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Add nFlags to CBloomFilter to make filter updating optional.

0.8
Matt Corallo 12 years ago
parent
commit
e1a4f3778c
  1. 16
      src/bloom.cpp
  2. 15
      src/bloom.h
  3. 140
      src/test/bloom_tests.cpp

16
src/bloom.cpp

@ -15,7 +15,7 @@ using namespace std;
static const unsigned char bit_mask[8] = {0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80}; static const unsigned char bit_mask[8] = {0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80};
CBloomFilter::CBloomFilter(unsigned int nElements, double nFPRate, unsigned int nTweakIn) : CBloomFilter::CBloomFilter(unsigned int nElements, double nFPRate, unsigned int nTweakIn, unsigned char nFlagsIn) :
// The ideal size for a bloom filter with a given number of elements and false positive rate is: // The ideal size for a bloom filter with a given number of elements and false positive rate is:
// - nElements * log(fp rate) / ln(2)^2 // - nElements * log(fp rate) / ln(2)^2
// We ignore filter parameters which will create a bloom filter larger than the protocol limits // We ignore filter parameters which will create a bloom filter larger than the protocol limits
@ -24,7 +24,8 @@ vData(min((unsigned int)(-1 / LN2SQUARED * nElements * log(nFPRate)), MAX_BLOOM
// Again, we ignore filter parameters which will create a bloom filter with more hash functions than the protocol limits // Again, we ignore filter parameters which will create a bloom filter with more hash functions than the protocol limits
// See http://en.wikipedia.org/wiki/Bloom_filter for an explanation of these formulas // See http://en.wikipedia.org/wiki/Bloom_filter for an explanation of these formulas
nHashFuncs(min((unsigned int)(vData.size() * 8 / nElements * LN2), MAX_HASH_FUNCS)), nHashFuncs(min((unsigned int)(vData.size() * 8 / nElements * LN2), MAX_HASH_FUNCS)),
nTweak(nTweakIn) nTweak(nTweakIn),
nFlags(nFlagsIn)
{ {
} }
@ -114,7 +115,16 @@ bool CBloomFilter::IsRelevantAndUpdate(const CTransaction& tx, const uint256& ha
if (data.size() != 0 && contains(data)) if (data.size() != 0 && contains(data))
{ {
fFound = true; fFound = true;
insert(COutPoint(hash, i)); if ((nFlags & BLOOM_UPDATE_MASK) == BLOOM_UPDATE_ALL)
insert(COutPoint(hash, i));
else if ((nFlags & BLOOM_UPDATE_MASK) == BLOOM_UPDATE_P2PUBKEY_ONLY)
{
txnouttype type;
vector<vector<unsigned char> > vSolutions;
if (Solver(txout.scriptPubKey, type, vSolutions) &&
(type == TX_PUBKEY || type == TX_MULTISIG))
insert(COutPoint(hash, i));
}
break; break;
} }
} }

15
src/bloom.h

@ -16,6 +16,16 @@ class CTransaction;
static const unsigned int MAX_BLOOM_FILTER_SIZE = 36000; // bytes static const unsigned int MAX_BLOOM_FILTER_SIZE = 36000; // bytes
static const unsigned int MAX_HASH_FUNCS = 50; 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 * BloomFilter is a probabilistic filter which SPV clients provide
@ -34,6 +44,7 @@ private:
std::vector<unsigned char> vData; std::vector<unsigned char> vData;
unsigned int nHashFuncs; unsigned int nHashFuncs;
unsigned int nTweak; 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, 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. // 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 // 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) // 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 // Using a filter initialized with this results in undefined behavior
// Should only be used for deserialization // Should only be used for deserialization
CBloomFilter() {} CBloomFilter() {}
@ -54,6 +66,7 @@ public:
READWRITE(vData); READWRITE(vData);
READWRITE(nHashFuncs); READWRITE(nHashFuncs);
READWRITE(nTweak); READWRITE(nTweak);
READWRITE(nFlags);
) )
void insert(const std::vector<unsigned char>& vKey); void insert(const std::vector<unsigned char>& vKey);

140
src/test/bloom_tests.cpp

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