如果UDP协议中的缓冲区插槽已满,将会怎样做?它用新的数据替换旧数据吗?它只是删除新数据?
如果它与UDP协议无关,并且在代码中指定了,如何在python和C中执行此操作?
答案 0 :(得分:0)
对于输出缓冲区(即一个保存要发送的数据包),import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import com.squareup.picasso.Picasso;
import java.util.ArrayList;
public class ElementsAdapter extends RecyclerView.Adapter<ElementsAdapter.ViewHolder> {
private ArrayList<String> mDataset;
private ArrayList<Integer> mDatamap;
public Context context;
private static final int VIEW_HEADER = 0;
private static final int VIEW_NORMAL = 1;
private View headerView;
private int datasetSize;
public class HeaderHolder extends RecyclerView.ViewHolder {
// each data item is just a string in this case
public TextView headertext;
public HeaderHolder(View v) {
super(v);
headertext = (TextView) v.findViewById(R.id.headertext);
}
}
public class ViewHolder extends RecyclerView.ViewHolder {
// each data item is just a string in this case
public TextView txtHeader;
public TextView txtFooter;
public ImageView imgImage;
public ViewHolder(View v) {
super(v);
txtHeader = (TextView) v.findViewById(R.id.firstLine);
txtFooter = (TextView) v.findViewById(R.id.secondLine);
imgImage = (ImageView) v.findViewById(R.id.icon);
}
}
public ElementsAdapter(ArrayList<String> myDataset, ArrayList<Integer> myDatamap) {
mDataset = myDataset;
myDatamap = mDatamap;
}
@Override
public int getItemViewType(int position) {
return isHeader(position) == 1 ? VIEW_HEADER : VIEW_NORMAL;
}
@Override
public int getItemCount() {
return mDataset.size();
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if (viewType == VIEW_HEADER) {
// create a new view
View sub_view = LayoutInflater.from(parent.getContext()).inflate(R.layout.header, parent, false);
Context context = sub_view.getContext();
// set the view's size, margins, paddings and layout parameters
ViewHolder vh = new ViewHolder(sub_view);
return vh;
// return new HeaderViewHolder(headerView);
} else {
// create a new view
View sub_view = LayoutInflater.from(parent.getContext()).inflate(R.layout.sub_layout, parent, false);
context = sub_view.getContext();
// set the view's size, margins, paddings and layout parameters
ViewHolder vh = new ViewHolder(sub_view);
return vh;
}
}
@Override
public void onBindViewHolder(ViewHolder viewHolder, int position) {
if (isHeader(position) == 1) {
// - get element from your dataset at this position
// - replace the contents of the view with that element
final String name = mDataset.get(position);
// holder.txtHeader.setText(mDataset.get(position));
viewHolder.headertext.setText(name);
} else {
// - get element from your dataset at this position
// - replace the contents of the view with that element
final String name = mDataset.get(position);
Picasso.with(context).load("http://www.500kgiveaway.co.uk/"+name).resize(200,200).into(viewHolder.imgImage);
// holder.txtHeader.setText(mDataset.get(position));
viewHolder.txtHeader.setText(name);
viewHolder.txtHeader.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick (View v){
//remove(name);
}
}
);
viewHolder.txtFooter.setText("Footer: "+mDataset.get(position));
}
//ViewHolder holder = (ViewHolder) viewHolder;
//holder.textView.setText("Position " + (position - 1));
}
public int isHeader(int position) {
return mDatamap.get(position) ==1 ? 1:0;}
}
或类似的调用将阻塞,直到缓冲区中有空间可用。
对于输入缓冲区(即持有收到的数据包的缓冲区),严格来说,它取决于OS网络堆栈的实现。在Linux中,新数据包将以静默方式丢弃。在任何情况下,如果某些数据包以这种方式丢失将不会出错,因为UDP不保证它们的传输。
顺便说一句,没有&#34; UDP连接&#34;。