godot/core/string/string_name.h
reduz 8580f377a3 Implement Scene Unique Nodes
Implements https://github.com/godotengine/godot-proposals/issues/4096

* Nodes can be marked unique to the scene in the editor (or via code).
* Unique nodes can be accessed via the **%** prefix at any point in the path. From that point in the path (depending on whether the scene of the path is), the unique node will be fetched.
* Implementation is very optimal, as these nodes are cached.
2022-04-25 12:19:17 +02:00

212 lines
7.1 KiB
C++

/*************************************************************************/
/* string_name.h */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md). */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#ifndef STRING_NAME_H
#define STRING_NAME_H
#include "core/os/mutex.h"
#include "core/string/ustring.h"
#include "core/templates/safe_refcount.h"
#define UNIQUE_NODE_PREFIX "%"
class Main;
struct StaticCString {
const char *ptr;
static StaticCString create(const char *p_ptr);
};
class StringName {
enum {
STRING_TABLE_BITS = 16,
STRING_TABLE_LEN = 1 << STRING_TABLE_BITS,
STRING_TABLE_MASK = STRING_TABLE_LEN - 1
};
struct _Data {
SafeRefCount refcount;
SafeNumeric<uint32_t> static_count;
const char *cname = nullptr;
String name;
#ifdef DEBUG_ENABLED
uint32_t debug_references = 0;
#endif
String get_name() const { return cname ? String(cname) : name; }
int idx = 0;
uint32_t hash = 0;
_Data *prev = nullptr;
_Data *next = nullptr;
_Data() {}
};
static _Data *_table[STRING_TABLE_LEN];
_Data *_data = nullptr;
union _HashUnion {
_Data *ptr = nullptr;
uint32_t hash;
};
void unref();
friend void register_core_types();
friend void unregister_core_types();
friend class Main;
static Mutex mutex;
static void setup();
static void cleanup();
static bool configured;
#ifdef DEBUG_ENABLED
struct DebugSortReferences {
bool operator()(const _Data *p_left, const _Data *p_right) const {
return p_left->debug_references > p_right->debug_references;
}
};
static bool debug_stringname;
#endif
StringName(_Data *p_data) { _data = p_data; }
public:
operator const void *() const { return (_data && (_data->cname || !_data->name.is_empty())) ? (void *)1 : nullptr; }
bool operator==(const String &p_name) const;
bool operator==(const char *p_name) const;
bool operator!=(const String &p_name) const;
_FORCE_INLINE_ bool is_node_unique_name() const {
if (!_data) {
return false;
}
if (_data->cname != nullptr) {
return (char32_t)_data->cname[0] == (char32_t)UNIQUE_NODE_PREFIX[0];
} else {
return (char32_t)_data->name[0] == (char32_t)UNIQUE_NODE_PREFIX[0];
}
}
_FORCE_INLINE_ bool operator<(const StringName &p_name) const {
return _data < p_name._data;
}
_FORCE_INLINE_ bool operator==(const StringName &p_name) const {
// the real magic of all this mess happens here.
// this is why path comparisons are very fast
return _data == p_name._data;
}
_FORCE_INLINE_ uint32_t hash() const {
if (_data) {
return _data->hash;
} else {
return 0;
}
}
_FORCE_INLINE_ const void *data_unique_pointer() const {
return (void *)_data;
}
bool operator!=(const StringName &p_name) const;
_FORCE_INLINE_ operator String() const {
if (_data) {
if (_data->cname) {
return String(_data->cname);
} else {
return _data->name;
}
}
return String();
}
static StringName search(const char *p_name);
static StringName search(const char32_t *p_name);
static StringName search(const String &p_name);
struct AlphCompare {
_FORCE_INLINE_ bool operator()(const StringName &l, const StringName &r) const {
const char *l_cname = l._data ? l._data->cname : "";
const char *r_cname = r._data ? r._data->cname : "";
if (l_cname) {
if (r_cname) {
return is_str_less(l_cname, r_cname);
} else {
return is_str_less(l_cname, r._data->name.ptr());
}
} else {
if (r_cname) {
return is_str_less(l._data->name.ptr(), r_cname);
} else {
return is_str_less(l._data->name.ptr(), r._data->name.ptr());
}
}
}
};
void operator=(const StringName &p_name);
StringName(const char *p_name, bool p_static = false);
StringName(const StringName &p_name);
StringName(const String &p_name, bool p_static = false);
StringName(const StaticCString &p_static_string, bool p_static = false);
StringName() {}
_FORCE_INLINE_ ~StringName() {
if (likely(configured) && _data) { //only free if configured
unref();
}
}
#ifdef DEBUG_ENABLED
static void set_debug_stringnames(bool p_enable) { debug_stringname = p_enable; }
#endif
};
bool operator==(const String &p_name, const StringName &p_string_name);
bool operator!=(const String &p_name, const StringName &p_string_name);
bool operator==(const char *p_name, const StringName &p_string_name);
bool operator!=(const char *p_name, const StringName &p_string_name);
StringName _scs_create(const char *p_chr, bool p_static = false);
/*
* The SNAME macro is used to speed up StringName creation, as it allows caching it after the first usage in a very efficient way.
* It should NOT be used everywhere, but instead in places where high performance is required and the creation of a StringName
* can be costly. Places where it should be used are:
* - Control::get_theme_*(<name> and Window::get_theme_*(<name> functions.
* - emit_signal(<name>,..) function
* - call_deferred(<name>,..) function
* - Comparisons to a StringName in overridden _set and _get methods.
*
* Use in places that can be called hundreds of times per frame (or more) is recommended, but this situation is very rare. If in doubt, do not use.
*/
#define SNAME(m_arg) ([]() -> const StringName & { static StringName sname = _scs_create(m_arg, true); return sname; })()
#endif // STRING_NAME_H