Today, even though our merge policy doesn't return new merge specs on SEGMENT_FLUSH, merge on the scheduler is still called on flush time, and can cause merges to stall indexing during merges. Both for the concurrent merge scheduler (the default) and the serial merge scheduler. This behavior become worse when throttling kicks in (today at 20mb per sec).
In order to solve it (outside of Lucene for now), we wrap the merge scheduler with an EnableMergeScheduler, where, on the thread level, using a thread local, the call to merge can be enabled/disabled.
A Merges helper class is added where all explicit merges operations should go through. If the scheduler is the enabled one, it will enable merges before calling the relevant explicit method call. In order to make sure Merges is the only class that calls the explicit merge calls, the IW variant of them is added to the forbidden APIs list.
closes#5319
StringReader is synchronized although input streams should always be consumed
by a single thread at a time. FastStringReader on the other hand is completely
thread unsafe.
Closes#3411
Character.codePointAt and codePointBefore have two versions: one which only
accepts an offset, and one which accepts an offset and a limit. The former can
be dangerous when working with buffers of characters because if the offset
is the last char of the buffer, a char outside the buffer might be used to
compute the code point, so one should always use the version which accepts a
limit.
Collections.sort is wasteful on random-access lists: it dumps data into an
array, sorts the list and then adds elements back to the list. However, the
sorting can easily be performed in-place by using Lucene's
CollectionUtil.(merge|quick|tim)Sort.
This commit integrates the forbiddenAPI checks that checks
Java byte code against a list of "forbidden" API signatures.
The commit also contains the fixes of the current source code
that didn't pass the default API checks.
See https://code.google.com/p/forbidden-apis/ for details.
Closes#3059
Shay Banon
Adrien Grand
Simon Willnauer