server: Only write CSV headers when initially creating the log file

[tattlekey] / client / config.c

diff --git a/client/config.c b/client/config.c
index de300ea29a468288d0dfe4f0d5e48381ac23ba56..a708df4aed9095b91f7333c69a612a73ed6af681 100644 (file)
--- a/client/config.c
+++ b/client/config.c
@@ -1,27 +1,58 @@
 #include "config.h"
 
 /* Wi-Fi credentials */
-char wifi_ssid[] = "THEWIFISSID";
-char wifi_pass[] = "THEWIFIPASSWORD";
+const char config_wifi_ssid[] = "THEWIFISSID";
+const char config_wifi_pass[] = "THEWIFIPASSWORD";
 
 /* Network address of the server to contact */
-char tattle_server_ip_address[] = "192.168.10.10";
-u16_t tattle_port = 29803; // 'tk'
+const char config_tattle_server_ip_address[] = "192.168.10.10";
+const u16_t config_tattle_port = 29803; // 'tk'
 
 /* For distinguishing reports from multiple tattlekey devices. */
-u16_t this_tattler_identity = 1;
+const u16_t config_this_tattler_identity = 1;
 
 /* Which GPIO pin is the button connected to?
  * The button should span this pin and ground, connecting this pin to ground
  * when pressed.
  * https://projects.raspberrypi.org/en/projects/introduction-to-the-pico/10
  * recommends pins 18, 22, or 28. */
-uint button_pin = 18;
+const uint config_button_pin = 18;
 
 /* Don't bother reporting each separate button press when it is pressed many
  * times in short succession.  (We also use this to de-bounce. :) */
-u32_t minimum_microseconds_between_button_presses = 1000000;
+const u32_t config_minimum_seconds_between_button_presses = 1;
 
-/* Send each report multiple times. */
-uint resend_count = 5;
-u32_t resend_interval_ms = 1000;
+/* Send each report multiple times. Re-sends are sent with exponential delay:
+ *   #1 sent immediately
+ *   #2 after 1 seconds
+ *   #3 after 2 seconds
+ *   #4 after 4 seconds
+ *   #5 after 8 seconds
+ *   ...
+ *   #11 after 8 minutes
+ *   #12 after 17 minutes
+ *   #13 after 34 minutes
+ *   #14 after 68 minutes
+ *   #15 after 2 hours
+ *   #16 after 4 hours
+ *   #17 after 9 hours
+ *   etc.
+ * This provides some robustness against network outages, automatically
+ * replaying the log periodically to be collected after connectivity
+ * is restored. */
+const uint config_resend_count = 16;
+
+/* These control the size of the per-send-count press queues.
+When the button is pressed more than config_maximum_queue_size times
+within the resend interval, some presses will be reported fewer
+than config_resend_count times. This is usually fine because it's
+the old, longest-delayed, most-redundant reports that get dropped;
+fresh, timely reports of new button presses will not get anywhere near
+config_resend_count in a resend interval because the early resend internals
+are so short.  */
+const uint config_maximum_queue_size = 512;
+
+/* This is paranoia about unanticipated delays.  Setting this to zero
+would probably be fine, but imposing a minimum queue size is an easy
+safety measure. */
+const uint config_minimum_queue_size = 32;