/// <param name="offset">Within the PST file</param>
public static void FreeAllocation(PSTFile file, long offset, int allocationLength)
{
int numberOfPages = file.Header.root.NumberOfAllocationMapPages;
if (offset < AllocationMapPage.FirstPageOffset)
{
throw new ArgumentException("Allocation offset to free cannot be before the first AMAP");
}
int pageIndex = (int)((offset - AllocationMapPage.FirstPageOffset) / AllocationMapPage.MapppedLength);
if (pageIndex >= numberOfPages)
{
throw new ArgumentException("Allocation offset to free cannot be after the area mapped by the last AMAP");
}
AllocationMapPage page = AllocationMapPage.ReadAllocationMapPage(file, pageIndex);
int pageStartOffset = (int)((offset - AllocationMapPage.FirstPageOffset) % AllocationMapPage.MapppedLength);
if (pageStartOffset < AllocationMapPage.Length)
{
throw new ArgumentException("Allocation offset to free cannot be within the AMAP page");
}
page.FreeAllocatedSpace(pageStartOffset, allocationLength);
page.WriteAllocationMapPage(file, pageIndex);
UpdateFMap(file, page, pageIndex);
file.Header.root.cbAMapFree += (uint)allocationLength;
}
/*
* private static void InvalidatePMap(PSTFile file)
* {
* file.BaseStream.Seek(PMapPage.FirstPageOffset, SeekOrigin.Begin);
* PMapPage pmap = PMapPage.GetFilledPMapPage();
* byte[] buffer = pmap.GetBytes(PMapPage.FirstPageOffset);
* file.BaseStream.Write(buffer, 0, buffer.Length);
* }
*
* private static void InvalidateDList(PSTFile file)
* {
* file.BaseStream.Seek(DensityListPage.FirstPageOffset, SeekOrigin.Begin);
* byte[] buffer = new byte[Page.Length];
* file.BaseStream.Write(buffer, 0, buffer.Length);
* }*/
private static AllocationMapPage GrowPST(PSTFile file, int newPageIndex)
{
// The PST file MUST grow at integer multiples of the number of bytes mapped by an AMap
ulong oldLength = (ulong)file.BaseStream.Length;
ulong newLength = oldLength + AllocationMapPage.MapppedLength;
file.BaseStream.Seek(0, SeekOrigin.End);
AllocationMapPage amap = new AllocationMapPage();
int freeSpaceInAMap = AllocationMapPage.MapppedLength - 512;
byte[] buffer = new byte[AllocationMapPage.MapppedLength];
if (newPageIndex % 8 == 0)
{
// We need to write a PMap for backward compatibility
PMapPage pmap = PMapPage.GetFilledPMapPage();
ulong pmapOffset = PMapPage.FirstPageOffset + (ulong)(newPageIndex / 8) * PMapPage.MapppedLength;
Array.Copy(pmap.GetBytes(pmapOffset), 0, buffer, 512, Page.Length);
// Allocate the PMap out of the AMap
amap.AllocateSpace(512, 512);
freeSpaceInAMap -= 512;
if (newPageIndex >= 128 && FreeMapPage.GetFreeMapEntryIndex(newPageIndex) == 0)
{
// We need to write an FMap for backward compatibility
FreeMapPage fmap = new FreeMapPage();
fmap.rgbFMapBits[0] = 255;
int fmapPageIndex = FreeMapPage.GetFreeMapPageIndex(newPageIndex);
ulong fmapOffset = FreeMapPage.FirstPageOffset + (ulong)fmapPageIndex * FreeMapPage.MapppedLength;
Array.Copy(fmap.GetBytes(fmapOffset), 0, buffer, 1024, Page.Length);
// Allocate the FMap out of the AMap
amap.AllocateSpace(1024, 512);
freeSpaceInAMap -= 512;
}
// FPMap page will always follow an FMap page
if (newPageIndex >= (128 * 64) && FPMapPage.GetFPMapEntryIndex(newPageIndex) == 0)
{
// We need to write a FPMap for backward compatibility
FPMapPage fpmap = new FPMapPage();
int fpmapPageIndex = FPMapPage.GetFPMapPageIndex(newPageIndex);
ulong fpmapOffset = FPMapPage.FirstPageOffset + (ulong)fpmapPageIndex * FPMapPage.MapppedLength;
Array.Copy(fpmap.GetBytes(fpmapOffset), 0, buffer, 1536, Page.Length);
// Allocate the FPMap out of the AMap
amap.AllocateSpace(1536, 512);
freeSpaceInAMap -= 512;
}
}
Array.Copy(amap.GetBytes(oldLength), 0, buffer, 0, AllocationMapPage.Length);
file.BaseStream.Write(buffer, 0, buffer.Length);
file.Header.root.ibFileEOF = newLength;
file.Header.root.ibAMapLast = oldLength;
file.Header.root.cbAMapFree += (ulong)freeSpaceInAMap;
file.Header.WriteToStream(file.BaseStream, file.WriterCompatibilityMode);
return(amap);
}
private static void UpdateFMap(PSTFile file, AllocationMapPage targetPage, int targetPageIndex)
{
byte fMax = (byte)Math.Min(255, targetPage.GetMaxContiguousSpace() / 64);
int fmapPageIndex = FreeMapPage.GetFreeMapPageIndex(targetPageIndex);
int fmapPageEntryIndex = FreeMapPage.GetFreeMapEntryIndex(targetPageIndex);
if (fmapPageIndex >= 0)
{
FreeMapPage fmap = FreeMapPage.ReadFreeMapPage(file, fmapPageIndex);
fmap.rgbFMapBits[fmapPageEntryIndex] = fMax;
fmap.WriteFreeMapPage(file, fmapPageIndex);
}
else
{
file.Header.rgbFM[fmapPageEntryIndex] = fMax;
}
}
/// <returns>Offset of space allocated</returns>
private static long AllocateSpace(PSTFile file, int allocationLength, bool pageAligned)
{
if (allocationLength > MaxAllocationLength)
{
throw new Exception("Invalid allocation length requested");
}
int numberOfPages = file.Header.root.NumberOfAllocationMapPages;
AllocationMapPage targetPage = null;
int targetPageIndex = 0;
for (int index = 0; index < numberOfPages; index++)
{
AllocationMapPage page = AllocationMapPage.ReadAllocationMapPage(file, index);
int startOffset = page.FindContiguousSpace(allocationLength, pageAligned);
if (startOffset > 0) // 0 is allocated to the AMAP itself and is not a valid value
{
targetPage = page;
targetPageIndex = index;
break;
}
}
if (targetPage == null)
{
// no space was found within existing pages
targetPageIndex = numberOfPages;
targetPage = GrowPST(file, targetPageIndex);
}
int targetPageStartOffset = targetPage.FindContiguousSpace(allocationLength, pageAligned);
targetPage.AllocateSpace(targetPageStartOffset, allocationLength);
targetPage.WriteAllocationMapPage(file, targetPageIndex);
UpdateFMap(file, targetPage, targetPageIndex);
file.Header.root.cbAMapFree -= (uint)allocationLength;
//InvalidatePMap(file);
//InvalidateDList(file);
return(AllocationMapPage.FirstPageOffset + (long)targetPageIndex * AllocationMapPage.MapppedLength + targetPageStartOffset);
}
