From 6832eaa9641f26725c8bae57a68d3d157beea3f3 Mon Sep 17 00:00:00 2001
From: harry <hrosen2016@gmail.com>
Date: Sun, 25 Feb 2024 16:08:35 -0500
Subject: [PATCH] Added custom string class that mirrors the C++ std::string
 API but also allows for fixed size buffers on the stack. This new class also
 has various C style functions (like sprintf) built into it.

---
 src/utils/StringUtils.h | 274 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 274 insertions(+)
 create mode 100644 src/utils/StringUtils.h

diff --git a/src/utils/StringUtils.h b/src/utils/StringUtils.h
new file mode 100644
index 00000000..ad175808
--- /dev/null
+++ b/src/utils/StringUtils.h
@@ -0,0 +1,274 @@
+// StringUtils.h
+#pragma once
+
+#include <string.h>
+#include <stdlib.h>
+
+#include "types.h"
+
+extern "C"
+{
+	// C Style string copy function that guarantees null termination
+	inline char *Strlcpy( char* dest, const char* src, size_t n )
+	{
+		if (n > 0)
+		{
+			size_t i=0;
+			n--; // minus 1 to make sure we have room for null byte
+			while ( (i < n) && (src[i] != 0) )
+			{
+				dest[i] = src[i]; i++;
+			}
+			dest[i] = 0; // Force Null
+		}
+		return dest;
+	}
+};
+
+#ifdef  __cplusplus
+
+#include <string>
+
+// Custom string type that will allows for fixed size strings on using stack memory with a similar C++ std::string API
+namespace FCEU
+{
+	template <typename T>
+	class BaseString
+	{
+		public:
+			BaseString(T* buffer = nullptr, size_t size = 0)
+			{
+				buf = buffer;
+				bufSize = size;
+				end = 0;
+			}
+
+			BaseString& assign( const T* str )
+			{
+				if (bufSize > 0)
+				{
+					size_t i=0;
+					const size_t bufEnd = bufSize - 1;
+					while ( (i < bufEnd) && (str[i] != 0) )
+					{
+						buf[i] = str[i]; i++;
+					}
+					buf[i] = 0;
+					end = i;
+				}
+				return *this;
+			}
+
+			BaseString& assign( BaseString& s )
+			{
+				assign( s.buf );
+
+				return *this;
+			}
+
+			BaseString& assign( std::string& s )
+			{
+				assign( s.c_str() );
+
+				return *this;
+			}
+
+			BaseString& append( const T* str )
+			{
+				if (bufSize > 0)
+				{
+					size_t j=0;
+					size_t i=end;
+					const size_t bufEnd = bufSize - 1;
+					while ( (i < bufEnd) && (str[j] != 0) )
+					{
+						buf[i] = str[j]; i++; j++;
+					}
+					buf[i] = 0;
+					end = i;
+				}
+				return *this;
+			}
+
+			BaseString& append( BaseString& s )
+			{
+				append( s.buf );
+
+				return *this;
+			}
+
+			BaseString& append( std::string& s )
+			{
+				append( s.c_str() );
+
+				return *this;
+			}
+
+			BaseString& operator= (const T* op)
+			{
+				assign(op);
+
+				return *this;
+			}
+
+			BaseString& operator= (BaseString& op)
+			{
+				assign(op);
+
+				return *this;
+			}
+
+			T& operator[] (int idx)
+			{
+				return buf[idx];
+			}
+
+			void clear()
+			{
+				if (bufSize > 0)
+				{
+					buf[0] = 0;
+				}
+				end = 0;
+			}
+
+			const T* c_str()
+			{
+				return buf;
+			}
+
+			size_t size()
+			{
+				return end;
+			}
+
+			std::string toStdString()
+			{
+				return std::string(c_str());
+			}
+
+			int sprintf( __FCEU_PRINTF_FORMAT const char *format, ...) __FCEU_PRINTF_ATTRIBUTE( 2, 3 )
+			{
+				int retval;
+				va_list args;
+				va_start(args, format);
+				retval = ::vsnprintf( buf, bufSize, format, args);
+				va_end(args);
+				return retval;
+			}
+
+			int append_sprintf( __FCEU_PRINTF_FORMAT const char *format, ...) __FCEU_PRINTF_ATTRIBUTE( 2, 3 )
+			{
+				int retval;
+				va_list args;
+				va_start(args, format);
+				size_t sizeAvail = 0;
+				if (bufSize > end)
+				{
+					sizeAvail = bufSize - end;
+				}
+				retval = ::vsnprintf( &buf[end], sizeAvail, format, args);
+				va_end(args);
+				return retval;
+			}
+
+			long strtol(int base = 10)
+			{
+				return ::strtol(buf, nullptr, base);
+			}
+
+			long long strtoll(int base = 10)
+			{
+				return ::strtoll(buf, nullptr, base);
+			}
+
+			unsigned long strtoul(int base = 10)
+			{
+				return ::strtoul(buf, nullptr, base);
+			}
+
+			unsigned long long strtoull(int base = 10)
+			{
+				return ::strtoull(buf, nullptr, base);
+			}
+
+		private:
+			T*      buf;
+			size_t  bufSize;
+			size_t  end;
+
+	};
+
+	template <size_t N, typename T = char>
+	class FixedString : public BaseString<T>
+	{
+		public:
+			FixedString()
+				: BaseString<T>( fixedBuffer, N )
+			{
+			}
+
+			FixedString(const char* initValue)
+				: BaseString<T>( fixedBuffer, N )
+			{
+				if (initValue != nullptr)
+				{
+					BaseString<T>::assign(initValue);
+				}
+			}
+
+			BaseString<T>& operator= (const T* op)
+			{
+				BaseString<T>::assign(op);
+
+				return *this;
+			}
+
+			BaseString<T>& operator= (BaseString<T>& op)
+			{
+				BaseString<T>::assign(op);
+
+				return *this;
+			}
+
+			BaseString<T>& operator= (std::string& op)
+			{
+				BaseString<T>::assign(op);
+
+				return *this;
+			}
+
+			BaseString<T>& operator+= (const T* op)
+			{
+				BaseString<T>::append(op);
+
+				return *this;
+			}
+
+			BaseString<T>& operator+= (BaseString<T>& op)
+			{
+				BaseString<T>::append(op);
+
+				return *this;
+			}
+
+			BaseString<T>& operator+= (std::string& op)
+			{
+				BaseString<T>::append(op);
+
+				return *this;
+			}
+
+			T& operator[] (int idx)
+			{
+				return fixedBuffer[idx];
+			}
+
+		private:
+			T fixedBuffer[N];
+	};
+
+
+};
+
+#endif