Fix unused parameter warnings.

include/rocksdb/db.h

@@ -258,9 +258,10 @@ class DB {
   // This check is potentially lighter-weight than invoking DB::Get(). One way
   // to make this lighter weight is to avoid doing any IOs.
   // Default implementation here returns true and sets 'value_found' to false
-  virtual bool KeyMayExist(const ReadOptions& options,
-                           ColumnFamilyHandle* column_family, const Slice& key,
-                           std::string* value, bool* value_found = nullptr) {
+  virtual bool KeyMayExist(const ReadOptions& /*options*/,
+                           ColumnFamilyHandle* /*column_family*/,
+                           const Slice& /*key*/, std::string* /*value*/,
+                           bool* value_found = nullptr) {
     if (value_found != nullptr) {
       *value_found = false;
     }
@@ -502,8 +503,8 @@ class DB {
     return CompactRange(options, DefaultColumnFamily(), begin, end);
   }
 
-  virtual Status SetOptions(ColumnFamilyHandle* column_family,
-      const std::unordered_map<std::string, std::string>& new_options) {
+  virtual Status SetOptions(ColumnFamilyHandle* /*column_family*/,
+      const std::unordered_map<std::string, std::string>& /*new_options*/) {
     return Status::NotSupported("Not implemented");
   }
   virtual Status SetOptions(
@@ -653,7 +654,8 @@ class DB {
 
   // Returns a list of all table files with their level, start key
   // and end key
-  virtual void GetLiveFilesMetaData(std::vector<LiveFileMetaData>* metadata) {}
+  virtual void GetLiveFilesMetaData(
+    std::vector<LiveFileMetaData>* /*metadata*/) {}
 
   // Obtains the meta data of the specified column family of the DB.
   // Status::NotFound() will be returned if the current DB does not have
@@ -662,8 +664,8 @@ class DB {
   // If cf_name is not specified, then the metadata of the default
   // column family will be returned.
   virtual void GetColumnFamilyMetaData(
-      ColumnFamilyHandle* column_family,
-      ColumnFamilyMetaData* metadata) {}
+      ColumnFamilyHandle* /*column_family*/,
+      ColumnFamilyMetaData* /*metadata*/) {}
 
   // Get the metadata of the default column family.
   void GetColumnFamilyMetaData(

include/rocksdb/listener.h

@@ -150,8 +150,8 @@ class EventListener {
   // Note that the this function must be implemented in a way such that
   // it should not run for an extended period of time before the function
   // returns.  Otherwise, RocksDB may be blocked.
-  virtual void OnFlushCompleted(
-      DB* db, const FlushJobInfo& flush_job_info) {}
+  virtual void OnFlushCompleted(DB* /*db*/,
+      const FlushJobInfo& /*flush_job_info*/) {}
 
   // A call-back function for RocksDB which will be called whenever
   // a SST file is deleted.  Different from OnCompactionCompleted and
@@ -164,8 +164,7 @@ class EventListener {
   // Note that if applications would like to use the passed reference
   // outside this function call, they should make copies from the
   // returned value.
-  virtual void OnTableFileDeleted(
-      const TableFileDeletionInfo& info) {}
+  virtual void OnTableFileDeleted(const TableFileDeletionInfo& /*info*/) {}
 
   // A call-back function for RocksDB which will be called whenever
   // a registered RocksDB compacts a file. The default implementation
@@ -180,7 +179,8 @@ class EventListener {
   // @param ci a reference to a CompactionJobInfo struct. 'ci' is released
   //  after this function is returned, and must be copied if it is needed
   //  outside of this function.
-  virtual void OnCompactionCompleted(DB *db, const CompactionJobInfo& ci) {}
+  virtual void OnCompactionCompleted(DB* /*db*/,
+      const CompactionJobInfo& /*ci*/) {}
 
   // A call-back function for RocksDB which will be called whenever
   // a SST file is created.  Different from OnCompactionCompleted and
@@ -193,8 +193,7 @@ class EventListener {
   // Note that if applications would like to use the passed reference
   // outside this function call, they should make copies from these
   // returned value.
-  virtual void OnTableFileCreated(
-      const TableFileCreationInfo& info) {}
+  virtual void OnTableFileCreated(const TableFileCreationInfo& /*info*/) {}
 
   virtual ~EventListener() {}
 };

include/rocksdb/table_properties.h

@@ -107,7 +107,7 @@ class TablePropertiesCollector {
   // Add() will be called when a new key/value pair is inserted into the table.
   // @params key    the user key that is inserted into the table.
   // @params value  the value that is inserted into the table.
-  virtual Status Add(const Slice& key, const Slice& value) {
+  virtual Status Add(const Slice& /*key*/, const Slice& /*value*/) {
     return Status::InvalidArgument(
         "TablePropertiesCollector::Add() deprecated.");
   }
@@ -116,10 +116,9 @@ class TablePropertiesCollector {
   // table.
   // @params key    the user key that is inserted into the table.
   // @params value  the value that is inserted into the table.
-  // @params file_size  file size up to now
   virtual Status AddUserKey(const Slice& key, const Slice& value,
-                            EntryType type, SequenceNumber seq,
-                            uint64_t file_size) {
+                            EntryType /*type*/, SequenceNumber /*seq*/,
+                            uint64_t /*file_size*/) {
     // For backwards-compatibility.
     return Add(key, value);
   }

include/rocksdb/write_batch.h

@@ -147,7 +147,7 @@ class WriteBatch : public WriteBatchBase {
       return Status::InvalidArgument(
           "non-default column family and PutCF not implemented");
     }
-    virtual void Put(const Slice& key, const Slice& value) {}
+    virtual void Put(const Slice& /*key*/, const Slice& /*value*/) {}
 
     virtual Status DeleteCF(uint32_t column_family_id, const Slice& key) {
       if (column_family_id == 0) {
@@ -157,7 +157,7 @@ class WriteBatch : public WriteBatchBase {
       return Status::InvalidArgument(
           "non-default column family and DeleteCF not implemented");
     }
-    virtual void Delete(const Slice& key) {}
+    virtual void Delete(const Slice& /*key*/) {}
 
     virtual Status SingleDeleteCF(uint32_t column_family_id, const Slice& key) {
       if (column_family_id == 0) {
@@ -167,7 +167,7 @@ class WriteBatch : public WriteBatchBase {
       return Status::InvalidArgument(
           "non-default column family and SingleDeleteCF not implemented");
     }
-    virtual void SingleDelete(const Slice& key) {}
+    virtual void SingleDelete(const Slice& /*key*/) {}
 
     // Merge and LogData are not pure virtual. Otherwise, we would break
     // existing clients of Handler on a source code level. The default
@@ -181,7 +181,7 @@ class WriteBatch : public WriteBatchBase {
       return Status::InvalidArgument(
           "non-default column family and MergeCF not implemented");
     }
-    virtual void Merge(const Slice& key, const Slice& value) {}
+    virtual void Merge(const Slice& /*key*/, const Slice& /*value*/) {}
 
     // The default implementation of LogData does nothing.
     virtual void LogData(const Slice& blob);