From 46725741fc82866e41652dee7adeddf376fde618 Mon Sep 17 00:00:00 2001
From: Mike Buland <eichlan@xagasoft.com>
Date: Thu, 15 Mar 2007 04:03:52 +0000
Subject: FString is totally usable, a few more helpers must be written before
 it surpases the other classes in functionality.  It's already rather fast.

---
 build.conf            |   1 +
 src/fstring.h         | 239 ++++++++++++++++++++++++++++++++++++++++++++++++--
 src/tests/fstring.cpp |  28 ++++++
 3 files changed, 260 insertions(+), 8 deletions(-)
 create mode 100644 src/tests/fstring.cpp

diff --git a/build.conf b/build.conf
index a9c6d49..5c4dbb6 100644
--- a/build.conf
+++ b/build.conf
@@ -4,6 +4,7 @@ default action: check "libbu++.a"
 "clean" action: clean targets()
 "tests" action: check targets() filter regexp("^tests/.*$")
 "all" action: check targets()
+"fstring" action: check "tests/fstring"
 
 set "CXXFLAGS" += "-ggdb -Wall"
 
diff --git a/src/fstring.h b/src/fstring.h
index 2eaa4ba..287641f 100644
--- a/src/fstring.h
+++ b/src/fstring.h
@@ -4,28 +4,251 @@
 #include <stdint.h>
 #include <memory>
 
+template< typename chr=char >
+struct FStringChunk
+{
+	long nLength;
+	chr *pData;
+	FStringChunk *pNext;
+};
+
 /**
  *
  */
-template< typename chr, typename chralloc = std::allocator<chr> >
-class FString
+template< typename chr=char, typename chralloc=std::allocator<chr>, typename chunkalloc=std::allocator<struct FStringChunk<chr> > >
+class FBasicString
 {
+private:
+	typedef struct FStringChunk<chr> Chunk;
+
 public:
-	FString() :
-		pData( NULL ),
-		pnRefs( NULL )
+	FBasicString() :
+		nLength( 0 ),
+		pnRefs( NULL ),
+		pFirst( NULL ),
+		pLast( NULL )
+	{
+	}
+
+	FBasicString( const chr *pData ) :
+		nLength( 0 ),
+		pnRefs( NULL ),
+		pFirst( NULL ),
+		pLast( NULL )
+	{
+		append( pData );
+	}
+
+	FBasicString( const chr *pData, long nLength ) :
+		nLength( 0 ),
+		pnRefs( NULL ),
+		pFirst( NULL ),
+		pLast( NULL )
+	{
+		append( pData, nLength );
+	}
+
+	virtual ~FBasicString()
+	{
+	}
+
+	void append( const chr *pData )
+	{
+		long nLen;
+		for( nLen = 0; pData[nLen] != (chr)0; nLen++ );
+		
+		Chunk *pNew = newChunk( nLen );
+		memcpy( pNew->pData, pData, nLen * sizeof(chr) );
+
+		appendChunk( pNew );
+	}
+
+	void append( const chr *pData, long nLen )
+	{
+		Chunk *pNew = newChunk( nLen );
+		
+		memcpy( pNew->pData, pData, nLen * sizeof(chr) );
+
+		appendChunk( pNew );
+	}
+
+	void prepend( const chr *pData )
+	{
+		long nLen;
+		for( nLen = 0; pData[nLen] != (chr)0; nLen++ );
+		
+		Chunk *pNew = newChunk( nLen );
+		memcpy( pNew->pData, pData, nLen * sizeof(chr) );
+
+		prependChunk( pNew );
+	}
+
+	void prepend( const chr *pData, long nLen )
+	{
+		Chunk *pNew = newChunk( nLen );
+		
+		memcpy( pNew->pData, pData, nLen * sizeof(chr) );
+
+		prependChunk( pNew );
+	}
+
+	void clear()
+	{
+		if( pFirst == NULL )
+			return;
+
+		Chunk *i = pFirst;
+		for(;;)
+		{
+			Chunk *n = i->pNext;
+			aChr.deallocate( i->pData, i->nLength+1 );
+			aChunk.deallocate( i, 1 );
+			if( n == NULL )
+				break;
+			i = n;
+		}
+		pFirst = pLast = NULL;
+		nLength = 0;
+	}
+
+	chr *c_str()
+	{
+		if( pFirst == NULL )
+			return NULL;
+
+		flatten();
+		return pFirst->pData;
+	}
+
+	FBasicString<chr, chralloc, chunkalloc> &operator +=( const chr *pData )
 	{
+		append( pData );
+
+		return (*this);
 	}
 
-	virtual ~FString()
+	FBasicString<chr, chralloc, chunkalloc> &operator =( const chr *pData )
 	{
+		clear();
+		append( pData );
+
+		return (*this);
+	}
+
+	bool operator ==( const chr *pData )
+	{
+		if( pFirst == NULL ) {
+			if( pData == NULL )
+				return true;
+			return false;
+		}
+
+		flatten();
+		const chr *a = pData;
+		chr *b = pFirst->pData;
+		for( ; *a!=(chr)0; a++, b++ )
+		{
+			if( *a != *b )
+				return false;
+		}
+
+		return true;
+	}
+
+	bool operator !=(const chr *pData )
+	{
+		return !(*this == pData);
+	}
+
+
+
+private:
+	void flatten()
+	{
+		if( isFlat() )
+			return;
+
+		if( pFirst == NULL )
+			return;
+
+		Chunk *pNew = newChunk( nLength );
+		chr *pos = pNew->pData;
+		Chunk *i = pFirst;
+		for(;;)
+		{
+			memcpy( pos, i->pData, i->nLength*sizeof(chr) );
+			pos += i->nLength;
+			i = i->pNext;
+			if( i == NULL )
+				break;
+		}
+		clear();
+
+		appendChunk( pNew );
+	}
+	
+	bool isFlat()
+	{
+		return (pFirst == pLast);
+	}
+
+	bool isShared()
+	{
+		return (pnRefs != NULL);
+	}
+
+	Chunk *newChunk()
+	{
+		Chunk *pNew = aChunk.allocate( 1 );
+		pNew->pNext = NULL;
+		return pNew;
+	}
+	
+	Chunk *newChunk( long nLen )
+	{
+		Chunk *pNew = aChunk.allocate( 1 );
+		pNew->pNext = NULL;
+		pNew->nLength = nLen;
+		pNew->pData = aChr.allocate( nLen+1 );
+		return pNew;
+	}
+
+	void appendChunk( Chunk *pNewChunk )
+	{
+		if( pFirst == NULL )
+			pLast = pFirst = pNewChunk;
+		else
+		{
+			pLast->pNext = pNewChunk;
+			pLast = pNewChunk;
+		}
+
+		nLength += pNewChunk->nLength;
+	}
+	
+	void prependChunk( Chunk *pNewChunk )
+	{
+		if( pFirst == NULL )
+			pLast = pFirst = pNewChunk;
+		else
+		{
+			pNewChunk->pNext = pFirst;
+			pFirst = pNewChunk;
+		}
+
+		nLength += pNewChunk->nLength;
 	}
 
 private:
 	long nLength;
-	chr *pData;
 	uint32_t *pnRefs;
-	chralloc aChars;
+	Chunk *pFirst;
+	Chunk *pLast;
+
+	chralloc aChr;
+	chunkalloc aChunk;
 };
 
+typedef FBasicString<char> FString;
+
 #endif
diff --git a/src/tests/fstring.cpp b/src/tests/fstring.cpp
new file mode 100644
index 0000000..26905ac
--- /dev/null
+++ b/src/tests/fstring.cpp
@@ -0,0 +1,28 @@
+#include "fstring.h"
+
+int main( int argc, char *argv )
+{
+	FString str("[] this won't be in there", 3);
+
+	str.append("Hello");
+	str.append(" th");
+	str.append("ere.");
+
+	if( str == "[] Hello there." )
+		printf("1) check\n");
+
+	if( str != "[] Hello there. " )
+		printf("2) check\n");
+
+	if( str != "[] Hello there." )
+		printf("3) failed\n");
+	else
+		printf("3) check\n");
+
+	str += "  How are you?";
+
+	str.prepend("Bob says:  ");
+
+	printf("%s\n", str.c_str() );
+}
+
-- 
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