Revert to old `StringMap` internal layout

src/string_map.cpp

@@ -24,6 +24,296 @@ gb_internal gb_inline StringHashKey string_hash_string(String const &s) {
 	return hash_key;
 }
 
+
+#if 1 /* old string map */
+
+template <typename T>
+struct StringMapEntry {
+	String        key;
+	u32           hash;
+	MapIndex      next;
+	T             value;
+};
+
+template <typename T>
+struct StringMap {
+	MapIndex *         hashes;
+	usize              hashes_count;
+	StringMapEntry<T> *entries;
+	u32                count;
+	u32                entries_capacity;
+};
+
+
+template <typename T> gb_internal void string_map_init    (StringMap<T> *h, usize capacity = 16);
+template <typename T> gb_internal void string_map_destroy (StringMap<T> *h);
+
+template <typename T> gb_internal T *  string_map_get     (StringMap<T> *h, char const *key);
+template <typename T> gb_internal T *  string_map_get     (StringMap<T> *h, String const &key);
+template <typename T> gb_internal T *  string_map_get     (StringMap<T> *h, StringHashKey const &key);
+
+template <typename T> gb_internal T &  string_map_must_get(StringMap<T> *h, char const *key);
+template <typename T> gb_internal T &  string_map_must_get(StringMap<T> *h, String const &key);
+template <typename T> gb_internal T &  string_map_must_get(StringMap<T> *h, StringHashKey const &key);
+
+template <typename T> gb_internal void string_map_set     (StringMap<T> *h, char const *key,   T const &value);
+template <typename T> gb_internal void string_map_set     (StringMap<T> *h, String const &key, T const &value);
+template <typename T> gb_internal void string_map_set     (StringMap<T> *h, StringHashKey const &key, T const &value);
+
+// template <typename T> gb_internal void string_map_remove  (StringMap<T> *h, StringHashKey const &key);
+template <typename T> gb_internal void string_map_clear   (StringMap<T> *h);
+template <typename T> gb_internal void string_map_grow    (StringMap<T> *h);
+template <typename T> gb_internal void string_map_reserve (StringMap<T> *h, usize new_count);
+
+gb_internal gbAllocator string_map_allocator(void) {
+	return heap_allocator();
+}
+
+template <typename T>
+gb_internal gb_inline void string_map_init(StringMap<T> *h, usize capacity) {
+	capacity = next_pow2_isize(capacity);
+	string_map_reserve(h, capacity);
+}
+
+template <typename T>
+gb_internal gb_inline void string_map_destroy(StringMap<T> *h) {
+	gb_free(string_map_allocator(), h->hashes);
+	gb_free(string_map_allocator(), h->entries);
+}
+
+
+template <typename T>
+gb_internal void string_map__resize_hashes(StringMap<T> *h, usize count) {
+	h->hashes_count = cast(u32)resize_array_raw(&h->hashes, string_map_allocator(), h->hashes_count, count, MAP_CACHE_LINE_SIZE);
+}
+
+
+template <typename T>
+gb_internal void string_map__reserve_entries(StringMap<T> *h, usize capacity) {
+	h->entries_capacity = cast(u32)resize_array_raw(&h->entries, string_map_allocator(), h->entries_capacity, capacity, MAP_CACHE_LINE_SIZE);
+}
+
+
+template <typename T>
+gb_internal MapIndex string_map__add_entry(StringMap<T> *h, u32 hash, String const &key) {
+	StringMapEntry<T> e = {};
+	e.key = key;
+	e.hash = hash;
+	e.next = MAP_SENTINEL;
+	if (h->count+1 >= h->entries_capacity) {
+		string_map__reserve_entries(h, gb_max(h->entries_capacity*2, 4));
+	}
+	h->entries[h->count++] = e;
+	return cast(MapIndex)(h->count-1);
+}
+
+template <typename T>
+gb_internal MapFindResult string_map__find(StringMap<T> *h, u32 hash, String const &key) {
+	MapFindResult fr = {MAP_SENTINEL, MAP_SENTINEL, MAP_SENTINEL};
+	if (h->hashes_count != 0) {
+		fr.hash_index = cast(MapIndex)(hash & (h->hashes_count-1));
+		fr.entry_index = h->hashes[fr.hash_index];
+		while (fr.entry_index != MAP_SENTINEL) {
+			auto *entry = &h->entries[fr.entry_index];
+			if (entry->hash == hash && entry->key == key) {
+				return fr;
+			}
+			fr.entry_prev = fr.entry_index;
+			fr.entry_index = entry->next;
+		}
+	}
+	return fr;
+}
+
+template <typename T>
+gb_internal MapFindResult string_map__find_from_entry(StringMap<T> *h, StringMapEntry<T> *e) {
+	MapFindResult fr = {MAP_SENTINEL, MAP_SENTINEL, MAP_SENTINEL};
+	if (h->hashes_count != 0) {
+		fr.hash_index  = cast(MapIndex)(e->hash & (h->hashes_count-1));
+		fr.entry_index = h->hashes[fr.hash_index];
+		while (fr.entry_index != MAP_SENTINEL) {
+			auto *entry = &h->entries[fr.entry_index];
+			if (entry == e) {
+				return fr;
+			}
+			fr.entry_prev = fr.entry_index;
+			fr.entry_index = entry->next;
+		}
+	}
+	return fr;
+}
+
+template <typename T>
+gb_internal b32 string_map__full(StringMap<T> *h) {
+	return 0.75f * h->hashes_count <= h->count;
+}
+
+template <typename T>
+gb_inline void string_map_grow(StringMap<T> *h) {
+	isize new_count = gb_max(h->hashes_count<<1, 16);
+	string_map_reserve(h, new_count);
+}
+
+
+template <typename T>
+gb_internal void string_map_reset_entries(StringMap<T> *h) {
+	for (u32 i = 0; i < h->hashes_count; i++) {
+		h->hashes[i] = MAP_SENTINEL;
+	}
+	for (isize i = 0; i < h->count; i++) {
+		MapFindResult fr;
+		StringMapEntry<T> *e = &h->entries[i];
+		e->next = MAP_SENTINEL;
+		fr = string_map__find_from_entry(h, e);
+		if (fr.entry_prev == MAP_SENTINEL) {
+			h->hashes[fr.hash_index] = cast(MapIndex)i;
+		} else {
+			h->entries[fr.entry_prev].next = cast(MapIndex)i;
+		}
+	}
+}
+
+template <typename T>
+gb_internal void string_map_reserve(StringMap<T> *h, usize cap) {
+	if (h->count*2 < h->hashes_count) {
+		return;
+	}
+	string_map__reserve_entries(h, cap);
+	string_map__resize_hashes(h,   cap*2);
+	string_map_reset_entries(h);
+}
+
+template <typename T>
+gb_internal T *string_map_get(StringMap<T> *h, u32 hash, String const &key) {
+	MapFindResult fr = {MAP_SENTINEL, MAP_SENTINEL, MAP_SENTINEL};
+	if (h->hashes_count != 0) {
+		fr.hash_index = cast(MapIndex)(hash & (h->hashes_count-1));
+		fr.entry_index = h->hashes[fr.hash_index];
+		while (fr.entry_index != MAP_SENTINEL) {
+			auto *entry = &h->entries[fr.entry_index];
+			if (entry->hash == hash && entry->key == key) {
+				return &entry->value;
+			}
+			fr.entry_prev = fr.entry_index;
+			fr.entry_index = entry->next;
+		}
+	}
+	return nullptr;
+}
+
+
+template <typename T>
+gb_internal gb_inline T *string_map_get(StringMap<T> *h, StringHashKey const &key) {
+	return string_map_get(h, key.hash, key.string);
+}
+
+template <typename T>
+gb_internal gb_inline T *string_map_get(StringMap<T> *h, String const &key) {
+	return string_map_get(h, string_hash(key), key);
+}
+
+template <typename T>
+gb_internal gb_inline T *string_map_get(StringMap<T> *h, char const *key) {
+	String k = make_string_c(key);
+	return string_map_get(h, string_hash(k), k);
+}
+
+template <typename T>
+gb_internal T &string_map_must_get(StringMap<T> *h, u32 hash, String const &key) {
+	isize index = string_map__find(h, hash, key).entry_index;
+	GB_ASSERT(index != MAP_SENTINEL);
+	return h->entries[index].value;
+}
+
+template <typename T>
+gb_internal T &string_map_must_get(StringMap<T> *h, StringHashKey const &key) {
+	return string_map_must_get(h, key.hash, key.string);
+}
+
+template <typename T>
+gb_internal gb_inline T &string_map_must_get(StringMap<T> *h, String const &key) {
+	return string_map_must_get(h, string_hash(key), key);
+}
+
+template <typename T>
+gb_internal gb_inline T &string_map_must_get(StringMap<T> *h, char const *key) {
+	String k = make_string_c(key);
+	return string_map_must_get(h, string_hash(k), k);
+}
+
+template <typename T>
+gb_internal void string_map_set(StringMap<T> *h, u32 hash, String const &key, T const &value) {
+	MapIndex index;
+	MapFindResult fr;
+	if (h->hashes_count == 0) {
+		string_map_grow(h);
+	}
+	fr = string_map__find(h, hash, key);
+	if (fr.entry_index != MAP_SENTINEL) {
+		index = fr.entry_index;
+	} else {
+		index = string_map__add_entry(h, hash, key);
+		if (fr.entry_prev != MAP_SENTINEL) {
+			h->entries[fr.entry_prev].next = index;
+		} else {
+			h->hashes[fr.hash_index] = index;
+		}
+	}
+	h->entries[index].value = value;
+
+	if (string_map__full(h)) {
+		string_map_grow(h);
+	}
+}
+
+template <typename T>
+gb_internal gb_inline void string_map_set(StringMap<T> *h, String const &key, T const &value) {
+	string_map_set(h, string_hash_string(key), value);
+}
+
+template <typename T>
+gb_internal gb_inline void string_map_set(StringMap<T> *h, char const *key, T const &value) {
+	string_map_set(h, string_hash_string(make_string_c(key)), value);
+}
+
+template <typename T>
+gb_internal gb_inline void string_map_set(StringMap<T> *h, StringHashKey const &key, T const &value) {
+	string_map_set(h, key.hash, key.string, value);
+}
+
+
+template <typename T>
+gb_internal gb_inline void string_map_clear(StringMap<T> *h) {
+	h->count = 0;
+	for (u32 i = 0; i < h->hashes_count; i++) {
+		h->hashes[i] = MAP_SENTINEL;
+	}
+}
+
+
+
+template <typename T>
+gb_internal StringMapEntry<T> *begin(StringMap<T> &m) noexcept {
+	return m.entries;
+}
+template <typename T>
+gb_internal StringMapEntry<T> const *begin(StringMap<T> const &m) noexcept {
+	return m.entries;
+}
+
+
+template <typename T>
+gb_internal StringMapEntry<T> *end(StringMap<T> &m) noexcept {
+	return m.entries + m.count;
+}
+
+template <typename T>
+gb_internal StringMapEntry<T> const *end(StringMap<T> const &m) noexcept {
+	return m.entries + m.count;
+}
+
+#else /* new string map */
+
 template <typename T>
 struct StringMapEntry {
 	String key;
@@ -305,3 +595,5 @@ gb_internal StringMapIterator<T> const begin(StringMap<T> const &m) noexcept {
 	}
 	return StringMapIterator<T>{&m, index};
 }
+
+#endif