public static void AssignPositions(IList <IResourceBlock> blocks, uint basePosition, out ResourceChunkFlags flags, uint usedPages)
{
flags = new ResourceChunkFlags();
if (blocks.Count <= 0)
{
return;
}
long largestBlockSize = 0; // find largest structure
long startPageSize = BASE_SIZE; // 0x2000; // find starting page size
long totalBlockSize = 0;
foreach (var block in blocks)
{
// Get size of all blocks padded
var blockLength = block.BlockLength;
totalBlockSize += blockLength;
totalBlockSize += Pad(totalBlockSize);
// Get biggest block
if (largestBlockSize < blockLength)
{
largestBlockSize = blockLength;
}
}
// Get minimum page size to contain biggest block
while (startPageSize < largestBlockSize)
{
startPageSize *= 2;
}
var pageSizeMult = 1;
long currentPosition;
var sys = (basePosition == 0x50000000);
bool invalidLayout;
do
{
invalidLayout = false;
var blockset = new ResourceBuilderBlockSet(blocks, sys);
var rootblock = blockset.RootBlock;
currentPosition = 0L;
var currentPageSize = startPageSize;
var currentPageStart = 0L;
var currentPageSpace = startPageSize;
long currentRemainder = totalBlockSize;
var bucketIndex = 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;
}
}
flags = new ResourceChunkFlags(new uint[9], baseShift);
var baseSizeMax = baseSize << 8;
var baseSizeMaxTest = startPageSize;
while (baseSizeMaxTest < baseSizeMax)
{
bucketIndex++;
baseSizeMaxTest *= 2;
}
if (!flags.TryAddChunk(bucketIndex))
{
break;
}
while (blockset.Count > 0)
{
var isroot = sys && (currentPosition == 0);
var block = isroot ? rootblock : blockset.GetBestBlock(currentPageSpace);
// If there is no block to fit in space left
if (block == null)
{
//allocate a new page
currentPageStart += currentPageSize;
currentPosition = currentPageStart;
// Get the biggest block
block = blockset.GetBestBlock(long.MaxValue);
var blockLength = block?.BlockLength ?? 0;
// Get the smallest page which can contain the block
while (blockLength <= (currentPageSize >> 1))
{
if (currentPageSize <= minPageSize)
{
break;
}
if (bucketIndex >= 8)
{
break;
}
if ((currentPageSize <= targetPageSize) && (currentRemainder >= (currentPageSize - minPageSize)))
{
break;
}
currentPageSize = currentPageSize >> 1;
bucketIndex++;
}
currentPageSpace = currentPageSize;
// Try adding another chunk to this bucket
if (!flags.TryAddChunk(bucketIndex))
{
invalidLayout = true;
break;
}
}
//add this block to the current page.
block.BlockPosition = basePosition + currentPosition;
var opos = currentPosition;
currentPosition += block.BlockLength;
currentPosition += Pad(currentPosition);
var usedspace = currentPosition - opos;
currentPageSpace -= usedspace;
currentRemainder -= usedspace;
}
startPageSize *= 2;
pageSizeMult *= 2;
}while ((invalidLayout) || (flags.Size < totalBlockSize) || (flags.Count + usedPages > 128));
}
