In fact, I am working on the hadoop-connector, so I should create a HDFSInput
that implements TsFileInput interface for reading tsfile from HDFS.
And actually, in DefaultTsFileInput, this method is unsupported which you can
see in the following.
@Override
public int read(byte[] b, int off, int len) throws IOException {
throw new UnsupportedOperationException();
}
Not all read methods in DefaultTsFileInput modify the position, such as 'int
read(ByteBuffer dst, long position)’.
So it seems that if you specify the position where you want to start in the
method signature, the method shouldn’t modify the position of TsFileInput which
is consistent with FileChannel’s interface.
Best,
--------------
Yuan Tian
School of Software, Tsinghua University
田原
清华大学 软件学院
> 在 2019年9月9日，下午11:19，Boris Zhu <[email protected]> 写道：
>
> Hi, tian
> DefaultTsFileInput is a class to implement TsFileInput
> interface. DefaultTsFileInput's method read actually change the position of
> itself because it uses java.io.FileChannel, and we can use a "position"
> method to change its position back. But I'm also confusing that why can't
> change the position of TsFileInput or modify this TsFileInput.
>
> Best,
> Boris zhu
>
> On Mon, Sep 9, 2019 at 10:55 PM Yuan Tian <[email protected]> wrote:
>
>> Hi,
>>
>> While implementing one read method(shown in the following) in TsFileInput
>> interface, I don’t know whether to modify the position of TsFileInput.
>>
>> /**
>> * read an array of byte from the Input.
>> *
>> * @param b -array of byte
>> * @param off -offset of the Input
>> * @param len -length
>> */
>> int read(byte[] b, int off, int len) throws IOException;
>>
>>
>> I think this method should not modify this TsFileInput and it should be
>> specified in the comments.
>>
>> Best,
>> --------------
>> Yuan Tian
>> School of Software, Tsinghua University
>>
>> 田原
>> 清华大学 软件学院
>>
>>
