1ZFRAME(3) CZMQ Manual ZFRAME(3)
2
6 zframe - Class for working with single message frames
7
9 // This is a stable class, and may not change except for emergencies. It
10 // is provided in stable builds.
11 // This class has draft methods, which may change over time. They are not
12 // in stable releases, by default. Use --enable-drafts to enable.
13 #define ZFRAME_MORE 1 //
14 #define ZFRAME_REUSE 2 //
15 #define ZFRAME_DONTWAIT 4 //
16 // Create a new frame. If size is not null, allocates the frame data
18 // to the specified size. If additionally, data is not null, copies
19 // size octets from the specified data into the frame body.
20 CZMQ_EXPORT zframe_t *
21 zframe_new (const void *data, size_t size);
22 // Create an empty (zero-sized) frame
24 CZMQ_EXPORT zframe_t *
25 zframe_new_empty (void);
26 // Create a frame with a specified string content.
28 CZMQ_EXPORT zframe_t *
29 zframe_from (const char *string);
30 // Receive frame from socket, returns zframe_t object or NULL if the recv
32 // was interrupted. Does a blocking recv, if you want to not block then use
33 // zpoller or zloop.
34 CZMQ_EXPORT zframe_t *
35 zframe_recv (void *source);
36 // Destroy a frame
38 CZMQ_EXPORT void
39 zframe_destroy (zframe_t **self_p);
40 // Send a frame to a socket, destroy frame after sending.
42 // Return -1 on error, 0 on success.
43 CZMQ_EXPORT int
44 zframe_send (zframe_t **self_p, void *dest, int flags);
45 // Return number of bytes in frame data
47 CZMQ_EXPORT size_t
48 zframe_size (zframe_t *self);
49 // Return address of frame data
51 CZMQ_EXPORT byte *
52 zframe_data (zframe_t *self);
53 // Return meta data property for frame
55 // The caller shall not modify or free the returned value, which shall be
56 // owned by the message.
57 CZMQ_EXPORT const char *
58 zframe_meta (zframe_t *self, const char *property);
59 // Create a new frame that duplicates an existing frame. If frame is null,
61 // or memory was exhausted, returns null.
62 // Caller owns return value and must destroy it when done.
63 CZMQ_EXPORT zframe_t *
64 zframe_dup (zframe_t *self);
65 // Return frame data encoded as printable hex string, useful for 0MQ UUIDs.
67 // Caller must free string when finished with it.
68 // Caller owns return value and must destroy it when done.
69 CZMQ_EXPORT char *
70 zframe_strhex (zframe_t *self);
71 // Return frame data copied into freshly allocated string
73 // Caller must free string when finished with it.
74 // Caller owns return value and must destroy it when done.
75 CZMQ_EXPORT char *
76 zframe_strdup (zframe_t *self);
77 // Return TRUE if frame body is equal to string, excluding terminator
79 CZMQ_EXPORT bool
80 zframe_streq (zframe_t *self, const char *string);
81 // Return frame MORE indicator (1 or 0), set when reading frame from socket
83 // or by the zframe_set_more() method
84 CZMQ_EXPORT int
85 zframe_more (zframe_t *self);
86 // Set frame MORE indicator (1 or 0). Note this is NOT used when sending
88 // frame to socket, you have to specify flag explicitly.
89 CZMQ_EXPORT void
90 zframe_set_more (zframe_t *self, int more);
91 // Return TRUE if two frames have identical size and data
93 // If either frame is NULL, equality is always false.
94 CZMQ_EXPORT bool
95 zframe_eq (zframe_t *self, zframe_t *other);
96 // Set new contents for frame
98 CZMQ_EXPORT void
99 zframe_reset (zframe_t *self, const void *data, size_t size);
100 // Send message to zsys log sink (may be stdout, or system facility as
102 // configured by zsys_set_logstream). Prefix shows before frame, if not null.
103 // Long messages are truncated.
104 CZMQ_EXPORT void
105 zframe_print (zframe_t *self, const char *prefix);
106 // Probe the supplied object, and report if it looks like a zframe_t.
108 CZMQ_EXPORT bool
109 zframe_is (void *self);
110 // Self test of this class.
112 CZMQ_EXPORT void
113 zframe_test (bool verbose);
114 #ifdef CZMQ_BUILD_DRAFT_API
116 // Destroy an item
117 typedef void (zframe_destructor_fn) (
118 void **hint);
119 // *** Draft method, for development use, may change without warning ***
121 // Create a new frame from memory. Take ownership of the memory and calling the destructor
122 // on destroy.
123 CZMQ_EXPORT zframe_t *
124 zframe_frommem (void *data, size_t size, zframe_destructor_fn destructor, void *hint);
125 // *** Draft method, for development use, may change without warning ***
127 // Return frame routing ID, if the frame came from a ZMQ_SERVER socket.
128 // Else returns zero.
129 CZMQ_EXPORT uint32_t
130 zframe_routing_id (zframe_t *self);
131 // *** Draft method, for development use, may change without warning ***
133 // Set routing ID on frame. This is used if/when the frame is sent to a
134 // ZMQ_SERVER socket.
135 CZMQ_EXPORT void
136 zframe_set_routing_id (zframe_t *self, uint32_t routing_id);
137 // *** Draft method, for development use, may change without warning ***
139 // Return frame group of radio-dish pattern.
140 CZMQ_EXPORT const char *
141 zframe_group (zframe_t *self);
142 // *** Draft method, for development use, may change without warning ***
144 // Set group on frame. This is used if/when the frame is sent to a
145 // ZMQ_RADIO socket.
146 // Return -1 on error, 0 on success.
147 CZMQ_EXPORT int
148 zframe_set_group (zframe_t *self, const char *group);
149 // *** Draft method, for development use, may change without warning ***
151 // Send message to zsys log sink (may be stdout, or system facility as
152 // configured by zsys_set_logstream). Prefix shows before frame, if not null.
153 // Message length is specified; no truncation unless length is zero.
154 // Backwards compatible with zframe_print when length is zero.
155 CZMQ_EXPORT void
156 zframe_print_n (zframe_t *self, const char *prefix, size_t length);
157 #endif // CZMQ_BUILD_DRAFT_API
159 Please add '@interface' section in './../src/zframe.c'.
160
162 The zframe class provides methods to send and receive single message
163 frames across 0MQ sockets. A frame corresponds to one zmq_msg_t. When
164 you read a frame from a socket, the zframe_more() method indicates if
165 the frame is part of an unfinished multipart message. The zframe_send
166 method normally destroys the frame, but with the ZFRAME_REUSE flag, you
167 can send the same frame many times. Frames are binary, and this class
168 has no special support for text data.
169 Please add @discuss section in ./../src/zframe.c.
171
173 From zframe_test method.
174 // Create two PAIR sockets and connect over TCP
176 zsock_t *output = zsock_new (ZMQ_PAIR);
177 assert (output);
178 int port = zsock_bind (output, "tcp://127.0.0.1:*");
179 assert (port != -1);
180 zsock_t *input = zsock_new (ZMQ_PAIR);
181 assert (input);
182 rc = zsock_connect (input, "tcp://127.0.0.1:%d", port);
183 assert (rc != -1);
184 // Send five different frames, test ZFRAME_MORE
186 int frame_nbr;
187 for (frame_nbr = 0; frame_nbr < 5; frame_nbr++) {
188 frame = zframe_new ("Hello", 5);
189 assert (frame);
190 rc = zframe_send (&frame, output, ZFRAME_MORE);
191 assert (rc == 0);
192 }
193 // Send same frame five times, test ZFRAME_REUSE
194 frame = zframe_new ("Hello", 5);
195 assert (frame);
196 for (frame_nbr = 0; frame_nbr < 5; frame_nbr++) {
197 rc = zframe_send (&frame, output, ZFRAME_MORE + ZFRAME_REUSE);
198 assert (rc == 0);
199 }
200 assert (frame);
201 zframe_t *copy = zframe_dup (frame);
202 assert (zframe_eq (frame, copy));
203 zframe_destroy (&frame);
204 assert (!zframe_eq (frame, copy));
205 assert (zframe_size (copy) == 5);
206 zframe_destroy (©);
207 assert (!zframe_eq (frame, copy));
208 // Test zframe_new_empty
210 frame = zframe_new_empty ();
211 assert (frame);
212 assert (zframe_size (frame) == 0);
213 zframe_destroy (&frame);
214 // Send END frame
216 frame = zframe_new ("NOT", 3);
217 assert (frame);
218 zframe_reset (frame, "END", 3);
219 char *string = zframe_strhex (frame);
220 assert (streq (string, "454E44"));
221 freen (string);
222 string = zframe_strdup (frame);
223 assert (streq (string, "END"));
224 freen (string);
225 rc = zframe_send (&frame, output, 0);
226 assert (rc == 0);
227 // Read and count until we receive END
229 frame_nbr = 0;
230 for (frame_nbr = 0;; frame_nbr++) {
231 zframe_t *frame = zframe_recv (input);
232 if (zframe_streq (frame, "END")) {
233 zframe_destroy (&frame);
234 break;
235 }
236 assert (zframe_more (frame));
237 zframe_set_more (frame, 0);
238 assert (zframe_more (frame) == 0);
239 zframe_destroy (&frame);
240 }
241 assert (frame_nbr == 10);
242 #if (ZMQ_VERSION >= ZMQ_MAKE_VERSION (4, 1, 0))
244 // Test zframe_meta
245 frame = zframe_new ("Hello", 5);
246 assert (frame);
247 rc = zframe_send (&frame, output, 0);
248 assert (rc == 0);
249 frame = zframe_recv (input);
250 const char *meta = zframe_meta (frame, "Socket-Type");
251 assert (meta != NULL);
252 assert (streq (meta, "PAIR"));
253 assert (zframe_meta (frame, "nonexistent") == NULL);
254 zframe_destroy (&frame);
255 #endif
256 zsock_destroy (&input);
258 zsock_destroy (&output);
259 #if defined (ZMQ_SERVER)
261 // Create server and client sockets and connect over inproc
262 zsock_t *server = zsock_new_server ("inproc://zframe-test-routing");
263 assert (server);
264 zsock_t *client = zsock_new_client ("inproc://zframe-test-routing");
265 assert (client);
266 // Send request from client to server
268 zframe_t *request = zframe_new ("Hello", 5);
269 assert (request);
270 rc = zframe_send (&request, client, 0);
271 assert (rc == 0);
272 assert (!request);
273 // Read request and send reply
275 request = zframe_recv (server);
276 assert (request);
277 assert (zframe_streq (request, "Hello"));
278 assert (zframe_routing_id (request));
279 zframe_t *reply = zframe_new ("World", 5);
281 assert (reply);
282 zframe_set_routing_id (reply, zframe_routing_id (request));
283 rc = zframe_send (&reply, server, 0);
284 assert (rc == 0);
285 zframe_destroy (&request);
286 // Read reply
288 reply = zframe_recv (client);
289 assert (zframe_streq (reply, "World"));
290 assert (zframe_routing_id (reply) == 0);
291 zframe_destroy (&reply);
292 // Client and server disallow multipart
294 frame = zframe_new ("Hello", 5);
295 rc = zframe_send (&frame, client, ZFRAME_MORE);
296 assert (rc == -1);
297 rc = zframe_send (&frame, server, ZFRAME_MORE);
298 assert (rc == -1);
299 zframe_destroy (&frame);
300 zsock_destroy (&client);
302 zsock_destroy (&server);
303 #endif
304 #ifdef ZMQ_RADIO
306 // Create radio and dish sockets and connect over inproc
307 zsock_t *radio = zsock_new_radio ("inproc://zframe-test-radio");
308 assert (radio);
309 zsock_t *dish = zsock_new_dish ("inproc://zframe-test-radio");
310 assert (dish);
311 // Join the group
313 rc = zsock_join (dish, "World");
314 assert (rc == 0);
315 // Publish message from radio
317 zframe_t *message = zframe_new ("Hello", 5);
318 assert (message);
319 rc = zframe_set_group (message, "World");
320 assert (rc == 0);
321 rc = zframe_send (&message, radio, 0);
322 assert (rc == 0);
323 assert (!message);
324 // Receive the message from dish
326 message = zframe_recv (dish);
327 assert (message);
328 assert (zframe_streq (message, "Hello"));
329 assert (strcmp("World", zframe_group (message)) == 0);
330 zframe_destroy (&message);
331 zsock_destroy (&dish);
333 zsock_destroy (&radio);
334 #else
335 frame = zframe_new ("Hello", 5);
336 rc = zframe_set_group (frame, "World");
337 assert(rc == -1);
338 assert(errno == ENOTSUP);
339 zframe_destroy (&frame);
340 #endif
341 char str[] = "hello";
343 frame = zframe_frommem (str, 5, mem_destructor, str);
344 assert (frame);
345 zframe_destroy (&frame);
346 // The destructor doesn't free the memory, only changing the strid,
348 // so we can check if the destructor was invoked
349 assert (streq (str, "world"));
350 // zframe_print tests
353 zsys_set_logstream(verbose ? stdout : NULL);
355 // == No data ==
357 frame = zframe_new ("", 0);
358 // no prefix, backwards compatible
360 // - emits nothing but the timestamp
361 zframe_print (frame, "");
362 zframe_print_n (frame, "", 0);
363 // prefix, backwards compatible
365 // - emits nothing but the timestamp
366 zframe_print (frame, "Prefix");
367 zframe_print_n (frame, "Prefix", 0);
368 // len > data
370 // - emits nothing but the timestamp
371 zframe_print_n (frame, "", 15);
372 zframe_print_n (frame, "Prefix", 15);
373 // max len
375 // - emits nothing but the timestamp
376 zframe_print_n (frame, "", -1);
377 zframe_print_n (frame, "Prefix", -1);
378 zframe_destroy (&frame);
380 // == Short data ==
383 frame = zframe_new ("Hello there!", 12);
384 // no prefix, backwards compatible: ellipsis
386 // - "[012] Hello there!"
387 zframe_print (frame, "");
388 zframe_print_n (frame, "", 0);
389 // prefix, backwards compatible: ellipsis
391 // - "Prefix[012] Hello there!"
392 zframe_print (frame, "Prefix");
393 zframe_print_n (frame, "Prefix", 0);
394 // len < data
396 // - "[012] Hello"
397 // - "Prefix[012] Hello"
398 zframe_print_n (frame, "", 5);
399 zframe_print_n (frame, "Prefix", 5);
400 // len > data
402 // - "[012] Hello there!"
403 // - "Prefix[012] Hello there!"
404 zframe_print_n (frame, "", 15);
405 zframe_print_n (frame, "Prefix", 15);
406 // max len
408 // - "[012] Hello there!"
409 // - "Prefix[012] Hello there!"
410 zframe_print_n (frame, "", -1);
411 zframe_print_n (frame, "Prefix", -1);
412 zframe_destroy (&frame);
414 // == Long data ==
417 frame = zframe_new ("Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin finibus ligula et aliquam tristique. Phasellus consequat, enim et blandit varius, sapien diam faucibus lorem, non ultricies lacus turpis sed lectus. Vivamus id elit urna. In sit amet lacinia mauris. Class aptent taciti sociosqu ad litora torquent per conubia nostra, per inceptos himenaeos. Integer ut cursus diam. Vestibulum semper vel leo eu finibus. Ut urna magna, commodo vel auctor sed, eleifend quis lacus. Aenean quis ipsum et velit auctor ultrices.", 519);
418 // no prefix, backwards compatible: ellipsis
420 // - "[070] Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin finibus..."
421 zframe_print (frame, "");
422 zframe_print_n (frame, "", 0);
423 // prefix, backwards compatible: ellipsis
425 // - "Prefix[070] Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin finibus..."
426 zframe_print (frame, "Prefix");
427 zframe_print_n (frame, "Prefix", 0);
428 // len < data
430 // - "[519] Lorem"
431 // - "Prefix[519] Lorem"
432 zframe_print_n (frame, "", 5);
433 zframe_print_n (frame, "Prefix", 5);
434 // small len
436 // - "[519] Lorem ipsum dolor sit amet"
437 // - "Prefix[519] Lorem ipsum dolor sit amet"
438 zframe_print_n (frame, "", 26);
439 zframe_print_n (frame, "Prefix", 26);
440 // mid len
442 // - "[519] Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin finibus"
443 // "[519] ligula et aliquam tristique. Phasellus consequat, enim et blandit var"
444 // "[519] ius, sapie"
445 // - "Prefix[519] Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin finibus"
446 // "Prefix[519] ligula et aliquam tristique. Phasellus consequat, enim et blandit var"
447 // "Prefix[519] ius, sapie"
448 zframe_print_n (frame, "", 150);
449 zframe_print_n (frame, "Prefix", 150);
450 // len > data
452 // - emits the whole paragraph
453 zframe_print_n (frame, "", 1500);
454 zframe_print_n (frame, "Prefix", 1500);
455 // max len
457 // - emits the whole paragraph
458 zframe_print_n (frame, "", -1);
459 zframe_print_n (frame, "Prefix", -1);
460 zframe_destroy (&frame);
462 #if defined (__WINDOWS__)
464 zsys_shutdown();
465 #endif
466
469 The czmq manual was written by the authors in the AUTHORS file.
470
472 Main web site:
473 Report bugs to the email <zeromq-dev@lists.zeromq.org[1]>
475
477 Copyright (c) the Contributors as noted in the AUTHORS file. This file
478 is part of CZMQ, the high-level C binding for 0MQ:
479 http://czmq.zeromq.org. This Source Code Form is subject to the terms
480 of the Mozilla Public License, v. 2.0. If a copy of the MPL was not
481 distributed with this file, You can obtain one at
482 http://mozilla.org/MPL/2.0/. LICENSE included with the czmq
483 distribution.
484
486 1. zeromq-dev@lists.zeromq.org
487 mailto:zeromq-dev@lists.zeromq.org
488CZMQ 4.2.1 01/20/2022 ZFRAME(3)