Statistics support in C API, additional improvements

db/c.cc

@@ -280,11 +280,7 @@ struct rocksdb_compactionfiltercontext_t {
   CompactionFilter::Context rep;
 };
 
-struct rocksdb_statistics_histogram_data_t {
-  rocksdb_statistics_histogram_data_t() : rep() {}
-
-  HistogramData rep;
-};
+struct rocksdb_statistics_histogram_data_t : public HistogramData {};
 
 struct rocksdb_compactionfilter_t : public CompactionFilter {
   void* state_;
@@ -3893,20 +3889,20 @@ char* rocksdb_options_statistics_get_string(rocksdb_options_t* opt) {
 }
 
 uint64_t rocksdb_options_statistics_get_ticker_count(rocksdb_options_t* opt,
-                                                     uint32_t type) {
+                                                     uint32_t ticker_type) {
   ROCKSDB_NAMESPACE::Statistics* statistics = opt->rep.statistics.get();
   if (statistics) {
-    return statistics->getTickerCount(type);
+    return statistics->getTickerCount(ticker_type);
   }
   return 0;
 }
 
 void rocksdb_options_statistics_get_histogram_data(
     rocksdb_options_t* opt, uint32_t type,
-    rocksdb_statistics_histogram_data_t* data) {
+    rocksdb_statistics_histogram_data_t* const data) {
   ROCKSDB_NAMESPACE::Statistics* statistics = opt->rep.statistics.get();
   if (statistics) {
-    statistics->histogramData(type, &data->rep);
+    statistics->histogramData(type, data);
   } else {
     *data = rocksdb_statistics_histogram_data_t{};
   }
@@ -5674,8 +5670,7 @@ int rocksdb_transactiondb_property_int(rocksdb_transactiondb_t* db,
   }
 }
 
-rocksdb_t* rocksdb_transactiondb_get_base_db(
-    rocksdb_transactiondb_t* txn_db) {
+rocksdb_t* rocksdb_transactiondb_get_base_db(rocksdb_transactiondb_t* txn_db) {
   DB* base_db = txn_db->rep->GetBaseDB();
 
   if (base_db != nullptr) {
@@ -5687,9 +5682,7 @@ rocksdb_t* rocksdb_transactiondb_get_base_db(
   return nullptr;
 }
 
-void rocksdb_transactiondb_close_base_db(rocksdb_t* base_db) {
-  delete base_db;
-}
+void rocksdb_transactiondb_close_base_db(rocksdb_t* base_db) { delete base_db; }
 
 rocksdb_transaction_t* rocksdb_transaction_begin(
     rocksdb_transactiondb_t* txn_db,
@@ -6670,7 +6663,7 @@ void rocksdb_enable_manual_compaction(rocksdb_t* db) {
 
 rocksdb_statistics_histogram_data_t*
 rocksdb_statistics_histogram_data_create() {
-  return new rocksdb_statistics_histogram_data_t;
+  return new rocksdb_statistics_histogram_data_t{};
 }
 
 void rocksdb_statistics_histogram_data_destroy(
@@ -6680,47 +6673,47 @@ void rocksdb_statistics_histogram_data_destroy(
 
 double rocksdb_statistics_histogram_data_get_median(
     rocksdb_statistics_histogram_data_t* data) {
-  return data->rep.median;
+  return data->median;
 }
 
 double rocksdb_statistics_histogram_data_get_p95(
     rocksdb_statistics_histogram_data_t* data) {
-  return data->rep.percentile95;
+  return data->percentile95;
 }
 
 double rocksdb_statistics_histogram_data_get_p99(
     rocksdb_statistics_histogram_data_t* data) {
-  return data->rep.percentile99;
+  return data->percentile99;
 }
 
 double rocksdb_statistics_histogram_data_get_average(
     rocksdb_statistics_histogram_data_t* data) {
-  return data->rep.average;
+  return data->average;
 }
 
 double rocksdb_statistics_histogram_data_get_std_dev(
     rocksdb_statistics_histogram_data_t* data) {
-  return data->rep.standard_deviation;
+  return data->standard_deviation;
 }
 
 double rocksdb_statistics_histogram_data_get_max(
     rocksdb_statistics_histogram_data_t* data) {
-  return data->rep.max;
+  return data->max;
 }
 
 uint64_t rocksdb_statistics_histogram_data_get_count(
     rocksdb_statistics_histogram_data_t* data) {
-  return data->rep.count;
+  return data->count;
 }
 
 uint64_t rocksdb_statistics_histogram_data_get_sum(
     rocksdb_statistics_histogram_data_t* data) {
-  return data->rep.sum;
+  return data->sum;
 }
 
 double rocksdb_statistics_histogram_data_get_min(
     rocksdb_statistics_histogram_data_t* data) {
-  return data->rep.min;
+  return data->min;
 }
 
 }  // end extern "C"

db/c_test.c

@@ -3128,12 +3128,12 @@ int main(int argc, char** argv) {
     CheckTxnDBGetCF(txn_db, roptions, cfh, "cf_foo", NULL);
     CheckTxnDBPinGetCF(txn_db, roptions, cfh, "cf_foo", NULL);
 
-
-    //memory usage
+    // memory usage
     rocksdb_t* base_db = rocksdb_transactiondb_get_base_db(txn_db);
     rocksdb_memory_consumers_t* consumers = rocksdb_memory_consumers_create();
     rocksdb_memory_consumers_add_db(consumers, base_db);
-    rocksdb_memory_usage_t* usage = rocksdb_approximate_memory_usage_create(consumers, &err);
+    rocksdb_memory_usage_t* usage =
+        rocksdb_approximate_memory_usage_create(consumers, &err);
     CheckNoError(err);
     rocksdb_approximate_memory_usage_destroy(usage);
     rocksdb_memory_consumers_destroy(consumers);
@@ -3666,7 +3666,15 @@ int main(int argc, char** argv) {
     CheckCondition(0 != rocksdb_options_statistics_get_ticker_count(
                             options, BYTES_WRITTEN_TICKER));
     rocksdb_options_statistics_get_histogram_data(options, DB_WRITE_HIST, hist);
+    CheckCondition(0.0 != rocksdb_statistics_histogram_data_get_median(hist));
+    CheckCondition(0.0 != rocksdb_statistics_histogram_data_get_p95(hist));
+    CheckCondition(0.0 != rocksdb_statistics_histogram_data_get_p99(hist));
+    CheckCondition(0.0 != rocksdb_statistics_histogram_data_get_average(hist));
+    CheckCondition(0.0 != rocksdb_statistics_histogram_data_get_std_dev(hist));
+    CheckCondition(0.0 != rocksdb_statistics_histogram_data_get_max(hist));
+    CheckCondition(0 != rocksdb_statistics_histogram_data_get_count(hist));
     CheckCondition(0 != rocksdb_statistics_histogram_data_get_sum(hist));
+    CheckCondition(0.0 != rocksdb_statistics_histogram_data_get_min(hist));
 
     rocksdb_statistics_histogram_data_destroy(hist);
   }

include/rocksdb/c.h

@@ -1256,14 +1256,14 @@ extern ROCKSDB_LIBRARY_API void rocksdb_options_enable_statistics(
     rocksdb_options_t*);
 
 enum {
-  rocksdb_statistics_level_disable_all,
+  rocksdb_statistics_level_disable_all = 0,
   rocksdb_statistics_level_except_tickers =
       rocksdb_statistics_level_disable_all,
-  rocksdb_statistics_level_except_histogram_or_timers,
-  rocksdb_statistics_level_except_timers,
-  rocksdb_statistics_level_except_detailed_timers,
-  rocksdb_statistics_level_except_time_for_mutex,
-  rocksdb_statistics_level_all,
+  rocksdb_statistics_level_except_histogram_or_timers = 1,
+  rocksdb_statistics_level_except_timers = 2,
+  rocksdb_statistics_level_except_detailed_timers = 3,
+  rocksdb_statistics_level_except_time_for_mutex = 4,
+  rocksdb_statistics_level_all = 5,
 };
 
 extern ROCKSDB_LIBRARY_API void rocksdb_options_set_statistics_level(
@@ -1350,7 +1350,7 @@ extern ROCKSDB_LIBRARY_API uint64_t rocksdb_options_statistics_get_ticker_count(
     rocksdb_options_t* opt, uint32_t ticker_type);
 extern ROCKSDB_LIBRARY_API void rocksdb_options_statistics_get_histogram_data(
     rocksdb_options_t* opt, uint32_t histogram_type,
-    rocksdb_statistics_histogram_data_t* data);
+    rocksdb_statistics_histogram_data_t* const data);
 
 extern ROCKSDB_LIBRARY_API void rocksdb_options_set_max_write_buffer_number(
     rocksdb_options_t*, int);