C++ zmq_assert函数代码示例

zmq::server_t::~server_t ()
{    
    zmq_assert (outpipes.empty ());
}

bool zmq::trie_t::rm (unsigned char *prefix_, size_t size_)
{
    //  TODO: Shouldn't an error be reported if the key does not exist?
    if (!size_) {
        if (!refcnt)
            return false;
        refcnt--;
        return refcnt == 0;
    }
    unsigned char c = *prefix_;
    if (!count || c < min || c >= min + count)
        return false;

    trie_t *next_node =
        count == 1 ? next.node : next.table [c - min];

    if (!next_node)
        return false;

    bool ret = next_node->rm (prefix_ + 1, size_ - 1);

    //  Prune redundant nodes
    if (next_node->is_redundant ()) {
        delete next_node;
        zmq_assert (count > 0);

        if (count == 1) {
            //  The just pruned node is was the only live node
            next.node = 0;
            count = 0;
            --live_nodes;
            zmq_assert (live_nodes == 0);
        }
        else {
            next.table [c - min] = 0;
            zmq_assert (live_nodes > 1);
            --live_nodes;

            //  Compact the table if possible
            if (live_nodes == 1) {
                //  We can switch to using the more compact single-node
                //  representation since the table only contains one live node
                trie_t *node = 0;
                //  Since we always compact the table the pruned node must
                //  either be the left-most or right-most ptr in the node
                //  table
                if (c == min) {
                    //  The pruned node is the left-most node ptr in the
                    //  node table => keep the right-most node
                    node = next.table [count - 1];
                    min += count - 1;
                }
                else
                if (c == min + count - 1) {
                    //  The pruned node is the right-most node ptr in the
                    //  node table => keep the left-most node
                    node = next.table [0];
                }
                zmq_assert (node);
                free (next.table);
                next.node = node;
                count = 1;
            }
            else
            if (c == min) {
                //  We can compact the table "from the left".
                //  Find the left-most non-null node ptr, which we'll use as
                //  our new min
                unsigned char new_min = min;
                for (unsigned short i = 1; i < count; ++i) {
                    if (next.table [i]) {
                        new_min = i + min;
                        break;
                    }
                }
                zmq_assert (new_min != min);

                trie_t **old_table = next.table;
                zmq_assert (new_min > min);
                zmq_assert (count > new_min - min);

                count = count - (new_min - min);
                next.table = (trie_t**) malloc (sizeof (trie_t*) * count);
                alloc_assert (next.table);

                memmove (next.table, old_table + (new_min - min),
                        sizeof (trie_t*) * count);
                free (old_table);

                min = new_min;
            }
            else
            if (c == min + count - 1) {
                //  We can compact the table "from the right".
                //  Find the right-most non-null node ptr, which we'll use to
                //  determine the new table size
                unsigned short new_count = count;
                for (unsigned short i = 1; i < count; ++i) {
                    if (next.table [count - 1 - i]) {
                        new_count = count - i;
//.........这里部分代码省略.........

int zmq::resolve_ip_interface (sockaddr_storage* addr_, socklen_t *addr_len_,
    char const *interface_)
{
    //  Find the ':' at end that separates NIC name from service.
    const char *delimiter = strrchr (interface_, ':');
    if (!delimiter) {
        errno = EINVAL;
        return -1;
    }

    //  Separate the name/port.
    std::string iface (interface_, delimiter - interface_);
    std::string service (delimiter + 1);

    //  Initialize the output parameter.
    memset (addr_, 0, sizeof (*addr_));

    //  Initialise IPv4-format family/port.
    sockaddr_in ip4_addr;
    memset (&ip4_addr, 0, sizeof (ip4_addr));
    ip4_addr.sin_family = AF_INET;
    ip4_addr.sin_port = htons ((uint16_t) atoi (service.c_str()));

    //  Initialize temporary output pointers with ip4_addr
    sockaddr *out_addr = (sockaddr *) &ip4_addr;
    size_t out_addrlen = sizeof (ip4_addr);

    //  0 is not a valid port.
    if (!ip4_addr.sin_port) {
        errno = EINVAL;
        return -1;
    }

    //  * resolves to INADDR_ANY.
    if (iface.compare("*") == 0) {
        ip4_addr.sin_addr.s_addr = htonl (INADDR_ANY);
        zmq_assert (out_addrlen <= sizeof (*addr_));
        memcpy (addr_, out_addr, out_addrlen);
        *addr_len_ = out_addrlen;
        return 0;
    }

    //  Try to resolve the string as a NIC name.
    int rc = resolve_nic_name (&ip4_addr.sin_addr, iface.c_str());
    if (rc != 0 && errno != ENODEV)
        return rc;
    if (rc == 0) {
        zmq_assert (out_addrlen <= sizeof (*addr_));
        memcpy (addr_, out_addr, out_addrlen);
        *addr_len_ = out_addrlen;
        return 0;
    }

    //  There's no such interface name. Assume literal address.
#if defined ZMQ_HAVE_OPENVMS && defined __ia64
    __addrinfo64 *res = NULL;
    __addrinfo64 req;
#else
    addrinfo *res = NULL;
    addrinfo req;
#endif
    memset (&req, 0, sizeof (req));

    //  We only support IPv4 addresses for now.
    req.ai_family = AF_INET;

    //  Arbitrary, not used in the output, but avoids duplicate results.
    req.ai_socktype = SOCK_STREAM;

    //  Restrict hostname/service to literals to avoid any DNS lookups or
    //  service-name irregularity due to indeterminate socktype.
    req.ai_flags = AI_PASSIVE | AI_NUMERICHOST | AI_NUMERICSERV;

    //  Resolve the literal address. Some of the error info is lost in case
    //  of error, however, there's no way to report EAI errors via errno.
    rc = getaddrinfo (iface.c_str(), service.c_str(), &req, &res);
    if (rc) {
        errno = ENODEV;
        return -1;
    }

    //  Use the first result.
    zmq_assert ((size_t) (res->ai_addrlen) <= sizeof (*addr_));
    memcpy (addr_, res->ai_addr, res->ai_addrlen);
    *addr_len_ = res->ai_addrlen;

    //  Cleanup getaddrinfo after copying the possibly referenced result.
    if (res)
        freeaddrinfo (res);

    return 0;
}

void zmq::socket_base_t::xhiccuped (pipe_t *pipe_)
{
    zmq_assert (false);
}

int zmq::router_t::xsend (msg_t *msg_, int flags_)
{
    //  If this is the first part of the message it's the ID of the
    //  peer to send the message to.
    if (!more_out) {
        zmq_assert (!current_out);

        int retval = 0;

        //  If we have malformed message (prefix with no subsequent message)
        //  then just silently ignore it.
        //  TODO: The connections should be killed instead.
        if (msg_->flags () & msg_t::more) {

            more_out = true;

            //  Find the pipe associated with the identity stored in the prefix.
            //  If there's no such pipe just silently ignore the message, unless
            //  fail_unreachable is set.
            blob_t identity ((unsigned char*) msg_->data (), msg_->size ());
            outpipes_t::iterator it = outpipes.find (identity);

            if (it != outpipes.end ()) {
                current_out = it->second.pipe;
                if (!current_out->check_write ()) {
                    it->second.active = false;
                    more_out = false;
                    current_out = NULL;
                }
            } else if(fail_unroutable) {
                more_out = false;
                errno = EHOSTUNREACH;
                retval = -1;
            }
        }

        int rc = msg_->close ();
        errno_assert (rc == 0);
        rc = msg_->init ();
        errno_assert (rc == 0);
        return retval;
    }

    //  Check whether this is the last part of the message.
    more_out = msg_->flags () & msg_t::more ? true : false;

    //  Push the message into the pipe. If there's no out pipe, just drop it.
    if (current_out) {
        bool ok = current_out->write (msg_);
        if (unlikely (!ok))
            current_out = NULL;
        else if (!more_out) {
            current_out->flush ();
            current_out = NULL;
        }
    }
    else {
        int rc = msg_->close ();
        errno_assert (rc == 0);
    }

    //  Detach the message from the data buffer.
    int rc = msg_->init ();
    errno_assert (rc == 0);

    return 0;
}

int zmq::curve_server_t::decode (msg_t *msg_)
{
    zmq_assert (state == connected);

    if (msg_->size () < 33) {
        //  Temporary support for security debugging
        puts ("CURVE I: invalid CURVE client, sent malformed command");
        errno = EPROTO;
        return -1;
    }

    const uint8_t *message = static_cast <uint8_t *> (msg_->data ());
    if (memcmp (message, "\x07MESSAGE", 8)) {
        //  Temporary support for security debugging
        puts ("CURVE I: invalid CURVE client, did not send MESSAGE");
        errno = EPROTO;
        return -1;
    }

    uint8_t message_nonce [crypto_box_NONCEBYTES];
    memcpy (message_nonce, "CurveZMQMESSAGEC", 16);
    memcpy (message_nonce + 16, message + 8, 8);
    uint64_t nonce = get_uint64(message + 8);
    if (nonce <= cn_peer_nonce) {
        errno = EPROTO;
        return -1;
    }
    cn_peer_nonce = nonce;

    const size_t clen = crypto_box_BOXZEROBYTES + msg_->size () - 16;

    uint8_t *message_plaintext = static_cast <uint8_t *> (malloc (clen));
    alloc_assert (message_plaintext);

    uint8_t *message_box = static_cast <uint8_t *> (malloc (clen));
    alloc_assert (message_box);

    memset (message_box, 0, crypto_box_BOXZEROBYTES);
    memcpy (message_box + crypto_box_BOXZEROBYTES,
            message + 16, msg_->size () - 16);

    int rc = crypto_box_open_afternm (message_plaintext, message_box,
                                      clen, message_nonce, cn_precom);
    if (rc == 0) {
        rc = msg_->close ();
        zmq_assert (rc == 0);

        rc = msg_->init_size (clen - 1 - crypto_box_ZEROBYTES);
        zmq_assert (rc == 0);

        const uint8_t flags = message_plaintext [crypto_box_ZEROBYTES];
        if (flags & 0x01)
            msg_->set_flags (msg_t::more);
        if (flags & 0x02)
            msg_->set_flags (msg_t::command);

        memcpy (msg_->data (),
                message_plaintext + crypto_box_ZEROBYTES + 1,
                msg_->size ());
    }
    else {
        //  Temporary support for security debugging
        puts ("CURVE I: connection key used for MESSAGE is wrong");
        errno = EPROTO;
    }
    free (message_plaintext);
    free (message_box);

    return rc;
}

//.........这里部分代码省略.........
        puts ("CURVE I: cannot open client INITIATE cookie");
        errno = EPROTO;
        return -1;
    }

    //  Check cookie plain text is as expected [C' + s']
    if (memcmp (cookie_plaintext + crypto_secretbox_ZEROBYTES, cn_client, 32)
    ||  memcmp (cookie_plaintext + crypto_secretbox_ZEROBYTES + 32, cn_secret, 32)) {
        //  Temporary support for security debugging
        puts ("CURVE I: client INITIATE cookie is not valid");
        errno = EPROTO;
        return -1;
    }

    const size_t clen = (msg_->size () - 113) + crypto_box_BOXZEROBYTES;

    uint8_t initiate_nonce [crypto_box_NONCEBYTES];
    uint8_t initiate_plaintext [crypto_box_ZEROBYTES + 128 + 256];
    uint8_t initiate_box [crypto_box_BOXZEROBYTES + 144 + 256];

    //  Open Box [C + vouch + metadata](C'->S')
    memset (initiate_box, 0, crypto_box_BOXZEROBYTES);
    memcpy (initiate_box + crypto_box_BOXZEROBYTES,
            initiate + 113, clen - crypto_box_BOXZEROBYTES);

    memcpy (initiate_nonce, "CurveZMQINITIATE", 16);
    memcpy (initiate_nonce + 16, initiate + 105, 8);
    cn_peer_nonce = get_uint64(initiate + 105);

    rc = crypto_box_open (initiate_plaintext, initiate_box,
                          clen, initiate_nonce, cn_client, cn_secret);
    if (rc != 0) {
        //  Temporary support for security debugging
        puts ("CURVE I: cannot open client INITIATE");
        errno = EPROTO;
        return -1;
    }

    const uint8_t *client_key = initiate_plaintext + crypto_box_ZEROBYTES;

    uint8_t vouch_nonce [crypto_box_NONCEBYTES];
    uint8_t vouch_plaintext [crypto_box_ZEROBYTES + 64];
    uint8_t vouch_box [crypto_box_BOXZEROBYTES + 80];

    //  Open Box Box [C',S](C->S') and check contents
    memset (vouch_box, 0, crypto_box_BOXZEROBYTES);
    memcpy (vouch_box + crypto_box_BOXZEROBYTES,
            initiate_plaintext + crypto_box_ZEROBYTES + 48, 80);

    memcpy (vouch_nonce, "VOUCH---", 8);
    memcpy (vouch_nonce + 8,
            initiate_plaintext + crypto_box_ZEROBYTES + 32, 16);

    rc = crypto_box_open (vouch_plaintext, vouch_box,
                          sizeof vouch_box,
                          vouch_nonce, client_key, cn_secret);
    if (rc != 0) {
        //  Temporary support for security debugging
        puts ("CURVE I: cannot open client INITIATE vouch");
        errno = EPROTO;
        return -1;
    }

    //  What we decrypted must be the client's short-term public key
    if (memcmp (vouch_plaintext + crypto_box_ZEROBYTES, cn_client, 32)) {
        //  Temporary support for security debugging
        puts ("CURVE I: invalid handshake from client (public key)");
        errno = EPROTO;
        return -1;
    }

    //  Precompute connection secret from client key
    rc = crypto_box_beforenm (cn_precom, cn_client, cn_secret);
    zmq_assert (rc == 0);

	puts("zmq::curve_server_t::process_initiate before zap_connect ");

	//  Use ZAP protocol (RFC 27) to authenticate the user.
    rc = session->zap_connect ();
    if (rc == 0) {
        send_zap_request (client_key);
        rc = receive_and_process_zap_reply ();
        if (rc == 0)
            state = status_code == "200"
                ? send_ready
                : send_error;
        else
        if (errno == EAGAIN)
            state = expect_zap_reply;
        else
            return -1;
    }
    else
        state = send_ready;

	puts("zmq::curve_server_t::process_initiate end");

    return parse_metadata (initiate_plaintext + crypto_box_ZEROBYTES + 128,
                           clen - crypto_box_ZEROBYTES - 128);
}

zmq::socks_connecter_t::~socks_connecter_t ()
{
    zmq_assert (s == retired_fd);
    LIBZMQ_DELETE(proxy_addr);
}

void zmq::devpoll_t::devpoll_ctl (fd_t fd_, short events_)
{
    struct pollfd pfd = {fd_, events_, 0};
    ssize_t rc = write (devpoll_fd, &pfd, sizeof pfd);
    zmq_assert (rc == sizeof pfd);
}

//.........这里部分代码省略.........
        }
        break;
#endif

    case ZMQ_CONFLATE:
        if (is_int) {
            *value = conflate;
            return 0;
        }
        break;

        //  If libgssapi isn't installed, these options provoke EINVAL
#ifdef HAVE_LIBGSSAPI_KRB5
    case ZMQ_GSSAPI_SERVER:
        if (is_int) {
            *value = as_server && mechanism == ZMQ_GSSAPI;
            return 0;
        }
        break;

    case ZMQ_GSSAPI_PRINCIPAL:
        if (*optvallen_ >= gss_principal.size () + 1) {
            memcpy (optval_, gss_principal.c_str (), gss_principal.size () + 1);
            *optvallen_ = gss_principal.size () + 1;
            return 0;
        }
        break;

    case ZMQ_GSSAPI_SERVICE_PRINCIPAL:
        if (*optvallen_ >= gss_service_principal.size () + 1) {
            memcpy (optval_, gss_service_principal.c_str (), gss_service_principal.size () + 1);
            *optvallen_ = gss_service_principal.size () + 1;
            return 0;
        }
        break;

    case ZMQ_GSSAPI_PLAINTEXT:
        if (is_int) {
            *value = gss_plaintext;
            return 0;
        }
        break;
#endif

    case ZMQ_HANDSHAKE_IVL:
        if (is_int) {
            *value = handshake_ivl;
            return 0;
        }
        break;

    case ZMQ_INVERT_MATCHING:
        if (is_int) {
            *value = invert_matching;
            return 0;
        }
        break;

    case ZMQ_HEARTBEAT_IVL:
        if (is_int) {
            *value = heartbeat_interval;
            return 0;
        }
        break;

    case ZMQ_HEARTBEAT_TTL:
        if (is_int) {
            // Convert the internal deciseconds value to milliseconds
            *value = heartbeat_ttl * 100;
            return 0;
        }
        break;

    case ZMQ_HEARTBEAT_TIMEOUT:
        if (is_int) {
            *value = heartbeat_timeout;
            return 0;
        }
        break;

    case ZMQ_USE_FD:
        if (is_int) {
            *value = use_fd;
            return 0;
        }
        break;

    default:
#if defined (ZMQ_ACT_MILITANT)
        malformed = false;
#endif
        break;
    }
#if defined (ZMQ_ACT_MILITANT)
    if (malformed)
        zmq_assert (false);
#endif
    errno = EINVAL;
    return -1;
}

int zmq_poll (zmq_pollitem_t *items_, int nitems_, long timeout_)
{
#if defined ZMQ_HAVE_LINUX || defined ZMQ_HAVE_FREEBSD ||\
    defined ZMQ_HAVE_OPENBSD || defined ZMQ_HAVE_SOLARIS ||\
    defined ZMQ_HAVE_OSX || defined ZMQ_HAVE_QNXNTO ||\
    defined ZMQ_HAVE_HPUX || defined ZMQ_HAVE_AIX ||\
    defined ZMQ_HAVE_NETBSD

    pollfd *pollfds = (pollfd*) malloc (nitems_ * sizeof (pollfd));
    zmq_assert (pollfds);
    int npollfds = 0;
    int nsockets = 0;

    zmq::app_thread_t *app_thread = NULL;

    for (int i = 0; i != nitems_; i++) {

        //  0MQ sockets.
        if (items_ [i].socket) {

            //  Get the app_thread the socket is living in. If there are two
            //  sockets in the same pollset with different app threads, fail.
            zmq::socket_base_t *s = (zmq::socket_base_t*) items_ [i].socket;
            if (app_thread) {
                if (app_thread != s->get_thread ()) {
                    free (pollfds);
                    errno = EFAULT;
                    return -1;
                }
            }
            else
                app_thread = s->get_thread ();

            nsockets++;
            continue;
        }

        //  Raw file descriptors.
        pollfds [npollfds].fd = items_ [i].fd;
        pollfds [npollfds].events =
            (items_ [i].events & ZMQ_POLLIN ? POLLIN : 0) |
            (items_ [i].events & ZMQ_POLLOUT ? POLLOUT : 0);
        npollfds++;
    }

    //  If there's at least one 0MQ socket in the pollset we have to poll
    //  for 0MQ commands. If ZMQ_POLL was not set, fail.
    if (nsockets) {
        pollfds [npollfds].fd = app_thread->get_signaler ()->get_fd ();
        if (pollfds [npollfds].fd == zmq::retired_fd) {
            free (pollfds);
            errno = ENOTSUP;
            return -1;
        }
        pollfds [npollfds].events = POLLIN;
        npollfds++;
    }

    //  First iteration just check for events, don't block. Waiting would
    //  prevent exiting on any events that may already been signaled on
    //  0MQ sockets.
    int rc = poll (pollfds, npollfds, 0);
    if (rc == -1 && errno == EINTR && timeout_ >= 0) {
        free (pollfds);
        return 0;
    }
    errno_assert (rc >= 0 || (rc == -1 && errno == EINTR));

    int timeout = timeout_ > 0 ? timeout_ / 1000 : -1;
    int nevents = 0;

    while (true) {

        //  Process 0MQ commands if needed.
        if (nsockets && pollfds [npollfds -1].revents & POLLIN)
            app_thread->process_commands (false, false);

        //  Check for the events.
        int pollfd_pos = 0;
        for (int i = 0; i != nitems_; i++) {

            //  If the poll item is a raw file descriptor, simply convert
            //  the events to zmq_pollitem_t-style format.
            if (!items_ [i].socket) {
                items_ [i].revents = 0;
                if (pollfds [pollfd_pos].revents & POLLIN)
                    items_ [i].revents |= ZMQ_POLLIN;
                if (pollfds [pollfd_pos].revents & POLLOUT)
                    items_ [i].revents |= ZMQ_POLLOUT;
                if (pollfds [pollfd_pos].revents & ~(POLLIN | POLLOUT))
                    items_ [i].revents |= ZMQ_POLLERR;

                if (items_ [i].revents)
                    nevents++;
                pollfd_pos++;
                continue;
            }

            //  The poll item is a 0MQ socket.
            zmq::socket_base_t *s = (zmq::socket_base_t*) items_ [i].socket;
//.........这里部分代码省略.........

void zmq::generic_mtrie_t<T>::rm_helper (value_t *pipe_,
                                         unsigned char **buff_,
                                         size_t buffsize_,
                                         size_t maxbuffsize_,
                                         void (*func_) (prefix_t data_,
                                                        size_t size_,
                                                        Arg arg_),
                                         Arg arg_,
                                         bool call_on_uniq_)
{
    //  Remove the subscription from this node.
    if (pipes && pipes->erase (pipe_)) {
        if (!call_on_uniq_ || pipes->empty ()) {
            func_ (*buff_, buffsize_, arg_);
        }

        if (pipes->empty ()) {
            LIBZMQ_DELETE (pipes);
        }
    }

    //  Adjust the buffer.
    if (buffsize_ >= maxbuffsize_) {
        maxbuffsize_ = buffsize_ + 256;
        *buff_ = (unsigned char *) realloc (*buff_, maxbuffsize_);
        alloc_assert (*buff_);
    }

    //  If there are no subnodes in the trie, return.
    if (count == 0)
        return;

    //  If there's one subnode (optimisation).
    if (count == 1) {
        (*buff_)[buffsize_] = min;
        buffsize_++;
        next.node->rm_helper (pipe_, buff_, buffsize_, maxbuffsize_, func_,
                              arg_, call_on_uniq_);

        //  Prune the node if it was made redundant by the removal
        if (next.node->is_redundant ()) {
            LIBZMQ_DELETE (next.node);
            count = 0;
            --live_nodes;
            zmq_assert (live_nodes == 0);
        }
        return;
    }

    //  If there are multiple subnodes.
    //
    //  New min non-null character in the node table after the removal
    unsigned char new_min = min + count - 1;
    //  New max non-null character in the node table after the removal
    unsigned char new_max = min;
    for (unsigned short c = 0; c != count; c++) {
        (*buff_)[buffsize_] = min + c;
        if (next.table[c]) {
            next.table[c]->rm_helper (pipe_, buff_, buffsize_ + 1, maxbuffsize_,
                                      func_, arg_, call_on_uniq_);

            //  Prune redundant nodes from the mtrie
            if (next.table[c]->is_redundant ()) {
                LIBZMQ_DELETE (next.table[c]);

                zmq_assert (live_nodes > 0);
                --live_nodes;
            } else {
                //  The node is not redundant, so it's a candidate for being
                //  the new min/max node.
                //
                //  We loop through the node array from left to right, so the
                //  first non-null, non-redundant node encountered is the new
                //  minimum index. Conversely, the last non-redundant, non-null
                //  node encountered is the new maximum index.
                if (c + min < new_min)
                    new_min = c + min;
                if (c + min > new_max)
                    new_max = c + min;
            }
        }
    }

    zmq_assert (count > 1);

    //  Free the node table if it's no longer used.
    if (live_nodes == 0) {
        free (next.table);
        next.table = NULL;
        count = 0;
    }
    //  Compact the node table if possible
    else if (live_nodes == 1) {
        //  If there's only one live node in the table we can
        //  switch to using the more compact single-node
        //  representation
        zmq_assert (new_min == new_max);
        zmq_assert (new_min >= min && new_min < min + count);
        generic_mtrie_t *node = next.table[new_min - min];
        zmq_assert (node);
//.........这里部分代码省略.........

int zmq::router_t::xrecv (msg_t *msg_, int flags_)
{
    //  if there is a prefetched identity, return it.
    if (prefetched == 2)
    {
        int rc = msg_->init_size (prefetched_id.size ());
        errno_assert (rc == 0);
        memcpy (msg_->data (), prefetched_id.data (), prefetched_id.size ());
        msg_->set_flags (msg_t::more);
        prefetched = 1;
        return 0;
    }

    //  If there is a prefetched message, return it.
    if (prefetched == 1) {
        int rc = msg_->move (prefetched_msg);
        errno_assert (rc == 0);
        more_in = msg_->flags () & msg_t::more ? true : false;
        prefetched = 0;
        return 0;
    }

    pipe_t *pipe = NULL;
    while (true) {

        //  Get next message part.
        int rc = fq.recvpipe (msg_, flags_, &pipe);
        if (rc != 0)
            return -1;

        //  If identity is received, change the key assigned to the pipe.
        if (likely (!(msg_->flags () & msg_t::identity)))
            break;

        zmq_assert (!more_in);

        //  Empty identity means we can preserve the auto-generated identity
        if (msg_->size ()) {
            blob_t identity ((unsigned char*) msg_->data (), msg_->size ());
            outpipes_t::iterator it = outpipes.find (identity);
            if (it == outpipes.end ()) {
                //  Find the pipe and change its identity
                bool changed = false;
                it = outpipes.begin ();
                while (it != outpipes.end ()) {
                    if (it->second.pipe == pipe) {
                        pipe->set_identity (identity);
                        outpipes.erase (it);
                        outpipe_t outpipe = {pipe, true};
                        if (!outpipes.insert (
                            outpipes_t::value_type (identity, outpipe)).second)
                            zmq_assert (false);
                        changed = true;
                        break;
                    }
                    ++it;
                }
                zmq_assert (changed);
            }
        }
    }

    //  If we are in the middle of reading a message, just return the next part.
    if (more_in) {
        more_in = msg_->flags () & msg_t::more ? true : false;
        return 0;
    }
 
    //  We are at the beginning of a new message. Move the message part we
    //  have to the prefetched and return the ID of the peer instead.
    int rc = prefetched_msg.move (*msg_);
    errno_assert (rc == 0);
    prefetched = 1;
    rc = msg_->close ();
    errno_assert (rc == 0);

    blob_t identity = pipe->get_identity ();
    rc = msg_->init_size (identity.size ());
    errno_assert (rc == 0);
    memcpy (msg_->data (), identity.data (), identity.size ());
    msg_->set_flags (msg_t::more);
    return 0;
}

typename zmq::generic_mtrie_t<T>::rm_result zmq::generic_mtrie_t<T>::rm_helper (
  prefix_t prefix_, size_t size_, value_t *pipe_)
{
    if (!size_) {
        if (!pipes)
            return not_found;

        typename pipes_t::size_type erased = pipes->erase (pipe_);
        if (pipes->empty ()) {
            zmq_assert (erased == 1);
            LIBZMQ_DELETE (pipes);
            return last_value_removed;
        }
        return (erased == 1) ? values_remain : not_found;
    }

    unsigned char c = *prefix_;
    if (!count || c < min || c >= min + count)
        return not_found;

    generic_mtrie_t *next_node = count == 1 ? next.node : next.table[c - min];

    if (!next_node)
        return not_found;

    rm_result ret = next_node->rm_helper (prefix_ + 1, size_ - 1, pipe_);

    if (next_node->is_redundant ()) {
        LIBZMQ_DELETE (next_node);
        zmq_assert (count > 0);

        if (count == 1) {
            next.node = 0;
            count = 0;
            --live_nodes;
            zmq_assert (live_nodes == 0);
        } else {
            next.table[c - min] = 0;
            zmq_assert (live_nodes > 1);
            --live_nodes;

            //  Compact the table if possible
            if (live_nodes == 1) {
                //  If there's only one live node in the table we can
                //  switch to using the more compact single-node
                //  representation
                unsigned short i;
                for (i = 0; i < count; ++i)
                    if (next.table[i])
                        break;

                zmq_assert (i < count);
                min += i;
                count = 1;
                generic_mtrie_t *oldp = next.table[i];
                free (next.table);
                next.node = oldp;
            } else if (c == min) {
                //  We can compact the table "from the left"
                unsigned short i;
                for (i = 1; i < count; ++i)
                    if (next.table[i])
                        break;

                zmq_assert (i < count);
                min += i;
                count -= i;
                generic_mtrie_t **old_table = next.table;
                next.table = (generic_mtrie_t **) malloc (
                  sizeof (generic_mtrie_t *) * count);
                alloc_assert (next.table);
                memmove (next.table, old_table + i,
                         sizeof (generic_mtrie_t *) * count);
                free (old_table);
            } else if (c == min + count - 1) {
                //  We can compact the table "from the right"
                unsigned short i;
                for (i = 1; i < count; ++i)
                    if (next.table[count - 1 - i])
                        break;

                zmq_assert (i < count);
                count -= i;
                generic_mtrie_t **old_table = next.table;
                next.table = (generic_mtrie_t **) malloc (
                  sizeof (generic_mtrie_t *) * count);
                alloc_assert (next.table);
                memmove (next.table, old_table,
                         sizeof (generic_mtrie_t *) * count);
                free (old_table);
            }
        }
    }

    return ret;
}

void zmq::stream_engine_t::plug (io_thread_t *io_thread_,
    session_base_t *session_)
{
    zmq_assert (!plugged);
    plugged = true;

    //  Connect to session object.
    zmq_assert (!session);
    zmq_assert (session_);
    session = session_;
    socket = session-> get_socket ();

    //  Connect to I/O threads poller object.
    io_object_t::plug (io_thread_);
    handle = add_fd (s);
    io_error = false;

    if (options.raw_socket) {
        // no handshaking for raw sock, instantiate raw encoder and decoders
        encoder = new (std::nothrow) raw_encoder_t (options.tcp_send_buffer_size);
        alloc_assert (encoder);

        decoder = new (std::nothrow) raw_decoder_t (options.tcp_recv_buffer_size);
        alloc_assert (decoder);

        // disable handshaking for raw socket
        handshaking = false;

        next_msg = &stream_engine_t::pull_msg_from_session;
        process_msg = &stream_engine_t::push_raw_msg_to_session;

        properties_t properties;
        if (init_properties(properties)) {
            //  Compile metadata.
            zmq_assert (metadata == NULL);
            metadata = new (std::nothrow) metadata_t (properties);
        }

        if (options.raw_notify) {
            //  For raw sockets, send an initial 0-length message to the
            // application so that it knows a peer has connected.
            msg_t connector;
            connector.init();
            push_raw_msg_to_session (&connector);
            connector.close();
            session->flush ();
        }
    }
    else {
        // start optional timer, to prevent handshake hanging on no input
        set_handshake_timer ();

        //  Send the 'length' and 'flags' fields of the identity message.
        //  The 'length' field is encoded in the long format.
        outpos = greeting_send;
        outpos [outsize++] = 0xff;
        put_uint64 (&outpos [outsize], options.identity_size + 1);
        outsize += 8;
        outpos [outsize++] = 0x7f;
    }

    set_pollin (handle);
    set_pollout (handle);
    //  Flush all the data that may have been already received downstream.
    in_event ();
}