--- JSON-XS/XS.xs	2007/06/25 04:08:17	1.44
+++ JSON-XS/XS.xs	2007/06/25 06:57:42	1.45
@@ -30,8 +30,11 @@
 #define F_CONV_BLESSED   0x00000800UL // NYI
 #define F_MAXDEPTH       0xf8000000UL
 #define S_MAXDEPTH       27
+#define F_MAXSIZE        0x01f00000UL
+#define S_MAXSIZE        20
 
 #define DEC_DEPTH(flags) (1UL << ((flags & F_MAXDEPTH) >> S_MAXDEPTH))
+#define DEC_SIZE(flags)  (1UL << ((flags & F_MAXSIZE ) >> S_MAXSIZE ))
 
 #define F_PRETTY    F_INDENT | F_SPACE_BEFORE | F_SPACE_AFTER
 #define F_DEFAULT   (9UL << S_MAXDEPTH)
@@ -1135,6 +1138,10 @@
   SvGETMAGIC (string);
   SvUPGRADE (string, SVt_PV);
 
+  if (flags & F_MAXSIZE && SvCUR (string) > DEC_SIZE (flags))
+    croak ("attempted decode of JSON text of %lu bytes size, but max_size is set to %lu",
+           (unsigned long)SvCUR (string), (unsigned long)DEC_SIZE (flags));
+
   if (flags & F_UTF8)
     sv_utf8_downgrade (string, 0);
   else
@@ -1275,6 +1282,25 @@
 
         RETVAL = newSVsv (self);
 }
+	OUTPUT:
+        RETVAL
+
+SV *max_size (SV *self, UV max_size = 0)
+	CODE:
+{
+  	UV *uv = SvJSON (self);
+        UV log2 = 0;
+
+        if (max_size > 0x80000000UL) max_size = 0x80000000UL;
+        if (max_size == 1)           max_size = 2;
+
+        while ((1UL << log2) < max_size)
+          ++log2;
+
+        *uv = *uv & ~F_MAXSIZE | (log2 << S_MAXSIZE);
+
+        RETVAL = newSVsv (self);
+}
 	OUTPUT:
         RETVAL