Add reset statistics method (#149)

librocksdb_sys/crocksdb/c.cc

@@ -1949,6 +1949,10 @@ void crocksdb_options_enable_statistics(crocksdb_options_t* opt) {
   opt->rep.statistics = rocksdb::CreateDBStatistics();
 }
 
+void crocksdb_options_reset_statistics(crocksdb_options_t* opt) {
+  opt->rep.statistics->Reset();
+}
+
 void crocksdb_options_set_num_levels(crocksdb_options_t* opt, int n) {
   opt->rep.num_levels = n;
 }

librocksdb_sys/crocksdb/crocksdb/c.h

@@ -787,6 +787,8 @@ crocksdb_options_set_max_bytes_for_level_multiplier_additional(
     crocksdb_options_t*, int* level_values, size_t num_levels);
 extern C_ROCKSDB_LIBRARY_API void crocksdb_options_enable_statistics(
     crocksdb_options_t*);
+extern C_ROCKSDB_LIBRARY_API void crocksdb_options_reset_statistics(
+    crocksdb_options_t*);
 
 /* returns a pointer to a malloc()-ed, null terminated string */
 extern C_ROCKSDB_LIBRARY_API char* crocksdb_options_statistics_get_string(

librocksdb_sys/src/lib.rs

@@ -450,6 +450,7 @@ extern "C" {
     pub fn crocksdb_options_set_max_subcompactions(options: *mut Options, v: u32);
     pub fn crocksdb_options_set_wal_bytes_per_sync(options: *mut Options, v: u64);
     pub fn crocksdb_options_enable_statistics(options: *mut Options);
+    pub fn crocksdb_options_reset_statistics(options: *mut Options);
     pub fn crocksdb_options_statistics_get_string(options: *mut Options) -> *const c_char;
     pub fn crocksdb_options_statistics_get_ticker_count(
         options: *mut Options,

src/rocksdb.rs

@@ -1124,6 +1124,10 @@ impl DB {
         self.opts.get_statistics()
     }
 
+    pub fn reset_statistics(&self) {
+        self.opts.reset_statistics();
+    }
+
     pub fn get_statistics_ticker_count(&self, ticker_type: DBStatisticsTickerType) -> u64 {
         self.opts.get_statistics_ticker_count(ticker_type)
     }

src/rocksdb_options.rs

@@ -672,6 +672,12 @@ impl DBOptions {
         }
     }
 
+    pub fn reset_statistics(&self) {
+        unsafe {
+            crocksdb_ffi::crocksdb_options_reset_statistics(self.inner);
+        }
+    }
+
     pub fn set_stats_dump_period_sec(&mut self, period: usize) {
         unsafe {
             crocksdb_ffi::crocksdb_options_set_stats_dump_period_sec(self.inner, period);

tests/test_statistics.rs

@@ -43,4 +43,12 @@ fn test_db_statistics() {
         db.get_statistics_histogram(HistogramType::GetMicros)
             .is_some()
     );
+
+    let get_micros = db.get_statistics_histogram(HistogramType::GetMicros)
+        .unwrap();
+    assert!(get_micros.max > 0.0);
+    db.reset_statistics();
+    let get_micros = db.get_statistics_histogram(HistogramType::GetMicros)
+        .unwrap();
+    assert_eq!(get_micros.max, 0.0);
 }