Added a Hashmap (WIP)

headers/Containers/Hashmap.hpp

@@ -0,0 +1,110 @@
+
+/*
+ * SPDX-FileCopyrightText: Dora "cat" <cat@thenight.club>
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public License,
+ * v. 2.0. If a copy of the MPL was not distributed with this file, You can
+ * obtain one at http://mozilla.org/MPL/2.0/.
+ */
+#include "../Concepts.hpp"
+#include "../Systems/Logging.hpp"
+
+#include <cstddef>
+#include <vector>
+
+#ifndef GUARD_TOURMALINE_HASHMAP_H
+#define GUARD_TOURMALINE_HASHMAP_H
+namespace Tourmaline::Containers {
+template <Concepts::Hashable Key, typename Value,
+          std::size_t baseBucketCount = 1024>
+class Hashmap {
+public:
+  Hashmap() { storage.resize(baseBucketCount); }
+  ~Hashmap() { Clear(); }
+
+  void Insert(Key key, Value value) {
+    std::size_t keyHash = std::hash<Key>{}(key),
+                keyHashPosition = keyHash % storage.size();
+
+    // Empty bucket
+    if (storage[keyHashPosition] == nullptr) {
+      storage[keyHashPosition] = new std::vector<hashStorage>;
+    }
+    storage[keyHashPosition]->emplace_back(keyHash, key, std::move(value));
+  }
+
+  void Remove(const Key &key) {
+    std::size_t keyHash = std::hash<Key>{}(key),
+                keyHashPosition = keyHash % storage.size();
+
+    // Throws
+    Systems::Logging::Log("Trying to remove a non-existant key! Throwing...",
+                          "Hashmap", Systems::Logging::LogLevel::Error,
+                          storage[keyHashPosition] == nullptr);
+    std::erase_if(*storage[keyHashPosition],
+                  [key, keyHash](const hashStorage &hash) {
+                    return hash.hash == keyHash && hash.key == key;
+                  });
+  }
+
+  bool Has(const Key &key) {
+    std::size_t keyHash = std::hash<Key>{}(key),
+                keyHashPosition = keyHash % storage.size();
+
+    // Empty bucket
+    if (storage[keyHashPosition] == nullptr) {
+      return false;
+    }
+
+    for (const hashStorage &hash : *storage[keyHashPosition]) {
+      if (hash.hash == keyHash && hash.key == key) {
+        return true;
+      }
+    }
+
+    return false;
+  }
+
+  Value &Get(const Key &key) {
+    std::size_t keyHash = std::hash<Key>{}(key),
+                keyHashPosition = keyHash % storage.size();
+
+    Systems::Logging::Log(
+        "Trying to access a non-existant bucket for a key! Throwing...",
+        "Hashmap", Systems::Logging::LogLevel::Error,
+        storage[keyHashPosition] == nullptr);
+
+    for (const hashStorage &hash : *storage[keyHashPosition]) {
+      if (hash.hash == keyHash && hash.key == key) {
+        return hash.value;
+      }
+    }
+
+    Systems::Logging::Log("Trying to access a non-existant key! Throwing...",
+                          "Hashmap", Systems::Logging::LogLevel::Error);
+  }
+
+  void Clear() noexcept {
+    for (bucket *entry : storage) {
+      if (entry == nullptr) {
+        continue;
+      }
+
+      entry->clear();
+      delete entry;
+    }
+  }
+
+private:
+  struct hashStorage {
+    const std::size_t hash;
+    const Key key;
+    mutable Value value;
+  };
+
+  using bucket = std::vector<hashStorage>;
+  std::vector<bucket *> storage;
+};
+} // namespace Tourmaline::Containers
+#endif