Satellite_buffer.c

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/************************************************************************************
* Copyright (C) 2021                                                                *
* TETCOS, Bangalore. India                                                          *
*                                                                                   *
* Tetcos owns the intellectual property rights in the Product and its content.      *
* The copying, redistribution, reselling or publication of any or all of the        *
* Product or its content without express prior written consent of Tetcos is         *
* prohibited. Ownership and / or any other right relating to the software and all   *
* intellectual property rights therein shall remain at all times with Tetcos.       *
*                                                                                   *
* This source code is licensed per the NetSim license agreement.                    *
*                                                                                   *
* No portion of this source code may be used as the basis for a derivative work,    *
* or used, for any purpose other than its intended use per the NetSim license       *
* agreement.                                                                        *
*                                                                                   *
* This source code and the algorithms contained within it are confidential trade    *
* secrets of TETCOS and may not be used as the basis for any other software,        *
* hardware, product or service.                                                     *
*                                                                                   *
* Author:    Shashi Kant Suman                                                      *
*                                                                                   *
* ----------------------------------------------------------------------------------*/
#include "main.h"
#include "SATELLITE.h"
#include "Satellite_MAC.h"
 
ptrSATELLITE_BUFFER satellite_buffer_init(NETSIM_ID utId, NETSIM_ID utIf,
                                          NETSIM_ID gwId, NETSIM_ID gwIf,
                                          double sizeInBytes, double maxUnitSizeInBytes)
{
    ptrSATELLITE_BUFFER buff = calloc(1, sizeof * buff);
    buff->utId = utId;
    buff->utIf = utIf;
    buff->gwId = gwId;
    buff->gwIf = gwIf;
    buff->maxSizeInBytes = sizeInBytes;
    buff->maxUnitSizeInBytes = maxUnitSizeInBytes;
    return buff;
}
 
void satellite_buffer_setMaxUnitSizeInBytes(ptrSATELLITE_BUFFER buffer, double maxUnitSizeInBytes)
{
    buffer->maxUnitSizeInBytes = maxUnitSizeInBytes;
}
 
bool satellite_buffer_add_packet(ptrSATELLITE_BUFFER buffer, NetSim_PACKET* packet)
{
    if (buffer->maxUnitSizeInBytes < packet->pstruMacData->dPayload)
    {
        fn_NetSim_Packet_FreePacket(packet);
        return false;
    }
 
    if (buffer->sizeInBytes + packet->pstruMacData->dPayload > buffer->maxSizeInBytes)
    {
        fn_NetSim_Packet_FreePacket(packet);
        return false;
    }
 
    if (buffer->head)
    {
        buffer->tail->pstruNextPacket = packet;
        buffer->tail = packet;
    }
    else
    {
        buffer->head = packet;
        buffer->tail = packet;
    }
 
    buffer->count++;
    buffer->sizeInBytes += packet->pstruMacData->dPayload;
    return true;
}
 
NetSim_PACKET* satellite_buffer_remove_packet(ptrSATELLITE_BUFFER buffer)
{
    if (!buffer->head) return NULL;
 
    NetSim_PACKET* packet = buffer->head;
    buffer->head = packet->pstruNextPacket;
    packet->pstruNextPacket = NULL;
 
    if (!buffer->head) buffer->tail = NULL;
 
    buffer->sizeInBytes -= packet->pstruMacData->dPayload;
    buffer->count--;
 
    return packet;
}
 
NetSim_PACKET* satellite_buffer_head_packet(ptrSATELLITE_BUFFER buffer)
{
    return buffer->head;
}
 
#pragma region SLOT_ALLOCATION
static void calculate_slot_reqd_per_buffer(ptrSATELLITE_BUFFER buf, UINT bitsPerSlot)
{
    buf->slotReqd = 0;
 
    double bufbits = (UINT)buf->sizeInBytes * 8;
    buf->slotReqd = (UINT)ceil(bufbits / bitsPerSlot);
}
 
static void calculate_slot_reqd(ptrSUPERFRAME sf)
{
    UINT i;
    for (i = 0; i < sf->bufferCount; i++)
    {
        calculate_slot_reqd_per_buffer(sf->buffers[i], sf->slotConfig->bitsPerSlot);
        if (sf->linkType == LINKTYPE_FORWARD)
        {
            print_satellite_log("Slot reqd for Buffer %d:%d-->%d:%d is %d\n",
                                sf->buffers[i]->gwId, sf->buffers[i]->gwIf,
                                sf->buffers[i]->utId, sf->buffers[i]->utIf,
                                sf->buffers[i]->slotReqd);
        }
        else
        {
            print_satellite_log("Slot reqd for Buffer %d:%d-->%d:%d is %d\n",
                                sf->buffers[i]->utId, sf->buffers[i]->utIf,
                                sf->buffers[i]->gwId, sf->buffers[i]->gwIf,
                                sf->buffers[i]->slotReqd);
 
        }
    }
}
 
static void sort_buffer(UINT count, ptrSATELLITE_BUFFER* buffers)
{
    ptrSATELLITE_BUFFER temp = NULL;
    UINT i, j;
    for (i = 0; i < count; i++)
    {
        for (j = i; j < count; j++)
        {
            if (buffers[j]->rank > buffers[i]->rank)
            {
                temp = buffers[i];
                buffers[i] = buffers[j];
                buffers[j] = temp;
            }
        }
    }
}
 
static void init_buffer_rank(ptrSUPERFRAME sf)
{
    UINT i;
    for (i = 0; i < sf->bufferCount; i++)
    {
        if(sf->buffers[i]->slotReqd)
            sf->buffers[i]->rank += 1;
        sf->buffers[i]->allocatedSlotCount = 0;
    }
}
 
static void allocate_slot_count(ptrSUPERFRAME sf, ptrFRAME fr)
{
    fr;
    UINT i;
    UINT slotCount = sf->frameConfig->slotCountInFrame;
    for (i = 0; i < sf->bufferCount; i++)
    {
        sf->buffers[i]->allocatedSlotCount = min(sf->buffers[i]->slotReqd, slotCount);
        slotCount -= sf->buffers[i]->allocatedSlotCount;
        if (slotCount == 0) break;
    }
}
 
static UINT calculate_slot_reqd_for_packet(double size, UINT bitsPerSlot)
{
    return (UINT)ceil(size * 8.0 / bitsPerSlot);
}
 
static void schedule_packet(ptrSUPERFRAME sf, ptrFRAME fr)
{
    UINT i;
    UINT slcount;
    for (i = 0; i < sf->bufferCount; i++)
    {
        ptrSATELLITE_BUFFER buf = sf->buffers[i];
        if (!buf->allocatedSlotCount) break;
 
        slcount = buf->allocatedSlotCount;
        NetSim_PACKET* h;
        while (buf->head)
        {
            h = buf->head;
            if (slcount == 0) break;
 
            UINT slreqd = calculate_slot_reqd_for_packet(h->pstruMacData->dPayload, sf->slotConfig->bitsPerSlot);
            if (slreqd > slcount) break;
            slcount -= slreqd;
            buf->head = h->pstruNextPacket;
            if (buf->head == NULL)buf->tail = NULL;
            buf->count--;
            buf->sizeInBytes -= h->pstruMacData->dPayload;
            h->pstruNextPacket = NULL;
 
            if (fr->head)
            {
                fr->tail->pstruNextPacket = h;
                fr->tail = h;
            }
            else
            {
                fr->head = h;
                fr->tail = h;
            }
        }
    }
}
 
static void update_rank(ptrSUPERFRAME sf,ptrFRAME fr)
{
    fr;
    UINT i;
    UINT slotCount = sf->frameConfig->slotCountInFrame;
    for (i = 0; i < sf->bufferCount; i++)
    {
        ptrSATELLITE_BUFFER buf = sf->buffers[i];
        buf->rank -= ((buf->allocatedSlotCount * 1.0) / slotCount);
    }
}
 
void satellite_allocate_slot(NETSIM_ID d, NETSIM_ID in,
                             ptrSUPERFRAME sf, ptrFRAME fr)
{
    d;
    in;
    print_satellite_log("Starting slot allocation for Superframe %d, Frame %d, LinkType = %s\n",
                        sf->superFrameId, fr->frameId, strLINKTYPE[sf->linkType]);
    satellite_log_add_tab();
    calculate_slot_reqd(sf);
    init_buffer_rank(sf);
    sort_buffer(sf->bufferCount, sf->buffers);
    allocate_slot_count(sf, fr);
    schedule_packet(sf, fr);
    update_rank(sf, fr);
    satellite_log_remove_tab();
}
#pragma endregion