Add size() and empty() to WaitFreeHashMap.

tdutils/td/utils/WaitFreeHashMap.h

@@ -61,6 +61,31 @@ class WaitFreeHashMap {
   size_t erase(const KeyT &key) {
     return get_storage(key).erase(key);
   }
+
+  size_t size() const {
+    if (wait_free_storage_ == nullptr) {
+      return default_map_.size();
+    }
+
+    size_t result = 0;
+    for (size_t i = 0; i < MAX_STORAGE_COUNT; i++) {
+      result += wait_free_storage_->maps_[i].size();
+    }
+    return result;
+  }
+
+  bool empty() const {
+    if (wait_free_storage_ == nullptr) {
+      return default_map_.empty();
+    }
+
+    for (size_t i = 0; i < MAX_STORAGE_COUNT; i++) {
+      if (!wait_free_storage_->maps_[i].empty()) {
+        return false;
+      }
+    }
+    return true;
+  }
 };
 
 }  // namespace td

tdutils/test/WaitFreeHashMap.cpp

@@ -30,6 +30,8 @@ TEST(WaitFreeHashMap, stress_test) {
     reference[key] = value;
     map.set(key, value);
     ASSERT_EQ(reference[key], map.get(key));
+    ASSERT_EQ(reference.size(), map.size());
+    ASSERT_EQ(reference.empty(), map.empty());
   });
 
   add_step(2000, [&] {
@@ -37,6 +39,8 @@ TEST(WaitFreeHashMap, stress_test) {
     auto ref_it = reference.find(key);
     auto ref_value = ref_it == reference.end() ? 0 : ref_it->second;
     ASSERT_EQ(ref_value, map.get(key));
+    ASSERT_EQ(reference.size(), map.size());
+    ASSERT_EQ(reference.empty(), map.empty());
   });
 
   add_step(500, [&] {
@@ -44,6 +48,8 @@ TEST(WaitFreeHashMap, stress_test) {
     size_t reference_erased_count = reference.erase(key);
     size_t map_erased_count = map.erase(key);
     ASSERT_EQ(reference_erased_count, map_erased_count);
+    ASSERT_EQ(reference.size(), map.size());
+    ASSERT_EQ(reference.empty(), map.empty());
   });
 
   td::RandomSteps runner(std::move(steps));