godot/core/string_buffer.h
Hein-Pieter van Braam 0e29f7974b Reduce unnecessary COW on Vector by make writing explicit
This commit makes operator[] on Vector const and adds a write proxy to it.  From
now on writes to Vectors need to happen through the .write proxy. So for
instance:

Vector<int> vec;
vec.push_back(10);
std::cout << vec[0] << std::endl;
vec.write[0] = 20;

Failing to use the .write proxy will cause a compilation error.

In addition COWable datatypes can now embed a CowData pointer to their data.
This means that String, CharString, and VMap no longer use or derive from
Vector.

_ALWAYS_INLINE_ and _FORCE_INLINE_ are now equivalent for debug and non-debug
builds. This is a lot faster for Vector in the editor and while running tests.
The reason why this difference used to exist is because force-inlined methods
used to give a bad debugging experience. After extensive testing with modern
compilers this is no longer the case.
2018-07-26 00:54:16 +02:00

168 lines
5.5 KiB
C++

/*************************************************************************/
/* string_buffer.h */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2018 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2018 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_BUFFER_H
#define STRING_BUFFER_H
#include "ustring.h"
#include <string.h>
template <int SHORT_BUFFER_SIZE = 64>
class StringBuffer {
CharType short_buffer[SHORT_BUFFER_SIZE];
String buffer;
int string_length;
_FORCE_INLINE_ CharType *current_buffer_ptr() {
return static_cast<String &>(buffer).empty() ? short_buffer : buffer.ptrw();
}
public:
StringBuffer &append(CharType p_char);
StringBuffer &append(const String &p_string);
StringBuffer &append(const char *p_str);
StringBuffer &append(const CharType *p_str, int p_clip_to_len = -1);
_FORCE_INLINE_ void operator+=(CharType p_char) {
append(p_char);
}
_FORCE_INLINE_ void operator+=(const String &p_string) {
append(p_string);
}
_FORCE_INLINE_ void operator+=(const char *p_str) {
append(p_str);
}
_FORCE_INLINE_ void operator+=(const CharType *p_str) {
append(p_str);
}
StringBuffer &reserve(int p_size);
int length() const;
String as_string();
double as_double();
int64_t as_int();
_FORCE_INLINE_ operator String() {
return as_string();
}
StringBuffer() {
string_length = 0;
}
};
template <int SHORT_BUFFER_SIZE>
StringBuffer<SHORT_BUFFER_SIZE> &StringBuffer<SHORT_BUFFER_SIZE>::append(CharType p_char) {
reserve(string_length + 2);
current_buffer_ptr()[string_length++] = p_char;
return *this;
}
template <int SHORT_BUFFER_SIZE>
StringBuffer<SHORT_BUFFER_SIZE> &StringBuffer<SHORT_BUFFER_SIZE>::append(const String &p_string) {
return append(p_string.c_str());
}
template <int SHORT_BUFFER_SIZE>
StringBuffer<SHORT_BUFFER_SIZE> &StringBuffer<SHORT_BUFFER_SIZE>::append(const char *p_str) {
int len = strlen(p_str);
reserve(string_length + len + 1);
CharType *buf = current_buffer_ptr();
for (const char *c_ptr = p_str; *c_ptr; ++c_ptr) {
buf[string_length++] = *c_ptr;
}
return *this;
}
template <int SHORT_BUFFER_SIZE>
StringBuffer<SHORT_BUFFER_SIZE> &StringBuffer<SHORT_BUFFER_SIZE>::append(const CharType *p_str, int p_clip_to_len) {
int len = 0;
while ((p_clip_to_len < 0 || len < p_clip_to_len) && p_str[len]) {
++len;
}
reserve(string_length + len + 1);
memcpy(&(current_buffer_ptr()[string_length]), p_str, len * sizeof(CharType));
string_length += len;
return *this;
}
template <int SHORT_BUFFER_SIZE>
StringBuffer<SHORT_BUFFER_SIZE> &StringBuffer<SHORT_BUFFER_SIZE>::reserve(int p_size) {
if (p_size < SHORT_BUFFER_SIZE || p_size < buffer.size())
return *this;
bool need_copy = string_length > 0 && buffer.empty();
buffer.resize(next_power_of_2(p_size));
if (need_copy) {
memcpy(buffer.ptrw(), short_buffer, string_length * sizeof(CharType));
}
return *this;
}
template <int SHORT_BUFFER_SIZE>
int StringBuffer<SHORT_BUFFER_SIZE>::length() const {
return string_length;
}
template <int SHORT_BUFFER_SIZE>
String StringBuffer<SHORT_BUFFER_SIZE>::as_string() {
current_buffer_ptr()[string_length] = '\0';
if (buffer.empty()) {
return String(short_buffer);
} else {
buffer.resize(string_length + 1);
return buffer;
}
}
template <int SHORT_BUFFER_SIZE>
double StringBuffer<SHORT_BUFFER_SIZE>::as_double() {
current_buffer_ptr()[string_length] = '\0';
return String::to_double(current_buffer_ptr());
}
template <int SHORT_BUFFER_SIZE>
int64_t StringBuffer<SHORT_BUFFER_SIZE>::as_int() {
current_buffer_ptr()[string_length] = '\0';
return String::to_int(current_buffer_ptr());
}
#endif