//Dynamic size entries are split into chunks that are spread around the file. We need to read per chunk
unsafe ReadHandle ScheduleDynamicSizeElementArrayReads(Entry entry, uint elementOffset, uint elementCount, long readSize, void *buffer)
{
var block = m_Blocks[(int)entry.Header.BlockIndex];
byte *dst = (byte *)buffer;
var chunkReads = new NativeBlockList <ReadCommand>(64, 64);
for (int i = 0; i < elementCount; ++i)
{
var e = new ElementRead();
e.start = entry.GetAdditionalStoragePtr()[i + elementOffset];
e.end = i + elementOffset + 1 == entry.Count ? (long)entry.Header.HeaderMeta : entry.GetAdditionalStoragePtr()[i + elementOffset + 1];
e.readDst = dst;
var readOffset = ProcessDynamicSizeElement(ref chunkReads, ref block, e);
dst += readOffset;
readSize -= readOffset;
}
Checks.CheckEquals(0, readSize);
//TODO: find a way to use the block array chunks directly for scheduling, probably add readcommandbuffer
using (NativeArray <ReadCommand> readCommands = new NativeArray <ReadCommand>((int)chunkReads.Count, Allocator.Temp))
{
var cmdsPtr = (ReadCommand *)readCommands.GetUnsafePtr();
for (int i = 0; i < readCommands.Length; ++i)
{
*(cmdsPtr + i) = chunkReads[i];
}
chunkReads.Dispose();
return(m_FileReader.Read(cmdsPtr, (uint)readCommands.Length, ReadMode.Async));
}
}
//Returns ammount of written bytes
unsafe static long ProcessDynamicSizeElement(ref NativeBlockList <ReadCommand> chunkReads, ref Block block, ElementRead elementRead)
{
long written = 0;
var chunkSize = (long)block.Header.ChunkSize;
var elementSize = elementRead.end - elementRead.start;
var dst = elementRead.readDst;
var chunkIndex = elementRead.start / chunkSize;
var chunkOffset = block.GetOffsetsPtr()[chunkIndex];
var elementOffsetInChunk = elementRead.start % chunkSize;
var remainingChunksize = chunkSize - elementOffsetInChunk;
var rSize = Math.Min(chunkSize, elementSize);
if (remainingChunksize != chunkSize)
{
chunkOffset += elementOffsetInChunk; //align the read
if (rSize > remainingChunksize)
{
rSize = remainingChunksize;
}
}
chunkReads.Push(ReadCommandBufferUtils.GetCommand(elementRead.readDst, rSize, chunkOffset));
elementRead.readDst += rSize;
elementSize -= rSize;
written += rSize;
//if the element spans multiple chunks
while (elementSize > 0)
{
chunkIndex++;
chunkOffset = block.GetOffsetsPtr()[chunkIndex];
rSize = Math.Min(chunkSize, elementSize);
chunkReads.Push(ReadCommandBufferUtils.GetCommand(elementRead.readDst, rSize, chunkOffset));
elementRead.readDst += rSize;
elementSize -= rSize;
written += rSize;
}
return(written);
}
