Create hash policies through factory.

src/BloomFilter.cc

@@ -34,8 +34,6 @@ BloomFilter* BloomFilter::Unserialize(UnserialInfo* info)
 bool BloomFilter::DoSerialize(SerialInfo* info) const
 	{
 	DO_SERIALIZE(SER_BLOOMFILTER, SerialObj);
-	// FIXME: Since we have a fixed hashing policy, we just serialize the
-	// information needed to reconstruct it.
   if ( ! SERIALIZE(static_cast<uint16>(hash_->K())) )
     return false;
   return SERIALIZE_STR(hash_->Name().c_str(), hash_->Name().size());
@@ -50,8 +48,7 @@ bool BloomFilter::DoUnserialize(UnserialInfo* info)
   const char* name;
   if ( ! UNSERIALIZE_STR(&name, 0) )
     return false;
-	// FIXME: for now Bloom filters always use double hashing.
+	hash_ = HashPolicy::Create(k, name);
-	hash_ = new DefaultHashing(k, name);
 	return true;
   }
 

src/HashPolicy.cc

@@ -32,6 +32,11 @@ size_t Hasher::compute_seed(size_t seed, const std::string& extra)
   }
 
 
+HashPolicy* HashPolicy::Create(size_t k, const std::string& name)
+  {
+  return new DefaultHashing(k, name);
+  }
+
 HashPolicy::HashPolicy(size_t k, const std::string& name)
   : k_(k), name_(name)
 	{

src/HashPolicy.h

@@ -42,6 +42,13 @@ private:
  */
 class HashPolicy {
 public:
+  /**
+   * Constructs the hashing policy used by the implementation. This factory
+   * function exists because the HashingPolicy class hierachy is not yet
+   * serializable.
+   */
+	static HashPolicy* Create(size_t k, const std::string& name);
+
   typedef Hasher::hash_type hash_type;
   typedef std::vector<hash_type> hash_vector;
 

src/bro.bif

@@ -5008,7 +5008,7 @@ function bloomfilter_basic_init%(fp: double, capacity: count,
 
   size_t cells = BasicBloomFilter::M(fp, capacity);
   size_t optimal_k = BasicBloomFilter::K(cells, capacity);
-  const HashPolicy* hp = new DefaultHashing(optimal_k, name->CheckString());
+  const HashPolicy* hp = HashPolicy::Create(optimal_k, name->CheckString());
   return new BloomFilterVal(new BasicBloomFilter(hp, cells));
   %}
 
@@ -5029,7 +5029,7 @@ function bloomfilter_basic_init%(fp: double, capacity: count,
 function bloomfilter_counting_init%(k: count, cells: count, max: count,
                                     name: string &default=""%): opaque of bloomfilter
   %{
-  const HashPolicy* hp = new DefaultHashing(k, name->CheckString());
+  const HashPolicy* hp = HashPolicy::Create(k, name->CheckString());
   uint16 width = 0;
   while ( max >>= 1 )
     ++width;