scbstream.c

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/*
 * File Name: scbstream.c
 */

/*
 * This file is part of liberscribble.
 *
 * liberscribble is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * liberscribble is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * Copyright (C) 2008 iRex Technologies B.V.
 * All rights reserved.
 */


#define _GNU_SOURCE

//----------------------------------------------------------------------------
// Include Files
//----------------------------------------------------------------------------

// system include files, between < >
#include <memory.h>

// ereader include files, between < >

// local include files, between " "
#include "scbstream.h"
#include "scblog.h"


//----------------------------------------------------------------------------
// Type Declarations
//----------------------------------------------------------------------------


//----------------------------------------------------------------------------
// Global Constants
//----------------------------------------------------------------------------


//----------------------------------------------------------------------------
// Static Variables
//----------------------------------------------------------------------------


//============================================================================
// Local Function Definitions
//============================================================================


//============================================================================
// Functions Implementation
//============================================================================

ScbStreamPtr erscribble_create_stream(const int size)
{
    ScbStreamPtr ptr = g_new0(ScbStream, 1);

    if (ptr == NULL)
    {
        ERRORPRINTF("Could not allocate memory stream!");
        return NULL;
    }

    ptr->buffer = g_malloc0(size);
    if (ptr->buffer == NULL)
    {
        ERRORPRINTF("Could not allocate memory stream!");
        g_free(ptr);
        return NULL;
    }
    ptr->size = size;

    return ptr;
}


void erscribble_free_stream(ScbStreamPtr stream, gboolean is_free_buffer)
{
    if (stream)
    {
        // release the memory
        if (stream->buffer && is_free_buffer)
        {
            g_free(stream->buffer);
            stream->buffer = NULL;
        }

        g_free(stream);
    }
}


gboolean erscribble_read_stream(ScbStreamPtr stream, void *data, const int length)
{
    if (stream->offset + length > stream->size)
    {
        return FALSE;
    }

    unsigned char * src = (unsigned char*)stream->buffer + stream->offset;

    memcpy(data, src, length);

    stream->offset += length;

    return TRUE;
}


gboolean erscribble_write_stream(ScbStreamPtr stream, const void *data, const int length)
{
    if (stream->offset + length > stream->size)
    {
        // reallocate memory
        void * new_mem = g_malloc0(stream->size + length);

        if (new_mem == NULL)
        {
            return FALSE;
        }

        // copy the content from previous buffer to new buffer
        memcpy(new_mem, stream->buffer, stream->offset);

        // free the previous buffer
        g_free(stream->buffer);

        stream->buffer = new_mem;

        stream->size += length;
    }

    unsigned char * dst = (unsigned char *)stream->buffer + stream->offset;

    // copy the memory to the buffer
    memcpy(dst, data, length);

    stream->offset += length;
    
    return TRUE;
}


void erscribble_reset_offset(ScbStreamPtr stream)
{
    stream->offset = 0;
}