| /** |
| * 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_LOCALBLOCKREADER_H_ |
| #define _HDFS_LIBHDFS3_CLIENT_LOCALBLOCKREADER_H_ |
| |
| #include "BlockReader.h" |
| #include "Checksum.h" |
| #include "FileWrapper.h" |
| #include "SessionConfig.h" |
| #include "common/SharedPtr.h" |
| #include "server/BlockLocalPathInfo.h" |
| |
| #include <stdint.h> |
| #include <vector> |
| |
| namespace hdfs { |
| namespace internal { |
| |
| class LocalBlockReader: public BlockReader { |
| public: |
| LocalBlockReader(const BlockLocalPathInfo & info, |
| const ExtendedBlock & block, int64_t offset, bool verify, |
| SessionConfig & conf, std::vector<char> & buffer); |
| |
| ~LocalBlockReader(); |
| |
| /** |
| * Get how many bytes can be read without blocking. |
| * @return The number of bytes can be read without blocking. |
| */ |
| virtual int64_t available() { |
| return length - cursor; |
| } |
| |
| /** |
| * 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 size); |
| |
| /** |
| * Move the cursor forward len bytes. |
| * @param len The number of bytes to skip. |
| */ |
| virtual void skip(int64_t len); |
| |
| private: |
| /** |
| * Fill buffer and verify checksum. |
| * @param bufferSize The size of buffer. |
| */ |
| void readAndVerify(int32_t bufferSize); |
| int32_t readInternal(char * buf, int32_t len); |
| |
| private: |
| bool verify; //verify checksum or not. |
| const char *pbuffer; |
| const char *pMetaBuffer; |
| const ExtendedBlock █ |
| int checksumSize; |
| int chunkSize; |
| int localBufferSize; |
| int position; //point in buffer. |
| int size; //data size in buffer. |
| int64_t cursor; //point in block. |
| int64_t length; //data size of block. |
| shared_ptr<Checksum> checksum; |
| shared_ptr<FileWrapper> dataFd; |
| shared_ptr<FileWrapper> metaFd; |
| std::string dataFilePath; |
| std::string metaFilePath; |
| std::vector<char> & buffer; |
| std::vector<char> metaBuffer; |
| }; |
| |
| } |
| } |
| |
| #endif /* _HDFS_LIBHDFS3_CLIENT_LOCALBLOCKREADER_H_ */ |