implement simple bloom filter

BloomFilter.h

@@ -0,0 +1,31 @@
+#ifndef BLOOM_FILTER_H_
+#define BLOOM_FILTER_H_
+#include <memory>
+#include <cstdint>
+
+namespace i2p
+{
+namespace util
+{
+
+  /** @brief interface for bloom filter */
+  struct IBloomFilter
+  {
+
+    /** @brief destructor */
+    virtual ~IBloomFilter();
+    /** @brief add entry to bloom filter, return false if filter hit otherwise return true */
+    virtual bool Add(const uint8_t * data, std::size_t len) = 0;
+    /** @brief optionally decay old entries */
+    virtual void Decay();
+  };
+
+  typedef std::shared_ptr<IBloomFilter> BloomFilterPtr;
+
+  /** @brief create bloom filter */
+  BloomFilterPtr BloomFilter(std::size_t capacity = 1024 * 8);
+
+}
+}
+
+#endif