Add basic mbstring encoding cache

Store the last used encoding and compare against it. It's quite
likely that an application is going to be using the same encoding
again and again.

The actual mbfl_name2encoding() function could also be optimized
to use a hash lookup rather than a linear scan, but we don't have
a hashtable implmentation in libmbfl...

diff --git a/ext/mbstring/mbstring.c b/ext/mbstring/mbstring.c
index 62b1dc38d702fa23eaf0b38cb817940cc1fe8740..44a8a1da4c5618b71fe7069c9053757fbd38165b 100644 (file)
--- a/ext/mbstring/mbstring.c
+++ b/ext/mbstring/mbstring.c
@@ -705,11 +705,23 @@ static sapi_post_entry mbstr_post_entries[] = {
 
 static const mbfl_encoding *php_mb_get_encoding(const char *encoding_name) {
        if (encoding_name) {
-               const mbfl_encoding *encoding = mbfl_name2encoding(encoding_name);
+               const mbfl_encoding *encoding;
+               if (MBSTRG(last_used_encoding_name)
+                               && !strcasecmp(encoding_name, MBSTRG(last_used_encoding_name))) {
+                       return MBSTRG(last_used_encoding);
+               }
+
+               encoding = mbfl_name2encoding(encoding_name);
                if (!encoding) {
                        php_error_docref(NULL, E_WARNING, "Unknown encoding \"%s\"", encoding_name);
                        return NULL;
                }
+
+               if (MBSTRG(last_used_encoding_name)) {
+                       efree(MBSTRG(last_used_encoding_name));
+               }
+               MBSTRG(last_used_encoding_name) = estrdup(encoding_name);
+               MBSTRG(last_used_encoding) = encoding;
                return encoding;
        } else {
                return MBSTRG(current_internal_encoding);
@@ -1545,6 +1557,8 @@ ZEND_TSRMLS_CACHE_UPDATE();
 #if HAVE_MBREGEX
        mbstring_globals->mb_regex_globals = php_mb_regex_globals_alloc();
 #endif
+       mbstring_globals->last_used_encoding_name = NULL;
+       mbstring_globals->last_used_encoding = NULL;
 }
 /* }}} */
 
@@ -1563,6 +1577,9 @@ static PHP_GSHUTDOWN_FUNCTION(mbstring)
 #if HAVE_MBREGEX
        php_mb_regex_globals_free(mbstring_globals->mb_regex_globals);
 #endif
+       if (mbstring_globals->last_used_encoding_name) {
+               efree(mbstring_globals->last_used_encoding_name);
+       }
 }
 /* }}} */
 

diff --git a/ext/mbstring/mbstring.h b/ext/mbstring/mbstring.h
index 6862bf039258ec8d2c881b2b755fde2149d8e7e9..49a1434bd85b71e2c888d281e628d478374d4792 100644 (file)
--- a/ext/mbstring/mbstring.h
+++ b/ext/mbstring/mbstring.h
@@ -192,6 +192,8 @@ ZEND_BEGIN_MODULE_GLOBALS(mbstring)
 #if HAVE_MBREGEX
     struct _zend_mb_regex_globals *mb_regex_globals;
 #endif
+       char *last_used_encoding_name;
+       const mbfl_encoding *last_used_encoding;
 ZEND_END_MODULE_GLOBALS(mbstring)
 
 #define MB_OVERLOAD_MAIL 1