libwinpr-utils: initial BipBuffer implementation

winpr/include/winpr/collections.h

@@ -623,6 +623,41 @@ WINPR_API int PubSub_OnEvent(wPubSub* pubSub, const char* EventName, void* conte
 WINPR_API wPubSub* PubSub_New(BOOL synchronized);
 WINPR_API void PubSub_Free(wPubSub* pubSub);
 
+/* BipBuffer */
+
+struct _wBipBuffer
+{
+	size_t size;
+	BYTE* buffer;
+	size_t headA;
+	size_t sizeA;
+	size_t headB;
+	size_t sizeB;
+	size_t headR;
+	size_t sizeR;
+};
+typedef struct _wBipBuffer wBipBuffer;
+
+WINPR_API BOOL BipBuffer_Grow(wBipBuffer* bb, size_t size);
+WINPR_API void BipBuffer_Clear(wBipBuffer* bb);
+
+WINPR_API size_t BipBuffer_BufferSize(wBipBuffer* bb);
+WINPR_API size_t BipBuffer_CommittedSize(wBipBuffer* bb);
+WINPR_API size_t BipBuffer_ReservedSize(wBipBuffer* bb);
+
+WINPR_API BYTE* BipBuffer_Reserve(wBipBuffer* bb, size_t size);
+WINPR_API BYTE* BipBuffer_TryReserve(wBipBuffer* bb, size_t size, size_t* reserved);
+WINPR_API void BipBuffer_Commit(wBipBuffer* bb, size_t size);
+
+WINPR_API BYTE* BipBuffer_PeekBlock(wBipBuffer* bb, size_t* size);
+WINPR_API void BipBuffer_Decommit(wBipBuffer* bb, size_t size);
+
+WINPR_API int BipBuffer_Read(wBipBuffer* bb, BYTE* data, size_t size);
+WINPR_API int BipBuffer_Write(wBipBuffer* bb, BYTE* data, size_t size);
+
+WINPR_API wBipBuffer* BipBuffer_New(size_t size);
+WINPR_API void BipBuffer_Free(wBipBuffer* bb);
+
 #ifdef __cplusplus
 }
 #endif

winpr/libwinpr/utils/CMakeLists.txt

@@ -21,6 +21,7 @@ set(${MODULE_PREFIX}_COLLECTIONS_SRCS
 	collections/Queue.c
 	collections/Stack.c
 	collections/PubSub.c
+	collections/BipBuffer.c
 	collections/BitStream.c
 	collections/Reference.c
 	collections/ArrayList.c

winpr/libwinpr/utils/collections/BipBuffer.c

@@ -0,0 +1,358 @@
+/**
+ * WinPR: Windows Portable Runtime
+ * BipBuffer
+ *
+ * Copyright 2014 Marc-Andre Moreau <marcandre.moreau@gmail.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <winpr/crt.h>
+
+#include <winpr/collections.h>
+
+/**
+ * The Bip Buffer - The Circular Buffer with a Twist:
+ * http://www.codeproject.com/Articles/3479/The-Bip-Buffer-The-Circular-Buffer-with-a-Twist
+ */
+
+void BipBuffer_Clear(wBipBuffer* bb)
+{
+	bb->headA = 0;
+	bb->sizeA = 0;
+	bb->headB = 0;
+	bb->sizeB = 0;
+	bb->headR = 0;
+	bb->sizeR = 0;
+}
+
+BOOL BipBuffer_AllocBuffer(wBipBuffer* bb, size_t size)
+{
+	if (size < 1)
+		return FALSE;
+
+	bb->buffer = (BYTE*) malloc(size);
+
+	if (!bb->buffer)
+		return FALSE;
+
+	bb->size = size;
+
+	return TRUE;
+}
+
+BOOL BipBuffer_Grow(wBipBuffer* bb, size_t size)
+{
+	BYTE* block;
+	BYTE* buffer;
+	size_t blockSize = 0;
+	size_t commitSize = 0;
+
+	size += size % 4096;
+
+	if (size <= bb->size)
+		return TRUE;
+
+	buffer = (BYTE*) malloc(size);
+
+	if (!buffer)
+		return FALSE;
+
+	block = BipBuffer_PeekBlock(bb, &blockSize);
+
+	if (block)
+	{
+		CopyMemory(&buffer[commitSize], block, blockSize);
+		BipBuffer_Decommit(bb, blockSize);
+		commitSize += blockSize;
+	}
+
+	block = BipBuffer_PeekBlock(bb, &blockSize);
+
+	if (block)
+	{
+		CopyMemory(&buffer[commitSize], block, blockSize);
+		BipBuffer_Decommit(bb, blockSize);
+		commitSize += blockSize;
+	}
+
+	BipBuffer_Clear(bb);
+
+	free(bb->buffer);
+	bb->buffer = buffer;
+	bb->size = size;
+
+	bb->headA = 0;
+	bb->sizeA = commitSize;
+
+	return TRUE;
+}
+
+void BipBuffer_FreeBuffer(wBipBuffer* bb)
+{
+	if (bb->buffer)
+	{
+		free(bb->buffer);
+		bb->buffer = NULL;
+	}
+
+	BipBuffer_Clear(bb);
+}
+
+size_t BipBuffer_BufferSize(wBipBuffer* bb)
+{
+	return bb->size;
+}
+
+size_t BipBuffer_CommittedSize(wBipBuffer* bb)
+{
+	return bb->sizeA + bb->sizeB;
+}
+
+size_t BipBuffer_ReservedSize(wBipBuffer* bb)
+{
+	return bb->sizeR;
+}
+
+BYTE* BipBuffer_TryReserve(wBipBuffer* bb, size_t size, size_t* reserved)
+{
+	size_t freeSpace;
+
+	if (!bb->sizeB)
+	{
+		/* block B does not exist */
+
+		freeSpace = bb->size - bb->headA - bb->sizeA; /* space after block A */
+
+		if (freeSpace >= bb->headA)
+		{
+			if (freeSpace == 0)
+				return NULL;
+
+			if (size < freeSpace)
+				freeSpace = size;
+
+			bb->sizeR = freeSpace;
+			*reserved = freeSpace;
+
+			bb->headR = bb->headA + bb->sizeA;
+			return &bb->buffer[bb->headR];
+		}
+
+		if (bb->headA == 0)
+			return NULL;
+
+		if (bb->headA < size)
+			size = bb->headA;
+
+		bb->sizeR = size;
+		*reserved = size;
+
+		bb->headR = 0;
+		return bb->buffer;
+	}
+
+	/* block B exists */
+
+	freeSpace = bb->headA - bb->headB - bb->sizeB; /* space after block B */
+
+	if (size < freeSpace)
+		freeSpace = size;
+
+	if (freeSpace == 0)
+		return NULL;
+
+	bb->sizeR = freeSpace;
+	*reserved = freeSpace;
+
+	bb->headR = bb->headB + bb->sizeB;
+	return &bb->buffer[bb->headR];
+}
+
+BYTE* BipBuffer_Reserve(wBipBuffer* bb, size_t size)
+{
+	BYTE* block = NULL;
+	size_t reserved = 0;
+
+	block = BipBuffer_TryReserve(bb, size, &reserved);
+
+	if (reserved == size)
+		return block;
+
+	if (!BipBuffer_Grow(bb, size))
+		return NULL;
+
+	block = BipBuffer_TryReserve(bb, size, &reserved);
+
+	return block;
+}
+
+void BipBuffer_Commit(wBipBuffer* bb, size_t size)
+{
+	if (size == 0)
+	{
+		bb->headR = 0;
+		bb->sizeR = 0;
+		return;
+	}
+
+	if (size > bb->sizeR)
+		size = bb->sizeR;
+
+	if ((bb->sizeA == 0) && (bb->sizeB == 0))
+	{
+		bb->headA = bb->headR;
+		bb->sizeA = size;
+		bb->headR = 0;
+		bb->sizeR = 0;
+		return;
+	}
+
+	if (bb->headR == (bb->sizeA + bb->headA))
+		bb->sizeA += size;
+	else
+		bb->sizeB += size;
+
+	bb->headR = 0;
+	bb->sizeR = 0;
+}
+
+BYTE* BipBuffer_PeekBlock(wBipBuffer* bb, size_t* size)
+{
+	if (bb->sizeA == 0)
+	{
+		*size = 0;
+		return NULL;
+	}
+
+	*size = bb->sizeA;
+
+	return &bb->buffer[bb->headA];
+}
+
+void BipBuffer_Decommit(wBipBuffer* bb, size_t size)
+{
+	if (!bb)
+		return;
+
+	if (size >= bb->sizeA)
+	{
+		bb->headA = bb->headB;
+		bb->sizeA = bb->sizeB;
+		bb->headB = 0;
+		bb->sizeB = 0;
+	}
+	else
+	{
+		bb->sizeA -= size;
+		bb->headA += size;
+	}
+}
+
+int BipBuffer_Read(wBipBuffer* bb, BYTE* data, size_t size)
+{
+	int status = 0;
+	BYTE* block = NULL;
+	size_t readSize = 0;
+	size_t blockSize = 0;
+
+	if (!bb)
+		return -1;
+
+	block = BipBuffer_PeekBlock(bb, &blockSize);
+
+	if (block)
+	{
+		readSize = size - status;
+
+		if (readSize > blockSize)
+			readSize = blockSize;
+
+		CopyMemory(&data[status], block, readSize);
+		BipBuffer_Decommit(bb, readSize);
+		status += readSize;
+
+		if ((status == size) || (readSize < blockSize))
+			return status;
+	}
+
+	block = BipBuffer_PeekBlock(bb, &blockSize);
+
+	if (block)
+	{
+		readSize = size - status;
+
+		if (readSize > blockSize)
+			readSize = blockSize;
+
+		CopyMemory(&data[status], block, readSize);
+		BipBuffer_Decommit(bb, readSize);
+		status += readSize;
+
+		if ((status == size) || (readSize < blockSize))
+			return status;
+	}
+
+	return status;
+}
+
+int BipBuffer_Write(wBipBuffer* bb, BYTE* data, size_t size)
+{
+	BYTE* block;
+
+	block = BipBuffer_Reserve(bb, size);
+
+	if (!block)
+		return -1;
+
+	CopyMemory(block, data, size);
+	BipBuffer_Commit(bb, size);
+
+	return (int) size;
+}
+
+/**
+ * Construction, Destruction
+ */
+
+wBipBuffer* BipBuffer_New(size_t size)
+{
+	wBipBuffer* bb;
+
+	bb = (wBipBuffer*) calloc(1, sizeof(wBipBuffer));
+
+	if (bb)
+	{
+		if (!BipBuffer_AllocBuffer(bb, size))
+		{
+			free(bb);
+			return NULL;
+		}
+	}
+
+	return bb;
+}
+
+void BipBuffer_Free(wBipBuffer* bb)
+{
+	if (!bb)
+		return;
+
+	BipBuffer_FreeBuffer(bb);
+
+	free(bb);
+}

winpr/libwinpr/utils/test/CMakeLists.txt

@@ -7,6 +7,7 @@ set(${MODULE_PREFIX}_DRIVER ${MODULE_NAME}.c)
 set(${MODULE_PREFIX}_TESTS
 	TestIni.c
 	TestImage.c
+	TestBipBuffer.c
 	TestBacktrace.c
 	TestQueue.c
 	TestPrint.c

winpr/libwinpr/utils/test/TestBipBuffer.c

@@ -0,0 +1,23 @@
+
+#include <winpr/crt.h>
+#include <winpr/collections.h>
+
+int TestBipBuffer(int argc, char* argv[])
+{
+	BYTE* data;
+	wBipBuffer* bb;
+	size_t reserved = 0;
+
+	bb = BipBuffer_New(1024);
+
+	if (!bb)
+		return -1;
+
+	data = BipBuffer_Reserve(bb, 1024 * 2);
+
+	fprintf(stderr, "BipBuffer_BufferSize: %d\n", (int) BipBuffer_BufferSize(bb));
+
+	BipBuffer_Free(bb);
+
+	return 0;
+}