/* (C) 2003 XDA Developers  itsme@xs4all.nl
 *
 * $Header$
 */

#include <windows.h>
#include "CircularBuffer.h"

CircularBuffer::CircularBuffer(int max) {
    InitializeCriticalSection(&m_lock);
    m_hEvent= CreateEvent(NULL, false, false, NULL);
    m_buf.resize(max);
    m_head= m_buf.begin();
    m_tail= m_buf.begin();
    m_size= 0;
    m_overflows= 0;
}
CircularBuffer::~CircularBuffer() {
    DeleteCriticalSection(&m_lock);
    CloseHandle(m_hEvent);
}

int CircularBuffer::Get(ByteVector& buf, int timeout) {
    if (m_size || WaitForSingleObject(m_hEvent, timeout)==WAIT_OBJECT_0)
    {
        EnterCriticalSection(&m_lock);
        DWORD size= m_size;

        if (m_head<m_tail) {
            buf.insert(buf.end(), m_tail, m_buf.end());
            buf.insert(buf.end(), m_buf.begin(), m_head);
        }
        else {
            buf.insert(buf.end(), m_tail, m_head);
        }
        m_tail= m_head;
        m_size= 0;
        LeaveCriticalSection(&m_lock);

        return size;
    }
    return 0;
}
bool CircularBuffer::Put(const ByteVector& buf) {
    EnterCriticalSection(&m_lock);
    if (buf.size()+m_size>m_buf.size()) {
        m_overflows++;
        LeaveCriticalSection(&m_lock);
        return false;
    }

    if (m_head==m_buf.end())
        m_head= m_buf.begin();

    if (m_buf.end()-m_head < buf.size()) {
        copy(buf.begin(), buf.begin() + (m_buf.end()-m_head), m_head);
        m_head= copy(buf.begin() + (m_buf.end()-m_head), buf.end(), m_buf.begin());
    }
    else {
        m_head= copy(buf.begin(), buf.end(), m_head);
    }
    m_size += buf.size();

    LeaveCriticalSection(&m_lock);

    SetEvent(m_hEvent);

    return true;
}