| /******************************************************************** |
| * 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_INPUTSTREAM_H_ |
| #define _HDFS_LIBHDFS3_CLIENT_INPUTSTREAM_H_ |
| |
| #include "FileSystem.h" |
| |
| namespace Hdfs { |
| namespace Internal { |
| class InputStreamInter; |
| } |
| |
| /** |
| * A input stream used read data from hdfs. |
| */ |
| class InputStream { |
| public: |
| InputStream(); |
| |
| ~InputStream(); |
| |
| /** |
| * Open a file to read |
| * @param fs hdfs file system. |
| * @param path the file to be read. |
| * @param verifyChecksum verify the checksum. |
| */ |
| void open(FileSystem & fs, const char * path, bool verifyChecksum = true); |
| |
| /** |
| * To read data from hdfs. |
| * @param buf the buffer used to filled. |
| * @param size buffer size. |
| * @return return the number of bytes filled in the buffer, it may less than size. |
| */ |
| int32_t read(char * buf, int32_t size); |
| |
| /** |
| * To read data from hdfs, block until get the given size of bytes. |
| * @param buf the buffer used to filled. |
| * @param size the number of bytes to be read. |
| */ |
| void readFully(char * buf, int64_t size); |
| |
| /** |
| * Get how many bytes can be read without blocking. |
| * @return The number of bytes can be read without blocking. |
| */ |
| int64_t available(); |
| |
| /** |
| * To move the file point to the given position. |
| * @param pos the given position. |
| */ |
| void seek(int64_t pos); |
| |
| /** |
| * To get the current file point position. |
| * @return the position of current file point. |
| */ |
| int64_t tell(); |
| |
| /** |
| * Close the stream. |
| */ |
| void close(); |
| |
| private: |
| Internal::InputStreamInter * impl; |
| }; |
| |
| } |
| |
| #endif /* _HDFS_LIBHDFS3_CLIENT_INPUTSTREAM_H_ */ |