| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef _HDFS_LIBHDFS3_CLIENT_REMOTEBLOCKREADER_H_ |
| #define _HDFS_LIBHDFS3_CLIENT_REMOTEBLOCKREADER_H_ |
| |
| #include "BlockReader.h" |
| #include "Checksum.h" |
| #include "DataTransferProtocol.h" |
| #include "PacketHeader.h" |
| #include "SessionConfig.h" |
| #include "common/SharedPtr.h" |
| #include "network/BufferedSocketReader.h" |
| #include "network/TcpSocket.h" |
| #include "server/DatanodeInfo.h" |
| #include "server/LocatedBlocks.h" |
| |
| #include <stdint.h> |
| |
| namespace hdfs { |
| namespace internal { |
| |
| class RemoteBlockReader: public BlockReader { |
| public: |
| RemoteBlockReader(const ExtendedBlock &eb, DatanodeInfo &datanode, |
| int64_t start, int64_t len, const Token &token, |
| const char *clientName, bool verify, SessionConfig &conf); |
| |
| ~RemoteBlockReader(); |
| |
| /** |
| * Get how many bytes can be read without blocking. |
| * @return The number of bytes can be read without blocking. |
| */ |
| virtual int64_t available(); |
| |
| /** |
| * To read data from block. |
| * @param buf the buffer used to filled. |
| * @param size the number of bytes to be read. |
| * @return return the number of bytes filled in the buffer, |
| * it may less than size. Return 0 if reach the end of block. |
| */ |
| virtual int32_t read(char *buf, int32_t len); |
| |
| /** |
| * Move the cursor forward len bytes. |
| * @param len The number of bytes to skip. |
| */ |
| virtual void skip(int64_t len); |
| |
| private: |
| bool readTrailingEmptyPacket(); |
| shared_ptr<PacketHeader> readPacketHeader(); |
| void checkResponse(); |
| void readNextPacket(); |
| void sendStatus(); |
| void verifyChecksum(int chunks); |
| |
| private: |
| bool verify; //verify checksum or not. |
| DatanodeInfo &datanode; |
| const ExtendedBlock &binfo; |
| int checksumSize; |
| int chunkSize; |
| int connTimeout; |
| int position; //point in buffer. |
| int readTimeout; |
| int size; //data size in buffer. |
| int writeTimeout; |
| int64_t cursor; //point in block. |
| int64_t endOffset; //offset in block requested to read to. |
| int64_t lastSeqNo; //segno of the last chunk received |
| shared_ptr<BufferedSocketReader> in; |
| shared_ptr<Checksum> checksum; |
| shared_ptr<DataTransferProtocol> sender; |
| shared_ptr<PacketHeader> lastHeader; |
| shared_ptr<Socket> sock; |
| std::vector<char> buffer; |
| }; |
| |
| } |
| } |
| |
| #endif /* _HDFS_LIBHDFS3_CLIENT_REMOTEBLOCKREADER_H_ */ |