public IPage Retrieve(ulong pageId, BrightstarProfiler profiler)
{
using (profiler.Step("BinaryFilePageStore.GetPage"))
{
// Look in the page cache
IPage page = PageCache.Instance.Lookup(_partitionId, pageId) as BinaryFilePage;
if (page != null)
{
profiler.Incr("PageCache Hit");
return(page);
}
// See if the page is queued for writing
if (_backgroundPageWriter != null && _backgroundPageWriter.TryGetPage(pageId, out page))
{
profiler.Incr("BackgroundWriter Queue Hit");
return(page);
}
// Not found in memory, so go to the disk
profiler.Incr("PageCache Miss");
using (profiler.Step("Load Page"))
{
page = _modifiedPages.ContainsKey(pageId)
? new BinaryFilePage(_inputStream, pageId, _nominalPageSize, _writeTxnId, true)
: new BinaryFilePage(_inputStream, pageId, _nominalPageSize, _readTxnId, false);
PageCache.Instance.InsertOrUpdate(_partitionId, page);
return(page);
}
}
}
public IPage Retrieve(ulong pageId, BrightstarProfiler profiler)
{
using (profiler.Step("PageStore.Retrieve"))
{
if (!_readonly && pageId >= _newPageOffset)
{
var newPageRef = _newPages[(int)(pageId - _newPageOffset)];
if (newPageRef.IsAlive)
{
var newPage = newPageRef.Target as IPage;
if (newPage != null)
{
return(newPage);
}
}
}
var page = PageCache.Instance.Lookup(_path, pageId) as IPage;
if (page != null)
{
profiler.Incr("PageCache Hit");
return(page);
}
if (_backgroundPageWriter != null)
{
// See if the page is currently queued for background write
if (_backgroundPageWriter.TryGetPage(pageId, out page))
{
profiler.Incr("BackgroundWriter Queue Hit");
return(page);
}
}
using (profiler.Step("Load Page"))
{
profiler.Incr("PageCache Miss");
using (profiler.Step("Create FilePage"))
{
page = new FilePage(_stream, pageId, _pageSize);
if (_backgroundPageWriter != null)
{
_backgroundPageWriter.ResetTimestamp(pageId);
}
#if DEBUG_PAGESTORE
Logging.LogDebug("Load {0} {1}", pageId, BitConverter.ToInt32(page.Data, 0));
#endif
}
using (profiler.Step("Add FilePage To Cache"))
{
PageCache.Instance.InsertOrUpdate(_path, page);
}
return(page);
}
}
}
