CubeTileHandler.cpp

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#include "CubeTileHandler.h"

#include <QFile>

#include "IException.h"
#include "Pvl.h"
#include "PvlObject.h"
#include "PvlKeyword.h"
#include "RawCubeChunk.h"

using namespace std;

namespace Isis {
  CubeTileHandler::CubeTileHandler(QFile * dataFile,
      const QList<int> *virtualBandList, const Pvl &labels, bool alreadyOnDisk)
      : CubeIoHandler(dataFile, virtualBandList, labels, alreadyOnDisk) {

    const PvlObject &core = labels.findObject("IsisCube").findObject("Core");

    if(core.hasKeyword("Format")) {
      setChunkSizes(core["TileSamples"], core["TileLines"], 1);
    }
    else {
      // up to 1MB chunks
      int sampleChunkSize =
          findGoodSize(512 * 4 / SizeOf(pixelType()), sampleCount());
      int lineChunkSize =
          findGoodSize(512 * 4 / SizeOf(pixelType()), lineCount());

      setChunkSizes(sampleChunkSize, lineChunkSize, 1);
    }
  }


  CubeTileHandler::~CubeTileHandler() {
    clearCache();
  }


  void CubeTileHandler::updateLabels(Pvl &labels) {
    PvlObject &core = labels.findObject("IsisCube").findObject("Core");
    core.addKeyword(PvlKeyword("Format", "Tile"),
                    PvlContainer::Replace);
    core.addKeyword(PvlKeyword("TileSamples", toString(getSampleCountInChunk())),
                    PvlContainer::Replace);
    core.addKeyword(PvlKeyword("TileLines", toString(getLineCountInChunk())),
                    PvlContainer::Replace);
  }


  void CubeTileHandler::readRaw(RawCubeChunk &chunkToFill) {
    BigInt startByte = getTileStartByte(chunkToFill);

    bool success = false;

    QFile * dataFile = getDataFile();
    if(dataFile->seek(startByte)) {
      QByteArray binaryData = dataFile->read(chunkToFill.getByteCount());

      if(binaryData.size() == chunkToFill.getByteCount()) {
        chunkToFill.setRawData(binaryData);
        success = true;
      }
    }

    if(!success) {
      IString msg = "Reading from the file [" + dataFile->fileName() + "] "
          "failed with reading [" +
          QString::number(chunkToFill.getByteCount()) +
          "] bytes at position [" + QString::number(startByte) + "]";
      throw IException(IException::Io, msg, _FILEINFO_);
    }
  }


  void CubeTileHandler::writeRaw(const RawCubeChunk &chunkToWrite) {
    BigInt startByte = getTileStartByte(chunkToWrite);
    bool success = false;

    QFile * dataFile = getDataFile();
    if(dataFile->seek(startByte)) {
      BigInt dataWritten = dataFile->write(chunkToWrite.getRawData());

      if(dataWritten == chunkToWrite.getByteCount()) {
        success = true;
      }
    }

    if(!success) {
      IString msg = "Writing to the file [" + dataFile->fileName() + "] "
          "failed with writing [" +
          QString::number(chunkToWrite.getByteCount()) +
          "] bytes at position [" + QString::number(startByte) + "]";
      throw IException(IException::Io, msg, _FILEINFO_);
    }
  }


  int CubeTileHandler::findGoodSize(int maxSize, int dimensionSize) const {
    int ideal = 128;

    if(dimensionSize <= maxSize) {
      ideal = dimensionSize;
    }
    else {
      int greatestDividend = maxSize;

      while(greatestDividend > ideal) {
        if(dimensionSize % greatestDividend == 0) {
          ideal = greatestDividend;
        }

        greatestDividend --;
      }
    }

    return ideal;
  }


  BigInt CubeTileHandler::getTileStartByte(const RawCubeChunk &chunk) const {
    return getDataStartByte() + getChunkIndex(chunk) * getBytesPerChunk();
  }
}