From 946922b365befebcf03ceab0c5eae9c284465def Mon Sep 17 00:00:00 2001
From: John Hodge <tpg@prelude.mutabah.net>
Date: Thu, 15 Apr 2010 10:09:47 +0800
Subject: [PATCH] Added the ADT library (not really abstract, but it's a common
 data type library) - Currenly only includes Ring Buffer code

---
 Kernel/adt.c         | 57 ++++++++++++++++++++++++++++++++++++++++++++
 Kernel/include/adt.h | 33 +++++++++++++++++++++++++
 2 files changed, 90 insertions(+)
 create mode 100644 Kernel/adt.c
 create mode 100644 Kernel/include/adt.h

diff --git a/Kernel/adt.c b/Kernel/adt.c
new file mode 100644
index 00000000..7a238341
--- /dev/null
+++ b/Kernel/adt.c
@@ -0,0 +1,57 @@
+/*
+ */
+#include <acess.h>
+#include <adt.h>
+
+// === CODE ===
+// --- Ring Buffers ---
+tRingBuffer *RingBuffer_Create(size_t Space)
+{
+	tRingBuffer	*ret = malloc(sizeof(tRingBuffer)+Space);
+	ret->Start = 0;
+	ret->Length = 0;
+	ret->Space = Space;
+	return ret;
+}
+
+size_t RingBuffer_Read(void *Dest, tRingBuffer *Buffer, size_t Length)
+{
+	if(Length > Buffer->Length)	Length = Buffer->Length;
+	
+	if( Buffer->Start + Length > Buffer->Space )
+	{
+		 int	endData = Buffer->Space - Buffer->Start;
+		memcpy(Dest, &Buffer->Data[Buffer->Start], endData);
+		memcpy(Dest + endData, &Buffer->Data, Length - endData);
+	}
+	else
+	{
+		memcpy(Dest, &Buffer->Data[Buffer->Start], Length);
+	}
+	Buffer->Length -= Length;
+	return Length;
+}
+
+size_t RingBuffer_Write(tRingBuffer *Buffer, void *Source, size_t Length)
+{
+	size_t	bufEnd = Buffer->Start + Buffer->Length;
+	size_t	endSpace = Buffer->Space - bufEnd;
+	
+	// Force to bounds
+	if(Length > Buffer->Space - Buffer->Length)
+		Length = Buffer->Space - Buffer->Length;
+	
+	if(endSpace < Length)
+	{
+		memcpy( &Buffer->Data[bufEnd], Source, endSpace );
+		memcpy( Buffer->Data, Source + endSpace, Length - endSpace );
+		Buffer->Length = Length - endSpace;
+	}
+	else
+	{
+		memcpy( &Buffer->Data[bufEnd], Source, Length );
+		Buffer->Length += Length;
+	}
+	
+	return Length;
+}
diff --git a/Kernel/include/adt.h b/Kernel/include/adt.h
new file mode 100644
index 00000000..724877c6
--- /dev/null
+++ b/Kernel/include/adt.h
@@ -0,0 +1,33 @@
+/* 
+ * Acess2
+ * - Abstract Data Types
+ */
+#ifndef _ADT_H_
+#define _ADT_H_
+
+/**
+ * \name Ring Buffer
+ * \{
+ */
+typedef struct sRingBuffer
+{
+	size_t	Start;
+	size_t	Length;
+	size_t	Space;
+	char	Data[];
+}	tRingBuffer;
+
+/**
+ * \brief Create a ring buffer \a Space bytes large
+ * \param Space	Ammount of space to allocate within the buffer
+ * \return Pointer to the buffer structure
+ */
+extern tRingBuffer	*RingBuffer_Create(size_t Space);
+extern size_t	RingBuffer_Read(void *Dest, tRingBuffer *Buffer, size_t Length);
+extern size_t	RingBuffer_Write(tRingBuffer *Buffer, void *Source, size_t Length);
+/**
+ * \}
+ */
+
+
+#endif
-- 
2.20.1