2 * Copyright (c) 2014, Peter Thorson. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 * * Redistributions of source code must retain the above copyright
7 * notice, this list of conditions and the following disclaimer.
8 * * Redistributions in binary form must reproduce the above copyright
9 * notice, this list of conditions and the following disclaimer in the
10 * documentation and/or other materials provided with the distribution.
11 * * Neither the name of the WebSocket++ Project nor the
12 * names of its contributors may be used to endorse or promote products
13 * derived from this software without specific prior written permission.
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL PETER THORSON BE LIABLE FOR ANY
19 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
20 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
21 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
22 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
24 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 #ifndef WEBSOCKETPP_TRANSPORT_BASE_CON_HPP
29 #define WEBSOCKETPP_TRANSPORT_BASE_CON_HPP
31 #include <websocketpp/common/cpp11.hpp>
32 #include <websocketpp/common/connection_hdl.hpp>
33 #include <websocketpp/common/functional.hpp>
34 #include <websocketpp/common/system_error.hpp>
38 namespace websocketpp {
39 /// Transport policies provide network connectivity and timers
41 * ### Connection Interface
43 * Transport connection components needs to provide:
46 * `void init(init_handler handler)`\n
47 * Called once shortly after construction to give the policy the chance to
48 * perform one time initialization. When complete, the policy must call the
49 * supplied `init_handler` to continue setup. The handler takes one argument
50 * with the error code if any. If an error is returned here setup will fail and
51 * the connection will be aborted or terminated.
53 * WebSocket++ will call init only once. The transport must call `handler`
56 * **async_read_at_least**\n
57 * `void async_read_at_least(size_t num_bytes, char *buf, size_t len,
58 * read_handler handler)`\n
59 * start an async read for at least num_bytes and at most len
60 * bytes into buf. Call handler when done with number of bytes read.
62 * WebSocket++ promises to have only one async_read_at_least in flight at a
63 * time. The transport must promise to only call read_handler once per async
67 * `void async_write(const char* buf, size_t len, write_handler handler)`\n
68 * `void async_write(std::vector<buffer> & bufs, write_handler handler)`\n
69 * Start a write of all of the data in buf or bufs. In second case data is
70 * written sequentially and in place without copying anything to a temporary
73 * Websocket++ promises to have only one async_write in flight at a time.
74 * The transport must promise to only call the write_handler once per async
78 * `void set_handle(connection_hdl hdl)`\n
79 * Called by WebSocket++ to let this policy know the hdl to the connection. It
80 * may be stored for later use or ignored/discarded. This handle should be used
81 * if the policy adds any connection handlers. Connection handlers must be
82 * called with the handle as the first argument so that the handler code knows
83 * which connection generated the callback.
86 * `timer_ptr set_timer(long duration, timer_handler handler)`\n
87 * WebSocket++ uses the timers provided by the transport policy as the
88 * implementation of timers is often highly coupled with the implementation of
89 * the networking event loops.
91 * Transport timer support is an optional feature. A transport method may elect
92 * to implement a dummy timer object and have this method return an empty
93 * pointer. If so, all timer related features of WebSocket++ core will be
94 * disabled. This includes many security features designed to prevent denial of
95 * service attacks. Use timer-free transport policies with caution.
97 * **get_remote_endpoint**\n
98 * `std::string get_remote_endpoint()`\n
99 * retrieve address of remote endpoint
102 * `void is_secure()`\n
103 * whether or not the connection to the remote endpoint is secure
106 * `lib::error_code dispatch(dispatch_handler handler)`: invoke handler within
107 * the transport's event system if it uses one. Otherwise, this method should
108 * simply call `handler` immediately.
110 * **async_shutdown**\n
111 * `void async_shutdown(shutdown_handler handler)`\n
112 * Perform any cleanup necessary (if any). Call `handler` when complete.
114 namespace transport {
116 /// The type and signature of the callback passed to the init hook
117 typedef lib::function<void(lib::error_code const &)> init_handler;
119 /// The type and signature of the callback passed to the read method
120 typedef lib::function<void(lib::error_code const &,size_t)> read_handler;
122 /// The type and signature of the callback passed to the write method
123 typedef lib::function<void(lib::error_code const &)> write_handler;
125 /// The type and signature of the callback passed to the read method
126 typedef lib::function<void(lib::error_code const &)> timer_handler;
128 /// The type and signature of the callback passed to the shutdown method
129 typedef lib::function<void(lib::error_code const &)> shutdown_handler;
131 /// The type and signature of the callback passed to the interrupt method
132 typedef lib::function<void()> interrupt_handler;
134 /// The type and signature of the callback passed to the dispatch method
135 typedef lib::function<void()> dispatch_handler;
137 /// A simple utility buffer class
139 buffer(char const * b, size_t l) : buf(b),len(l) {}
145 /// Generic transport related errors
148 /// Catch-all error for transport policy errors that don't fit in other
152 /// underlying transport pass through
155 /// async_read_at_least call requested more bytes than buffer can store
158 /// async_read called while another async_read was in progress
161 /// Operation aborted
164 /// Operation not supported
165 operation_not_supported,
176 /// read or write after shutdown
177 action_after_shutdown,
183 class category : public lib::error_category {
187 char const * name() const _WEBSOCKETPP_NOEXCEPT_TOKEN_ {
188 return "websocketpp.transport";
191 std::string message(int value) const {
194 return "Generic transport policy error";
196 return "Underlying Transport Error";
197 case invalid_num_bytes:
198 return "async_read_at_least call requested more bytes than buffer can store";
199 case operation_aborted:
200 return "The operation was aborted";
201 case operation_not_supported:
202 return "The operation is not supported by this transport";
204 return "End of File";
206 return "TLS Short Read";
208 return "Timer Expired";
209 case action_after_shutdown:
210 return "A transport action was requested after shutdown";
212 return "Generic TLS related error";
219 inline lib::error_category const & get_category() {
220 static category instance;
224 inline lib::error_code make_error_code(error::value e) {
225 return lib::error_code(static_cast<int>(e), get_category());
229 } // namespace transport
230 } // namespace websocketpp
231 _WEBSOCKETPP_ERROR_CODE_ENUM_NS_START_
232 template<> struct is_error_code_enum<websocketpp::transport::error::value>
234 static bool const value = true;
236 _WEBSOCKETPP_ERROR_CODE_ENUM_NS_END_
238 #endif // WEBSOCKETPP_TRANSPORT_BASE_CON_HPP