Browse Source

Add nFlags to CBloomFilter to make filter updating optional.

tags/v0.15.1
Matt Corallo 8 years ago
parent
commit
e1a4f3778c
3 changed files with 145 additions and 26 deletions
  1. 13
    3
      src/bloom.cpp
  2. 14
    1
      src/bloom.h
  3. 118
    22
      src/test/bloom_tests.cpp

+ 13
- 3
src/bloom.cpp View File

@@ -15,7 +15,7 @@ using namespace std;

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:
// - nElements * log(fp rate) / ln(2)^2
// 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
// 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)),
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))
{
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;
}
}

+ 14
- 1
src/bloom.h View File

@@ -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);

+ 118
- 22
src/test/bloom_tests.cpp
File diff suppressed because it is too large
View File


Loading…
Cancel
Save