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Diffstat (limited to 'websocketpp/transport/iostream/connection.hpp')
| -rw-r--r-- | websocketpp/transport/iostream/connection.hpp | 714 |
1 files changed, 714 insertions, 0 deletions
diff --git a/websocketpp/transport/iostream/connection.hpp b/websocketpp/transport/iostream/connection.hpp new file mode 100644 index 00000000..81c4f411 --- /dev/null +++ b/websocketpp/transport/iostream/connection.hpp @@ -0,0 +1,714 @@ +/* + * Copyright (c) 2014, Peter Thorson. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * * Neither the name of the WebSocket++ Project nor the + * names of its contributors may be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL PETER THORSON BE LIABLE FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ + +#ifndef WEBSOCKETPP_TRANSPORT_IOSTREAM_CON_HPP +#define WEBSOCKETPP_TRANSPORT_IOSTREAM_CON_HPP + +#include <websocketpp/transport/iostream/base.hpp> + +#include <websocketpp/transport/base/connection.hpp> + +#include <websocketpp/uri.hpp> + +#include <websocketpp/logger/levels.hpp> + +#include <websocketpp/common/connection_hdl.hpp> +#include <websocketpp/common/memory.hpp> +#include <websocketpp/common/platforms.hpp> + +#include <algorithm> +#include <iostream> +#include <sstream> +#include <string> +#include <vector> + +namespace websocketpp { +namespace transport { +namespace iostream { + +/// Empty timer class to stub out for timer functionality that iostream +/// transport doesn't support +struct timer { + void cancel() {} +}; + +template <typename config> +class connection : public lib::enable_shared_from_this< connection<config> > { +public: + /// Type of this connection transport component + typedef connection<config> type; + /// Type of a shared pointer to this connection transport component + typedef lib::shared_ptr<type> ptr; + + /// transport concurrency policy + typedef typename config::concurrency_type concurrency_type; + /// Type of this transport's access logging policy + typedef typename config::alog_type alog_type; + /// Type of this transport's error logging policy + typedef typename config::elog_type elog_type; + + // Concurrency policy types + typedef typename concurrency_type::scoped_lock_type scoped_lock_type; + typedef typename concurrency_type::mutex_type mutex_type; + + typedef lib::shared_ptr<timer> timer_ptr; + + explicit connection(bool is_server, alog_type & alog, elog_type & elog) + : m_output_stream(NULL) + , m_reading(false) + , m_is_server(is_server) + , m_is_secure(false) + , m_alog(alog) + , m_elog(elog) + , m_remote_endpoint("iostream transport") + { + m_alog.write(log::alevel::devel,"iostream con transport constructor"); + } + + /// Get a shared pointer to this component + ptr get_shared() { + return type::shared_from_this(); + } + + /// Register a std::ostream with the transport for writing output + /** + * Register a std::ostream with the transport. All future writes will be + * done to this output stream. + * + * @param o A pointer to the ostream to use for output. + */ + void register_ostream(std::ostream * o) { + // TODO: lock transport state? + scoped_lock_type lock(m_read_mutex); + m_output_stream = o; + } + + /// Set uri hook + /** + * Called by the endpoint as a connection is being established to provide + * the uri being connected to to the transport layer. + * + * This transport policy doesn't use the uri so it is ignored. + * + * @since 0.6.0 + * + * @param u The uri to set + */ + void set_uri(uri_ptr) {} + + /// Overloaded stream input operator + /** + * Attempts to read input from the given stream into the transport. Bytes + * will be extracted from the input stream to fulfill any pending reads. + * Input in this manner will only read until the current read buffer has + * been filled. Then it will signal the library to process the input. If the + * library's input handler adds a new async_read, additional bytes will be + * read, otherwise the input operation will end. + * + * When this function returns one of the following conditions is true: + * - There is no outstanding read operation + * - There are no more bytes available in the input stream + * + * You can use tellg() on the input stream to determine if all of the input + * bytes were read or not. + * + * If there is no pending read operation when the input method is called, it + * will return immediately and tellg() will not have changed. + */ + friend std::istream & operator>> (std::istream & in, type & t) { + // this serializes calls to external read. + scoped_lock_type lock(t.m_read_mutex); + + t.read(in); + + return in; + } + + /// Manual input supply (read some) + /** + * Copies bytes from buf into WebSocket++'s input buffers. Bytes will be + * copied from the supplied buffer to fulfill any pending library reads. It + * will return the number of bytes successfully processed. If there are no + * pending reads read_some will return immediately. Not all of the bytes may + * be able to be read in one call. + * + * @since 0.3.0-alpha4 + * + * @param buf Char buffer to read into the websocket + * @param len Length of buf + * @return The number of characters from buf actually read. + */ + size_t read_some(char const * buf, size_t len) { + // this serializes calls to external read. + scoped_lock_type lock(m_read_mutex); + + return this->read_some_impl(buf,len); + } + + /// Manual input supply (read all) + /** + * Similar to read_some, but continues to read until all bytes in the + * supplied buffer have been read or the connection runs out of read + * requests. + * + * This method still may not read all of the bytes in the input buffer. if + * it doesn't it indicates that the connection was most likely closed or + * is in an error state where it is no longer accepting new input. + * + * @since 0.3.0 + * + * @param buf Char buffer to read into the websocket + * @param len Length of buf + * @return The number of characters from buf actually read. + */ + size_t read_all(char const * buf, size_t len) { + // this serializes calls to external read. + scoped_lock_type lock(m_read_mutex); + + size_t total_read = 0; + size_t temp_read = 0; + + do { + temp_read = this->read_some_impl(buf+total_read,len-total_read); + total_read += temp_read; + } while (temp_read != 0 && total_read < len); + + return total_read; + } + + /// Manual input supply (DEPRECATED) + /** + * @deprecated DEPRECATED in favor of read_some() + * @see read_some() + */ + size_t readsome(char const * buf, size_t len) { + return this->read_some(buf,len); + } + + /// Signal EOF + /** + * Signals to the transport that data stream being read has reached EOF and + * that no more bytes may be read or written to/from the transport. + * + * @since 0.3.0-alpha4 + */ + void eof() { + // this serializes calls to external read. + scoped_lock_type lock(m_read_mutex); + + if (m_reading) { + complete_read(make_error_code(transport::error::eof)); + } + } + + /// Signal transport error + /** + * Signals to the transport that a fatal data stream error has occurred and + * that no more bytes may be read or written to/from the transport. + * + * @since 0.3.0-alpha4 + */ + void fatal_error() { + // this serializes calls to external read. + scoped_lock_type lock(m_read_mutex); + + if (m_reading) { + complete_read(make_error_code(transport::error::pass_through)); + } + } + + /// Set whether or not this connection is secure + /** + * The iostream transport does not provide any security features. As such + * it defaults to returning false when `is_secure` is called. However, the + * iostream transport may be used to wrap an external socket API that may + * provide secure transport. This method allows that external API to flag + * whether or not this connection is secure so that users of the WebSocket++ + * API will get more accurate information. + * + * @since 0.3.0-alpha4 + * + * @param value Whether or not this connection is secure. + */ + void set_secure(bool value) { + m_is_secure = value; + } + + /// Tests whether or not the underlying transport is secure + /** + * iostream transport will return false always because it has no information + * about the ultimate remote endpoint. This may or may not be accurate + * depending on the real source of bytes being input. The `set_secure` + * method may be used to flag connections that are secured by an external + * API + * + * @return Whether or not the underlying transport is secure + */ + bool is_secure() const { + return m_is_secure; + } + + /// Set human readable remote endpoint address + /** + * Sets the remote endpoint address returned by `get_remote_endpoint`. This + * value should be a human readable string that describes the remote + * endpoint. Typically an IP address or hostname, perhaps with a port. But + * may be something else depending on the nature of the underlying + * transport. + * + * If none is set the default is "iostream transport". + * + * @since 0.3.0-alpha4 + * + * @param value The remote endpoint address to set. + */ + void set_remote_endpoint(std::string value) { + m_remote_endpoint = value; + } + + /// Get human readable remote endpoint address + /** + * The iostream transport has no information about the ultimate remote + * endpoint. It will return the string "iostream transport". The + * `set_remote_endpoint` method may be used by external network code to set + * a more accurate value. + * + * This value is used in access and error logs and is available to the end + * application for including in user facing interfaces and messages. + * + * @return A string identifying the address of the remote endpoint + */ + std::string get_remote_endpoint() const { + return m_remote_endpoint; + } + + /// Get the connection handle + /** + * @return The handle for this connection. + */ + connection_hdl get_handle() const { + return m_connection_hdl; + } + + /// Call back a function after a period of time. + /** + * Timers are not implemented in this transport. The timer pointer will + * always be empty. The handler will never be called. + * + * @param duration Length of time to wait in milliseconds + * @param callback The function to call back when the timer has expired + * @return A handle that can be used to cancel the timer if it is no longer + * needed. + */ + timer_ptr set_timer(long, timer_handler) { + return timer_ptr(); + } + + /// Sets the write handler + /** + * The write handler is called when the iostream transport receives data + * that needs to be written to the appropriate output location. This handler + * can be used in place of registering an ostream for output. + * + * The signature of the handler is + * `lib::error_code (connection_hdl, char const *, size_t)` The + * code returned will be reported and logged by the core library. + * + * See also, set_vector_write_handler, for an optional write handler that + * allows more efficient handling of multiple writes at once. + * + * @see set_vector_write_handler + * + * @since 0.5.0 + * + * @param h The handler to call when data is to be written. + */ + void set_write_handler(write_handler h) { + m_write_handler = h; + } + + /// Sets the vectored write handler + /** + * The vectored write handler is called when the iostream transport receives + * multiple chunks of data that need to be written to the appropriate output + * location. This handler can be used in conjunction with the write_handler + * in place of registering an ostream for output. + * + * The sequence of buffers represents bytes that should be written + * consecutively and it is suggested to group the buffers into as few next + * layer packets as possible. Vector write is used to allow implementations + * that support it to coalesce writes into a single TCP packet or TLS + * segment for improved efficiency. + * + * This is an optional handler. If it is not defined then multiple calls + * will be made to the standard write handler. + * + * The signature of the handler is + * `lib::error_code (connection_hdl, std::vector<websocketpp::transport::buffer> + * const & bufs)`. The code returned will be reported and logged by the core + * library. The `websocketpp::transport::buffer` type is a struct with two + * data members. buf (char const *) and len (size_t). + * + * @since 0.6.0 + * + * @param h The handler to call when vectored data is to be written. + */ + void set_vector_write_handler(vector_write_handler h) { + m_vector_write_handler = h; + } + + /// Sets the shutdown handler + /** + * The shutdown handler is called when the iostream transport receives a + * notification from the core library that it is finished with all read and + * write operations and that the underlying transport can be cleaned up. + * + * If you are using iostream transport with another socket library, this is + * a good time to close/shutdown the socket for this connection. + * + * The signature of the handler is `lib::error_code (connection_hdl)`. The + * code returned will be reported and logged by the core library. + * + * @since 0.5.0 + * + * @param h The handler to call on connection shutdown. + */ + void set_shutdown_handler(shutdown_handler h) { + m_shutdown_handler = h; + } +protected: + /// Initialize the connection transport + /** + * Initialize the connection's transport component. + * + * @param handler The `init_handler` to call when initialization is done + */ + void init(init_handler handler) { + m_alog.write(log::alevel::devel,"iostream connection init"); + handler(lib::error_code()); + } + + /// Initiate an async_read for at least num_bytes bytes into buf + /** + * Initiates an async_read request for at least num_bytes bytes. The input + * will be read into buf. A maximum of len bytes will be input. When the + * operation is complete, handler will be called with the status and number + * of bytes read. + * + * This method may or may not call handler from within the initial call. The + * application should be prepared to accept either. + * + * The application should never call this method a second time before it has + * been called back for the first read. If this is done, the second read + * will be called back immediately with a double_read error. + * + * If num_bytes or len are zero handler will be called back immediately + * indicating success. + * + * @param num_bytes Don't call handler until at least this many bytes have + * been read. + * @param buf The buffer to read bytes into + * @param len The size of buf. At maximum, this many bytes will be read. + * @param handler The callback to invoke when the operation is complete or + * ends in an error + */ + void async_read_at_least(size_t num_bytes, char *buf, size_t len, + read_handler handler) + { + std::stringstream s; + s << "iostream_con async_read_at_least: " << num_bytes; + m_alog.write(log::alevel::devel,s.str()); + + if (num_bytes > len) { + handler(make_error_code(error::invalid_num_bytes),size_t(0)); + return; + } + + if (m_reading == true) { + handler(make_error_code(error::double_read),size_t(0)); + return; + } + + if (num_bytes == 0 || len == 0) { + handler(lib::error_code(),size_t(0)); + return; + } + + m_buf = buf; + m_len = len; + m_bytes_needed = num_bytes; + m_read_handler = handler; + m_cursor = 0; + m_reading = true; + } + + /// Asyncronous Transport Write + /** + * Write len bytes in buf to the output method. Call handler to report + * success or failure. handler may or may not be called during async_write, + * but it must be safe for this to happen. + * + * Will return 0 on success. Other possible errors (not exhaustive) + * output_stream_required: No output stream was registered to write to + * bad_stream: a ostream pass through error + * + * This method will attempt to write to the registered ostream first. If an + * ostream is not registered it will use the write handler. If neither are + * registered then an error is passed up to the connection. + * + * @param buf buffer to read bytes from + * @param len number of bytes to write + * @param handler Callback to invoke with operation status. + */ + void async_write(char const * buf, size_t len, transport::write_handler + handler) + { + m_alog.write(log::alevel::devel,"iostream_con async_write"); + // TODO: lock transport state? + + lib::error_code ec; + + if (m_output_stream) { + m_output_stream->write(buf,len); + + if (m_output_stream->bad()) { + ec = make_error_code(error::bad_stream); + } + } else if (m_write_handler) { + ec = m_write_handler(m_connection_hdl, buf, len); + } else { + ec = make_error_code(error::output_stream_required); + } + + handler(ec); + } + + /// Asyncronous Transport Write (scatter-gather) + /** + * Write a sequence of buffers to the output method. Call handler to report + * success or failure. handler may or may not be called during async_write, + * but it must be safe for this to happen. + * + * Will return 0 on success. Other possible errors (not exhaustive) + * output_stream_required: No output stream was registered to write to + * bad_stream: a ostream pass through error + * + * This method will attempt to write to the registered ostream first. If an + * ostream is not registered it will use the write handler. If neither are + * registered then an error is passed up to the connection. + * + * @param bufs vector of buffers to write + * @param handler Callback to invoke with operation status. + */ + void async_write(std::vector<buffer> const & bufs, transport::write_handler + handler) + { + m_alog.write(log::alevel::devel,"iostream_con async_write buffer list"); + // TODO: lock transport state? + + lib::error_code ec; + + if (m_output_stream) { + std::vector<buffer>::const_iterator it; + for (it = bufs.begin(); it != bufs.end(); it++) { + m_output_stream->write((*it).buf,(*it).len); + + if (m_output_stream->bad()) { + ec = make_error_code(error::bad_stream); + break; + } + } + } else if (m_vector_write_handler) { + ec = m_vector_write_handler(m_connection_hdl, bufs); + } else if (m_write_handler) { + std::vector<buffer>::const_iterator it; + for (it = bufs.begin(); it != bufs.end(); it++) { + ec = m_write_handler(m_connection_hdl, (*it).buf, (*it).len); + if (ec) {break;} + } + + } else { + ec = make_error_code(error::output_stream_required); + } + + handler(ec); + } + + /// Set Connection Handle + /** + * @param hdl The new handle + */ + void set_handle(connection_hdl hdl) { + m_connection_hdl = hdl; + } + + /// Call given handler back within the transport's event system (if present) + /** + * Invoke a callback within the transport's event system if it has one. If + * it doesn't, the handler will be invoked immediately before this function + * returns. + * + * @param handler The callback to invoke + * + * @return Whether or not the transport was able to register the handler for + * callback. + */ + lib::error_code dispatch(dispatch_handler handler) { + handler(); + return lib::error_code(); + } + + /// Perform cleanup on socket shutdown_handler + /** + * If a shutdown handler is set, call it and pass through its return error + * code. Otherwise assume there is nothing to do and pass through a success + * code. + * + * @param handler The `shutdown_handler` to call back when complete + */ + void async_shutdown(transport::shutdown_handler handler) { + lib::error_code ec; + + if (m_shutdown_handler) { + ec = m_shutdown_handler(m_connection_hdl); + } + + handler(ec); + } +private: + void read(std::istream &in) { + m_alog.write(log::alevel::devel,"iostream_con read"); + + while (in.good()) { + if (!m_reading) { + m_elog.write(log::elevel::devel,"write while not reading"); + break; + } + + in.read(m_buf+m_cursor,static_cast<std::streamsize>(m_len-m_cursor)); + + if (in.gcount() == 0) { + m_elog.write(log::elevel::devel,"read zero bytes"); + break; + } + + m_cursor += static_cast<size_t>(in.gcount()); + + // TODO: error handling + if (in.bad()) { + m_reading = false; + complete_read(make_error_code(error::bad_stream)); + } + + if (m_cursor >= m_bytes_needed) { + m_reading = false; + complete_read(lib::error_code()); + } + } + } + + size_t read_some_impl(char const * buf, size_t len) { + m_alog.write(log::alevel::devel,"iostream_con read_some"); + + if (!m_reading) { + m_elog.write(log::elevel::devel,"write while not reading"); + return 0; + } + + size_t bytes_to_copy = (std::min)(len,m_len-m_cursor); + + std::copy(buf,buf+bytes_to_copy,m_buf+m_cursor); + + m_cursor += bytes_to_copy; + + if (m_cursor >= m_bytes_needed) { + complete_read(lib::error_code()); + } + + return bytes_to_copy; + } + + /// Signal that a requested read is complete + /** + * Sets the reading flag to false and returns the handler that should be + * called back with the result of the read. The cursor position that is sent + * is whatever the value of m_cursor is. + * + * It MUST NOT be called when m_reading is false. + * it MUST be called while holding the read lock + * + * It is important to use this method rather than directly setting/calling + * m_read_handler back because this function makes sure to delete the + * locally stored handler which contains shared pointers that will otherwise + * cause circular reference based memory leaks. + * + * @param ec The error code to forward to the read handler + */ + void complete_read(lib::error_code const & ec) { + m_reading = false; + + read_handler handler = m_read_handler; + m_read_handler = read_handler(); + + handler(ec,m_cursor); + } + + // Read space (Protected by m_read_mutex) + char * m_buf; + size_t m_len; + size_t m_bytes_needed; + read_handler m_read_handler; + size_t m_cursor; + + // transport resources + std::ostream * m_output_stream; + connection_hdl m_connection_hdl; + write_handler m_write_handler; + vector_write_handler m_vector_write_handler; + shutdown_handler m_shutdown_handler; + + bool m_reading; + bool const m_is_server; + bool m_is_secure; + alog_type & m_alog; + elog_type & m_elog; + std::string m_remote_endpoint; + + // This lock ensures that only one thread can edit read data for this + // connection. This is a very coarse lock that is basically locked all the + // time. The nature of the connection is such that it cannot be + // parallelized, the locking is here to prevent intra-connection concurrency + // in order to allow inter-connection concurrency. + mutex_type m_read_mutex; +}; + + +} // namespace iostream +} // namespace transport +} // namespace websocketpp + +#endif // WEBSOCKETPP_TRANSPORT_IOSTREAM_CON_HPP |