On Thu, 19 Nov 2020 20:20:17 GMT, Brian Burkhalter <[email protected]> wrote:
>> Please review this modification of `java.io.InputStream.skipNBytes(long)` to
>> improve its performance when `skip(long)` skips fewer than the requested
>> number of bytes. In the current implementation, `skip(long)` is invoked once
>> and, if not enough bytes have been skipped, then `read()` is invoked for
>> each of the remaining bytes to be skipped. The proposed implementation
>> instead repeatedly invokes `skip(long)` until the requested number of bytes
>> has been skipped, or an error condition is encountered. For cases where
>> `skip(long)` skips fewer bytes than the number requested, the new version
>> was measured to be up to more than one thousand times faster than the old
>> version. When `skip(long)` actually skips the requested number of bytes, the
>> performance difference is insignificant.
>
> Brian Burkhalter has updated the pull request incrementally with two
> additional commits since the last revision:
>
> - 8246739: InputStream.skipNBytes could be implemented more efficiently
> - 8246739: InputStream.skipNBytes could be implemented more efficiently
src/java.base/share/classes/java/io/InputStream.java line 605:
> 603: } else if (ns == 0) { // no bytes skipped
> 604: // read one byte to check for EOS
> 605: if (read() < 0) {
Wouldn't it be better to compare return value with -1 (as it was before)?
Since the documentation of read method says:
_Returns:
the next byte of data, or **-1 if the end of the stream is reached**._
-------------
PR: https://git.openjdk.java.net/jdk/pull/1329
