Improve pull example

examples/unix/c11/z_pull.c

@@ -22,18 +22,26 @@
 int main(int argc, char **argv) {
     const char *keyexpr = "demo/example/**";
     char *locator = NULL;
+    size_t interval = 5000;
+    size_t size = 3;
 
     int opt;
-    while ((opt = getopt(argc, argv, "k:e:")) != -1) {
+    while ((opt = getopt(argc, argv, "k:e:i:s:")) != -1) {
         switch (opt) {
             case 'k':
                 keyexpr = optarg;
                 break;
             case 'e':
                 locator = optarg;
                 break;
+            case 'i':
+                interval = (size_t)atoi(optarg);
+                break;
+            case 's':
+                size = (size_t)atoi(optarg);
+                break;
             case '?':
-                if (optopt == 'k' || optopt == 'e') {
+                if (optopt == 'k' || optopt == 'e' || optopt == 'i' || optopt == 's') {
                     fprintf(stderr, "Option -%c requires an argument.\n", optopt);
                 } else {
                     fprintf(stderr, "Unknown option `-%c'.\n", optopt);
@@ -64,29 +72,25 @@ int main(int argc, char **argv) {
     }
 
     printf("Declaring Subscriber on '%s'...\n", keyexpr);
-    z_owned_sample_channel_t channel = z_sample_channel_ring_new(3);
+    z_owned_sample_channel_t channel = z_sample_channel_ring_new(size);
     z_owned_subscriber_t sub = z_declare_subscriber(z_loan(s), z_keyexpr(keyexpr), z_move(channel.send), NULL);
     if (!z_check(sub)) {
         printf("Unable to declare subscriber.\n");
         return -1;
     }
 
-    printf("Enter any key to pull data or 'q' to quit...\n");
-    char c = '\0';
-    for (int ret = scanf("%c", &c); c != 'q'; ret = scanf("%c", &c)) {
-        // Try to receive one sample from the ring channel
-        z_owned_sample_t sample = z_sample_null();
-        z_call(channel.recv, &sample);
-        // Check if we actually received something
-        if (z_check(sample)) {
+    printf("Pulling data every %zu ms... Ring size: %zd\n", interval, size);
+    z_owned_sample_t sample = z_sample_null();
+    while (true) {
+        for (z_call(channel.recv, &sample); z_check(sample); z_call(channel.recv, &sample)) {
             z_owned_str_t keystr = z_keyexpr_to_string(z_loan(sample.keyexpr));
             printf(">> [Subscriber] Pulled ('%s': '%.*s')\n", z_loan(keystr), (int)sample.payload.len,
                    sample.payload.start);
             z_drop(z_move(keystr));
-        } else {
-            printf(">> [Subscriber] Nothing to pull...\n");
+            z_drop(z_move(sample));
         }
-        z_drop(z_move(sample));
+        printf(">> [Subscriber] Nothing to pull... sleep for %zu ms\n", interval);
+        zp_sleep_ms(interval);
     }
 
     z_undeclare_subscriber(z_move(sub));