Merge #9480: De-duplicate SignatureCacheHasher

f9c8807 Deduplicate SignatureCacheHasher (Jeremy Rubin)

Tree-SHA512: 714a0f39d1c836fedd1868369b4ebf1096cd800cc544d57b54101da338c80c627a3e59c6644b3268054efe85053cf1a7be508af935f624491e7acfae61123994
This commit is contained in:
Pieter Wuille 2017-04-13 09:54:05 -07:00
commit b7365f0545
No known key found for this signature in database
GPG Key ID: A636E97631F767E0
3 changed files with 27 additions and 41 deletions

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@ -15,28 +15,6 @@
#include <boost/thread.hpp>
namespace {
/**
* We're hashing a nonce into the entries themselves, so we don't need extra
* blinding in the set hash computation.
*
* This may exhibit platform endian dependent behavior but because these are
* nonced hashes (random) and this state is only ever used locally it is safe.
* All that matters is local consistency.
*/
class SignatureCacheHasher
{
public:
template <uint8_t hash_select>
uint32_t operator()(const uint256& key) const
{
static_assert(hash_select <8, "SignatureCacheHasher only has 8 hashes available.");
uint32_t u;
std::memcpy(&u, key.begin()+4*hash_select, 4);
return u;
}
};
/**
* Valid signature cache, to avoid doing expensive ECDSA signature checking
* twice for every transaction (once when accepted into memory pool, and

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@ -19,6 +19,27 @@ static const int64_t MAX_MAX_SIG_CACHE_SIZE = 16384;
class CPubKey;
/**
* We're hashing a nonce into the entries themselves, so we don't need extra
* blinding in the set hash computation.
*
* This may exhibit platform endian dependent behavior but because these are
* nonced hashes (random) and this state is only ever used locally it is safe.
* All that matters is local consistency.
*/
class SignatureCacheHasher
{
public:
template <uint8_t hash_select>
uint32_t operator()(const uint256& key) const
{
static_assert(hash_select <8, "SignatureCacheHasher only has 8 hashes available.");
uint32_t u;
std::memcpy(&u, key.begin()+4*hash_select, 4);
return u;
}
};
class CachingTransactionSignatureChecker : public TransactionSignatureChecker
{
private:

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@ -3,6 +3,7 @@
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include <boost/test/unit_test.hpp>
#include "cuckoocache.h"
#include "script/sigcache.h"
#include "test/test_bitcoin.h"
#include "random.h"
#include <thread>
@ -36,20 +37,6 @@ void insecure_GetRandHash(uint256& t)
*(ptr++) = insecure_rand.rand32();
}
/** Definition copied from /src/script/sigcache.cpp
*/
class uint256Hasher
{
public:
template <uint8_t hash_select>
uint32_t operator()(const uint256& key) const
{
static_assert(hash_select <8, "SignatureCacheHasher only has 8 hashes available.");
uint32_t u;
std::memcpy(&u, key.begin() + 4 * hash_select, 4);
return u;
}
};
/* Test that no values not inserted into the cache are read out of it.
@ -59,7 +46,7 @@ public:
BOOST_AUTO_TEST_CASE(test_cuckoocache_no_fakes)
{
insecure_rand = FastRandomContext(true);
CuckooCache::cache<uint256, uint256Hasher> cc{};
CuckooCache::cache<uint256, SignatureCacheHasher> cc{};
size_t megabytes = 4;
cc.setup_bytes(megabytes << 20);
uint256 v;
@ -138,7 +125,7 @@ BOOST_AUTO_TEST_CASE(cuckoocache_hit_rate_ok)
double HitRateThresh = 0.98;
size_t megabytes = 4;
for (double load = 0.1; load < 2; load *= 2) {
double hits = test_cache<CuckooCache::cache<uint256, uint256Hasher>>(megabytes, load);
double hits = test_cache<CuckooCache::cache<uint256, SignatureCacheHasher>>(megabytes, load);
BOOST_CHECK(normalize_hit_rate(hits, load) > HitRateThresh);
}
}
@ -206,7 +193,7 @@ void test_cache_erase(size_t megabytes)
BOOST_AUTO_TEST_CASE(cuckoocache_erase_ok)
{
size_t megabytes = 4;
test_cache_erase<CuckooCache::cache<uint256, uint256Hasher>>(megabytes);
test_cache_erase<CuckooCache::cache<uint256, SignatureCacheHasher>>(megabytes);
}
template <typename Cache>
@ -293,7 +280,7 @@ void test_cache_erase_parallel(size_t megabytes)
BOOST_AUTO_TEST_CASE(cuckoocache_erase_parallel_ok)
{
size_t megabytes = 4;
test_cache_erase_parallel<CuckooCache::cache<uint256, uint256Hasher>>(megabytes);
test_cache_erase_parallel<CuckooCache::cache<uint256, SignatureCacheHasher>>(megabytes);
}
@ -389,7 +376,7 @@ void test_cache_generations()
}
BOOST_AUTO_TEST_CASE(cuckoocache_generations)
{
test_cache_generations<CuckooCache::cache<uint256, uint256Hasher>>();
test_cache_generations<CuckooCache::cache<uint256, SignatureCacheHasher>>();
}
BOOST_AUTO_TEST_SUITE_END();