StreamerInputFile.cc

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#include "IOPool/Streamer/interface/StreamerInputFile.h"

#include "FWCore/MessageLogger/interface/MessageLogger.h"
#include "FWCore/Sources/interface/EventSkipperByID.h"
#include "FWCore/Utilities/interface/DebugMacros.h"
#include "FWCore/Utilities/interface/EDMException.h"
#include "FWCore/Utilities/interface/Exception.h"
#include "FWCore/Utilities/interface/TimeOfDay.h"

#include "Utilities/StorageFactory/interface/IOFlags.h"
#include "Utilities/StorageFactory/interface/StorageFactory.h"

#include <iomanip>
#include <iostream>

namespace edm {

  StreamerInputFile::~StreamerInputFile() { closeStreamerFile(); }

  StreamerInputFile::StreamerInputFile(std::string const& name, std::shared_ptr<EventSkipperByID> eventSkipperByID)
      : startMsg_(),
        currentEvMsg_(),
        headerBuf_(1000 * 1000),
        eventBuf_(1000 * 1000 * 7),
        currentFile_(0),
        streamerNames_(),
        multiStreams_(false),
        currentFileName_(),
        currentFileOpen_(false),
        eventSkipperByID_(eventSkipperByID),
        currRun_(0),
        currProto_(0),
        newHeader_(false),
        storage_(),
        endOfFile_(false) {
    openStreamerFile(name);
    readStartMessage();
  }

  StreamerInputFile::StreamerInputFile(std::vector<std::string> const& names,
                                       std::shared_ptr<EventSkipperByID> eventSkipperByID)
      : startMsg_(),
        currentEvMsg_(),
        headerBuf_(1000 * 1000),
        eventBuf_(1000 * 1000 * 7),
        currentFile_(0),
        streamerNames_(names),
        multiStreams_(true),
        currentFileName_(),
        currentFileOpen_(false),
        eventSkipperByID_(eventSkipperByID),
        currRun_(0),
        currProto_(0),
        newHeader_(false),
        endOfFile_(false) {
    openStreamerFile(names.at(0));
    ++currentFile_;
    readStartMessage();
    currRun_ = startMsg_->run();
    currProto_ = startMsg_->protocolVersion();
  }

  void StreamerInputFile::openStreamerFile(std::string const& name) {
    closeStreamerFile();

    currentFileName_ = name;
    logFileAction("  Initiating request to open file ");

    IOOffset size = -1;
    if (StorageFactory::get()->check(name, &size)) {
      try {
        storage_ = StorageFactory::get()->open(name, IOFlags::OpenRead);
      } catch (cms::Exception& e) {
        Exception ex(errors::FileOpenError, "", e);
        ex.addContext("Calling StreamerInputFile::openStreamerFile()");
        ex.clearMessage();
        ex << "Error Opening Streamer Input File: " << name << "\n";
        throw ex;
      }
    } else {
      throw Exception(errors::FileOpenError, "StreamerInputFile::openStreamerFile")
          << "Error Opening Streamer Input File, file does not exist: " << name << "\n";
    }
    currentFileOpen_ = true;
    logFileAction("  Successfully opened file ");
  }

  void StreamerInputFile::closeStreamerFile() {
    if (currentFileOpen_ && storage_) {
      storage_->close();
      logFileAction("  Closed file ");
    }
    currentFileOpen_ = false;
  }

  IOSize StreamerInputFile::readBytes(char* buf, IOSize nBytes) {
    IOSize n = 0;
    try {
      n = storage_->read(buf, nBytes);
    } catch (cms::Exception& ce) {
      Exception ex(errors::FileReadError, "", ce);
      ex.addContext("Calling StreamerInputFile::readBytes()");
      throw ex;
    }
    return n;
  }

  IOOffset StreamerInputFile::skipBytes(IOSize nBytes) {
    IOOffset n = 0;
    try {
      // We wish to return the number of bytes skipped, not the final offset.
      n = storage_->position(0, Storage::CURRENT);
      n = storage_->position(nBytes, Storage::CURRENT) - n;
    } catch (cms::Exception& ce) {
      Exception ex(errors::FileReadError, "", ce);
      ex.addContext("Calling StreamerInputFile::skipBytes()");
      throw ex;
    }
    return n;
  }

  void StreamerInputFile::readStartMessage() {
    IOSize nWant = sizeof(HeaderView);
    IOSize nGot = readBytes(&headerBuf_[0], nWant);
    if (nGot != nWant) {
      throw Exception(errors::FileReadError, "StreamerInputFile::readStartMessage")
          << "Failed reading streamer file, first read in readStartMessage\n";
    }

    HeaderView head(&headerBuf_[0]);
    uint32 code = head.code();
    if (code != Header::INIT) 
    {
      throw Exception(errors::FileReadError, "StreamerInputFile::readStartMessage")
          << "Expecting an init Message at start of file\n";
      return;
    }

    uint32 headerSize = head.size();
    if (headerBuf_.size() < headerSize)
      headerBuf_.resize(headerSize);

    if (headerSize > sizeof(HeaderView)) {
      nWant = headerSize - sizeof(HeaderView);
      nGot = readBytes(&headerBuf_[sizeof(HeaderView)], nWant);
      if (nGot != nWant) {
        throw Exception(errors::FileReadError, "StreamerInputFile::readStartMessage")
            << "Failed reading streamer file, second read in readStartMessage\n";
      }
    } else {
      throw Exception(errors::FileReadError, "StreamerInputFile::readStartMessage")
          << "Failed reading streamer file, init header size from data too small\n";
    }

    startMsg_ = std::make_shared<InitMsgView>(&headerBuf_[0]);  // propagate_const<T> has no reset() function
  }

  bool StreamerInputFile::next() {
    if (this->readEventMessage()) {
      return true;
    }
    if (multiStreams_) {
      //Try opening next file
      if (openNextFile()) {
        endOfFile_ = false;
        if (this->readEventMessage()) {
          return true;
        }
      }
    }
    return false;
  }

  bool StreamerInputFile::openNextFile() {
    if (currentFile_ <= streamerNames_.size() - 1) {
      FDEBUG(10) << "Opening file " << streamerNames_.at(currentFile_).c_str() << std::endl;

      openStreamerFile(streamerNames_.at(currentFile_));

      // If start message was already there, then compare the
      // previous and new headers
      if (startMsg_) {
        FDEBUG(10) << "Comparing Header" << std::endl;
        if (!compareHeader()) {
          return false;
        }
      }
      ++currentFile_;
      return true;
    }
    return false;
  }

  bool StreamerInputFile::compareHeader() {
    //Get the new header
    readStartMessage();

    //Values from new Header should match up
    if (currRun_ != startMsg_->run() || currProto_ != startMsg_->protocolVersion()) {
      throw Exception(errors::MismatchedInputFiles, "StreamerInputFile::compareHeader")
          << "File " << streamerNames_.at(currentFile_)
          << "\nhas different run number or protocol version than previous\n";
      return false;
    }
    newHeader_ = true;
    return true;
  }

  int StreamerInputFile::readEventMessage() {
    if (endOfFile_)
      return 0;

    bool eventRead = false;
    while (!eventRead) {
      IOSize nWant = sizeof(EventHeader);
      IOSize nGot = readBytes(&eventBuf_[0], nWant);
      if (nGot == 0) {
        // no more data available
        endOfFile_ = true;
        return 0;
      }
      if (nGot != nWant) {
        throw edm::Exception(errors::FileReadError, "StreamerInputFile::readEventMessage")
            << "Failed reading streamer file, first read in readEventMessage\n"
            << "Requested " << nWant << " bytes, read function returned " << nGot << " bytes\n";
      }
      HeaderView head(&eventBuf_[0]);
      uint32 code = head.code();

      // If it is not an event then something is wrong.
      if (code != Header::EVENT) {
        throw Exception(errors::FileReadError, "StreamerInputFile::readEventMessage")
            << "Failed reading streamer file, unknown code in event header\n"
            << "code = " << code << "\n";
      }
      uint32 eventSize = head.size();
      if (eventSize <= sizeof(EventHeader)) {
        throw edm::Exception(errors::FileReadError, "StreamerInputFile::readEventMessage")
            << "Failed reading streamer file, event header size from data too small\n";
      }
      eventRead = true;
      if (eventSkipperByID_) {
        EventHeader* evh = (EventHeader*)(&eventBuf_[0]);
        if (eventSkipperByID_->skipIt(convert32(evh->run_), convert32(evh->lumi_), convert64(evh->event_))) {
          eventRead = false;
        }
      }
      nWant = eventSize - sizeof(EventHeader);
      if (eventRead) {
        if (eventBuf_.size() < eventSize)
          eventBuf_.resize(eventSize);
        nGot = readBytes(&eventBuf_[sizeof(EventHeader)], nWant);
        if (nGot != nWant) {
          throw Exception(errors::FileReadError, "StreamerInputFile::readEventMessage")
              << "Failed reading streamer file, second read in readEventMessage\n"
              << "Requested " << nWant << " bytes, read function returned " << nGot << " bytes\n";
        }
      } else {
        nGot = skipBytes(nWant);
        if (nGot != nWant) {
          throw Exception(errors::FileReadError, "StreamerInputFile::readEventMessage")
              << "Failed reading streamer file, skip event in readEventMessage\n"
              << "Requested " << nWant << " bytes skipped, seek function returned " << nGot << " bytes\n";
        }
      }
    }
    currentEvMsg_ = std::make_shared<EventMsgView>((void*)&eventBuf_[0]);  // propagate_const<T> has no reset() function
    return 1;
  }

  void StreamerInputFile::logFileAction(char const* msg) {
    LogAbsolute("fileAction") << std::setprecision(0) << TimeOfDay() << msg << currentFileName_;
    FlushMessageLog();
  }
}  // namespace edm