Sample 9. channel using regex name matching

This sample modifies chat_direct sample to show how we can pass messages and events among distributed processes based on regex name matching.

Lets walk thru the code.

All name space related types are defined in chat_defs.hpp.

First we set regex_id to be the id_type. With regex_id, applications can use strings and regex patterns (Boost.Regex) as message ids and names (also we need to include <boost/regex.hpp>).
Next we instantiate the channel type. A associative name space is implemented as a linear namespace with associative lookup. The lookup method is defined as the last template argument of linear_name_space class template. The default value "true" means "exact matching"; for "associative lookup" we set it to false.

typedef regex_id id_type;
typedef channel<
id_type,
boost_platform,
mt_synch<boost_platform>,
abstract_executor, //force in place execution
linear_name_space<id_type, abstract_executor, mt_synch<boost_platform>, false> ///false - assoc matching
> chat_chan;

Next we define ids/names we are going to use in this channel application. We define 2 sets of ids: plain text strings and regex patterns:

id_type basketball = "[sports]: basketball";
id_type tennis = "[sports]: tennis";
id_type baseball = "[sports]: baseball";
id_type all_balls(new boost::regex(".*ball.*"));

id_type tax = "[financial]: tax";
id_type stock = "[financial]: stock";
id_type investment = "[financial]: investment";
id_type all_financial(new boost::regex(".*financial.*"));

Next we define a simple structure for message data:

struct chat_msg {
string source_;
string data_;
chat_msg(char *s, char *d) : source_(s), data_(d) {}
chat_msg() {} //have to define this for marshaling to work
//serialization function for chat_msg
template <typename Archive>
void serialize(Archive & ar, const unsigned int version)
{
ar &source_ & data_;
}
};

The code in the peer process (chat1.cpp, chat2.cpp) are similar to other samples. We bind to names to send messages to distributed processes, except that we are using regex matching for name-matching. So if application subscribe to "all_balls", it will receive messages for both "basketball", "baseball" and any other balls.

Complete source code listing:
chat_defs.hpp
chat1.cpp
chat2.cpp