xref: /hardware/qcom/media/msm8974/mm-video-legacy/vidc/vdec/src/queue.c

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/*
	Queue with Linked list
*/

#include "queue.h"
#include <stdio.h>
#include <stdlib.h>


typedef struct Node
{
  void *element;
  struct Node *next;
} Node;

struct Queue
{
  Node *head;
  Node *tail;
  int  current_size;
};

Queue *alloc_queue()
{
  Queue *q = (Queue *) malloc(sizeof(Queue));
  if (q)
  {
    q->head = q->tail = NULL;
    q->current_size = 0;
  }
  return q;
}

void free_queue(Queue *q)
{
  while (q->current_size)
  {
    pop(q);
  }
}

void free_queue_and_qelement(Queue *q)
{
  while (q->current_size)
  {
    void *element = pop(q);
    if (element)
      free(element);
  }
}

int push(Queue *q, void * element)
{
  Node *new_node = (Node *) malloc(sizeof(Node));

  if (new_node == NULL)
    return -1;

  new_node->element = element;
  new_node->next = NULL;

  if (q->current_size == 0)
  {
    q->head = new_node;
  }
  else
  {
    q->tail->next = new_node;
  }

  q->tail = new_node;
  q->current_size++;

  return 0;
}

void *pop(Queue *q)
{
  Node *temp;
  void *element;

  if (q->current_size == 0)
    return NULL;

  temp = q->head;
  element = temp->element;

  if (q->current_size == 1)
  {
    q->head = q->tail = NULL;
  }
  else
  {
    q->head = q->head->next;
  }

  free(temp);
  q->current_size--;
  return element;
}