/// <summary>
/// 删除任务
/// </summary>
/// <param name="id">任务标识id</param>
public void ReleaseTask(Guid id)
{
try
{
if (id == Guid.Empty)
{
return;
}
lock (_data_lck)
{
if (!_guid_begpos_mapping.ContainsKey(id))
{
//Tracer.GlobalTracer.TraceWarning("Missing id " + id.ToString() + " in mapping, maybe it's a bug?");
return;
}
var beg_pos = _guid_begpos_mapping[id];
_guid_begpos_mapping.Remove(id);
_segment_list[beg_pos] = new _t_struct(Guid.Empty, _segment_list[beg_pos].end_pos);
#pragma warning disable
if (_enable_tracing)
{
Tracer.GlobalTracer.TraceInfo("TaskDispatcher.ReleaseTask called: Guid id=" + id + " [segment=" + _segment_list.Count + ", task=" + _guid_begpos_mapping.Count + "]");
}
#pragma warning restore
}
}
catch (Exception ex)
{
Tracer.GlobalTracer.TraceError(ex.ToString());
}
}
/// <summary>
/// 分配新的任务，并返回该任务的标识id，若分配失败会返回Guid.Empty
/// </summary>
/// <param name="beg_position">文件的开始位置</param>
/// <returns></returns>
public Guid AllocateNewTask(out ulong beg_position)
{
try
{
//todo:优化停止段的重新分配
lock (_data_lck)
{
if (!_debug_check())
{
throw new Exception("Debug check failed");
}
ulong max_length = _segment_list.First().Key;
beg_position = 0;
int last_index = -1;
//减小分段的优化模式
//if (_segment_list.Count == _guid_begpos_mapping.Count + 1)
//{
//找到最大的空间进行分配
for (int i = 1; i < _segment_list.Count; i++)
{
var tmp_length = _segment_list.ElementAt(i).Key - _segment_list.ElementAt(i - 1).Value.end_pos;
//last_index = i - 1;
var last_index_has_task = _segment_list.ElementAt(i - 1).Value.id != Guid.Empty;
if (last_index_has_task)
{
//上一片段已经有执行中的任务就从中间分配
var allocated_length = tmp_length >> 1;
if (allocated_length > max_length)
{
last_index = -1;
//beg_position = _segment_list.ElementAt(i - 1).Key;
beg_position = _segment_list.ElementAt(i - 1).Value.end_pos;
beg_position += (tmp_length - allocated_length);
max_length = allocated_length;
}
}
else
{
//没有的话从头开始分配
if (tmp_length > max_length)
{
last_index = i - 1;
beg_position = _segment_list.ElementAt(i - 1).Value.end_pos;
max_length = tmp_length;
}
}
}
//}
//else
//{
// //找到最大的空间进行分配，跳过已经有任务的
// for (int i = 1; i < _segment_list.Count; i++)
// {
// var tmp_length = _segment_list.ElementAt(i).Key - _segment_list.ElementAt(i - 1).Value.end_pos;
// var last_index_has_task = _segment_list.ElementAt(i - 1).Value.id != Guid.Empty;
// if (!last_index_has_task)
// {
// if (tmp_length > max_length)
// {
// last_index = i - 1;
// beg_position = _segment_list.ElementAt(i - 1).Value.end_pos;
// max_length = tmp_length;
// }
// }
// }
//}
//length is too small, ignored
if (max_length == 0 || (max_length < _MIN_DISPATCH_LENGTH && last_index == -1 && _segment_list.Count > 1))
{
beg_position = 0;
#pragma warning disable
if (_enable_tracing)
{
Tracer.GlobalTracer.TraceInfo("TaskDispatcher.AllocateNewTask called: out ulong beg_position=" + beg_position + ", Guid id=" + Guid.Empty.ToString() + " \r\n[segment=" + _segment_list.Count + ", task=" + _guid_begpos_mapping.Count + ", last_index=" + last_index + "]");
}
#pragma warning restore
return(Guid.Empty);
}
//saving segment data
var id = Guid.NewGuid();
//assign mode
if (last_index == -1)
{
_segment_list.Add(beg_position, new _t_struct(id, beg_position));
_guid_begpos_mapping.Add(id, beg_position);
}
//update mode
else
{
var last_begin_pos = _segment_list.ElementAt(last_index).Key;
_segment_list[last_begin_pos] = new _t_struct(id, _segment_list[last_begin_pos].end_pos);
_guid_begpos_mapping.Add(id, last_begin_pos);
}
#pragma warning disable
if (_enable_tracing)
{
Tracer.GlobalTracer.TraceInfo("TaskDispatcher.AllocateNewTask called: out ulong beg_position=" + beg_position + ", Guid id=" + id.ToString() + " \r\n[segment=" + _segment_list.Count + ", task=" + _guid_begpos_mapping.Count + ", last_index=" + last_index + "]");
}
return(id);
#pragma warning restore
}
}
catch (Exception ex)
{
Tracer.GlobalTracer.TraceError(ex.ToString());
beg_position = 0;
return(Guid.Empty);
}
}
/// <summary>
/// 更新任务的位置，返回是否需要继续下载
/// </summary>
/// <param name="id">任务标识id</param>
/// <param name="current_position">该任务目前已完成的位置</param>
/// <returns></returns>
public bool UpdateTaskSituation(Guid id, ulong current_position)
{
try
{
if (id == Guid.Empty)
{
return(false);
}
lock (_data_lck)
{//合理性检测
if (!_guid_begpos_mapping.ContainsKey(id))
{
return(false);
}
var beg_pos = _guid_begpos_mapping[id];
//当前分段数据
var segment_data = _segment_list[beg_pos];
if (segment_data.end_pos > current_position)
{
throw new ArgumentException("Decreasing position is forbidden");
}
//修改当前数据
_complete_length += (current_position - segment_data.end_pos);
_segment_list[beg_pos] = new _t_struct(id, current_position);
//下一分段数据
var next_segment_index = _segment_list.IndexOfKey(beg_pos) + 1;
do
{
if (next_segment_index == _segment_list.Count - 1)
{
//在获取下一分段之前，为了不影响最后一个标记文件结束位置segment，加入以下判断
if (current_position >= _length)
{
_complete_length -= current_position - _length;
current_position = _length;
_segment_list[beg_pos] = new _t_struct(Guid.Empty, _length);
_guid_begpos_mapping.Remove(id);
return(false);
}
else
{
return(true);
}
}
var next_segment_data = _segment_list.ElementAt(next_segment_index);
//合并检测
if (current_position >= next_segment_data.Key)
{
if (current_position >= next_segment_data.Value.end_pos)
{
//直接吞掉下一段的数据
_complete_length -= next_segment_data.Value.end_pos - next_segment_data.Key;
var next_guid = next_segment_data.Value.id;
_segment_list.RemoveAt(next_segment_index);
if (next_guid != Guid.Empty)
{
_guid_begpos_mapping.Remove(next_guid);
}
#pragma warning disable
if (_enable_tracing)
{
Tracer.GlobalTracer.TraceInfo("TaskDispatcher.TaskMerge: Merging Task #" + next_segment_index + " -> #" + (next_segment_index - 1) + " segments=" + _segment_list.Count + ", task=" + _guid_begpos_mapping.Count);
}
#pragma warning restore
}
else
{
//这一段宣告死亡，由下一段接管
_complete_length -= current_position - next_segment_data.Key;
current_position = next_segment_data.Key;
_segment_list[beg_pos] = next_segment_data.Value;
var next_guid = next_segment_data.Value.id;
if (next_guid != Guid.Empty)
{
_guid_begpos_mapping[next_guid] = beg_pos;
}
_guid_begpos_mapping.Remove(id);
_segment_list.RemoveAt(next_segment_index);
#pragma warning disable
if (_enable_tracing)
{
Tracer.GlobalTracer.TraceInfo("TaskDispatcher.TaskMerge: Merging Task #" + (next_segment_index - 1) + " -> #" + next_segment_index + " segments=" + _segment_list.Count + ", task=" + _guid_begpos_mapping.Count);
}
#pragma warning restore
_debug_check();
return(false);
}
}
else
{
break;
}
} while (true);
//执行到这里应该都是未完成该段的，包括合并后的情况
//Tracer.GlobalTracer.TraceInfo("TaskDispatcher.TaskMerge: segments=" + _segment_list.Count + ", task=" + _guid_begpos_mapping.Count);
_debug_check();
return(true);
}
}
catch (Exception ex)
{
Tracer.GlobalTracer.TraceError(ex.ToString());
return(false);
}
}
