private void writeFiles(UnityBinaryWriter writer)
{
// calc total size
int totalsize = Files.Sum(f => f.Data.Length);
// teardown into blocks
// 1.File is not aligned to block boundary (Simple concatation)
// 2.Maximum block size is BLOCK_SIZE
// Calculate block count
var totalbytes = Files.Sum(f => f.Data.Length);
var blockcount = totalbytes / BLOCK_SIZE + (totalbytes % BLOCK_SIZE != 0 ? 1 : 0);
// Build blockinfo
BlockInfo[] blockinfos = new BlockInfo[blockcount];
short blockflag = EnableCompression ? (short)2 : (short)0;
for (int i = 0; i < blockcount; i++)
{
blockinfos[i].uncompressedSize = BLOCK_SIZE;
blockinfos[i].compressedSize = BLOCK_SIZE;
blockinfos[i].flag = blockflag;
}
if (totalbytes % BLOCK_SIZE != 0)
{
blockinfos[blockcount - 1].uncompressedSize = totalbytes % BLOCK_SIZE;
blockinfos[blockcount - 1].compressedSize = totalbytes % BLOCK_SIZE;
}
// Seek Writer (Skip Info)
//int infoheadersize = 4 + 4 + 4;
int blockinfosize = 0x10 + 4 + (4 + 4 + 2) * blockinfos.Length;
int fileinfosize = 4 + Files.Sum(f => f.CalcInfoSize());
int info_offset = writer.Position;
// Write Blocks
// If no compression required, just copy all files
if (!EnableCompression)
{
// Write Header
// Info Header
writer.WriteIntBE(blockinfosize + fileinfosize);
writer.WriteIntBE(blockinfosize + fileinfosize);
writer.WriteIntBE(0x40);
writer.Position += 0x10;
// BlockInfo
writer.WriteIntBE(blockcount);
blockinfos.Write(writer);
// FileInfo
writer.WriteIntBE(Files.Length);
int curoffset = 0;
for (int i = 0; i < Files.Length; i++)
{
writer.WriteLongBE(curoffset);
writer.WriteLongBE(Files[i].Data.LongLength);
writer.WriteIntBE(4);
writer.WriteStringToNull(Files[i].Name);
curoffset += Files[i].Data.Length;
}
// Write Files
for (int i = 0; i < Files.Length; i++)
{
writer.WriteBytes(Files[i].Data);
}
}
// In compression mode, try to parallelize the compression
else
{
// First of all, Prepare buffer for compression
byte[] compbuf = MemoryPool <AssetBundleFile> .GetBuffer(blockcount *BLOCK_SIZE);
// don't parallelize when block count is small
if (blockcount < 128)
{
byte[] boundarybuf = MiniMemoryPool <AssetBundleFile> .GetBuffer(BLOCK_SIZE);
int remainlength = 0;
int curblock = 0;
for (int i = 0; i < Files.Length; i++)
{
// If previous file has overflow, concat and compress
if (remainlength > 0)
{
Buffer.BlockCopy(Files[i].Data, 0, boundarybuf, remainlength, BLOCK_SIZE - remainlength);
blockinfos[curblock].compressedSize = TryLZ4Compress(boundarybuf, 0, compbuf, curblock * BLOCK_SIZE, BLOCK_SIZE);
if (blockinfos[curblock].compressedSize == BLOCK_SIZE)
{
blockinfos[curblock].flag &= ~0x3F;
}
curblock++;
}
// update remainlength
int blockstart = 0;
if (remainlength > 0)
{
blockstart = BLOCK_SIZE - remainlength;
}
// compress fullblocks
int fullblockcount = (Files[i].Data.Length - blockstart) / BLOCK_SIZE;
for (int j = 0; j < fullblockcount; j++, curblock++)
{
blockinfos[curblock].compressedSize = TryLZ4Compress(Files[i].Data, blockstart + j * BLOCK_SIZE, compbuf, curblock * BLOCK_SIZE, BLOCK_SIZE);
if (blockinfos[curblock].compressedSize == BLOCK_SIZE)
{
blockinfos[curblock].flag &= ~0x3F;
}
}
// If the file has remaindata, buffer them
remainlength = (Files[i].Data.Length - blockstart) % BLOCK_SIZE;
if (remainlength > 0)
{
Buffer.BlockCopy(Files[i].Data, Files[i].Data.Length - remainlength, boundarybuf, 0, remainlength);
}
}
if (remainlength > 0) // Process last block
{
blockinfos[curblock].compressedSize = TryLZ4Compress(boundarybuf, 0, compbuf, curblock * BLOCK_SIZE, remainlength);
if (blockinfos[curblock].compressedSize == remainlength)
{
blockinfos[curblock].flag &= ~0x3F;
}
}
}
else
{
// Create CompressionInfo & Compress file boundary
CompressionInfo[] compinfos = new CompressionInfo[blockcount];
byte[] boundarybuf = MiniMemoryPool <AssetBundleFile> .GetBuffer(BLOCK_SIZE);
int curblock = 0;
int remainlength = 0;
for (int i = 0; i < Files.Length; i++)
{
// If previous file has overflow, concat and compress
if (remainlength > 0)
{
Buffer.BlockCopy(Files[i].Data, 0, boundarybuf, remainlength, BLOCK_SIZE - remainlength);
blockinfos[curblock].compressedSize = TryLZ4Compress(boundarybuf, 0, compbuf, curblock * BLOCK_SIZE, BLOCK_SIZE);
if (blockinfos[curblock].compressedSize == BLOCK_SIZE)
{
blockinfos[curblock].flag &= ~0x3F;
}
curblock++;
}
int blockstart = 0;
if (remainlength > 0)
{
blockstart = BLOCK_SIZE - remainlength;
}
int fullblockcount = (Files[i].Data.Length - blockstart) / BLOCK_SIZE;
for (int j = 0; j < fullblockcount; j++, curblock++)
{
compinfos[curblock].data = Files[i].Data;
compinfos[curblock].length = BLOCK_SIZE;
compinfos[curblock].offset = blockstart + j * BLOCK_SIZE;
}
// If the file has remaindata, buffer them
remainlength = (Files[i].Data.Length - blockstart) % BLOCK_SIZE;
if (remainlength > 0)
{
Buffer.BlockCopy(Files[i].Data, Files[i].Data.Length - remainlength, boundarybuf, 0, remainlength);
}
}
if (remainlength > 0) // Process last block
{
blockinfos[curblock].compressedSize =
LZ4.LZ4Codec.Encode(boundarybuf, 0, remainlength,
compbuf, curblock * BLOCK_SIZE, remainlength);
// If compression is no use, just copy
if (blockinfos[curblock].compressedSize == 0)
{
blockinfos[curblock].compressedSize = remainlength;
blockinfos[curblock].flag &= ~0x3F;
Buffer.BlockCopy(boundarybuf, 0, compbuf, curblock * BLOCK_SIZE, BLOCK_SIZE);
}
}
// Parallelly compress the data
Parallel.For(0, blockcount, i => {
if (compinfos[i].data == null)
{
return;
}
blockinfos[i].compressedSize = TryLZ4Compress(compinfos[i].data, compinfos[i].offset, compbuf, i * BLOCK_SIZE, compinfos[i].length);
if (blockinfos[i].compressedSize == BLOCK_SIZE)
{
blockinfos[i].flag &= ~0x3F;
}
});
}
// Write Headers
UnityBinaryWriter headerwriter = new UnityBinaryWriter();
// Info Header
headerwriter.Position += 0x10;
// BlockInfo
headerwriter.WriteIntBE(blockcount);
blockinfos.Write(headerwriter);
// FileInfo
headerwriter.WriteIntBE(Files.Length);
int curoffset = 0;
for (int i = 0; i < Files.Length; i++)
{
headerwriter.WriteLongBE(curoffset);
headerwriter.WriteLongBE(Files[i].Data.LongLength);
headerwriter.WriteIntBE(4);
headerwriter.WriteStringToNull(Files[i].Name);
curoffset += Files[i].Data.Length;
}
// Compress and write header
writer.Position += 4 + 4 + 4;
int header_compsize = writer.WriteLZ4Data(headerwriter.ToBytes());
int final_pos = writer.Position;
writer.Position = info_offset;
writer.WriteIntBE(header_compsize);
writer.WriteIntBE(blockinfosize + fileinfosize);
writer.WriteIntBE(0x42);
writer.Position = final_pos;
// Write Blocks
for (int i = 0; i < blockcount; i++)
{
writer.WriteBytes(compbuf, i * BLOCK_SIZE, blockinfos[i].compressedSize);
}
}
}
