/// <summary>
/// 数据取出后就从当前列表中移除
/// </summary>
/// <param name="len"></param>
/// <returns></returns>
public BufferListStream getBytesTo(int len) {
if (available() < len) return null;
if (Count < 1) return null;
BufferListStream bs = new BufferListStream();
int offset = 0;
while (offset < len) {
BufferListSegment seg = this.m_List[0];
if (offset + seg.Count > len) {
var level = BufferListPoolMgr.CaculBufLevel(seg.Count);
var buf = BufferListPoolMgr.AllocBuf(level);
//Buffer.BlockCopy(seg.Array, seg.Offset, buf.Array, buf.Offset, len - offset);
buf.SetDataFast(seg.Array, seg.Offset, buf.Offset, len - offset);
updateOffset(seg.Offset + (len - offset));
//
bs.Add(buf);
break;
}
else {
//Buffer.BlockCopy(seg.Array, seg.Offset, buf, 0, seg.Count);
offset += seg.Count;
this.m_List.RemoveAt(0);
//回收seg 如果不是通过BufferListPoolMgr申请的byte[] 并且长度不是64偶数倍（最大64）的数据将直接丢弃，由GC回收
//BufferListPoolMgr.FreeBuf(seg.Array);
bs.Add(seg);
}
}
return bs;
}
/// <summary>
/// ArraySegmen.array最大长度为64K,超过64K报错
/// </summary>
/// <returns></returns>
public BufferListStream Copy() {
BufferListStream bs = new BufferListStream();
for (int i = 0; i < this.Count; i++) {
var level = BufferListPoolMgr.CaculBufLevel(this.m_List[i].Count);
if (level == BufferListPool.BufferLevel.None) throw new OutOfMemoryException("ArraySegmen.array最大长度超过64K");
var buf = BufferListPoolMgr.AllocBuf(level);
//Buffer.BlockCopy(this[i].Source.Array, this[i].Source.Offset, buf.Source.Array, buf.Source.Offset, this[i].Source.Count);
buf.SetDataFast(this.m_List[i].Array, this.m_List[i].Offset, buf.Offset, this.m_List[i].Count);
bs.Add(buf);
}
return bs;
}
