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// IOChannel.h - a virtual IO channel, for Gnash
//
// Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010,
// 2011 Free Software Foundation, Inc
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
//
// This program 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
#ifndef GNASH_IOCHANNEL_H
#define GNASH_IOCHANNEL_H
#include <string>
#include <boost/cstdint.hpp> // for boost int types
#include <ios>
#include "dsodefs.h" // DSOEXPORT
#include "GnashException.h" // for IOException inheritance
namespace gnash {
/// Exception signalling an IO error
class DSOEXPORT IOException : public GnashException
{
public:
IOException(const std::string& s) : GnashException(s) {}
IOException() : GnashException("IO error") {}
};
/// A virtual IO channel
class DSOEXPORT IOChannel
{
public:
virtual ~IOChannel() {}
/// \brief Read a 32-bit word from a little-endian stream.
/// returning it as a native-endian word.
//
/// Throw IOException on error
///
boost::uint32_t read_le32();
/// Read a 16-bit word from a little-endian stream.
//
/// Throw IOException on error
///
boost::uint16_t read_le16();
/// Read a single byte from the stream
//
/// Throw IOException on error
///
boost::uint8_t read_byte();
/// Read the given number of bytes from the stream
//
/// Return the number of bytes actually read.
/// EOF might cause it to be < num.
///
/// Throw IOException on error
///
virtual std::streamsize read(void* dst, std::streamsize num)=0;
/// Read at most the given number of bytes w/out blocking
//
/// Throw IOException on error
///
/// @return The number of bytes actually read.
/// A short count may mean EOF was hit or
/// data didn't arrive yet.
///
/// Default implementation proxies the call to the
/// blocking version.
///
virtual std::streamsize readNonBlocking(void* dst, std::streamsize num)
{
return read(dst, num);
}
/// Write the given number of bytes to the stream
//
/// Throw IOException on error/unsupported op.
///
virtual std::streamsize write(const void* src, std::streamsize num);
/// \brief
/// Read up to max_length characters, returns the number of characters
/// read, or -1 if the string length is longer than max_length.
//
/// Stops at the first \0 character if it comes before max_length.
///
/// Guarantees termination of the string.
///
/// @return the number of characters read, or -1 no null-termination
/// was found within max_length
///
/// Throw IOException on error
///
int read_string(char* dst, int max_length);
/// Read a 32-bit float from a little-endian stream.
//
/// NOTE: this currently relies on host FP format being the
/// same as the Flash one (presumably IEEE 754).
///
/// Throw IOException on error
///
float read_float32();
/// Return current stream position
//
/// Throw IOException on error
///
virtual std::streampos tell() const = 0;
/// Seek to the specified position
//
///
/// Throw IOException on error
///
/// @return true on success, or false on failure.
///
virtual bool seek(std::streampos p) = 0;
/// Seek to the end of the stream
//
/// Throw IOException on error
///
virtual void go_to_end() = 0;
/// Return true if the end of the stream has been reached.
//
/// Throw IOException on error
///
virtual bool eof() const = 0;
/// Return true if the stream is in an error state
//
/// When the stream is in an error state there's nothing
/// you can do about it, just delete it and log the error.
virtual bool bad() const = 0;
/// Get the size of the stream (unreliably).
//
/// Size of stream is unreliable as not all input
/// channels have a mechanism to advertise size,
/// and some have one but isn't necessarely truthful
/// (a few HTTP severs are bogus in this reguard).
///
/// @return unreliable input size, (size_t)-1 if not known.
///
virtual size_t size() const { return static_cast<size_t>(-1); }
};
} // namespace gnash
#endif // GNASH_IOCHANNEL_H
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