private CachingBin.Page SyncReadPage(long startAddress)
{
CachingBin.Page page = new CachingBin.Page(_pageSize);
LoadPage(page, startAddress);
page.EnsureEndAddress(_fileLength);
return(page);
}
private CachingBin.Page GetPage(long startAddress, IFunction4 producer)
{
CachingBin.Page page = ((CachingBin.Page)_cache.Produce(PageAddressFor(startAddress
), producer, _onDiscardPage));
page.EnsureEndAddress(_fileLength);
return(page);
}
/// <exception cref="Db4objects.Db4o.Ext.Db4oIOException"></exception>
private void FlushPage(CachingBin.Page page)
{
if (!page._dirty)
{
return;
}
WritePageToDisk(page);
}
/// <exception cref="Db4objects.Db4o.Ext.Db4oIOException"></exception>
protected virtual void FlushAllPages()
{
for (IEnumerator pIter = _cache.GetEnumerator(); pIter.MoveNext();)
{
CachingBin.Page p = ((CachingBin.Page)pIter.Current);
FlushPage(p);
}
}
public object Apply(object pageAddress)
{
// in case that page is not found in the cache
CachingBin.Page newPage = ((CachingBin.Page) this._enclosing._pagePool.BorrowObject
());
this._enclosing.ResetPageAddress(newPage, ((long)pageAddress));
return(newPage);
}
private CachingBin.Page[] NewPagePool(int pageCount)
{
CachingBin.Page[] pages = new CachingBin.Page[pageCount];
for (int i = 0; i < pages.Length; ++i)
{
pages[i] = new CachingBin.Page(_pageSize);
}
return pages;
}
private CachingBin.Page[] NewPagePool(int pageCount)
{
CachingBin.Page[] pages = new CachingBin.Page[pageCount];
for (int i = 0; i < pages.Length; ++i)
{
pages[i] = new CachingBin.Page(_pageSize);
}
return(pages);
}
/// <exception cref="Db4objects.Db4o.Ext.Db4oIOException"></exception>
private void LoadPage(CachingBin.Page page, long pos)
{
long startAddress = pos - pos % _pageSize;
page._startAddress = startAddress;
int count = _bin.Read(page._startAddress, page._buffer, page._bufferSize);
if (count > 0)
{
page._endAddress = startAddress + count;
}
else
{
page._endAddress = startAddress;
}
}
/// <summary>Writes the buffer to cache using pages</summary>
/// <param name="pos">start position to write</param>
/// <param name="buffer">source buffer</param>
/// <param name="length">how many bytes to write</param>
/// <exception cref="Db4objects.Db4o.Ext.Db4oIOException"></exception>
public override void Write(long pos, byte[] buffer, int length)
{
long startAddress = pos;
int bytesToWrite = length;
int bufferOffset = 0;
while (bytesToWrite > 0)
{
// page doesn't need to loadFromDisk if the whole page is dirty
bool loadFromDisk = (bytesToWrite < _pageSize) || (startAddress % _pageSize != 0);
CachingBin.Page page = GetPage(startAddress, loadFromDisk);
int writtenBytes = page.Write(buffer, bufferOffset, startAddress, bytesToWrite);
bytesToWrite -= writtenBytes;
startAddress += writtenBytes;
bufferOffset += writtenBytes;
}
long endAddress = startAddress;
_fileLength = Math.Max(endAddress, _fileLength);
}
private int ReadInternal(long pos, byte[] buffer, int length, bool syncRead)
{
long startAddress = pos;
int bytesToRead = length;
int totalRead = 0;
while (bytesToRead > 0)
{
CachingBin.Page page = syncRead ? SyncReadPage(startAddress) : GetPage(startAddress
, _producerFromDisk);
int readBytes = page.Read(buffer, totalRead, startAddress, bytesToRead);
if (readBytes <= 0)
{
break;
}
bytesToRead -= readBytes;
startAddress += readBytes;
totalRead += readBytes;
}
return totalRead == 0 ? -1 : totalRead;
}
private CachingBin.Page SyncReadPage(long startAddress)
{
CachingBin.Page page = new CachingBin.Page(_pageSize);
LoadPage(page, startAddress);
page.EnsureEndAddress(_fileLength);
return page;
}
/// <exception cref="Db4objects.Db4o.Ext.Db4oIOException"></exception>
private void WritePageToDisk(CachingBin.Page page)
{
base.Write(page._startAddress, page._buffer, page.Size());
page._dirty = false;
}
private void ResetPageAddress(CachingBin.Page page, long startAddress)
{
page._startAddress = startAddress;
page._endAddress = startAddress + _pageSize;
}