public static void AssignPositions(IList <IResourceBlock> blocks, uint basePosition, out RpfResourcePageFlags pageFlags)
{
var sys = (basePosition == 0x50000000);
long pad(long p)
{
return((ALIGN_SIZE - (p % ALIGN_SIZE)) % ALIGN_SIZE);
}
long largestBlockSize = 0; // find largest structure
long startPageSize = BASE_SIZE; // 0x2000; // find starting page size
long totalBlockSize = 0;
foreach (var block in blocks)
{
var blockLength = block.BlockLength;
totalBlockSize += blockLength;
totalBlockSize += pad(totalBlockSize);
if (largestBlockSize < blockLength)
{
largestBlockSize = blockLength;
}
}
while (startPageSize < largestBlockSize)
{
startPageSize *= 2;
}
pageFlags = new RpfResourcePageFlags();
var pageSizeMult = 1;
while (true)
{
if (blocks.Count == 0)
{
break;
}
var blockset = new ResourceBuilderBlockSet(blocks, sys);
var rootblock = blockset.RootBlock;
var currentPosition = 0L;
var currentPageSize = startPageSize;
var currentPageStart = 0L;
var currentPageSpace = startPageSize;
var currentRemainder = totalBlockSize;
var pageCount = 1;
var pageCounts = new uint[9];
var pageCountIndex = 0;
var targetPageSize = Math.Max(65536 * pageSizeMult, startPageSize >> (sys ? 5 : 2));
var minPageSize = Math.Max(512 * pageSizeMult, Math.Min(targetPageSize, startPageSize) >> 4);
var baseShift = 0u;
var baseSize = 512;
while (baseSize < minPageSize)
{
baseShift++;
baseSize *= 2;
if (baseShift >= 0xF)
{
break;
}
}
var baseSizeMax = baseSize << 8;
var baseSizeMaxTest = startPageSize;
while (baseSizeMaxTest < baseSizeMax)
{
pageCountIndex++;
baseSizeMaxTest *= 2;
}
pageCounts[pageCountIndex] = 1;
while (true)
{
var isroot = sys && (currentPosition == 0);
var block = isroot ? rootblock : blockset.TakeBestBlock(currentPageSpace);
var blockLength = block?.Length ?? 0;
if (block != null)
{
//add this block to the current page.
block.Block.FilePosition = basePosition + currentPosition;
var opos = currentPosition;
currentPosition += blockLength;
currentPosition += pad(currentPosition);
var usedspace = currentPosition - opos;
currentPageSpace -= usedspace;
currentRemainder -= usedspace;//blockLength;//
}
else if (blockset.Count > 0)
{
//allocate a new page
currentPageStart += currentPageSize;
currentPosition = currentPageStart;
block = blockset.FindBestBlock(long.MaxValue); //just find the biggest block
blockLength = block?.Length ?? 0;
while (blockLength <= (currentPageSize >> 1)) //determine best new page size
{
if (currentPageSize <= minPageSize)
{
break;
}
if (pageCountIndex >= 8)
{
break;
}
if ((currentPageSize <= targetPageSize) && (currentRemainder >= (currentPageSize - minPageSize)))
{
break;
}
currentPageSize = currentPageSize >> 1;
pageCountIndex++;
}
currentPageSpace = currentPageSize;
pageCounts[pageCountIndex]++;
pageCount++;
}
else
{
break;
}
}
pageFlags = new RpfResourcePageFlags(pageCounts, baseShift);
if ((pageCount == pageFlags.Count) && (pageFlags.Size >= currentPosition)) //make sure page counts fit in the flags value
{
break;
}
startPageSize *= 2;
pageSizeMult *= 2;
}
}
