bloom: use Span instead of std::vector for `insert` and `contains`

We can avoid many unnecessary std::vector allocations by changing
CBloomFilter to take Spans instead of std::vector's for the `insert`
and `contains` operations.

CBloomFilter currently converts types such as CDataStream and uint256
to std::vector on `insert` and `contains`. This is unnecessary because
CDataStreams and uint256 are already std::vectors internally. We just
need a way to point to the right data within those types. Span gives
us this ability.

Signed-off-by: William Casarin <jb55@jb55.com>

1 files changed, 5 insertions, 10 deletions

diff --git a/src/bloom.h b/src/bloom.h
index fdaa8abfb2..391e2cc888 100644
--- a/src/bloom.h
+++ b/src/bloom.h
@@ -11,7 +11,6 @@
 
 class COutPoint;
 class CTransaction;
-class uint256;
 
 //! 20,000 items with fp rate < 0.1% or 10,000 items and <0.0001%
 static const unsigned int MAX_BLOOM_FILTER_SIZE = 36000; // bytes
@@ -49,7 +48,7 @@ private:
     unsigned int nTweak;
     unsigned char nFlags;
 
-    unsigned int Hash(unsigned int nHashNum, const std::vector<unsigned char>& vDataToHash) const;
+    unsigned int Hash(unsigned int nHashNum, Span<const unsigned char> vDataToHash) const;
 
 public:
     /**
@@ -66,13 +65,11 @@ public:
 
     SERIALIZE_METHODS(CBloomFilter, obj) { READWRITE(obj.vData, obj.nHashFuncs, obj.nTweak, obj.nFlags); }
 
-    void insert(const std::vector<unsigned char>& vKey);
+    void insert(Span<const unsigned char> vKey);
     void insert(const COutPoint& outpoint);
-    void insert(const uint256& hash);
 
-    bool contains(const std::vector<unsigned char>& vKey) const;
+    bool contains(Span<const unsigned char> vKey) const;
     bool contains(const COutPoint& outpoint) const;
-    bool contains(const uint256& hash) const;
 
     //! True if the size is <= MAX_BLOOM_FILTER_SIZE and the number of hash functions is <= MAX_HASH_FUNCS
     //! (catch a filter which was just deserialized which was too big)
@@ -112,10 +109,8 @@ class CRollingBloomFilter
 public:
     CRollingBloomFilter(const unsigned int nElements, const double nFPRate);
 
-    void insert(const std::vector<unsigned char>& vKey);
-    void insert(const uint256& hash);
-    bool contains(const std::vector<unsigned char>& vKey) const;
-    bool contains(const uint256& hash) const;
+    void insert(Span<const unsigned char> vKey);
+    bool contains(Span<const unsigned char> vKey) const;
 
     void reset();