//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in C#:
//ORIGINAL LINE: private long acquireNewIdFromFreelistOrEnd(long stableGeneration, long unstableGeneration, boolean allowTakeLastFromPage) throws java.io.IOException
private long AcquireNewIdFromFreelistOrEnd(long stableGeneration, long unstableGeneration, bool allowTakeLastFromPage)
{
if ((_readPageId != _writePageId || _readPos < _writePos) && (allowTakeLastFromPage || _readPos < _freelistNode.maxEntries() - 1))
{
// It looks like reader isn't even caught up to the writer page-wise,
// or the read pos is < write pos so check if we can grab the next id (generation could still mismatch).
using (PageCursor cursor = _pagedFile.io(_readPageId, Org.Neo4j.Io.pagecache.PagedFile_Fields.PF_SHARED_READ_LOCK))
{
if (!cursor.Next())
{
throw new IOException("Couldn't go to free-list read page " + _readPageId);
}
long resultPageId;
do
{
resultPageId = _freelistNode.read(cursor, stableGeneration, _readPos);
} while (cursor.ShouldRetry());
if (resultPageId != FreelistNode.NoPageId)
{
// FreelistNode compares generation and so this means that we have an available
// id in the free list which we can acquire from a stable generation. Increment readPos
_readPos++;
if (_readPos >= _freelistNode.maxEntries())
{
// The current reader page is exhausted, go to the next free-list page.
_readPos = 0;
do
{
_readPageId = FreelistNode.Next(cursor);
} while (cursor.ShouldRetry());
// Put the exhausted free-list page id itself on the free-list
long exhaustedFreelistPageId = cursor.CurrentPageId;
ReleaseId(stableGeneration, unstableGeneration, exhaustedFreelistPageId);
_monitor.releasedFreelistPageId(exhaustedFreelistPageId);
}
return(resultPageId);
}
}
}
// Fall-back to acquiring at the end of the file
return(NextLastId());
}
//JAVA TO C# CONVERTER TODO TASK: Most Java annotations will not have direct .NET equivalent attributes:
//ORIGINAL LINE: @Test void shouldReadAndWriteFreeListEntries()
internal virtual void ShouldReadAndWriteFreeListEntries()
{
// GIVEN
long generationA = 34;
long pointerA = 56;
long generationB = 78;
long pointerB = 90;
// WHEN
_freelist.write(_cursor, generationA, pointerA, 0);
_freelist.write(_cursor, generationB, pointerB, 1);
long readPointerA = _freelist.read(_cursor, generationA + 1, 0);
long readPointerB = _freelist.read(_cursor, generationB + 1, 1);
// THEN
assertEquals(pointerA, readPointerA);
assertEquals(pointerB, readPointerB);
}