4 // Fraunhofer Institut fuer offene Kommunikationssysteme (FOKUS)
5 // Kompetenzzentrum fuer Satelitenkommunikation (SatCom)
6 // Stefan Bund <stefan.bund@fokus.fraunhofer.de>
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 2 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the
20 // Free Software Foundation, Inc.,
21 // 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
24 \brief FileHandle public header
27 /** \defgroup handle_group The Handle Hierarchy
29 \image html FhHierarchy.png
31 The senf::FileHandle class is the base of a hierarchy of socket handle classes (realized as
32 templates). These classes provide an interface to the complete socket API. While going down the
33 inheritance hierarchy, the interface will be more and more complete.
35 The most complete interface is provided by senf::ProtocolClientSocketHandle and
36 senf::ProtocolServerSocketHandle. The template Arguments specifies the Protocol class of the
37 underlying socket type. These are the \e only classes having public constructors and are
38 therefore the only classes, which may be created by the library user. You will normally use
39 these classes by naming a specific socket typedef (e.g. senf::TCPv4ClientSocketHandle).
41 However, to aid writing flexible and generic code, the socket library provides the
42 senf::ClientSocketHandle and senf::ServerSocketHandle class templates. These templates implement
43 a family of closely related classes based on the specification of the socket policy. This policy
44 specification may be \e incomplete (see below). Instances of
45 senf::ClientSocketHandle/senf::ServerSocketHandle can be assigned and converted to different
46 ClientSocketHandle/ServerSocketHandle types as long as the policy specifications are compatible.
48 \attention It is very important, to (almost) always pass the socket handle <em>by
49 value</em>. The socket handle is a very lightweight class and designed to be used like an
50 ordinary built-in type. This is very important in combination with the policy interface.
52 \note The FileHandle hierarchy below the SocketHandle template is \e not meant to be user
53 extensible. To add new socket types, you should introduce new protocol and/or policy classes,
54 the SocketHandle classes should not be changed.
57 #ifndef HH_FileHandle_
58 #define HH_FileHandle_ 1
61 #include <memory> // std::auto_ptr
62 #include "Utils/SafeBool.hh"
64 //#include "FileHandle.mpp"
65 ///////////////////////////////hh.p////////////////////////////////////////
66 #include "FileHandle.ih"
70 /// \addtogroup handle_group
73 /** \brief Basic file handle wrapper
75 senf::FileHandle provides a simple wrapper for arbitrary file handles. It exposes only a
76 minimal interface which does \e not include reading or writing (since some filehandles are
77 not readable or writable or only using special function calls like sendto).
79 The FileHandle class provides handle/body handling and uses automatic reference
80 counting. The senf::FileHandle instance is very lightweight and should be used like a
83 \attention You should mostly pass around senf::FileHandle objects by \e value and not by
86 The FileHandle abstraction is only applicable to real filehandles. It is \e not possible to
87 wrap any provider or consumer into a filehandle like interface using this wrapper. The
88 wrapper will forward some calls directly to the underlying API without relying on virtual
89 methods. This allows important members to be inlined.
91 It is not possible to use the senf::FileHandle class directly since it does not have any
92 public constructor. The FileHandle class is however the baseclass of all handle classes of
95 \section filehandle_new Writing senf::FileHandle derived classes
97 To build a new FileHandle type you need to derive from senf::FileHandle. The derived class
98 will have to call the protected FileHandle constructor passing a new senf::FileBody
99 instance. This instance may either be a simple senf::FileBody or a class derived from
103 : public SafeBool<FileHandle>
106 ///////////////////////////////////////////////////////////////////////////
109 ///////////////////////////////////////////////////////////////////////////
110 ///\name Structors and default members
115 // my default constructor
116 // default copy constructor
117 // default copy assignment
118 // default destructor
120 // no conversion constructors
123 ///////////////////////////////////////////////////////////////////////////
125 void close(); ///< Close filehandle
126 /**< \throws senf::SystemException */
127 void terminate(); ///< Close filehandle ignoring error conditions
129 bool readable() const; ///< Check, whether a read on the handle would not block
130 ///< (ignoring blocking state)
131 void waitReadable() const; ///< Wait, until read on the handle would not block (ignoring
133 bool writeable() const; ///< Check, whether a write on the handle would not block
134 ///< (ignoring blocking state)
135 void waitWriteable() const; ///< Wait, until a write on the handle would not block
136 ///< (ignoring blocking state)
138 bool blocking() const; ///< Return current blocking state
139 void blocking(bool status); ///< Set blocking state
141 bool eof() const; ///< Check EOF condition
142 /**< Depending on the socket type, this might never return \p
145 This member is somewhat problematic performance wise if
146 called frequently since it relies on virtual
147 functions. However, since the eof() handling is extremely
148 protocol dependent, a policy based implementation does not
150 bool valid() const; ///< Check filehandle validity
151 /**< Any operation besides valid() will fail on an invalid
154 bool boolean_test() const; ///< Short for valid() && ! eof()
155 /**< This is called when using a FileHandle instance in a boolean
158 See the performance comments for the eof() member */
160 int fd() const; ///< Return the raw FileHandle
162 static FileHandle cast_static(FileHandle handle); /**< \internal */
163 static FileHandle cast_dynamic(FileHandle handle); /**< \internal */
166 explicit FileHandle(std::auto_ptr<FileBody> body);
167 ///< create new FileHandle instance
168 /**< The FileHandle instance will take over ownership over the
169 given FileBody instance which must have been allocated using
170 \c new. To configure the FileHandle behavior, A derived class
171 may provide any class derived from FileBody here. */
173 FileBody & body(); ///< Access body
174 FileBody const & body() const; ///< Access body in const context
175 static FileBody & body(FileHandle & handle); ///< Access body of another FileHandle instance
176 static FileBody const & body(FileHandle const & handle); ///< Access body of another
177 ///< FileHandle instance in const context
179 void fd(int fd); ///< Set raw filehandle
185 /** \brief Adapt FileHandle to senf::Scheduler
186 \related senf::FileHandle
190 This function will be called by the Scheduler to retrieve the file descriptor of the
193 int retrieve_filehandle(FileHandle handle);
199 ///////////////////////////////hh.e////////////////////////////////////////
200 #include "FileHandle.cci"
201 //#include "FileHandle.ct"
202 //#include "FileHandle.cti"
209 // c-file-style: "senf"
210 // indent-tabs-mode: nil
211 // ispell-local-dictionary: "american"
212 // compile-command: "scons -u test"
213 // comment-column: 40