Fix performance-inefficient-vector-operation warning reported by clang-tidy

.clang-tidy

@@ -1,7 +1,7 @@
 # refer to https://clang.llvm.org/extra/clang-tidy/checks/list.html
 Checks: -*, clang-analyzer-core.*, clang-analyzer-cplusplus.*, clang-analyzer-deadcode.*, clang-analyzer-nullability.*, clang-analyzer-security.*, clang-analyzer-unix.*, clang-analyzer-valist.*, cppcoreguidelines-init-variables, cppcoreguidelines-macro-usage, cppcoreguidelines-interfaces-global-init, cppcoreguidelines-narrowing-conversions, cppcoreguidelines-no-malloc, cppcoreguidelines-prefer-member-initializer, cppcoreguidelines-special-member-functions, cppcoreguidelines-slicing, google-build-explicit-make-pair, google-default-arguments, google-explicit-constructor, modernize-avoid-bind, modernize-loop-convert, modernize-macro-to-enum, modernize-make-shared, modernize-make-unique, modernize-pass-by-value, modernize-redundant-void-arg, modernize-return-braced-init-list, modernize-use-auto, modernize-use-bool-literals, modernize-use-emplace, modernize-use-equals-default, modernize-use-equals-delete, modernize-use-nullptr, modernize-use-override, modernize-use-using, performance-faster-string-find, performance-for-range-copy, performance-implicit-conversion-in-loop, performance-inefficient-algorithm, performance-inefficient-vector-operation, performance-move-const-arg, performance-move-constructor-init, performance-no-automatic-move, performance-trivially-destructible, performance-type-promotion-in-math-fn, performance-unnecessary-copy-initialization, performance-unnecessary-value-param
 
-WarningsAsErrors: clang-analyzer-*, -clang-analyzer-security.insecureAPI.rand, cppcoreguidelines-interfaces-global-init, cppcoreguidelines-no-malloc, cppcoreguidelines-slicing, google-*, modernize-use-emplace, modernize-use-equals-default, modernize-use-equals-delete, performance-implicit-conversion-in-loop, performance-inefficient-algorithm, performance-move-constructor-init, performance-no-automatic-move, performance-trivially-destructible, performance-type-promotion-in-math-fn, performance-unnecessary-copy-initialization
+WarningsAsErrors: clang-analyzer-*, -clang-analyzer-security.insecureAPI.rand, cppcoreguidelines-interfaces-global-init, cppcoreguidelines-no-malloc, cppcoreguidelines-slicing, google-*, modernize-use-emplace, modernize-use-equals-default, modernize-use-equals-delete, performance-implicit-conversion-in-loop, performance-inefficient-algorithm, performance-move-constructor-init, performance-no-automatic-move, performance-trivially-destructible, performance-type-promotion-in-math-fn, performance-unnecessary-copy-initialization, performance-inefficient-vector-operation
 
 CheckOptions:
   - key:           cppcoreguidelines-special-member-functions.AllowSoleDefaultDtor

src/commands/redis_cmd.cc

@@ -1458,6 +1458,7 @@ class CommandHKeys : public Commander {
       return Status(Status::RedisExecErr, s.ToString());
     }
     std::vector<std::string> keys;
+    keys.reserve(field_values.size());
     for (const auto &fv : field_values) {
       keys.emplace_back(fv.field);
     }
@@ -1476,6 +1477,7 @@ class CommandHVals : public Commander {
       return Status(Status::RedisExecErr, s.ToString());
     }
     std::vector<std::string> values;
+    values.reserve(field_values.size());
     for (const auto &p : field_values) {
       values.emplace_back(p.value);
     }
@@ -4275,6 +4277,7 @@ class CommandCommand : public Commander {
           return Status::OK();
         }
         std::vector<std::string> keys;
+        keys.reserve(keys_indexes.size());
         for (const auto &key_index : keys_indexes) {
           keys.emplace_back(args_[key_index + 2]);
         }
@@ -4558,6 +4561,7 @@ class CommandZScan : public CommandSubkeyScanBase {
       return Status(Status::RedisExecErr, s.ToString());
     }
     std::vector<std::string> score_strings;
+    score_strings.reserve(scores.size());
     for (const auto &score : scores) {
       score_strings.emplace_back(Util::Float2String(score));
     }

src/types/redis_string.cc

@@ -398,6 +398,7 @@ rocksdb::Status String::MSetNX(const std::vector<StringPair> &pairs, int ttl, in
 
   int exists;
   std::vector<Slice> keys;
+  keys.reserve(pairs.size());
   for (StringPair pair : pairs) {
     keys.emplace_back(pair.key);
   }

src/types/redis_zset.cc

@@ -751,6 +751,7 @@ rocksdb::Status ZSet::UnionStore(const Slice &dst, const std::vector<KeyWeight>
   }
   if (!dst_zset.empty()) {
     std::vector<MemberScore> mscores;
+    mscores.reserve(dst_zset.size());
     for (const auto &iter : dst_zset) {
       mscores.emplace_back(MemberScore{iter.first, iter.second});
     }