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Diffstat (limited to '3rdparty/clucene/src/CLucene/util/streambase.h')
-rw-r--r-- | 3rdparty/clucene/src/CLucene/util/streambase.h | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/3rdparty/clucene/src/CLucene/util/streambase.h b/3rdparty/clucene/src/CLucene/util/streambase.h new file mode 100644 index 000000000..b0d9dc167 --- /dev/null +++ b/3rdparty/clucene/src/CLucene/util/streambase.h @@ -0,0 +1,148 @@ +/*------------------------------------------------------------------------------ +* Copyright (C) 2003-2006 Jos van den Oever +* +* Distributable under the terms of either the Apache License (Version 2.0) or +* the GNU Lesser General Public License, as specified in the COPYING file. +* +* Changes are Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +------------------------------------------------------------------------------*/ +/* This file is part of Strigi Desktop Search + * + * Copyright (C) 2006 Jos van den Oever <jos@vandenoever.info> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public License + * along with this library; see the file COPYING.LIB. If not, write to + * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, + * Boston, MA 02110-1301, USA. + */ +#ifndef STREAMBASE_H +#define STREAMBASE_H + +#include <string> + +#if defined(_BUILD_FOR_QT_) + #include "StdHeader.h" +#endif + +#define INT32MAX 0x7FFFFFFFL + +namespace jstreams { + +enum StreamStatus { Ok, Eof, Error }; + +/** + * @short Base class for stream read access to many different file types. + * + * This class is based on the interface java.io.InputStream. It allows + * for uniform access to streamed resources. + * The main difference with the java equivalent is a performance improvement. + * When reading data, data is not copied into a buffer provided by the caller, + * but a pointer to the read data is provided. This makes this interface + * especially useful for deriving from it and implementing filterers or + * transformers. + */ +// java mapping: long=int64, int=int32, byte=uint8_t +template <class T> +class StreamBase { +protected: + int64_t size; + int64_t position; + std::string error; + StreamStatus status; +public: + StreamBase() :size(-1), position(0), status(Ok){ } + virtual ~StreamBase(){} + /** + * @brief Return a string representation of the last error. + * If no error has occurred, an empty string is returned. + **/ + const char* getError() const { return error.c_str(); } + StreamStatus getStatus() const { return status; } + /** + * @brief Get the current position in the stream. + * The value obtained from this function can be used to reset the stream. + **/ + int64_t getPosition() const { return position; } + /** + * @brief Return the size of the stream. + * If the size of the stream is unknown, -1 + * is returned. If the end of the stream has been reached the size is + * always known. + **/ + int64_t getSize() const { return size; } + /** + * @brief Reads characters from the stream and sets \a start to + * the first character that was read. + * + * If @p ntoread is @c 0, then at least one character will be read. + * + * @param start Pointer passed by reference that will be set to point to + * the retrieved array of characters. If the end of the stream + * is encountered or an error occurs, the value of @p start + * is undefined. + * @param min The number of characters to read from the stream. + * @param max The maximum number of characters to read from the stream. + * @return the number of characters that were read. If -1 is returned, the + * end of the stream has been reached. If -2 is returned, an error + * has occurred. + **/ + virtual int32_t read(const T*& start, int32_t min, int32_t max) = 0; + /** + * Skip @param ntoskip bytes. Unless an error occurs or the end of file is + * encountered, this amount of bytes is skipped. + * This function returns new position in the stream. + **/ + virtual int64_t skip(int64_t ntoskip); + /** + * @brief Repositions this stream to given requested position. + * Reset is guaranteed to work after a successful call to read(), + * when the new position is in the range of the data returned by read(). + * This means that @p pos must lie between than the position + * corresponding to the start parameter (x) of the read function + * and the position corresponding to the last position in the returned + * buffer (x + nread). + **/ + virtual int64_t reset(int64_t pos) = 0; + int64_t mark(int32_t readlimit) { + int64_t p = getPosition(); + const T* ptr; + read(ptr, readlimit, -1); + return reset(p); + } +}; +#define SKIPSTEP 1024 +template <class T> +int64_t +StreamBase<T>::skip(int64_t ntoskip) { + const T *begin; + int32_t nread; + int64_t skipped = 0; + while (ntoskip) { + int32_t step = (int32_t)((ntoskip > SKIPSTEP) ?SKIPSTEP :ntoskip); + nread = read(begin, 1, step); + if (nread < -1 ) { + // an error occurred + return nread; + } else if (nread < 1) { + ntoskip = 0; + } else { + skipped += nread; + ntoskip -= nread; + } + } + return skipped; +} + +} // end namespace jstreams + +#endif |