Refactor SIMD/SSE

Wiebe Cazemier
1 parent 367579cc
Showing 10 changed files with 145 additions and 65 deletions
FlashMQTests/tst_maintests.cpp
main.cpp
mainapp.cpp
mainapp.h
mqttpacket.cpp
mqttpacket.h
threadlocalutils.cpp
threadlocalutils.h
utils.cpp
utils.h
@@ -78,11 +78,13 @@ private slots:
     void test_sse_split();
-    void test_validUtf8();
+    void test_validUtf8Generic();
     void test_validUtf8Sse();
     void testPacketInt16Parse();
+    void testTopicsMatch();
+
 };
 MainTests::MainTests()
@@ -600,7 +602,8 @@ void MainTests::test_acl_patterns_clientid()
 void MainTests::test_sse_split()
 {
-    Utils data;
+    SimdUtils data;
+    std::vector<std::string> output;
     std::list<std::string> topics;
     topics.push_back("one/two/threeabcasdfasdf/koe");
@@ -619,50 +622,51 @@ void MainTests::test_sse_split()
     for (const std::string &t : topics)
     {
-        QCOMPARE(*data.splitTopic(t), splitToVector(t, '/'));
+        data.splitTopic(t, output);
+        QCOMPARE(output, splitToVector(t, '/'));
     }
 }
-void MainTests::test_validUtf8()
+void MainTests::test_validUtf8Generic()
 {
     char m[16];
-    QVERIFY(isValidUtf8(""));
-    QVERIFY(isValidUtf8("ƀ"));
-    QVERIFY(isValidUtf8("Hello"));
+    QVERIFY(isValidUtf8Generic(""));
+    QVERIFY(isValidUtf8Generic("ƀ"));
+    QVERIFY(isValidUtf8Generic("Hello"));
     std::memset(m, 0, 16);
-    QVERIFY(!isValidUtf8(std::string(m, 16)));
+    QVERIFY(!isValidUtf8Generic(std::string(m, 16)));
-    QVERIFY(isValidUtf8("Straƀe")); // two byte chars
-    QVERIFY(isValidUtf8("StraƀeHelloHelloHelloHelloHelloHello")); // two byte chars
-    QVERIFY(isValidUtf8("HelloHelloHelloHelloHelloHelloHelloHelloStraƀeHelloHelloHelloHelloHelloHello")); // two byte chars
+    QVERIFY(isValidUtf8Generic("Straƀe")); // two byte chars
+    QVERIFY(isValidUtf8Generic("StraƀeHelloHelloHelloHelloHelloHello")); // two byte chars
+    QVERIFY(isValidUtf8Generic("HelloHelloHelloHelloHelloHelloHelloHelloStraƀeHelloHelloHelloHelloHelloHello")); // two byte chars
     std::memset(m, 0, 16);
     m[0] = 'a';
     m[1] = 13; // is \r
-    QVERIFY(!isValidUtf8(std::string(m, 16)));
+    QVERIFY(!isValidUtf8Generic(std::string(m, 16)));
     const std::string unicode_ballet_shoes("🩰");
     QVERIFY(unicode_ballet_shoes.length() == 4);
-    QVERIFY(isValidUtf8(unicode_ballet_shoes));
+    QVERIFY(isValidUtf8Generic(unicode_ballet_shoes));
     const std::string unicode_ballot_box("☐");
     QVERIFY(unicode_ballot_box.length() == 3);
-    QVERIFY(isValidUtf8(unicode_ballot_box));
+    QVERIFY(isValidUtf8Generic(unicode_ballot_box));
     std::memset(m, 0, 16);
     m[0] = 0b11000001; // Start 2 byte char
     m[1] = 0b00000001; // Next byte doesn't start with 1, which is wrong
     std::string a(m, 2);
-    QVERIFY(!isValidUtf8(a));
+    QVERIFY(!isValidUtf8Generic(a));
     std::memset(m, 0, 16);
     m[0] = 0b11100001; // Start 3 byte char
     m[1] = 0b10100001;
     m[2] = 0b00000001; // Next byte doesn't start with 1, which is wrong
     std::string b(m, 3);
-    QVERIFY(!isValidUtf8(b));
+    QVERIFY(!isValidUtf8Generic(b));
     std::memset(m, 0, 16);
     m[0] = 0b11110001; // Start 4 byte char
@@ -670,7 +674,7 @@ void MainTests::test_validUtf8()
     m[2] = 0b10100001;
     m[3] = 0b00000001; // Next byte doesn't start with 1, which is wrong
     std::string c(m, 4);
-    QVERIFY(!isValidUtf8(c));
+    QVERIFY(!isValidUtf8Generic(c));
     std::memset(m, 0, 16);
     m[0] = 0b11110001; // Start 4 byte char
@@ -678,18 +682,18 @@ void MainTests::test_validUtf8()
     m[2] = 0b00100001; // Doesn't start with 1: invalid.
     m[3] = 0b10000001;
     std::string d(m, 4);
-    QVERIFY(!isValidUtf8(d));
+    QVERIFY(!isValidUtf8Generic(d));
     // Upper ASCII, invalid
     std::memset(m, 0, 16);
     m[0] = 127;
     std::string e(m, 1);
-    QVERIFY(!isValidUtf8(e));
+    QVERIFY(!isValidUtf8Generic(e));
 }
 void MainTests::test_validUtf8Sse()
 {
-    Utils data;
+    SimdUtils data;
     char m[16];
@@ -776,6 +780,33 @@ void MainTests::testPacketInt16Parse()
     }
 }
+void MainTests::testTopicsMatch()
+{
+    QVERIFY(topicsMatch("#", ""));
+    QVERIFY(topicsMatch("#", "asdf/b/sdf"));
+    QVERIFY(topicsMatch("#", "+/b/sdf"));
+    QVERIFY(topicsMatch("#", "/one/two/asdf"));
+    QVERIFY(topicsMatch("#", "/one/two/asdf/"));
+    QVERIFY(topicsMatch("+/+/+/+/+", "/one/two/asdf/"));
+    QVERIFY(topicsMatch("+/+/#", "/one/two/asdf/"));
+    QVERIFY(topicsMatch("+/+/#", "/1234567890abcdef/two/asdf/"));
+    QVERIFY(topicsMatch("+/+/#", "/1234567890abcdefg/two/asdf/"));
+    QVERIFY(topicsMatch("+/+/#", "/1234567890abcde/two/asdf/"));
+    QVERIFY(topicsMatch("+/+/#", "1234567890abcde//two/asdf/"));
+
+    QVERIFY(!topicsMatch("+/santa", "/one/two/asdf/"));
+    QVERIFY(!topicsMatch("+/+/+/+/", "/one/two/asdf/a"));
+    QVERIFY(!topicsMatch("+/one/+/+/", "/one/two/asdf/a"));
+
+    QVERIFY(topicsMatch("$SYS/cow", "$SYS/cow"));
+    QVERIFY(topicsMatch("$SYS/cow/+", "$SYS/cow/bla"));
+    QVERIFY(topicsMatch("$SYS/#", "$SYS/broker/clients/connected"));
+
+    QVERIFY(!topicsMatch("$SYS/cow/+", "$SYS/cow/bla/foobar"));
+    QVERIFY(!topicsMatch("#", "$SYS/cow"));
+
+}
+
 QTEST_GUILESS_MAIN(MainTests)
 #include "tst_maintests.moc"
@@ -84,14 +84,11 @@ int main(int argc, char *argv[])
         check<std::runtime_error>(register_signal_handers());
         std::string sse = "without SSE support";
-#ifdef __SSE2__
-        sse = "with SSE2 support";
-#endif
 #ifdef __SSE4_2__
         sse = "with SSE4.2 support";
 #endif
 #ifdef NDEBUG
-        logger->logf(LOG_NOTICE, "Starting FlashMQ version %s, release build.", VERSION, sse.c_str());
+        logger->logf(LOG_NOTICE, "Starting FlashMQ version %s, release build %s.", VERSION, sse.c_str());
 #else
         logger->logf(LOG_NOTICE, "Starting FlashMQ version %s, debug build %s.", VERSION, sse.c_str());
 #endif
@@ -340,10 +340,11 @@ void MainApp::publishStatsOnDollarTopic()
 void MainApp::publishStat(const std::string &topic, uint64_t n)
 {
-    std::vector<std::string> *subtopics = utils.splitTopic(topic);
+    std::vector<std::string> subtopics;
+    splitTopic(topic, subtopics);
     const std::string payload = std::to_string(n);
     Publish p(topic, payload, 0);
-    subscriptionStore->queuePacketAtSubscribers(*subtopics, p, true);
+    subscriptionStore->queuePacketAtSubscribers(subtopics, p, true);
     subscriptionStore->setRetainedMessage(topic, payload, 0);
 }
@@ -41,7 +41,6 @@ License along with FlashMQ. If not, see &lt;https://www.gnu.org/licenses/&gt;.
 #include "timer.h"
 #include "scopedsocket.h"
 #include "oneinstancelock.h"
-#include "threadlocalutils.h"
 #define VERSION "0.7.0"
@@ -65,7 +64,6 @@ class MainApp
     std::mutex quitMutex;
     std::string fuzzFilePath;
     OneInstanceLock oneInstanceLock;
-    Utils utils;
     Logger *logger = Logger::getInstance();
@@ -23,9 +23,9 @@ License along with FlashMQ. If not, see &lt;https://www.gnu.org/licenses/&gt;.
 #include "utils.h"
-#include "threadlocalutils.h"
-
-thread_local Utils utils;
+// We can void constant reallocation of space for parsed subtopics by using this. But, beware to only use it during handling of the current
+// packet. Don't access it for a stored packet, because then it will have changed.
+thread_local std::vector<std::string> gSubtopics;
 RemainingLength::RemainingLength()
 {
@@ -106,7 +106,8 @@ MqttPacket::MqttPacket(const Publish &amp;publish) :
     }
     this->topic = publish.topic;
-    this->subtopics = utils.splitTopic(this->topic);
+    this->subtopics = &gSubtopics;
+    splitTopic(this->topic, gSubtopics);
     packetType = PacketType::PUBLISH;
     this->qos = publish.qos;
@@ -299,7 +300,7 @@ void MqttPacket::handleConnect()
         }
         // The specs don't really say what to do when client id not UTF8, so including here.
-        if (!utils.isValidUtf8(client_id) || !utils.isValidUtf8(username) || !utils.isValidUtf8(password) || !utils.isValidUtf8(will_topic))
+        if (!isValidUtf8(client_id) || !isValidUtf8(username) || !isValidUtf8(password) || !isValidUtf8(will_topic))
         {
             ConnAck connAck(ConnAckReturnCodes::MalformedUsernameOrPassword);
             MqttPacket response(connAck);
@@ -419,7 +420,7 @@ void MqttPacket::handleSubscribe()
         uint16_t topicLength = readTwoBytesToUInt16();
         std::string topic(readBytes(topicLength), topicLength);
-        if (topic.empty() || !utils.isValidUtf8(topic))
+        if (topic.empty() || !isValidUtf8(topic))
             throw ProtocolError("Subscribe topic not valid UTF-8.");
         if (!isValidSubscribePath(topic))
@@ -438,6 +439,7 @@ void MqttPacket::handleSubscribe()
     SubAck subAck(packet_id, subs_reponse_codes);
     MqttPacket response(subAck);
     sender->writeMqttPacket(response);
+    this->subtopics = nullptr;
 }
 void MqttPacket::handleUnsubscribe()
@@ -454,7 +456,7 @@ void MqttPacket::handleUnsubscribe()
         uint16_t topicLength = readTwoBytesToUInt16();
         std::string topic(readBytes(topicLength), topicLength);
-        if (topic.empty() || !utils.isValidUtf8(topic))
+        if (topic.empty() || !isValidUtf8(topic))
             throw ProtocolError("Subscribe topic not valid UTF-8.");
         sender->getThreadData()->getSubscriptionStore()->removeSubscription(sender, topic);
@@ -485,9 +487,10 @@ void MqttPacket::handlePublish()
         throw ProtocolError("Duplicate flag is set for QoS 0 packet. This is illegal.");
     topic = std::string(readBytes(variable_header_length), variable_header_length);
-    subtopics = utils.splitTopic(topic);
+    subtopics = &gSubtopics;
+    splitTopic(topic, gSubtopics);
-    if (!utils.isValidUtf8(topic, true))
+    if (!isValidUtf8(topic, true))
     {
         logger->logf(LOG_WARNING, "Client '%s' published a message with invalid UTF8 or +/# in it. Dropping.", sender->repr().c_str());
         return;
@@ -546,6 +549,7 @@ void MqttPacket::handlePublish()
         // For the existing clients, we can just write the same packet back out, with our small alterations.
         sender->getThreadData()->getSubscriptionStore()->queuePacketAtSubscribers(*subtopics, *this);
     }
+    this->subtopics = nullptr;
 }
 void MqttPacket::handlePubAck()
@@ -678,6 +682,10 @@ const std::string &amp;MqttPacket::getTopic() const
     return this->topic;
 }
+/**
+ * @brief MqttPacket::getSubtopics returns a pointer to the parsed subtopics. Use with care!
+ * @return a pointer to a vector of subtopics that will be overwritten the next packet!
+ */
 const std::vector<std::string> *MqttPacket::getSubtopics() const
 {
     return this->subtopics;
@@ -48,7 +48,7 @@ class MqttPacket
 #endif
     std::string topic;
-    std::vector<std::string> *subtopics; // comes from local thread storage. See std::vector<std::string> *ThreadData::splitTopic(std::string &topic)
+    std::vector<std::string> *subtopics = nullptr;
     std::vector<char> bites;
     size_t fixed_header_length = 0; // if 0, this packet does not contain the bytes of the fixed header.
     RemainingLength remainingLength;
+#ifdef __SSE4_2__
+
 #include "threadlocalutils.h"
 #include <cstring>
 #include <cassert>
-Utils::Utils() :
+SimdUtils::SimdUtils() :
     subtopicParseMem(TOPIC_MEMORY_LENGTH),
     topicCopy(TOPIC_MEMORY_LENGTH)
 {
@@ -11,15 +13,14 @@ Utils::Utils() :
 }
 /**
- * @brief ThreadData::splitTopic uses SSE4.2 to detect the '/' chars, 16 chars at a time, and returns a pointer to thread-local memory.
- * @param topic string is altered: some extra space is reserved.
- * @return Pointer to thread-owned vector of subtopics.
- *
- * Because it returns a pointer to the thread-local vector, only the current thread should touch it.
+ * @brief SimdUtils::splitTopic uses SSE4.2 to detect the '/' chars, 16 chars at a time, and returns a pointer to thread-local memory.
+ * @param topic
+ * @param output is cleared and emplaced in. You can give it members from the Utils class, to avoid re-allocation.
+ * @return
  */
-std::vector<std::string> *Utils::splitTopic(const std::string &topic)
+std::vector<std::string> *SimdUtils::splitTopic(const std::string &topic, std::vector<std::string> &output)
 {
-    subtopics.clear();
+    output.clear();
     const int s = topic.size();
     std::memcpy(topicCopy.data(), topic.c_str(), s+1);
@@ -41,16 +42,16 @@ std::vector&lt;std::string&gt; *Utils::splitTopic(const std::string &amp;topic)
         if (index < 16 || n >= s)
         {
-            subtopics.emplace_back(subtopicParseMem.data(), carryi);
+            output.emplace_back(subtopicParseMem.data(), carryi);
             carryi = 0;
             n++;
         }
     }
-    return &subtopics;
+    return &output;
 }
-bool Utils::isValidUtf8(const std::string &s, bool alsoCheckInvalidPublishChars)
+bool SimdUtils::isValidUtf8(const std::string &s, bool alsoCheckInvalidPublishChars)
 {
     const int len = s.size();
@@ -136,3 +137,5 @@ bool Utils::isValidUtf8(const std::string &amp;s, bool alsoCheckInvalidPublishChars)
     return true;
 }
+
+#endif
 #ifndef THREADLOCALUTILS_H
 #define THREADLOCALUTILS_H
+#ifdef __SSE4_2__
+
 #include <vector>
 #include <string>
 #include <immintrin.h>
 #define TOPIC_MEMORY_LENGTH 65560
-/**
- * @brief The Utils class have utility functions that make use of pre-allocated memory. Use with thread_local or create per thread manually.
- */
-class Utils
+
+
+class SimdUtils
 {
-    std::vector<std::string> subtopics;
     std::vector<char> subtopicParseMem;
     std::vector<char> topicCopy;
     __m128i slashes = _mm_set1_epi8('/');
@@ -23,11 +23,13 @@ class Utils
     __m128i plus = _mm_set1_epi8('+');
 public:
-    Utils();
+    SimdUtils();
-    std::vector<std::string> *splitTopic(const std::string &topic);
+    std::vector<std::string> *splitTopic(const std::string &topic, std::vector<std::string> &output);
     bool isValidUtf8(const std::string &s, bool alsoCheckInvalidPublishChars = false);
 };
+#endif
+
 #endif // THREADLOCALUTILS_H
@@ -34,6 +34,12 @@ License along with FlashMQ. If not, see &lt;https://www.gnu.org/licenses/&gt;.
 #include "logger.h"
 #include "evpencodectxmanager.h"
+
+#ifdef __SSE4_2__
+#include "threadlocalutils.h"
+thread_local SimdUtils simdUtils;
+#endif
+
 std::list<std::string> split(const std::string &input, const char sep, size_t max, bool keep_empty_parts)
 {
     std::list<std::string> list;
@@ -60,8 +66,16 @@ bool topicsMatch(const std::string &amp;subscribeTopic, const std::string &amp;publishTo
     if (!subscribeTopic.empty() && !publishTopic.empty() && publishTopic[0] == '$' && subscribeTopic[0] != '$')
         return false;
-    const std::vector<std::string> subscribeParts = splitToVector(subscribeTopic, '/');
-    const std::vector<std::string> publishParts = splitToVector(publishTopic, '/');
+    std::vector<std::string> subscribeParts;
+    std::vector<std::string> publishParts;
+
+#ifdef __SSE4_2__
+    simdUtils.splitTopic(subscribeTopic, subscribeParts);
+    simdUtils.splitTopic(publishTopic, publishParts);
+#else
+    splitToVector(subscribeTopic, subscribeParts, '/');
+    splitToVector(publishTopic, publishParts, '/');
+#endif
     auto subscribe_itr = subscribeParts.begin();
     auto publish_itr = publishParts.begin();
@@ -84,7 +98,7 @@ bool topicsMatch(const std::string &amp;subscribeTopic, const std::string &amp;publishTo
     return result;
 }
-bool isValidUtf8(const std::string &s, bool alsoCheckInvalidPublishChars)
+bool isValidUtf8Generic(const std::string &s, bool alsoCheckInvalidPublishChars)
 {
     int multibyte_remain = 0;
     int cur_code_point = 0;
@@ -146,6 +160,15 @@ bool isValidUtf8(const std::string &amp;s, bool alsoCheckInvalidPublishChars)
     return multibyte_remain == 0;
 }
+bool isValidUtf8(const std::string &s, bool alsoCheckInvalidPublishChars)
+{
+#ifdef __SSE4_2__
+    return simdUtils.isValidUtf8(s, alsoCheckInvalidPublishChars);
+#else
+    return isValidUtf8Generic(s, alsoCheckInvalidPublishChars);
+#endif
+}
+
 bool strContains(const std::string &s, const std::string &needle)
 {
     return s.find(needle) != std::string::npos;
@@ -209,25 +232,39 @@ bool containsDangerousCharacters(const std::string &amp;s)
     return false;
 }
-const std::vector<std::string> splitToVector(const std::string &input, const char sep, size_t max, bool keep_empty_parts)
+void splitTopic(const std::string &topic, std::vector<std::string> &output)
+{
+#ifdef __SSE4_2__
+    simdUtils.splitTopic(topic, output);
+#else
+    splitToVector(topic, output, '/');
+#endif
+}
+
+void splitToVector(const std::string &input, std::vector<std::string> &output, const char sep, size_t max, bool keep_empty_parts)
 {
     const auto subtopic_count = std::count(input.begin(), input.end(), '/') + 1;
-    std::vector<std::string> result;
-    result.reserve(subtopic_count);
+    output.reserve(subtopic_count);
     size_t start = 0;
     size_t end;
     const auto npos = std::string::npos;
-    while (result.size() < max && (end = input.find(sep, start)) != npos)
+    while (output.size() < max && (end = input.find(sep, start)) != npos)
     {
         if (start != end || keep_empty_parts)
-            result.push_back(input.substr(start, end - start));
+            output.push_back(input.substr(start, end - start));
         start = end + 1; // increase by length of seperator.
     }
     if (start != input.size() || keep_empty_parts)
-        result.push_back(input.substr(start, npos));
+        output.push_back(input.substr(start, npos));
+}
+
+const std::vector<std::string> splitToVector(const std::string &input, const char sep, size_t max, bool keep_empty_parts)
+{
+    std::vector<std::string> result;
+    splitToVector(input, result, sep, max, keep_empty_parts);
     return result;
 }
@@ -46,9 +46,12 @@ template&lt;typename T&gt; int check(int rc)
 std::list<std::string> split(const std::string &input, const char sep, size_t max = std::numeric_limits<int>::max(), bool keep_empty_parts = true);
 const std::vector<std::string> splitToVector(const std::string &input, const char sep, size_t max = std::numeric_limits<int>::max(), bool keep_empty_parts = true);
+void splitToVector(const std::string &input, std::vector<std::string> &output, const char sep, size_t max = std::numeric_limits<int>::max(), bool keep_empty_parts = true);
+void splitTopic(const std::string &topic, std::vector<std::string> &output);
 bool topicsMatch(const std::string &subscribeTopic, const std::string &publishTopic);
+bool isValidUtf8Generic(const std::string &s, bool alsoCheckInvalidPublishChars = false);
 bool isValidUtf8(const std::string &s, bool alsoCheckInvalidPublishChars = false);
 bool strContains(const std::string &s, const std::string &needle);