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core/ASCOfficeXlsFile2/source/XlsFormat/Binary/CFStreamCacheReader.h
Alexander.Trofimov 04d197375c change license to 2017
2017-01-17 18:17:26 +03:00

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/*
* (c) Copyright Ascensio System SIA 2010-2017
*
* This program is a free software product. You can redistribute it and/or
* modify it under the terms of the GNU Affero General Public License (AGPL)
* version 3 as published by the Free Software Foundation. In accordance with
* Section 7(a) of the GNU AGPL its Section 15 shall be amended to the effect
* that Ascensio System SIA expressly excludes the warranty of non-infringement
* of any third-party rights.
*
* This program is distributed WITHOUT ANY WARRANTY; without even the implied
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. For
* details, see the GNU AGPL at: http://www.gnu.org/licenses/agpl-3.0.html
*
* You can contact Ascensio System SIA at Lubanas st. 125a-25, Riga, Latvia,
* EU, LV-1021.
*
* The interactive user interfaces in modified source and object code versions
* of the Program must display Appropriate Legal Notices, as required under
* Section 5 of the GNU AGPL version 3.
*
* Pursuant to Section 7(b) of the License you must retain the original Product
* logo when distributing the program. Pursuant to Section 7(e) we decline to
* grant you any rights under trademark law for use of our trademarks.
*
* All the Product's GUI elements, including illustrations and icon sets, as
* well as technical writing content are licensed under the terms of the
* Creative Commons Attribution-ShareAlike 4.0 International. See the License
* terms at http://creativecommons.org/licenses/by-sa/4.0/legalcode
*
*/
#pragma once
#include "CFRecordType.h"
#include "BinSmartPointers.h"
#include <Logic/GlobalWorkbookInfo.h>
#include <Logic/Biff_structures/ODRAW/OfficeArtRecordHeader.h>
namespace XLS
{
// The only purpose of the reader is to avoid seeking back through IStream when, for example,
// we have read a record from a binary stream to the CFRecord, but the record of this type is
// not waitable right at the moment and shall be read a little bit later.
// Example of a construction:
// PIVOTTH = SXTH *ContinueFrt
// ContinueFrt may appear in the stream and may not. So, this class will increase performance much
class CFStreamCacheReader
{
public:
CFStreamCacheReader(CFStreamPtr stream, const GlobalWorkbookInfoPtr global_info);
~CFStreamCacheReader();
// Reads the next CFRecord from the CFStream and if it's type is not the desired one, caches it for the next call
CFRecordPtr getNextRecord(const CFRecordType::TypeId desirable_type, const bool gen_except = false);
// Check if the next read record would be of desired type
const bool checkNextRecord(const CFRecordType::TypeId desirable_type, const size_t num_records_to_check = 1);
// Checks whether the next record is Continue and append its data to the real record if so
void checkAndAppendContinueData();
const bool isEOF() const;
// Skip the specified number of unsigned chars without processing
void skipNunBytes(const size_t n);
void SkipRecord();
// Seek to the next substream (Read all records till EOF then skip EOF)
// Doesn't generate EndOfStreamReached if the stream is the last one
const bool SeekToEOF();
// Extract the next record from the stream leaving it in the cache for future read.
// Always call resetPointerToBegin for the extracted CFRecord after using it
CFRecordPtr touchTheNextRecord();
// Check the next record type
const CFRecordType::TypeId getNextRecordType();
GlobalWorkbookInfoPtr getGlobalWorkbookInfo() { return global_info_; }
private:
// Make sure the internal buffer has concrete number of records. Returns number of records read
const size_t readFromStream(const size_t num_of_records_min_necessary);
private:
CFStreamPtr stream_;
CFRecordPtrList records_cache;
GlobalWorkbookInfoPtr global_info_;
std::vector<std::string> skippable_records_names;
};
} // namespace XLS