dev@1430: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
dev@1430: 
dev@1430: /*
dev@1430:     Sonic Visualiser
dev@1430:     An audio file viewer and annotation editor.
dev@1430:     Centre for Digital Music, Queen Mary, University of London.
dev@1438:     This file copyright 2017 Queen Mary, University of London.
dev@1430:     
dev@1430:     This program is free software; you can redistribute it and/or
dev@1430:     modify it under the terms of the GNU General Public License as
dev@1430:     published by the Free Software Foundation; either version 2 of the
dev@1430:     License, or (at your option) any later version.  See the file
dev@1430:     COPYING included with this distribution for more information.
dev@1430: */
dev@1430: 
dev@1438: #ifndef CSV_STREAM_WRITER_H
dev@1438: #define CSV_STREAM_WRITER_H
dev@1430: 
dev@1434: #include "base/BaseTypes.h"
dev@1434: #include "base/Selection.h"
dev@1434: #include "base/ProgressReporter.h"
dev@1434: #include "base/DataExportOptions.h"
dev@1434: #include "data/model/Model.h"
dev@1434: #include <QString>
dev@1434: #include <algorithm>
dev@1434: 
dev@1441: namespace 
dev@1441: {
dev@1441:     const auto initProgressCalculator = [](sv_frame_t nFramesToWrite) {
dev@1441:         return [nFramesToWrite](sv_frame_t nFramesWritten) {
dev@1441:             return 100 * nFramesWritten / nFramesToWrite;
dev@1441:         };
dev@1441:     };
dev@1441: } // namespace
dev@1441: 
dev@1438: namespace CSVStreamWriter
dev@1430: {
dev@1430: 
dev@1441: template <
dev@1441:     class OutStream,
dev@1441:     class ProgressCalculatorInit = decltype(initProgressCalculator)
dev@1441: >
dev@1441: bool 
dev@1441: writeInChunks(OutStream& oss,
dev@1441:               const Model& model,
dev@1441:               const Selection& extents,
dev@1441:               ProgressReporter* reporter = nullptr,
dev@1441:               QString delimiter = ",",
dev@1441:               DataExportOptions options = DataExportDefaults,
dev@1441:               const sv_frame_t blockSize = 16384,
dev@1441:               const ProgressCalculatorInit& initCalc = initProgressCalculator)
dev@1434: {
dev@1434:     if (blockSize <= 0) return false;
dev@1441:     const auto startFrame = extents.isEmpty() ?
dev@1434:         model.getStartFrame() : extents.getStartFrame();
dev@1441:     const auto endFrame = extents.isEmpty() ?
dev@1434:         model.getEndFrame() : extents.getEndFrame();
dev@1441:     const auto hasValidExtents = startFrame >= 0 && endFrame > startFrame;
dev@1441:     if (!hasValidExtents) return false;
dev@1441:     const auto calculateProgress = initCalc(endFrame - startFrame);
dev@1441: 
dev@1441:     auto readPtr = startFrame;
dev@1434:     int previousPercentagePoint = 0;
dev@1430: 
dev@1434:     const auto wasCancelled = [&reporter]() { 
dev@1434:         return reporter && reporter->wasCancelled(); 
dev@1434:     };
dev@1430: 
dev@1434:     while (readPtr < endFrame) {
dev@1434:         if (wasCancelled()) return false;
dev@1434: 
dev@1434:         const auto start = readPtr;
dev@1434:         const auto end = std::min(start + blockSize, endFrame);
dev@1434: 
dev@1434:         oss << model.toDelimitedDataStringSubsetWithOptions(
dev@1434:             delimiter,
dev@1434:             options,
dev@1434:             start,
dev@1434:             end
dev@1434:         ) << (end < endFrame ? "\n" : "");
dev@1441:         const auto nFramesWritten = end - startFrame;
dev@1441:         const auto currentPercentage = calculateProgress(nFramesWritten);
dev@1434:         const bool hasIncreased = currentPercentage > previousPercentagePoint;
dev@1434: 
dev@1434:         if (hasIncreased) {
dev@1434:             if (reporter) reporter->setProgress(currentPercentage);
dev@1434:             previousPercentagePoint = currentPercentage;
dev@1434:         }
dev@1434:         readPtr = end;
dev@1434:     }
dev@1434:     return !wasCancelled(); // setProgress could process event loop
dev@1434: }
dev@1434: 
dev@1434: template <class OutStream>
dev@1441: bool 
dev@1441: writeInChunks(OutStream& oss,
dev@1441:               const Model& model,
dev@1441:               ProgressReporter* reporter = nullptr,
dev@1441:               QString delimiter = ",",
dev@1441:               DataExportOptions options = DataExportDefaults,
dev@1441:               const sv_frame_t blockSize = 16384)
dev@1434: {
dev@1434:     const Selection empty;
dev@1438:     return CSV::writeInChunks(
dev@1434:         oss,
dev@1434:         model,
dev@1434:         empty,
dev@1434:         reporter,
dev@1434:         delimiter,
dev@1434:         options,
dev@1434:         blockSize
dev@1434:     );
dev@1434: }
dev@1438: } // namespace CSVStreamWriter
dev@1434: #endif