type, TTF_Font*> pair_type;
+    cache_type m_cache;
+    TTF_Font *load_font(const char *font_path, int size);
+public:
+    TTF_Font *get_font(const char *font_path, int size)
+    {
+        cache_type::iterator it;
+        key_type key = key_type(font_path, size);
+        if (m_cache.count(key) == 0) {
+            m_cache.insert(pair_type(key, load_font(font_path, size)));
+            it = m_cache.find(key);
+        } else {
+            it = m_cache.find(key);
+        }
+        return it->second;
+    }
+} font_cache;
+
 TTF_Font *load_font(const char *font_path, int size)
 {
+    return font_cache.get_font(font_path, size);
+}
+
+TTF_Font *FontCache::load_font(const char *font_path, int size)
+{
 	TTF_Font *font;
 	
 	font = TTF_OpenFont(font_path, size); // Point size
-- 
1.7.9.1