Improved performance of json_encode()

diff --git a/ext/json/json.c b/ext/json/json.c
index cbdec32d8884ae418add374e57fcc970e74b67c4..7e27daf36b6bda90fc866aca0cdf6a96130fd039 100644 (file)
--- a/ext/json/json.c
+++ b/ext/json/json.c
@@ -167,7 +167,7 @@ static PHP_MINFO_FUNCTION(json)
 }
 /* }}} */
 
-static void json_escape_string(smart_str *buf, char *s, int len, int options TSRMLS_DC);
+static void json_escape_string(smart_str *buf, char *s, size_t len, int options TSRMLS_DC);
 
 static int json_determine_array_type(zval *val TSRMLS_DC) /* {{{ */
 {
@@ -380,12 +380,11 @@ static int json_utf8_to_utf16(unsigned short *utf16, char utf8[], int len) /* {{
 }
 /* }}} */
 
-static void json_escape_string(smart_str *buf, char *s, int len, int options TSRMLS_DC) /* {{{ */
+static void json_escape_string(smart_str *buf, char *s, size_t len, int options TSRMLS_DC) /* {{{ */
 {
-       int pos = 0, ulen = 0;
-       unsigned short us;
-       unsigned short *utf16;
-       size_t newlen;
+       int status;
+       unsigned int us, next_us = 0;
+       size_t pos, checkpoint, newlen;
 
        if (len == 0) {
                smart_str_appendl(buf, "\"\"", 2);
@@ -416,34 +415,51 @@ static void json_escape_string(smart_str *buf, char *s, int len, int options TSR
 
        }
 
-       utf16 = (options & PHP_JSON_UNESCAPED_UNICODE) ? NULL : (unsigned short *) safe_emalloc(len, sizeof(unsigned short), 0);
-       ulen = json_utf8_to_utf16(utf16, s, len);
-       if (ulen <= 0) {
-               if (utf16) {
-                       efree(utf16);
-               }
-               if (ulen < 0) {
+       if (options & PHP_JSON_UNESCAPED_UNICODE) {
+               /* validate UTF-8 string first */
+               if (json_utf8_to_utf16(NULL, s, len) < 0) {
                        JSON_G(error_code) = PHP_JSON_ERROR_UTF8;
                        smart_str_appendl(buf, "null", 4);
-               } else {
-                       smart_str_appendl(buf, "\"\"", 2);
+                       return;                 
                }
-               return;
-       }
-       if (!(options & PHP_JSON_UNESCAPED_UNICODE)) {
-               len = ulen;
        }
 
+       pos = 0;
+       checkpoint = buf->s ? buf->s->len : 0;
+
        /* pre-allocate for string length plus 2 quotes */
        smart_str_alloc(buf, len+2, 0);
        smart_str_appendc(buf, '"');
 
-       while (pos < len)
-       {
-               us = (options & PHP_JSON_UNESCAPED_UNICODE) ? s[pos++] : utf16[pos++];
+       do {
+               if (UNEXPECTED(next_us)) {
+                       us = next_us;
+                       next_us = 0;
+               } else {
+                       us = (unsigned char)s[pos];
+                       if (!(options & PHP_JSON_UNESCAPED_UNICODE) && us >= 0x80) {
+                               /* UTF-8 character */
+                               us = php_next_utf8_char((const unsigned char *)s, len, &pos, &status);
+                               if (status != SUCCESS) {
+                                       if (buf->s) {
+                                               buf->s->len = checkpoint;
+                                       }
+                                       JSON_G(error_code) = PHP_JSON_ERROR_UTF8;
+                                       smart_str_appendl(buf, "null", 4);
+                                       return;
+                               }
+                               /* From http://en.wikipedia.org/wiki/UTF16 */
+                               if (us >= 0x10000) {
+                                       us -= 0x10000;
+                                       next_us = (unsigned short)((us & 0x3ff) | 0xdc00);
+                                       us = (unsigned short)((us >> 10) | 0xd800);
+                               }
+                       } else {
+                               pos++;
+                       }
+               }
 
-               switch (us)
-               {
+               switch (us) {
                        case '"':
                                if (options & PHP_JSON_HEX_QUOT) {
                                        smart_str_appendl(buf, "\\u0022", 6);
@@ -528,12 +544,9 @@ static void json_escape_string(smart_str *buf, char *s, int len, int options TSR
                                }
                                break;
                }
-       }
-
+       } while (pos < len || next_us);
+       
        smart_str_appendc(buf, '"');
-       if (utf16) {
-               efree(utf16);
-       }
 }
 /* }}} */