diff options
Diffstat (limited to 'serial/VirtualSerial/ringbuffer.cpp')
| -rw-r--r-- | serial/VirtualSerial/ringbuffer.cpp | 258 |
1 files changed, 0 insertions, 258 deletions
diff --git a/serial/VirtualSerial/ringbuffer.cpp b/serial/VirtualSerial/ringbuffer.cpp deleted file mode 100644 index fbbbd6b8..00000000 --- a/serial/VirtualSerial/ringbuffer.cpp +++ /dev/null @@ -1,258 +0,0 @@ -#include "internal.h" - -CRingBuffer::CRingBuffer( - VOID - ) : m_Size(0), - m_Base(NULL), - m_End(NULL), - m_Head(NULL), - m_Tail(NULL) -{ - return; -} - -CRingBuffer::~CRingBuffer( - VOID - ) -{ - if (m_Base) - { - delete[] m_Base; - } -} - -HRESULT -CRingBuffer::Initialize( - _In_ SIZE_T BufferSize - ) -{ - HRESULT hr = S_OK; - PBYTE buffer = NULL; - - if (0 == BufferSize) - { - hr = E_INVALIDARG; - } - - // - // Allocate the buffer. - // - if (SUCCEEDED(hr)) - { - buffer = new BYTE[BufferSize]; - if (buffer == NULL) - { - hr = E_OUTOFMEMORY; - } - } - - // - // Initialize the ring buffer pointers. - // - if (SUCCEEDED(hr)) - { - m_Size = BufferSize; - m_Base = buffer; - m_End = buffer + BufferSize; - m_Head = buffer; - m_Tail = buffer; - } - - if (FAILED(hr)) - { - if (buffer) - { - delete[] buffer; - m_Base = NULL; - } - } - - return hr; -} - -HRESULT -CRingBuffer::Write( - _In_reads_bytes_(DataSize) PBYTE Data, - _In_ SIZE_T DataSize - ) -{ - SIZE_T availableSpace; - SIZE_T bytesToCopy; - SIZE_T spaceFromCurrToEnd; - - WUDF_TEST_DRIVER_ASSERT(Data && (0 != DataSize)); - - if (m_Tail >= m_End) - { - return E_UNEXPECTED; - } - - // - // Get the amount of space available in the buffer - // - GetAvailableSpace(&availableSpace); - - // - // If there is not enough space to fit in all the data passed in by the - // caller then copy as much as possible and throw away the rest - // - if (availableSpace < DataSize) - { - bytesToCopy = availableSpace; - } - else - { - bytesToCopy = DataSize; - } - - if (bytesToCopy) - { - // - // The buffer has some space at least - // - if ((m_Tail+bytesToCopy) > m_End) - { - // - // The data being written will wrap around the end of the buffer. - // So the copy has to be done in two steps - - // * X bytes from current position to end of the buffer - // * the remaining (bytesToCopy - X) from the start of the buffer - // - - // - // The first step of the copy ... - // - spaceFromCurrToEnd = m_End - m_Tail; - CopyMemory(m_Tail, Data, spaceFromCurrToEnd); - Data += spaceFromCurrToEnd; - bytesToCopy -= spaceFromCurrToEnd; - - // - // The second step of the copy ... - // - CopyMemory(m_Base, Data, bytesToCopy); - - // - // Advance the tail pointer - // - m_Tail = m_Base + bytesToCopy; - } - else - { - // - // Data does NOT wrap around the end of the buffer. Just copy it - // over in a single step - // - CopyMemory(m_Tail, Data, bytesToCopy); - - // - // Advance the tail pointer - // - m_Tail += bytesToCopy; - if (m_Tail == m_End) - { - // - // We have exactly reached the end of the buffer. The next - // write should wrap around and start from the beginning. - // - m_Tail = m_Base; - } - } - - WUDF_TEST_DRIVER_ASSERT(m_Tail < m_End); - } - - return S_OK; -} - -HRESULT -CRingBuffer::Read( - _Out_writes_bytes_to_(DataSize, *BytesCopied) PBYTE Data, - _In_ SIZE_T DataSize, - _Out_ SIZE_T *BytesCopied - ) -{ - SIZE_T availableData; - SIZE_T dataFromCurrToEnd; - - WUDF_TEST_DRIVER_ASSERT(Data && (DataSize != 0)); - - if (m_Head >= m_End) - { - return E_UNEXPECTED; - } - - // - // Get the amount of data available in the buffer - // - GetAvailableData(&availableData); - - if (availableData == 0) - { - *BytesCopied = 0; - return S_OK; - } - - if (DataSize > availableData) - { - DataSize = availableData; - } - - *BytesCopied = DataSize; - - if ((m_Head + DataSize) > m_End) - { - // - // The data requested by the caller is wrapped around the end of the - // buffer. So we'll do the copy in two steps - - // * Copy X bytes from the current position to the end buffer into - // the caller's buffer - // * Copy (DataSize - X) bytes from the beginning to the buffer into - // the caller's buffer - // - - // - // The first step of the copy ... - // - dataFromCurrToEnd = m_End - m_Head; - CopyMemory(Data, m_Head, dataFromCurrToEnd); - Data += dataFromCurrToEnd; - DataSize -= dataFromCurrToEnd; - - // - // The second step of the copy ... - // - CopyMemory(Data, m_Base, DataSize); - - // - // Advance the head pointer - // - m_Head = m_Base + DataSize; - } - else - { - // - // The data in the buffer is NOT wrapped around the end of the buffer. - // Simply copy the data over to the caller's buffer in a single step. - // - CopyMemory(Data, m_Head, DataSize); - - // - // Advance the head pointer - // - m_Head += DataSize; - if (m_Head == m_End) - { - // - // We have exactly reached the end of the buffer. The next - // read should wrap around and start from the beginning. - // - m_Head = m_Base; - } - } - - WUDF_TEST_DRIVER_ASSERT(m_Head < m_End); - - return S_OK; -} - |