diff options
| -rw-r--r-- | src/bloom.cpp | 19 | ||||
| -rw-r--r-- | src/bloom.h | 12 | ||||
| -rw-r--r-- | src/main.cpp | 2 | ||||
| -rw-r--r-- | src/net.cpp | 2 | ||||
| -rw-r--r-- | src/test/bloom_tests.cpp | 6 |
5 files changed, 29 insertions, 12 deletions
diff --git a/src/bloom.cpp b/src/bloom.cpp index 3f50b1da91..89959d7326 100644 --- a/src/bloom.cpp +++ b/src/bloom.cpp @@ -8,6 +8,7 @@ #include "hash.h" #include "script/script.h" #include "script/standard.h" +#include "random.h" #include "streams.h" #include <math.h> @@ -121,6 +122,12 @@ void CBloomFilter::clear() isEmpty = true; } +void CBloomFilter::reset(unsigned int nNewTweak) +{ + clear(); + nTweak = nNewTweak; +} + bool CBloomFilter::IsWithinSizeConstraints() const { return vData.size() <= MAX_BLOOM_FILTER_SIZE && nHashFuncs <= MAX_HASH_FUNCS; @@ -217,7 +224,8 @@ CRollingBloomFilter::CRollingBloomFilter(unsigned int nElements, double fpRate, // inserted, so at least one always contains the last nElements // inserted. nBloomSize = nElements * 2; - nInsertions = 0; + + reset(nTweak); } void CRollingBloomFilter::insert(const std::vector<unsigned char>& vKey) @@ -254,9 +262,12 @@ bool CRollingBloomFilter::contains(const uint256& hash) const return contains(data); } -void CRollingBloomFilter::clear() +void CRollingBloomFilter::reset(unsigned int nNewTweak) { - b1.clear(); - b2.clear(); + if (!nNewTweak) + nNewTweak = GetRand(std::numeric_limits<unsigned int>::max()); + + b1.reset(nNewTweak); + b2.reset(nNewTweak); nInsertions = 0; } diff --git a/src/bloom.h b/src/bloom.h index 0daa3728ed..12bf6d99a8 100644 --- a/src/bloom.h +++ b/src/bloom.h @@ -89,6 +89,7 @@ public: bool contains(const uint256& hash) const; void clear(); + void reset(unsigned int nNewTweak); //! 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) @@ -103,7 +104,11 @@ public: /** * RollingBloomFilter is a probabilistic "keep track of most recently inserted" set. - * Construct it with the number of items to keep track of, and a false-positive rate. + * Construct it with the number of items to keep track of, and a false-positive + * rate. Unlike CBloomFilter, by default nTweak is set to a cryptographically + * secure random value for you. Similarly rather than clear() the method + * reset() is provided, which also changes nTweak to decrease the impact of + * false-positives. * * contains(item) will always return true if item was one of the last N things * insert()'ed ... but may also return true for items that were not inserted. @@ -111,14 +116,15 @@ public: class CRollingBloomFilter { public: - CRollingBloomFilter(unsigned int nElements, double nFPRate, unsigned int nTweak); + CRollingBloomFilter(unsigned int nElements, double nFPRate, + unsigned int nTweak = 0); 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 clear(); + void reset(unsigned int nNewTweak = 0); private: unsigned int nBloomSize; diff --git a/src/main.cpp b/src/main.cpp index 601d72b996..8cbc049a96 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -4909,7 +4909,7 @@ bool SendMessages(CNode* pto, bool fSendTrickle) { // Periodically clear addrKnown to allow refresh broadcasts if (nLastRebroadcast) - pnode->addrKnown.clear(); + pnode->addrKnown.reset(); // Rebroadcast our address AdvertizeLocal(pnode); diff --git a/src/net.cpp b/src/net.cpp index b45f862b3a..f94771aa06 100644 --- a/src/net.cpp +++ b/src/net.cpp @@ -1933,7 +1933,7 @@ unsigned int SendBufferSize() { return 1000*GetArg("-maxsendbuffer", 1*1000); } CNode::CNode(SOCKET hSocketIn, CAddress addrIn, std::string addrNameIn, bool fInboundIn) : ssSend(SER_NETWORK, INIT_PROTO_VERSION), - addrKnown(5000, 0.001, insecure_rand()), + addrKnown(5000, 0.001), setInventoryKnown(SendBufferSize() / 1000) { nServices = 0; diff --git a/src/test/bloom_tests.cpp b/src/test/bloom_tests.cpp index 1bda8a7ea1..d927be6b81 100644 --- a/src/test/bloom_tests.cpp +++ b/src/test/bloom_tests.cpp @@ -469,7 +469,7 @@ static std::vector<unsigned char> RandomData() BOOST_AUTO_TEST_CASE(rolling_bloom) { // last-100-entry, 1% false positive: - CRollingBloomFilter rb1(100, 0.01, 0); + CRollingBloomFilter rb1(100, 0.01, 1); // Overfill: static const int DATASIZE=399; @@ -500,7 +500,7 @@ BOOST_AUTO_TEST_CASE(rolling_bloom) BOOST_CHECK(nHits < 175); BOOST_CHECK(rb1.contains(data[DATASIZE-1])); - rb1.clear(); + rb1.reset(1); BOOST_CHECK(!rb1.contains(data[DATASIZE-1])); // Now roll through data, make sure last 100 entries @@ -527,7 +527,7 @@ BOOST_AUTO_TEST_CASE(rolling_bloom) BOOST_CHECK(nHits < 100); // last-1000-entry, 0.01% false positive: - CRollingBloomFilter rb2(1000, 0.001, 0); + CRollingBloomFilter rb2(1000, 0.001, 1); for (int i = 0; i < DATASIZE; i++) { rb2.insert(data[i]); } |