//////////////////////////////////////////////////////////////////////////////// /// @brief nonces /// /// @file /// /// DISCLAIMER /// /// Copyright 2014 ArangoDB GmbH, Cologne, Germany /// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany /// /// Licensed under the Apache License, Version 2.0 (the "License"); /// you may not use this file except in compliance with the License. /// You may obtain a copy of the License at /// /// http://www.apache.org/licenses/LICENSE-2.0 /// /// Unless required by applicable law or agreed to in writing, software /// distributed under the License is distributed on an "AS IS" BASIS, /// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. /// See the License for the specific language governing permissions and /// limitations under the License. /// /// Copyright holder is ArangoDB GmbH, Cologne, Germany /// /// @author Frank Celler /// @author Achim Brandt /// @author Copyright 2014, ArangoDB GmbH, Cologne, Germany /// @author Copyright 2010-2013, triAGENS GmbH, Cologne, Germany //////////////////////////////////////////////////////////////////////////////// #include "Nonce.h" #include #include "Basics/logging.h" #include "Basics/MutexLocker.h" #include "Basics/RandomGenerator.h" #include "Basics/StringUtils.h" using namespace std; using namespace triagens::basics; // ----------------------------------------------------------------------------- // statistic nonce buffer // ----------------------------------------------------------------------------- namespace { Mutex MutexNonce; size_t SizeNonces = 16777216; uint32_t* TimestampNonces = 0; uint32_t StatisticsNonces[32][5] = { { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 } }; } namespace triagens { namespace basics { namespace Nonce { // ----------------------------------------------------------------------------- // static functions // ----------------------------------------------------------------------------- void create (size_t size) { if (SizeNonces < 64) { SizeNonces = 64; } if (TimestampNonces != 0) { delete[] TimestampNonces; } TimestampNonces = new uint32_t[size]; memset(TimestampNonces, 0, sizeof(uint32_t) * size); for (size_t i = 0; i < 32; ++i) { for (size_t j = 0; j < 5; ++j) { StatisticsNonces[i][j] = 0; } } } void destroy () { if (TimestampNonces != 0) { delete[] TimestampNonces; } } string createNonce () { uint32_t timestamp = (uint32_t) time(0); uint32_t rand1 = Random::interval(0U, UINT32_MAX); uint32_t rand2 = Random::interval(0U, UINT32_MAX); uint8_t buffer[12]; buffer[0] = (timestamp >> 24) & 0xFF; buffer[1] = (timestamp >> 16) & 0xFF; buffer[2] = (timestamp >> 8) & 0xFF; buffer[3] = (timestamp ) & 0xFF; memcpy(buffer + 4, &rand1, 4); memcpy(buffer + 8, &rand2, 4); return StringUtils::encodeBase64U(string((char*) buffer, 12)); } bool checkAndMark (string const& nonce) { if (nonce.length() != 12) { return false; } uint8_t const* buffer = (uint8_t const*) nonce.c_str(); uint32_t timestamp = (uint32_t(buffer[0]) << 24) | (uint32_t(buffer[1]) << 16) | (uint32_t(buffer[2]) << 8) | uint32_t(buffer[3]); uint64_t random = (uint64_t(buffer[ 4]) << 56) | (uint64_t(buffer[ 5]) << 48) | (uint64_t(buffer[ 6]) << 40) | (uint64_t(buffer[ 7]) << 32) | (uint64_t(buffer[ 8]) << 24) | (uint64_t(buffer[ 9]) << 16) | (uint64_t(buffer[10]) << 8) | uint64_t(buffer[11]); return checkAndMark(timestamp, random); } bool checkAndMark (uint32_t timestamp, uint64_t random) { MUTEX_LOCKER(MutexNonce); if (TimestampNonces == 0) { LOG_TRACE("setting nonce hash size to %d", (int) SizeNonces); create(SizeNonces); } TRI_ASSERT(TimestampNonces != 0); int proofs = 0; // first count to avoid miscounts if two hashes are equal if (timestamp > TimestampNonces[random % (SizeNonces - 3)]) { proofs++; } if (timestamp > TimestampNonces[random % (SizeNonces - 17)]) { proofs++; } if (timestamp > TimestampNonces[random % (SizeNonces - 33)]) { proofs++; } if (timestamp > TimestampNonces[random % (SizeNonces - 63)]) { proofs++; } // statistics, compute the log2 of the age and increment the proofs count uint32_t now = (uint32_t) time(0); uint32_t age = 1; if (timestamp < now) { age = now - timestamp; } uint32_t l2age = 0; while (1 < age) { l2age += 1; age >>= 1; } LOG_TRACE("age of timestamp %ld is %ld (log %ld)", (unsigned long) timestamp, (unsigned long) age, (unsigned long) l2age); StatisticsNonces[l2age][proofs]++; // mark the nonce as used if (timestamp > TimestampNonces[random % (SizeNonces - 3)]) { TimestampNonces[random % (SizeNonces - 3)] = timestamp; } if (timestamp > TimestampNonces[random % (SizeNonces - 17)]) { TimestampNonces[random % (SizeNonces - 17)] = timestamp; } if (timestamp > TimestampNonces[random % (SizeNonces - 33)]) { TimestampNonces[random % (SizeNonces - 33)] = timestamp; } if (timestamp > TimestampNonces[random % (SizeNonces - 63)]) { TimestampNonces[random % (SizeNonces - 63)] = timestamp; } return 0 < proofs; } vector statistics () { MUTEX_LOCKER(MutexNonce); int const N = 4; vector result; for (uint32_t l2age = 0, age = 1; l2age < 32; ++l2age) { uint32_t T = 0; uint32_t coeff = 1; double S0 = 1.0; double x = 1.0; for (int i = 1; i < N + 1; ++i) { T = T + StatisticsNonces[l2age][i]; coeff = coeff * (N - i + 1) / i; S0 = S0 * pow((double)(StatisticsNonces[l2age][i] / coeff), (double)((4 * N + 2 - 6 * i) / (N * N - N))); x = x * pow((double)(StatisticsNonces[l2age][i] / coeff), (double)((12 * i - 6 * N - 6) / (N * N * N - N))); } Statistics current; current.age = age; current.checks = T + StatisticsNonces[l2age][0]; current.isUnused = T; current.isUsed = StatisticsNonces[l2age][0]; current.marked = (uint32_t) (StatisticsNonces[l2age][0] - S0); current.falselyUsed = (uint32_t) S0; current.fillingDegree = 1 / (1 + x); result.push_back(current); age *= 2U; } return result; } } } } // ----------------------------------------------------------------------------- // --SECTION-- END-OF-FILE // ----------------------------------------------------------------------------- // Local Variables: // mode: outline-minor // outline-regexp: "/// @brief\\|/// {@inheritDoc}\\|/// @page\\|// --SECTION--\\|/// @\\}" // End: