godot/core/string/optimized_translation.h

/**************************************************************************/
/*  optimized_translation.h                                               */
/**************************************************************************/
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/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
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#pragma once

#include "core/string/translation.h"

class OptimizedTranslation : public Translation {
	GDCLASS(OptimizedTranslation, Translation);

	// This translation uses a sort of modified perfect hash algorithm
	// it requires hashing strings twice and then does a binary search,
	// so it's slower, but at the same time it has an extremely high chance
	// of catching untranslated strings.

	// `hash_table[hash(0, text)]` produces a `bucket_table` index or 0xFFFFFFFF if not found.
	Vector<int> hash_table;

	// Continuous `Bucket`s in a flat layout.
	Vector<int> bucket_table;

	// Data for translated strings, UTF-8 encoded, either compressed or uncompressed.
	Vector<uint8_t> strings;

	struct Bucket {
		// Number of `Elem` objects at `elem`.
		int size;

		// Use `hash(func, text)` to generate the unique `Elem::key` in this bucket.
		uint32_t func;

		struct Elem {
			// Unique key for the text.
			uint32_t key;

			// Used to index into `strings`.
			uint32_t str_offset;

			// The string is not compressed if `comp_size` equals `uncomp_size`.
			uint32_t comp_size;
			uint32_t uncomp_size;
		};

		Elem elem[1];
	};

	_FORCE_INLINE_ uint32_t hash(uint32_t d, const char *p_str) const {
		if (d == 0) {
			d = 0x1000193;
		}
		while (*p_str) {
			d = (d * 0x1000193) ^ static_cast<uint8_t>(*p_str);
			p_str++;
		}

		return d;
	}

	virtual Vector<String> _get_message_list() const override;

protected:
	bool _set(const StringName &p_name, const Variant &p_value);
	bool _get(const StringName &p_name, Variant &r_ret) const;
	void _get_property_list(List<PropertyInfo> *p_list) const;
	static void _bind_methods();

public:
	virtual StringName get_message(const StringName &p_src_text, const StringName &p_context = "") const override; //overridable for other implementations
	virtual StringName get_plural_message(const StringName &p_src_text, const StringName &p_plural_text, int p_n, const StringName &p_context = "") const override;
	virtual Vector<String> get_translated_message_list() const override;
	void generate(const Ref<Translation> &p_from);

	virtual void get_message_list(List<StringName> *r_messages) const override;
	virtual int get_message_count() const override;
};