RFR: 8080272 Refactor I/O stream copying to use InputStream.transferTo/readAllBytes and Files.copy [v11]

[Andrey Turbanov]

On Fri, 19 Feb 2021 15:03:11 GMT, Sean Mullan <mullan at openjdk.org> wrote:

>> As I can see only ByteArrayInputStream is actually passed in `InputStream` in current JDK code:
>> 
>>     PKCS7 pkcs7 = new PKCS7(is.readAllBytes());
>>         private static List<X509Certificate> parsePKCS7(InputStream is)
>>             certs = parsePKCS7(is);
>>                 public X509CertPath(InputStream is, String encoding)
>>                     return new X509CertPath(new ByteArrayInputStream(data), encoding);
>> 
>>     PKCS7 pkcs7 = new PKCS7(is.readAllBytes());
>>         private static List<X509Certificate> parsePKCS7(InputStream is)
>>             certs = parsePKCS7(is);
>>                 public X509CertPath(InputStream is, String encoding)
>>                     this(is, PKIPATH_ENCODING);
>>                         public X509CertPath(InputStream is) throws CertificateException {
>>                             return new X509CertPath(new ByteArrayInputStream(encoding));
>> 
>> ![изображение](https://user-images.githubusercontent.com/741251/108475587-f4f61080-72a1-11eb-91e0-ac2b98c7c490.png)
>> 
>> Perhaps original marking approach was lost during refactoring?
>
> You are right, the code was refactored (way back in 2010) [1] to read one block at a time, so this check on mark can be removed. So, in this case, I think it is probably safe to just pass the InputStream as-is to PKCS7(InputStream), but maybe you can add a comment that says this should always be a ByteArrayInputStream. We can look at refactoring this code and clean it up a bit more later.
> 
> [1] https://hg.openjdk.java.net/jdk/jdk/rev/337ae296b6d6

I find implementation of `sun.security.pkcs.PKCS7#PKCS7(java.io.InputStream)` a bit confusing (or even buggy). It uses only `InputStream.available()` to parse block.
So I would prefer to not use it.

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PR: https://git.openjdk.java.net/jdk/pull/1853