HTTPSession.h

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//
// HTTPSession.h
//
// Library: Net
// Package: HTTP
// Module:  HTTPSession
//
// Definition of the HTTPSession class.
//
// Copyright (c) 2005-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
 
 
#ifndef Net_HTTPSession_INCLUDED
#define Net_HTTPSession_INCLUDED
 
 
#include "Poco/Net/Net.h"
#include "Poco/Net/StreamSocket.h"
#include "Poco/Timespan.h"
#include "Poco/Exception.h"
#include "Poco/Any.h"
#include "Poco/Buffer.h"
#include <ios>
 
 
namespace Poco {
namespace Net {
 
 
class Net_API HTTPSession
    /// HTTPSession implements basic HTTP session management
    /// for both HTTP clients and HTTP servers.
    ///
    /// HTTPSession implements buffering for HTTP connections, as well
    /// as specific support for the various HTTP stream classes.
    ///
    /// This class can not be instantiated. HTTPClientSession or
    /// HTTPServerSession must be used instead.
{
public:
    void setKeepAlive(bool keepAlive);
        /// Sets the keep-alive flag for this session.
        ///
        /// If the keep-alive flag is enabled, persistent
        /// HTTP/1.1 connections are supported.
 
    bool getKeepAlive() const;
        /// Returns the value of the keep-alive flag for
        /// this session.
 
    void setTimeout(const Poco::Timespan& timeout);
        /// Sets the timeout for the HTTP session.
 
    void setTimeout(const Poco::Timespan& connectionTimeout, const Poco::Timespan& sendTimeout, const Poco::Timespan& receiveTimeout);
        /// Sets different timeouts for the HTTP session.
 
    Poco::Timespan getTimeout() const;
        /// Returns the timeout for the HTTP session.
 
    bool connected() const;
        /// Returns true if the underlying socket is connected.
 
    virtual void abort();
        /// Aborts a session in progress by shutting down
        /// and closing the underlying socket.
 
    const Poco::Exception* networkException() const;
        /// If sending or receiving data over the underlying
        /// socket connection resulted in an exception, a
        /// pointer to this exception is returned.
        /// 
        /// Otherwise, NULL is returned.
 
    void attachSessionData(const Poco::Any& data);
        /// Allows to attach an application-specific data 
        /// item to the session.
        ///
        /// On the server side, this can be used to manage
        /// data that must be maintained over the entire
        /// lifetime of a persistent connection (that is,
        /// multiple requests sent over the same connection).
 
    const Poco::Any& sessionData() const;
        /// Returns the data attached with attachSessionData(),
        /// or an empty Poco::Any if no user data has been
        /// attached.
 
    enum
    {
        HTTP_PORT = 80
    };
 
    StreamSocket detachSocket();
        /// Detaches the socket from the session.
        ///
        /// The socket is returned, and a new, uninitialized socket is
        /// attached to the session.
 
    StreamSocket& socket();
        /// Returns a reference to the underlying socket.
 
    void drainBuffer(Poco::Buffer<char>& buffer);
        /// Copies all bytes remaining in the internal buffer to the
        /// given Poco::Buffer, resizing it as necessary.
        ///
        /// This is usually used together with detachSocket() to
        /// obtain any data already read from the socket, but not
        /// yet processed.
 
protected:
    HTTPSession();
        /// Creates a HTTP session using an
        /// unconnected stream socket.
 
    HTTPSession(const StreamSocket& socket);
        /// Creates a HTTP session using the
        /// given socket. The session takes ownership
        /// of the socket and closes it when it's no
        /// longer used.
 
    HTTPSession(const StreamSocket& socket, bool keepAlive);
        /// Creates a HTTP session using the
        /// given socket. The session takes ownership
        /// of the socket and closes it when it's no
        /// longer used.
 
    virtual ~HTTPSession();
        /// Destroys the HTTPSession and closes the
        /// underlying socket.
 
    int get();
        /// Returns the next byte in the buffer.
        /// Reads more data from the socket if there are
        /// no bytes left in the buffer.
 
    int peek();
        /// Peeks at the next character in the buffer.
        /// Reads more data from the socket if there are
        /// no bytes left in the buffer.
 
    virtual int read(char* buffer, std::streamsize length);
        /// Reads up to length bytes.
        ///
        /// If there is data in the buffer, this data
        /// is returned. Otherwise, data is read from
        /// the socket to avoid unnecessary buffering.
 
    virtual int write(const char* buffer, std::streamsize length);
        /// Writes data to the socket.
 
    int receive(char* buffer, int length);
        /// Reads up to length bytes.
 
    int buffered() const;
        /// Returns the number of bytes in the buffer.
 
    void refill();
        /// Refills the internal buffer.
 
    virtual void connect(const SocketAddress& address);
        /// Connects the underlying socket to the given address
        /// and sets the socket's receive timeout.  
 
    void attachSocket(const StreamSocket& socket);
        /// Attaches a socket to the session, replacing the
        /// previously attached socket.
 
    void close();
        /// Closes the underlying socket.
 
    void setException(const Poco::Exception& exc);
        /// Stores a clone of the exception.
 
    void clearException();
        /// Clears the stored exception.
 
private:
    enum
    {
        HTTP_DEFAULT_TIMEOUT = 60000000,
        HTTP_DEFAULT_CONNECTION_TIMEOUT = 30000000
    };
 
    HTTPSession(const HTTPSession&);
    HTTPSession& operator = (const HTTPSession&);
 
    StreamSocket     _socket;
    char*            _pBuffer;
    char*            _pCurrent;
    char*            _pEnd;
    bool             _keepAlive;
    Poco::Timespan   _connectionTimeout;
    Poco::Timespan   _receiveTimeout;
    Poco::Timespan   _sendTimeout;
    Poco::Exception* _pException;
    Poco::Any        _data;
 
    friend class HTTPStreamBuf;
    friend class HTTPHeaderStreamBuf;
    friend class HTTPFixedLengthStreamBuf;
    friend class HTTPChunkedStreamBuf;
};
 
 
//
// inlines
//
inline bool HTTPSession::getKeepAlive() const
{
    return _keepAlive;
}
 
 
inline Poco::Timespan HTTPSession::getTimeout() const
{
    return _receiveTimeout;
}
 
 
inline StreamSocket& HTTPSession::socket()
{
    return _socket;
}
 
 
inline const Poco::Exception* HTTPSession::networkException() const
{
    return _pException;
}
 
 
inline int HTTPSession::buffered() const
{
    return static_cast<int>(_pEnd - _pCurrent);
}
 
 
inline const Poco::Any& HTTPSession::sessionData() const
{
    return _data;
}
 
 
} } // namespace Poco::Net
 
 
#endif // Net_HTTPSession_INCLUDED