Statistics code cleanup

Summary: I'm separating code-cleanup part of https://reviews.facebook.net/D14517. This will make D14517 easier to understand and this diff easier to review.

Test Plan: make check

Reviewers: haobo, kailiu, sdong, dhruba, tnovak

Reviewed By: tnovak

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15099

Author: igorcanadi

db/compaction_picker.cc

@@ -8,6 +8,7 @@
 // found in the LICENSE file. See the AUTHORS file for names of contributors.
 
 #include "db/compaction_picker.h"
+#include "util/statistics.h"
 
 namespace rocksdb {
 
@@ -589,10 +590,8 @@ Compaction* UniversalCompactionPicker::PickCompaction(Version* version) {
   }
 
   // update statistics
-  if (options_->statistics != nullptr) {
-    options_->statistics->measureTime(NUM_FILES_IN_SINGLE_COMPACTION,
-                                      c->inputs_[0].size());
-  }
+  MeasureTime(options_->statistics.get(), NUM_FILES_IN_SINGLE_COMPACTION,
+              c->inputs_[0].size());
 
   // mark all the files that are being compacted
   c->MarkFilesBeingCompacted(true);

db/db_bench.cc

@@ -14,7 +14,7 @@
 #include <gflags/gflags.h>
 #include "db/db_impl.h"
 #include "db/version_set.h"
-#include "db/db_statistics.h"
+#include "rocksdb/statistics.h"
 #include "rocksdb/options.h"
 #include "rocksdb/cache.h"
 #include "rocksdb/db.h"
@@ -30,6 +30,7 @@
 #include "util/random.h"
 #include "util/stack_trace.h"
 #include "util/string_util.h"
+#include "util/statistics.h"
 #include "util/testutil.h"
 #include "hdfs/env_hdfs.h"
 #include "utilities/merge_operators.h"
@@ -355,9 +356,9 @@ static bool ValidateCompressionLevel(const char* flagname, int32_t value) {
   return true;
 }
 
-static const bool FLAGS_compression_level_dummy =
-  google::RegisterFlagValidator(&FLAGS_compression_level,
-                                &ValidateCompressionLevel);
+static const bool FLAGS_compression_level_dummy __attribute__((unused)) =
+    google::RegisterFlagValidator(&FLAGS_compression_level,
+                                  &ValidateCompressionLevel);
 
 DEFINE_int32(min_level_to_compress, -1, "If non-negative, compression starts"
              " from this level. Levels with number < min_level_to_compress are"

db/db_impl.cc

@@ -2564,9 +2564,7 @@ Status DBImpl::DoCompactionWork(CompactionState* compact,
 
   CompactionStats stats;
   stats.micros = env_->NowMicros() - start_micros - imm_micros;
-  if (options_.statistics.get()) {
-    options_.statistics.get()->measureTime(COMPACTION_TIME, stats.micros);
-  }
+  MeasureTime(options_.statistics.get(), COMPACTION_TIME, stats.micros);
   stats.files_in_leveln = compact->compaction->num_input_files(0);
   stats.files_in_levelnp1 = compact->compaction->num_input_files(1);
 
@@ -3062,8 +3060,8 @@ Status DBImpl::Write(const WriteOptions& options, WriteBatch* my_batch) {
           // have succeeded in memtable but Status reports error for all writes.
           throw std::runtime_error("In memory WriteBatch corruption!");
         }
-        SetTickerCount(options_.statistics.get(),
-                       SEQUENCE_NUMBER, last_sequence);
+        SetTickerCount(options_.statistics.get(), SEQUENCE_NUMBER,
+                       last_sequence);
       }
       if (updates == &tmp_batch_) tmp_batch_.Clear();
       mutex_.Lock();