| /******************************************************************** |
| * 2014 - |
| * open source under Apache License Version 2.0 |
| ********************************************************************/ |
| /** |
| * 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_BLOCKREADER_H_ |
| #define _HDFS_LIBHDFS3_CLIENT_BLOCKREADER_H_ |
| |
| #include <stdint.h> |
| |
| namespace Hdfs { |
| namespace Internal { |
| |
| class BlockReader { |
| public: |
| virtual ~BlockReader() { |
| } |
| |
| /** |
| * Get how many bytes can be read without blocking. |
| * @return The number of bytes can be read without blocking. |
| */ |
| virtual int64_t available() = 0; |
| |
| /** |
| * 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) = 0; |
| |
| /** |
| * Move the cursor forward len bytes. |
| * @param len The number of bytes to skip. |
| */ |
| virtual void skip(int64_t len) = 0; |
| }; |
| |
| } |
| } |
| |
| #endif /* _HDFS_LIBHDFS3_CLIENT_BLOCKREADER_H_ */ |