feat(IO): MCOL-5555 Reduce number of direct writes to the file storing BRM journal and tablelocks (#2974)

versioning/BRM/brmtypes.cpp

@@ -444,7 +444,40 @@ void TableLockInfo::deserialize(istream& i)
   dbrootList.resize(dbrootListSize);
 
   for (uint32_t j = 0; j < dbrootListSize; j++)
-    i.read((char*)&dbrootList[j], 4);
+    i.read((char*)&dbrootList[j], sizeof(uint32_t));
+}
+
+uint32_t TableLockInfo::getInternalSize() const
+{
+  const uint32_t nameLen = ownerName.length();
+  const uint32_t dbrootListSize = dbrootList.size();
+  return (32 + sizeof(time_t) + nameLen + (dbrootListSize * sizeof(uint32_t)));
+}
+
+void TableLockInfo::serializeElement(char* buffer, const char* src, const uint32_t size, uint32_t& offset)
+{
+  std::memcpy(&buffer[offset], src, size);
+  offset += size;
+}
+
+void TableLockInfo::serialize(char* buffer, uint32_t& offset)
+{
+  const uint32_t nameLen = ownerName.length();
+  const uint32_t dbrootListSize = dbrootList.size();
+
+  serializeElement(buffer, (char*)&id, 8, offset);
+  serializeElement(buffer, (char*)&tableOID, 4, offset);
+  serializeElement(buffer, (char*)&ownerPID, 4, offset);
+  serializeElement(buffer, (char*)&state, 4, offset);
+  serializeElement(buffer, (char*)&ownerSessionID, 4, offset);
+  serializeElement(buffer, (char*)&ownerTxnID, 4, offset);
+  serializeElement(buffer, (char*)&creationTime, sizeof(time_t), offset);
+  serializeElement(buffer, (char*)&nameLen, 2, offset);
+  serializeElement(buffer, (char*)ownerName.c_str(), nameLen, offset);
+  serializeElement(buffer, (char*)&dbrootListSize, 2, offset);
+
+  for (uint32_t j = 0; j < dbrootListSize; j++)
+    serializeElement(buffer, (char*)&dbrootList[j], sizeof(uint32_t), offset);
 }
 
 void TableLockInfo::serialize(IDBDataFile* o) const

versioning/BRM/brmtypes.h

@@ -254,7 +254,12 @@ struct TableLockInfo : public messageqcpp::Serializeable
   EXPORT void deserialize(messageqcpp::ByteStream& bs);
   EXPORT void serialize(idbdatafile::IDBDataFile*) const;
   EXPORT void deserialize(idbdatafile::IDBDataFile*);
+  EXPORT void serialize(char* buffer, uint32_t& offset);
+  EXPORT uint32_t getInternalSize() const;
   bool operator<(const TableLockInfo&) const;
+
+ private:
+  void serializeElement(char* buffer, const char* src, const uint32_t size, uint32_t& offset);
 };
 
 /// A Serializeable version of InlineLBIDRange

versioning/BRM/slavecomm.cpp

@@ -191,7 +191,6 @@ SlaveComm::SlaveComm()
   slave = std::make_unique<SlaveDBRMNode>();
 }
 
-
 void SlaveComm::stop()
 {
   die = true;
@@ -1928,7 +1927,8 @@ void SlaveComm::do_confirm()
   {
     if (!currentSaveFile)
     {
-      currentSaveFile.reset(IDBDataFile::open(IDBPolicy::getType(tmp.c_str(), IDBPolicy::WRITEENG), tmp.c_str(), "wb", 0));
+      currentSaveFile.reset(
+          IDBDataFile::open(IDBPolicy::getType(tmp.c_str(), IDBPolicy::WRITEENG), tmp.c_str(), "wb", 0));
     }
 
     if (currentSaveFile == NULL)
@@ -1951,7 +1951,8 @@ void SlaveComm::do_confirm()
     if (err < (int)relative.length())
     {
       ostringstream os;
-      os << "WorkerComm: currentfile write() returned " << err << " file pointer is " << currentSaveFile.get();
+      os << "WorkerComm: currentfile write() returned " << err << " file pointer is "
+         << currentSaveFile.get();
 
       if (err < 0)
         os << " errno: " << strerror(errno);
@@ -2182,11 +2183,16 @@ void SlaveComm::saveDelta()
 {
   try
   {
-    uint32_t len = delta.length();
+    const uint32_t deltaLen = delta.length();
+    const uint32_t bufferSize = sizeof(deltaLen) + deltaLen;
+    std::unique_ptr<char[]> buffer(new char[bufferSize]);
+    uint32_t offset = 0;
+    std::memcpy(&buffer[offset], (char*)&deltaLen, sizeof(deltaLen));
+    offset += sizeof(deltaLen);
+    std::memcpy(&buffer[offset], (char*)delta.buf(), deltaLen);
 
     journalh->seek(0, SEEK_END);
-    journalh->write((const char*)&len, sizeof(len));
-    journalh->write((const char*)delta.buf(), delta.length());
+    journalh->write((const char*)buffer.get(), bufferSize);
     journalh->flush();
     journalCount++;
   }
@@ -2326,4 +2332,3 @@ void SlaveComm::do_dmlReleaseLBIDRanges(ByteStream& msg)
 }
 
 }  // namespace BRM
-

versioning/BRM/tablelockserver.cpp

@@ -70,14 +70,28 @@ void TableLockServer::save()
   if (!out)
     throw runtime_error("TableLockServer::save():  could not open save file");
 
-  out->write((char*)&count, 4);
+  uint32_t bufferSize = 4;
+  for (const auto& lock : locks)
+    bufferSize += lock.second.getInternalSize();
+
+  std::unique_ptr<char[]> buffer(new char[bufferSize]);
+  uint32_t offset = 0;
+  std::memcpy(&buffer[offset], (char*)&count, 4);
+  offset += 4;
 
   for (it = locks.begin(); it != locks.end(); ++it)
-  {
-    if (!out)
-      throw runtime_error("TableLockServer::save():  could not write save file");
+    it->second.serialize(buffer.get(), offset);
 
-    it->second.serialize(out.get());
+  uint32_t writtenSize = 0;
+  uint32_t sizeToWrite = bufferSize;
+  while (writtenSize != bufferSize)
+  {
+    uint32_t ret = out->write(&buffer[writtenSize], sizeToWrite);
+    if (!ret)
+      throw runtime_error("TableLockServer::save():  could not write to the file");
+
+    writtenSize += ret;
+    sizeToWrite -= ret;
   }
 }