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qhttpengine/include/QHttpEngine/qhttprange.h
2016-10-10 13:49:34 -07:00

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/*
* Copyright (c) 2016 Aleksei Ermakov
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#ifndef QHTTPENGINE_QHTTPRANGE_H
#define QHTTPENGINE_QHTTPRANGE_H
#include <QString>
#include "qhttpengine_global.h"
class QHTTPENGINE_EXPORT QHttpRangePrivate;
/**
* @brief HTTP range representation
* @headerfile qhttprange.h QHttpEngine/QHttpRange
*
* This class provides a representation of HTTP range, described in RFC 7233
* and used when partial content is requested by the client. When an object is
* created, optional dataSize can be specified, so that relative ranges can
* be represented as absolute.
*
* Example:
* @code
* QHttpRange range(10, -1, 90);
* range.from(); // 10
* range.to(); // 89
* range.length(); // 80
*
* range = QHttpRange("-500", 1000);
* range.from(); // 500
* range.to(); // 999
* range.length(); // 500
*
* range = QHttpRange(0, -1);
* range.from(); // 0
* range.to(); // -1
* range.length(); // -1
*
* range = QHttpRange(range, 100);
* range.from(); // 0
* range.to(); // 99
* range.length(); // 100
* @endcode
*
*/
class QHTTPENGINE_EXPORT QHttpRange
{
public:
/**
* @brief Default QHttpRange constructor
*
* An empty QHttpRange is considered invalid.
*/
QHttpRange();
/**
* @brief Construct QHttpRange by parsing range
*
* Parses string representation range and constructs new QHttpRange.
* For raw header "Range: bytes=0-100" only "0-100" should be passed to
* constructor. dataSize may be supplied so that relative ranges could be
* represented as absolute values.
*/
QHttpRange(const QString &range, qint64 dataSize = -1);
/**
* @brief Construct QHttpRange, using from and to values
*
* Initialises a new QHttpRange with from and to values. dataSize may be
* supplied so that relative ranges could be represented as
* absolute values.
*/
QHttpRange(qint64 from, qint64 to, qint64 dataSize = -1);
/**
* @brief Construct QHttpRange from other QHttpRange and dataSize
*
* Initialises a new QHttpRange with from and to values of other
* QHttpRequest. Supplied dataSize is used instead of other dataSize.
*/
QHttpRange(const QHttpRange &other, qint64 dataSize);
/**
* @brief Destroy the range
*/
~QHttpRange();
/**
* @brief Assignment operator
*/
QHttpRange& operator=(const QHttpRange &other);
/**
* @brief Return starting position of range
*
* If range is set as 'last N bytes' and dataSize is not set, returns -N.
*
* Example:
* @code
* QHttpRange range("-500");
* range.from(); // -500
* range.to(); // -1
* range.length(); // 500
*
* range = QHttpRange(range, 800);
* range.from(); // 300
* range.to(); // 799
* range.length(); // 500
*
* range = QHttpRange("10-");
* range.from(); // 10
* range.to(); // -1
* range.length(); // -1
*
* range = QHttpRange(range, 100);
* range.from(); // 10
* range.to(); // 99
* range.length(); // 90
* @endcode
*
*/
qint64 from() const;
/**
* @brief Returns ending position of range.
*
* If range is set as 'last N bytes' and dataSize is not set, returns -1.
* If ending position is not set, and dataSize is not set, returns -1.
*
* Example:
* @code
* QHttpRange range("-500");
* range.from(); // -500
* range.to(); // -1
* range.length(); // 500
*
* range = QHttpRange(range, 800);
* range.from(); // 300
* range.to(); // 799
* range.length(); // 500
*
* range = QHttpRange("10-");
* range.from(); // 10
* range.to(); // -1
* range.length(); // -1
*
* range = QHttpRange(range, 100);
* range.from(); // 10
* range.to(); // 99
* range.length(); // 90
* @endcode
*
*/
qint64 to() const;
/**
* @brief Returns length of range.
*
* If ending position is not set, and dataSize is not set, and range is
* not set as 'last N bytes', returns -1. If range is invalid, returns -1.
*
* Example:
* @code
* QHttpRange range("-500");
* range.from(); // -500
* range.to(); // -1
* range.length(); // 500
*
* range = QHttpRange(range, 800);
* range.from(); // 300
* range.to(); // 799
* range.length(); // 500
*
* range = QHttpRange("10-");
* range.from(); // 10
* range.to(); // -1
* range.length(); // -1
*
* range = QHttpRange(range, 100);
* range.from(); // 10
* range.to(); // 99
* range.length(); // 90
* @endcode
*
*/
qint64 length() const;
/**
* @brief Returns dataSize of range.
*
* If dataSize is not set, returns -1.
*/
qint64 dataSize() const;
/**
* @brief Checks if range is valid
*
* Range is considered invalid if it is out of bounds, that is when this
* inequality is false - (from <= to < dataSize).
* When QHttpRange(const QString&) fails to parse range string, resulting
* range is also considered invalid.
*
* Example:
* @code
* QHttpRange range(1, 0, -1);
* range.isValid(); // false
*
* range = QHttpRange(512, 1024);
* range.isValid(); // true
*
* range = QHttpRange("-");
* range.isValid(); // false
*
* range = QHttpRange("abccbf");
* range.isValid(); // false
*
* range = QHttpRange(0, 512, 128);
* range.isValid(); // false
*
* range = QHttpRange(128, 64, 512);
* range.isValid(); // false
* @endcode
*/
bool isValid() const;
/**
* @brief Returns representation suitable for Content-Range header.
*
* Example:
* @code
* QHttpRange range(0, 100, 1000);
* range.contentRange(); // "0-100/1000"
*
* // When resource size is unknown
* range = QHttpRange(512, 1024);
* range.contentRange(); // "512-1024/*"
*
* // if range request was bad, return resource size
* range = QHttpRange(1, 0, 1200);
* range.contentRange(); // "*\/1200"
* @endcode
*/
QString contentRange() const;
private:
QHttpRangePrivate *const d;
};
#endif // QHTTPENGINE_QHTTPRANGE_H