4 // Fraunhofer Institute for Open Communication Systems (FOKUS)
5 // Competence Center NETwork research (NET), St. Augustin, GERMANY
6 // Stefan Bund <g0dil@berlios.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 <div class="diamap" name="FhHierarchy">
30 <span coords="233,47,438,89">\ref SocketHandle</span>
31 <span coords="32,126,281,168">\ref ClientSocketHandle</span>
32 <span coords="0,187,326,229">\ref ProtocolClientSocketHandle</span>
33 <span coords="350,187,684,229">\ref ProtocolServerSocketHandle</span>
34 <span coords="243,0,343,28">\ref FileHandle</span>
35 <span coords="382,126,638,168">\ref ServerSocketHandle</span>
37 \htmlonly <img src="FhHierarchy.png" border="0" alt="FhHierarchy" usemap="#FhHierarchy"> \endhtmlonly
39 The senf::FileHandle class is the base of a hierarchy of socket handle classes (realized as
40 templates). These classes provide an interface to the complete socket API. While going down the
41 inheritance hierarchy, the interface will be more and more complete.
43 The most complete interface is provided by senf::ProtocolClientSocketHandle and
44 senf::ProtocolServerSocketHandle. The template Arguments specifies the Protocol class of the
45 underlying socket type. These are the \e only classes having public constructors and are
46 therefore the only classes, which may be created by the library user. You will normally use
47 these classes by naming a specific socket typedef (e.g. senf::TCPv4ClientSocketHandle).
49 However, to aid writing flexible and generic code, the socket library provides the
50 senf::ClientSocketHandle and senf::ServerSocketHandle class templates. These templates implement
51 a family of closely related classes based on the specification of the socket policy. This policy
52 specification may be \e incomplete (see below). Instances of
53 senf::ClientSocketHandle/senf::ServerSocketHandle can be assigned and converted to different
54 ClientSocketHandle/ServerSocketHandle types as long as the policy specifications are compatible.
56 \attention It is very important, to (almost) always pass the socket handle <em>by
57 value</em>. The socket handle is a very lightweight class and designed to be used like an
58 ordinary built-in type. This is very important in combination with the policy interface.
60 \note The FileHandle hierarchy below the SocketHandle template is \e not meant to be user
61 extensible. To add new socket types, you should introduce new protocol and/or policy classes,
62 the SocketHandle classes should not be changed.
65 #ifndef HH_FileHandle_
66 #define HH_FileHandle_ 1
69 #include <memory> // std::auto_ptr
70 #include "../Utils/safe_bool.hh"
72 //#include "FileHandle.mpp"
73 ///////////////////////////////hh.p////////////////////////////////////////
74 #include "FileHandle.ih"
78 /// \addtogroup handle_group
81 /** \brief Basic file handle wrapper
83 senf::FileHandle provides a simple wrapper for arbitrary file handles. It exposes only a
84 minimal interface which does \e not include reading or writing (since some filehandles are
85 not readable or writable or only using special function calls like sendto).
87 The FileHandle class provides handle/body handling and uses automatic reference
88 counting. The senf::FileHandle instance is very lightweight and should be used like a
91 \attention You should mostly pass around senf::FileHandle objects by \e value and not by
94 The FileHandle abstraction is only applicable to real filehandles. It is \e not possible to
95 wrap any provider or consumer into a filehandle like interface using this wrapper. The
96 wrapper will forward some calls directly to the underlying API without relying on virtual
97 methods. This allows important members to be inlined.
99 It is not possible to use the senf::FileHandle class directly since it does not have any
100 public constructor. The FileHandle class is however the baseclass of all handle classes of
103 \section filehandle_new Writing senf::FileHandle derived classes
105 To build a new FileHandle type you need to derive from senf::FileHandle. The derived class
106 will have to call the protected FileHandle constructor passing a new senf::FileBody
107 instance. This instance may either be a simple senf::FileBody or a class derived from
111 : public safe_bool<FileHandle>
114 ///////////////////////////////////////////////////////////////////////////
117 ///////////////////////////////////////////////////////////////////////////
118 ///\name Structors and default members
124 // my default constructor
125 // default copy constructor
126 // default copy assignment
127 // default destructor
129 // no conversion constructors
132 ///////////////////////////////////////////////////////////////////////////
134 void close(); ///< Close filehandle
135 /**< \throws senf::SystemException */
136 void terminate(); ///< Close filehandle ignoring error conditions
138 bool readable() const; ///< Check, whether a read on the handle would not block
139 ///< (ignoring blocking state)
140 void waitReadable() const; ///< Wait, until read on the handle would not block (ignoring
142 bool writeable() const; ///< Check, whether a write on the handle would not block
143 ///< (ignoring blocking state)
144 void waitWriteable() const; ///< Wait, until a write on the handle would not block
145 ///< (ignoring blocking state)
147 bool blocking() const; ///< Return current blocking state
148 void blocking(bool status); ///< Set blocking state
150 bool eof() const; ///< Check EOF condition
151 /**< Depending on the socket type, this might never return \p
154 This member is somewhat problematic performance wise if
155 called frequently since it relies on virtual
156 functions. However, since the eof() handling is extremely
157 protocol dependent, a policy based implementation does not
159 bool valid() const; ///< Check filehandle validity
160 /**< Any operation besides valid() will fail on an invalid
163 bool boolean_test() const; ///< Short for valid() && ! eof()
164 /**< This is called when using a FileHandle instance in a boolean
167 See the performance comments for the eof() member */
169 int fd() const; ///< Return the raw FileHandle
171 static FileHandle cast_static(FileHandle handle); /**< \internal */
172 static FileHandle cast_dynamic(FileHandle handle); /**< \internal */
175 explicit FileHandle(std::auto_ptr<FileBody> body);
176 ///< create new FileHandle instance
177 /**< The FileHandle instance will take over ownership over the
178 given FileBody instance which must have been allocated using
179 \c new. To configure the FileHandle behavior, A derived class
180 may provide any class derived from FileBody here. */
182 explicit FileHandle(FileBody::ptr body);
184 FileBody & body(); ///< Access body
185 FileBody const & body() const; ///< Access body in const context
186 static FileBody & body(FileHandle & handle); ///< Access body of another FileHandle instance
187 static FileBody const & body(FileHandle const & handle); ///< Access body of another
188 ///< FileHandle instance in const context
190 void fd(int fd); ///< Set raw filehandle
195 friend class FileBody;
198 /** \brief Adapt FileHandle to senf::Scheduler
199 \related senf::FileHandle
203 This function will be called by the Scheduler to retrieve the file descriptor of the
206 int retrieve_filehandle(FileHandle handle);
212 ///////////////////////////////hh.e////////////////////////////////////////
213 #include "FileHandle.cci"
214 //#include "FileHandle.ct"
215 //#include "FileHandle.cti"
222 // c-file-style: "senf"
223 // indent-tabs-mode: nil
224 // ispell-local-dictionary: "american"
225 // compile-command: "scons -u test"
226 // comment-column: 40