zproxy_v2(3)
============

NAME
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zproxy_v2 - run a steerable proxy in the background (deprecated)

SYNOPSIS
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//  Constructor
//  Create a new zproxy object. You must create the frontend and backend
//  sockets, configure them, and connect or bind them, before you pass them
//  to the constructor. Do NOT use the sockets again, after passing them to
//  this method.
CZMQ_EXPORT zproxy_t *
    zproxy_new (zctx_t *ctx, void *frontend, void *backend);

//  Destructor
//  Destroy a zproxy object; note this first stops the proxy.
CZMQ_EXPORT void
    zproxy_destroy (zproxy_t **self_p);

//  Copy all proxied messages to specified endpoint; if this is NULL, any
//  in-progress capturing will be stopped. You must already have bound the
//  endpoint to a PULL socket.
CZMQ_EXPORT void
    zproxy_capture (zproxy_t *self, const char *endpoint);

//  Pauses a zproxy object; a paused proxy will cease processing messages,
//  causing them to be queued up and potentially hit the high-water mark on
//  the frontend socket, causing messages to be dropped, or writing
//  applications to block.
CZMQ_EXPORT void
    zproxy_pause (zproxy_t *self);

//  Resume a zproxy object
CZMQ_EXPORT void
    zproxy_resume (zproxy_t *self);

// Self test of this class
CZMQ_EXPORT void
    zproxy_v2_test (bool verbose);
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DESCRIPTION
-----------

The zproxy class provides an equivalent to the ZMQ steerable proxy, on
all versions of ZeroMQ.

This class is deprecated in CZMQ v3; it works together with zctx, zsocket,
and other deprecated V2 classes. New applications should use the V3 zproxy
interface, based on zactor, together with the zsock class for sockets.

EXAMPLE
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.From zproxy_v2_test method
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zctx_t *ctx = zctx_new ();
assert (ctx);
void *frontend = zsocket_new (ctx, ZMQ_PULL);
assert (frontend);
int rc = zsocket_bind (frontend, "inproc://frontend");
assert (rc == 0);
void *backend = zsocket_new (ctx, ZMQ_PUSH);
assert (backend);
rc = zsocket_bind (backend, "inproc://backend");
assert (rc == 0);
zproxy_t *proxy = zproxy_new (ctx, frontend, backend);
assert (proxy);

//  Connect application sockets to proxy
void *faucet = zsocket_new (ctx, ZMQ_PUSH);
assert (faucet);
rc = zsocket_connect (faucet, "inproc://frontend");
assert (rc == 0);
void *sink = zsocket_new (ctx, ZMQ_PULL);
assert (sink);
rc = zsocket_connect (sink, "inproc://backend");
assert (rc == 0);

//  Send some messages and check they arrived
zstr_send (faucet, "Hello");
char *string = zstr_recv (sink);
assert (streq (string, "Hello"));
zstr_free (&string);

//  Check pause/resume functionality
zproxy_pause (proxy);
zstr_send (faucet, "World");

zproxy_resume (proxy);
string = zstr_recv (sink);
assert (streq (string, "World"));
zstr_free (&string);

//  Create capture socket, must be a PULL socket
void *capture = zsocket_new (ctx, ZMQ_PULL);
assert (capture);
rc = zsocket_bind (capture, "inproc://capture");
assert (rc == 0);

//  Switch on capturing, check that it works
zproxy_capture (proxy, "inproc://capture");
zstr_send (faucet, "Hello");

string = zstr_recv (sink);
assert (streq (string, "Hello"));
zstr_free (&string);

string = zstr_recv (capture);
assert (streq (string, "Hello"));
zstr_free (&string);
zproxy_destroy (&proxy);
zctx_destroy (&ctx);

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