These procedures return an unspecified value, unless documented otherwise. Should an invocation
of the Spread API fail, a composite condition of the kinds
(exn spread) will be signalled,
with the additional property
code, containing the spread error code.
Connects to a Spread daemon. SPREAD-NAME should be of the form "<port-number>" or
"<port-number>@<host-name>". PRIVATE-NAME is a string naming the connection (defaults to a randomly
generated name) and should be unique on the machine running the daemon. If GROUP-MEMBERSHIP is given and
not #f, then this connection will receive group-membership messages. PRIORITY is currently not used.
If SPREAD-NAME is not given it defaults to a string containing the default port for spread (usually 4803).
Returns a connection object.
Returns #t if X is a connection object or #f otherwise.
Returns the private group name of this connection as assigned by the Spread daemon.
Terminates the connection. Note that a process may have multiple connections.
Joins the group with the name GROUP (a string). If no group with this name exists, it is created.
Leaves the group with the name GROUP (a string). If the group does not exist, this operation is does nothing.
Sends a message to one or more groups. MESSAGE is a string containing the message to be sent, via CONNECTION and to the group or groups given in GROUP (either a string or a list of strings). The SERVICE-TYPE argument should be one of the symbols
unreliable, reliable, fifo, causal, agreed or
safe and specifies what kind of service is
requested. MESSAGE-TYPE can be an arbitrary message code that Spread will send unchanged to all recipients.
If SELF-DISCARD is given and true, then messages sent by this connection are not sent back to the sender (the same connection).
Waits for a message from the Spread daemon on the given connection. MAX-GROUPS gives the maximal number of groups
to be returned in the message object and defaults to 16. MAX-MESSAGE-LENGTH gives the maximal size of the
buffer receiving the message (defaults to 1024 bytes). DESTINATION is the buffer to store the message in. If no
destination is given a new buffer will be allocated. If the received message is larger than the destination buffer and
MAX-MESSAGE-LENGTH is not given, then the buffer will be automatically resized and the receive-operation will be
repeated. If MAX-MESSAGE-LENGTH is given and the destination is too small, an error will be signalled.
Returns a message object.
FIXME: find explanation for
Returns #t if X is a message object or #f otherwise.
Returns the contents of the message: either a string (if a regular message) or a list of groups (if a regular membership message).
Returns #t if the endianness of the sending machine differs from that of this receiving machine.
Returns the private group name of the sending connection or the group name, if a membership message.
A list of the names of all groups receiving this message.
A list of symbols designating the type of this message. Possible members are:
An arbitrary integer code sent with the message.
Returns #t if the message is a regular (data) message, or #f otherwise.
Returns #t if the message is a regular membership (join/leave) message, or #f otherwise.
Returns #t if the message is a transitional membership message, or #f otherwise. (This is a message that designates a membership-change to be occurring in the future. Unfortunately this is not fully documented in the Spread manuals).
Returns #t if the message is a membership (leave) message of this connection, or #f otherwise.
Returns #t if there is a message ready for receival (i.e. the next
sp:receive will not block), or
Returns three values, the major- and minor version number of the used Spread library and its patch-level.
; sender.scm (require-extension spread posix srfi-1) (define c (sp:connect)) (sp:join c "foobar") (define (print-message x) (print "SENDER: " (sp:message-service-type x) " - " (sp:message-data x)) ) (let loop () (sleep 1) (sp:multicast c 'reliable "foobar" (->string (reverse (iota (random (add1 100)))))) (do () ((not (sp:poll c))) (print-message (sp:receive c)) ) (loop) ) ; receiver.scm (require-extension spread) (define c (sp:connect)) (sp:join c "foobar") (define (print-message x) (print "RECEIVER: " (sp:message-service-type x) " - " (sp:message-data x)) ) (let loop () (let ([msg (sp:receive c)]) (print-message msg) (when (sp:regular-message? msg) (let ([lst (with-input-from-string (sp:message-data msg) read)]) (assert (= (add1 (car lst)) (length lst))) ) ) (loop) ) )
This product uses software developed by Spread Concepts LLC for use in the Spread toolkit.
For more information about Spread see http://www.spread.org
Copyright (c) 2004, Felix L. Winkelmann 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 author 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 THE COPYRIGHT HOLDERS OR CONTRIBUTORS 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.