/// <summary>
/// 数据取出后就从当前列表中移除
/// </summary>
/// <param name="len"></param>
/// <returns></returns>
public ByteListStream getBytesTo(int len)
{
if (available() < len)
{
return(null);
}
if (Count < 1)
{
return(null);
}
ByteListStream bs = new ByteListStream();
int offset = 0;
while (offset < len)
{
ArraySegment <byte> seg = this[0];
if (offset + seg.Count > len)
{
var level = ByteListPoolMgr.CaculBufLevel(seg.Count);
byte[] buf = ByteListPoolMgr.AllocBuf(level);
Buffer.BlockCopy(seg.Array, seg.Offset, buf, 0, len - offset);
updateOffset(seg.Offset + (len - offset));
//
bs.Add(new ArraySegment <byte>(buf, 0, len - offset));
break;
}
else
{
//Buffer.BlockCopy(seg.Array, seg.Offset, buf, 0, seg.Count);
offset += seg.Count;
this.RemoveAt(0);
//回收seg 如果不是通过ByteListPoolMgr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
//ByteListPoolMgr.FreeBuf(seg.Array);
bs.Add(seg);
}
}
return(bs);
}
/// <summary>
/// 把大字节数组分割成指定容量等级的ByteListStream
/// </summary>
/// <param name="largeBuf"></param>
/// <param name="level"></param>
/// <returns></returns>
public static ByteListStream Slice(byte[] largeBuf, ByteListPool.BufferLevel level)
{
ByteListStream bs = new ByteListStream();
int countleave = largeBuf.Length;
int offset = 0;
while (countleave > 0)
{
byte[] buf = AllocBuf(level);
int len = Math.Min(countleave, buf.Length);
Buffer.BlockCopy(largeBuf, offset, buf, 0, len);
bs.Add(new ArraySegment <byte>(buf, 0, len));
offset += len;
countleave -= len;
}
return(bs);
}
/// <summary>
/// ArraySegmen.array最大长度为64K,超过64K报错
/// </summary>
/// <returns></returns>
public ByteListStream Copy()
{
ByteListStream bs = new ByteListStream();
for (int i = 0; i < this.Count; i++)
{
var level = ByteListPoolMgr.CaculBufLevel(this[i].Count);
if (level == ByteListPool.BufferLevel.None)
{
throw new OutOfMemoryException("ArraySegmen.array最大长度超过64K");
}
byte[] buf = ByteListPoolMgr.AllocBuf(level);
Buffer.BlockCopy(this[i].Array, this[i].Offset, buf, 0, this[i].Count);
bs.Add(new ArraySegment <byte>(buf, 0, this[i].Count));
}
return(bs);
}
static void test()
{
//从缓存中取buf 用完回收 最大支持64K缓存数据
Random rn = new Random();
ByteListStream bs = new ByteListStream();
for (int i = 0; i < 10; i++)
{
//从缓存池中申请byte数组
var v128 = ByteListPoolMgr.AllocBuf(ByteListPool.BufferLevel.b128);
rn.NextBytes(v128);
//大数据分片放入ByteListStream
bs.Add(new ArraySegment <byte>(v128));
}
//读取数据
byte[] buf = bs.getBytes(256);
//覆盖读取数据
bs.getBytes(ref buf, 0, 256);
//销毁并回收关联的内存
bs.Dispose();
}