subscribe: minor improvement

revise progress persistent file format to reduce file size.
example: print out number of rows consumed

src/client/src/tscSub.c

@@ -265,7 +265,7 @@ static int tscLoadSubscriptionProgress(SSub* pSub) {
       return 0;
     }
     int64_t uid, key;
-    sscanf(buf, "uid=%" SCNd64 ",progress=%" SCNd64, &uid, &key);
+    sscanf(buf, "%" SCNd64 ":%" SCNd64, &uid, &key);
     progress[i].uid = uid;
     progress[i].key = key;
   }
@@ -300,7 +300,7 @@ void tscSaveSubscriptionProgress(void* sub) {
   for (int i = 0; i < pSub->numOfMeters; i++) {
     int64_t uid = pSub->progress[i].uid;
     TSKEY key = pSub->progress[i].key;
-    fprintf(fp, "uid=%" PRId64 ",progress=%" PRId64 "\n", uid, key);
+    fprintf(fp, "%" PRId64 ":%" PRId64 "\n", uid, key);
   }
 
   fclose(fp);

tests/examples/c/subscribe.c

@@ -11,9 +11,10 @@ void print_result(TAOS_RES* res, int blockFetch) {
   TAOS_ROW    row = NULL;
   int         num_fields = taos_num_fields(res);
   TAOS_FIELD* fields = taos_fetch_fields(res);
+  int         nRows = 0;
 
   if (blockFetch) {
-    int nRows = taos_fetch_block(res, &row);
+    nRows = taos_fetch_block(res, &row);
     for (int i = 0; i < nRows; i++) {
       char temp[256];
       taos_print_row(temp, row + i, fields, num_fields);
@@ -24,8 +25,11 @@ void print_result(TAOS_RES* res, int blockFetch) {
       char temp[256];
       taos_print_row(temp, row, fields, num_fields);
       puts(temp);
+      nRows++;
     }
   }
+
+  printf("%d rows consumed.\n", nRows);
 }