public List <IByteBuffer> decode(FecPacket pkt)
{
if (pkt.Flag == Fec.typeParity)
{
Snmp.snmp.FECParityShards++;
}
else
{
Snmp.snmp.FECDataShards++;
}
int n = rx.Count - 1;
int insertIdx = 0;
for (int i = n; i >= 0; i--)
{
//去重
if (pkt.Seqid == rx[i].Seqid)
{
Snmp.snmp.FECRepeatDataShards++;
pkt.release();
return(null);
}
if (pkt.Seqid > rx[i].Seqid)
{
// insertion
insertIdx = i + 1;
break;
}
}
//插入 rx中
if (insertIdx == n + 1)
{
this.rx.Add(pkt);
}
else
{
rx.Insert(insertIdx, pkt);
}
//所有消息列表中的第一个包
// shard range for current packet
long shardBegin = pkt.Seqid - pkt.Seqid % shardSize;
long shardEnd = shardBegin + shardSize - 1;
//rx数组中的第一个包
// max search range in ordered queue for current shard
int searchBegin = (int)(insertIdx - pkt.Seqid % shardSize);
if (searchBegin < 0)
{
searchBegin = 0;
}
int searchEnd = searchBegin + shardSize - 1;
if (searchEnd >= rx.Count)
{
searchEnd = rx.Count - 1;
}
List <IByteBuffer> result = null;
if (searchEnd - searchBegin + 1 >= dataShards)
{
//当前包组的已收到的包数量
int numshard = 0;
//当前包组中属于数据包的数量
int numDataShard = 0;
//搜到第一个包在搜索行中的位置
int first = 0;
//收到的最大包的字节长度
int maxlen = 0;
// zero cache
IByteBuffer[] shards = decodeCache;
bool[] shardsflag = flagCache;
for (int i = 0; i < shards.Length; i++)
{
shards[i] = null;
shardsflag[i] = false;
}
for (int i = searchBegin; i <= searchEnd; i++)
{
FecPacket fecPacket = rx[i];
long seqid = fecPacket.Seqid;
if (seqid > shardEnd)
{
break;
}
if (seqid < shardBegin)
{
continue;
}
shards[(int)(seqid % shardSize)] = fecPacket.Data;
shardsflag[(int)(seqid % shardSize)] = true;
numshard++;
if (fecPacket.Flag == Fec.typeData)
{
numDataShard++;
}
if (numshard == 1)
{
first = i;
}
if (fecPacket.Data.ReadableBytes > maxlen)
{
maxlen = fecPacket.Data.ReadableBytes;
}
}
if (numDataShard == dataShards)
{
freeRange(first, numshard, rx);
}
else if (numshard >= dataShards)
{
for (int i = 0; i < shards.Length; i++)
{
IByteBuffer shard = shards[i];
//如果数据不存在 用0填充起来
if (shard == null)
{
shards[i] = zeros.Copy(0, maxlen);
shards[i].SetWriterIndex(maxlen);
continue;
}
int left = maxlen - shard.ReadableBytes;
if (left > 0)
{
shard.WriteBytes(this.zeros, left);
zeros.ResetReaderIndex();
// zeros.resetReaderIndex();
}
}
codec.decodeMissing(shards, shardsflag, 0, maxlen);
result = new List <IByteBuffer>(this.dataShards);
for (int i = 0; i < shardSize; i++)
{
if (shardsflag[i])
{
continue;
}
IByteBuffer byteBufs = shards[i];
//释放构建的parityShards内存
if (i >= dataShards)
{
byteBufs.Release();
continue;
}
int packageSize = byteBufs.ReadShort();
if (byteBufs.ReadableBytes < packageSize)
{
//// System.out.println("bytebuf长度: " + byteBufs.writerIndex() + " 读出长度" + packageSize);
// byte[] bytes = new byte[byteBufs.writerIndex()];
// byteBufs.getBytes(0, bytes);
// for (byte aByte :
// bytes) {
// System.out.print("[" + aByte + "] ");
// }
Snmp.snmp.FECErrs++;
}
else
{
Snmp.snmp.FECRecovered++;
}
//去除fec头标记的消息体长度2字段
byteBufs = byteBufs.Slice(Fec.fecDataSize, packageSize);
//int packageSize =byteBufs.readUnsignedShort();
//byteBufs = byteBufs.slice(0,packageSize);
result.Add(byteBufs);
Snmp.snmp.FECRecovered++;
//int packageSize =byteBufs.getUnsignedShort(0);
////判断长度
//if(byteBufs.writerIndex()-Fec.fecHeaderSizePlus2>=packageSize&&packageSize>0)
//{
// byteBufs = byteBufs.slice(Fec.fecHeaderSizePlus2,packageSize);
// result.add(byteBufs);
// Snmp.snmp.FECRecovered.incrementAndGet();
//}else{
// System.out.println("bytebuf长度: "+byteBufs.writerIndex()+" 读出长度"+packageSize);
// byte[] bytes = new byte[byteBufs.writerIndex()];
// byteBufs.getBytes(0,bytes);
// for (byte aByte : bytes) {
// System.out.print("["+aByte+"] ");
// }
// Snmp.snmp.FECErrs.incrementAndGet();
//}
}
freeRange(first, numshard, rx);
}
}
if (rx.Count > rxlimit)
{
if (rx[0].Flag == Fec.typeData)
{
Snmp.snmp.FECShortShards++;
}
freeRange(0, 1, rx);
}
return(result);
}