BString::Private class to access BString internals

headers/build/private/support/StringPrivate.h

@@ -0,0 +1 @@
+#include <../private/support/StringPrivate.h>

headers/os/support/String.h

@@ -321,9 +321,20 @@ public:
 			BString&		operator<<(float value);
 			BString&		operator<<(double value);
 
+public:
+			class Private;
+			friend class Private;
+
 private:
-	class PosVect;
+			class PosVect;
-	friend class BStringRef;
+			friend class BStringRef;
+
+			enum PrivateDataTag {
+				PRIVATE_DATA
+			};
+
+private:
+							BString(char* privateData, PrivateDataTag tag);
 
 			// Management
 			status_t		_MakeWritable();

headers/private/support/StringPrivate.h

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2011, Ingo Weinhold, [email protected].
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef _SUPPORT_BSTRING_PRIVATE_H_
+#define _SUPPORT_BSTRING_PRIVATE_H_
+
+
+#include <stdlib.h>
+
+#include <String.h>
+
+
+class BString::Private {
+public:
+	static const uint32 kPrivateDataOffset = 2 * sizeof(int32);
+
+public:
+	Private(const BString& string)
+		:
+		fString(string)
+	{
+	}
+
+	char* Data()
+	{
+		return fString.fPrivateData;
+	}
+
+	static vint32& DataRefCount(char* data)
+	{
+		return *(((int32 *)data) - 2);
+	}
+
+	vint32& DataRefCount()
+	{
+		return DataRefCount(Data());
+	}
+
+	static int32& DataLength(char* data)
+	{
+		return *(((int32*)data) - 1);
+	}
+
+	int32& DataLength()
+	{
+		return DataLength(Data());
+	}
+
+	static void IncrementDataRefCount(char* data)
+	{
+		if (data != NULL)
+			atomic_add(&DataRefCount(data), 1);
+	}
+
+	static void DecrementDataRefCount(char* data)
+	{
+		if (data != NULL) {
+			if (atomic_add(&DataRefCount(data), -1) == 1)
+				free(data - kPrivateDataOffset);
+		}
+	}
+
+	static BString StringFromData(char* data)
+	{
+		return BString(data, BString::PRIVATE_DATA);
+	}
+
+private:
+	const BString&	fString;
+};
+
+
+#endif	// _SUPPORT_BSTRING_PRIVATE_H_
+

src/build/libbe/support/Jamfile

@@ -1,6 +1,6 @@
 SubDir HAIKU_TOP src build libbe support ;
 
-UsePrivateBuildHeaders app interface shared ;
+UsePrivateBuildHeaders app interface shared support ;
 
 USES_BE_API on <libbe_build>support_kit.o = true ;
 

src/kits/support/String.cpp

@@ -23,6 +23,7 @@
 
 #include <Debug.h>
 
+#include <StringPrivate.h>
 #include <utf8_functions.h>
 
 
@@ -34,7 +35,7 @@
 #define REPLACE_ALL 0x7FFFFFFF
 
 
-const uint32 kPrivateDataOffset = 2 * sizeof(int32);
+static const uint32 kPrivateDataOffset = BString::Private::kPrivateDataOffset;
 
 const char* B_EMPTY_STRING = "";
 
@@ -79,20 +80,6 @@ safestr(const char* str)
 }
 
 
-static inline vint32&
-data_reference_count(char* data)
-{
-	return *(((int32 *)data) - 2);
-}
-
-
-static inline int32&
-data_length(char* data)
-{
-	return *(((int32*)data) - 1);
-}
-
-
 //	#pragma mark - PosVect
 
 
@@ -202,14 +189,14 @@ BStringRef::operator&()
 inline vint32&
 BString::_ReferenceCount()
 {
-	return data_reference_count(fPrivateData);
+	return Private::DataRefCount(fPrivateData);
 }
 
 
 inline const vint32&
 BString::_ReferenceCount() const
 {
-	return data_reference_count(fPrivateData);
+	return Private::DataRefCount(fPrivateData);
 }
 
 
@@ -2132,6 +2119,15 @@ BString::operator<<(double value)
 //	#pragma mark - Private or reserved
 
 
+BString::BString(char* privateData, PrivateDataTag tag)
+	:
+	fPrivateData(privateData)
+{
+	if (fPrivateData != NULL)
+		atomic_add(&_ReferenceCount(), 1);
+}
+
+
 /*!	Detaches this string from an eventually shared fPrivateData, ie. this makes
 	this string writable.
 */
@@ -2210,8 +2206,8 @@ BString::_Allocate(int32 length)
 	newData[length] = '\0';
 
 	// initialize reference count & length
-	data_reference_count(newData) = 1;
+	Private::DataRefCount(newData) = 1;
-	data_length(newData) = length & 0x7fffffff;
+	Private::DataLength(newData) = length & 0x7fffffff;
 
 	return newData;
 }
@@ -2303,7 +2299,7 @@ BString::_ShrinkAtBy(int32 offset, int32 length)
 void
 BString::_SetLength(int32 length)
 {
-	data_length(fPrivateData) = length & 0x7fffffff;
+	Private::DataLength(fPrivateData) = length & 0x7fffffff;
 }