Implement rudimentary X-Mining-Hashrate support.

cgminer.c

@@ -100,6 +100,7 @@ int opt_scantime = 60;
 int opt_expiry = 120;
 int opt_bench_algo = -1;
 static const bool opt_time = true;
+unsigned long long global_hashrate;
 
 #ifdef HAVE_OPENCL
 int opt_dynamic_interval = 7;
@@ -3400,6 +3401,7 @@ static void hashmeter(int thr_id, struct timeval *diff,
 
 	local_secs = (double)total_diff.tv_sec + ((double)total_diff.tv_usec / 1000000.0);
 	decay_time(&rolling, local_mhashes_done / local_secs);
+	global_hashrate = roundl(rolling) * 1000000;
 
 	timeval_subtract(&total_diff, &total_tv_end, &total_tv_start);
 	total_secs = (double)total_diff.tv_sec +

miner.h

@@ -620,6 +620,7 @@ extern unsigned int local_work;
 extern unsigned int total_go, total_ro;
 extern const int opt_cutofftemp;
 extern int opt_log_interval;
+extern unsigned long long global_hashrate;
 
 #ifdef HAVE_OPENCL
 typedef struct {

util.c

@@ -256,17 +256,17 @@ json_t *json_rpc_call(CURL *curl, const char *url,
 		      bool probe, bool longpoll, int *rolltime,
 		      struct pool *pool, bool share)
 {
-	json_t *val, *err_val, *res_val;
-	int rc;
-	struct data_buffer all_data = {NULL, 0};
-	struct upload_buffer upload_data;
-	json_error_t err;
-	struct curl_slist *headers = NULL;
-	char len_hdr[64], user_agent_hdr[128];
-	char curl_err_str[CURL_ERROR_SIZE];
+	char len_hdr[64], user_agent_hdr[128], *ghashrate;
 	long timeout = longpoll ? (60 * 60) : 60;
+	struct data_buffer all_data = {NULL, 0};
 	struct header_info hi = {NULL, 0, NULL};
+	char curl_err_str[CURL_ERROR_SIZE];
+	struct curl_slist *headers = NULL;
+	struct upload_buffer upload_data;
+	json_t *val, *err_val, *res_val;
 	bool probing = false;
+	json_error_t err;
+	int rc;
 
 	memset(&err, 0, sizeof(err));
 
@@ -325,6 +325,13 @@ json_t *json_rpc_call(CURL *curl, const char *url,
 		"Content-type: application/json");
 	headers = curl_slist_append(headers,
 		"X-Mining-Extensions: longpoll midstate rollntime submitold");
+
+	if (likely(global_hashrate)) {
+		asprintf(&ghashrate, "X-Mining-Hashrate: %llu", global_hashrate);
+		headers = curl_slist_append(headers, ghashrate);
+		free(ghashrate);
+	}
+
 	headers = curl_slist_append(headers, len_hdr);
 	headers = curl_slist_append(headers, user_agent_hdr);
 	headers = curl_slist_append(headers, "Expect:"); /* disable Expect hdr*/