Add support for big integers to the native message format

runtime/vm/snapshot.cc

Index: runtime/vm/snapshot.cc
diff --git a/runtime/vm/snapshot.cc b/runtime/vm/snapshot.cc
index 016465ab74358eeb10683528c0766a82c18607a7..13511a2fd3435a96ef50a264342b44cb27976043 100644
--- a/runtime/vm/snapshot.cc
+++ b/runtime/vm/snapshot.cc
@@ -2,6 +2,8 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+#include <openssl/crypto.h>
+
 #include "vm/snapshot.h"
 
 #include "platform/assert.h"
@@ -539,6 +541,23 @@ void MessageWriter::WriteCObject(Dart_CObject* object) {
       WriteSmi(object->value.as_int32);
       break;
     }
+    case Dart_CObject::kBigint: {
+      // Write out the serialization header value for this object.
+      WriteInlinedHeader(object);
+      // Write out the class and tags information.
+      WriteObjectHeader(ObjectStore::kBigintClass, 0);
+      BIGNUM* bn = BN_new();
+      BN_dec2bn(&bn, object->value.as_bigint);
+      char* hex_string = BN_bn2hex(bn);

[siva, 2012/02/09 01:47:27]

Somebody came up with the BigintOperations class in the hope of hiding the fact
that we are using OPENSSL to do the bigint operations and be able to plug in
some other implementation without changing much of the rest of the code.

This assumption is being violated here.

[Søren Gjesse, 2012/02/09 14:08:33]

After changing to using the hex format for the data in the Dart_CObject
structure no bignum operations are needed any more.

+      intptr_t len = strlen(hex_string);
+      WriteIntptrValue(len);
+      for (intptr_t i = 0; i < len; i++) {
+        Write<uint8_t>(hex_string[i]);
+      }
+      OPENSSL_free(hex_string);
+      BN_free(bn);
+      break;
+    }
     case Dart_CObject::kDouble:
       // Write out the serialization header value for this object.
       WriteInlinedHeader(object);