Revision 2:4d49720c7200, committed 2016-11-11

Comitter:

sveljko

Date:

Fri Nov 11 22:46:57 2016 +0000

Parent:

1:9fbec3606b08

Commit message:

Added the module/function to srand() using the time returned from Pubnub's `time` operation (which can be started with pubnub_time())

Changed in this revision

diff -r 9fbec3606b08 -r 4d49720c7200 Pubnub_c_core_mbed2_pal.lib
--- a/Pubnub_c_core_mbed2_pal.lib	Thu Nov 10 22:40:25 2016 +0000
+++ b/Pubnub_c_core_mbed2_pal.lib	Fri Nov 11 22:46:57 2016 +0000
@@ -1,1 +1,1 @@
-https://developer.mbed.org/users/sveljko/code/Pubnub_c_core_mbed2_pal/#d29780e2c0ec
+https://developer.mbed.org/users/sveljko/code/Pubnub_c_core_mbed2_pal/#9c3ddeede137

diff -r 9fbec3606b08 -r 4d49720c7200 pubnub_sync.h
--- a/pubnub_sync.h	Thu Nov 10 22:40:25 2016 +0000
+++ b/pubnub_sync.h	Fri Nov 11 22:46:57 2016 +0000
@@ -31,7 +31,7 @@
 #include "pubnub_assert.h"
 #include "pubnub_coreapi.h"
 #include "pubnub_ntf_sync.h"
-//#include "pubnub_generate_uuid.h"
+#include "pubnub_generate_uuid.h"
 #include "pubnub_blocking_io.h"
 
 

diff -r 9fbec3606b08 -r 4d49720c7200 srand_from_pubnub_time.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/srand_from_pubnub_time.cpp	Fri Nov 11 22:46:57 2016 +0000
@@ -0,0 +1,37 @@
+#include "srand_from_pubnub_time.h"
+
+#include "pubnub_coreapi.h"
+#include "pubnub_ntf_sync.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+
+int srand_from_pubnub_time(pubnub_t *pbp)
+{
+    pubnub_res rslt = pubnub_time(pbp);
+    if (rslt != PNR_STARTED) {
+        return -1;
+    }
+    rslt = pubnub_await(pbp);
+    if (rslt != PNR_OK) {
+        return -1;
+    }
+    char const* pbtime = pubnub_get(pbp);
+    if (0 == pbtime)  {
+        return -1;
+    }
+    size_t length_of_time = strlen(pbtime);
+    if (0 == length_of_time) {
+        return -1;
+    }
+    char const *s = pbtime + length_of_time - 1;
+    unsigned int val_for_srand = 0;
+    for (int i = 0; (i < 10) && (s > pbtime); ++i, --s) {
+        val_for_srand = val_for_srand * 10 + *s - '0';
+    }
+    
+    srand(val_for_srand);
+    
+    return 0;
+}
\ No newline at end of file

diff -r 9fbec3606b08 -r 4d49720c7200 srand_from_pubnub_time.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/srand_from_pubnub_time.h	Fri Nov 11 22:46:57 2016 +0000
@@ -0,0 +1,25 @@
+#if !defined INC_SRAND_FROM_PUBNUB_TIME
+#define      INC_SRAND_FROM_PUBNUB_TIME
+
+
+#include "pubnub_api_types.h"
+
+
+/** This helper function will call the C standard srand() function with the seed
+    taken from the time returned from Pubnub's `time` operation (which can
+    be initiated with pubnub_time()).
+    
+    It's useful if you want a high-fidelity time used for srand() and on 
+    embedded system that don't have a Real-Time Clock.
+    
+    Keep in mind that this requires a round-trip to Pubnub, so it will take
+    some time, depending on your network, at least miliseconds. So, it's best
+    used only once, at the start of your program.
+    
+    @param pbp The Pubnub context to use to get time
+    @return 0: OK, -1: error (srand() was not called)
+*/
+int srand_from_pubnub_time(pubnub_t *pbp);
+
+
+#endif /* !defined INC_SRAND_FROM_PUBNUB_TIME */
\ No newline at end of file