Add nFlags to CBloomFilter to make filter updating optional.

src/bloom.h

@@ -16,6 +16,16 @@ class CTransaction;
 static const unsigned int MAX_BLOOM_FILTER_SIZE = 36000; // bytes
 static const unsigned int MAX_HASH_FUNCS = 50;
 
+// First two bits of nFlags control how much IsRelevantAndUpdate actually updates
+// The remaining bits are reserved
+enum bloomflags
+{
+    BLOOM_UPDATE_NONE = 0,
+    BLOOM_UPDATE_ALL = 1,
+    // Only adds outpoints to the filter if the output is a pay-to-pubkey/pay-to-multisig script
+    BLOOM_UPDATE_P2PUBKEY_ONLY = 2,
+    BLOOM_UPDATE_MASK = 3,
+};
 
 /**
  * BloomFilter is a probabilistic filter which SPV clients provide
@@ -34,6 +44,7 @@ private:
     std::vector<unsigned char> vData;
     unsigned int nHashFuncs;
     unsigned int nTweak;
+    unsigned char nFlags;
 
     unsigned int Hash(unsigned int nHashNum, const std::vector<unsigned char>& vDataToHash) const;
 
@@ -44,7 +55,8 @@ public:
     // This will apply if nFPRate is very low or nElements is unreasonably high.
     // nTweak is a constant which is added to the seed value passed to the hash function
     // It should generally always be a random value (and is largely only exposed for unit testing)
-    CBloomFilter(unsigned int nElements, double nFPRate, unsigned int nTweak);
+    // nFlags should be one of the BLOOM_UPDATE_* enums (not _MASK)
+    CBloomFilter(unsigned int nElements, double nFPRate, unsigned int nTweak, unsigned char nFlagsIn);
     // Using a filter initialized with this results in undefined behavior
     // Should only be used for deserialization
     CBloomFilter() {}
@@ -54,6 +66,7 @@ public:
         READWRITE(vData);
         READWRITE(nHashFuncs);
         READWRITE(nTweak);
+        READWRITE(nFlags);
     )
 
     void insert(const std::vector<unsigned char>& vKey);