public void Set(Pointer start, uint size, byte value)
{
for (var i = start.Address; i < start.Address + size; i++)
{
_memory[i] = value;
}
}
public void Copy(Pointer from, Pointer to, uint size)
{
var fromAddr = from.Address;
var toAddr = to.Address;
for (int i = 0; i < size; i++)
{
_memory[toAddr + i] = _memory[fromAddr + i];
}
}
public void Free(Pointer address)
{
Pointer blockStart = GetBlockStart(address);
uint blockCount = GetBlockSize(blockStart);
for (var i = 0; i < blockCount; i++)
{
SetBlockStatus(blockStart, BlockStatusFree);
blockStart = AddBlock(blockStart);
}
}
public uint ReadUint(Pointer address)
{
byte[] data = Read(address, 4);
uint result = 0;
for (int i = 3; i >= 0; i--)
{
result <<= 8;
result |= data[i];
}
return result;
}
public Pointer Reallocate(Pointer address, uint newSize)
{
if (newSize == 0)
{
Free(address);
return Pointer.Null;
}
Pointer blockStart = GetBlockStart(address);
uint allocatedBlocks = GetBlockSize(blockStart);
uint requiredBlocks = GetRequiredBlocks(newSize);
if (allocatedBlocks >= requiredBlocks)
{
TruncAllocated(blockStart, requiredBlocks);
return address;
}
else
{
uint freeBlocks = GetFreeBlockCountAfter(address);
if (allocatedBlocks + freeBlocks >= requiredBlocks)
{
ExpandAllocated(blockStart, requiredBlocks);
return address;
}
else
{
Pointer newBlocks = Allocate(newSize);
if (newBlocks != null)
{
_memory.Copy(address, newBlocks, allocatedBlocks * _blockSize - SystemDataSize);
Free(address);
return GetBlockDataStart(newBlocks);
}
else
{
return Pointer.Null;
}
}
}
}
private void ExpandAllocated(Pointer address, uint newBlockCount)
{
SetBlockSize(address, newBlockCount);
}
private void TruncAllocated(Pointer address, uint newBlockCount)
{
uint allocatedBlocks = GetBlockSize(address);
SetBlockSize(address, newBlockCount);
Pointer freeBlock = AddBlocks(address, newBlockCount);
for (uint i = newBlockCount; i < allocatedBlocks; i++)
{
SetBlockStatus(freeBlock, BlockStatusFree);
freeBlock = AddBlock(freeBlock);
}
}
public byte[] Read(Pointer start, uint size)
{
return _memory.Skip((int)(start.Address)).Take((int)size).ToArray();
}
private void SetBlockSize(Pointer address, uint size)
{
_memory.WriteUint(address, size);
}
private void SetBlockStatus(Pointer address, uint status)
{
_memory.WriteUint(address, status);
}
private uint GetFreeBlockCountAfter(Pointer address)
{
uint freeBlockCount = 0;
uint allocatedBlocks = GetBlockSize(address);
Pointer currentBlockAddress = AddBlocks(address, allocatedBlocks);
while (GetBlockStatus(currentBlockAddress) == BlockStatusFree)
{
freeBlockCount++;
currentBlockAddress = AddBlock(currentBlockAddress);
}
return freeBlockCount;
}
private void PrepareMemory()
{
_blockCount = _memory.Size / _blockSize;
Pointer blockStart = _memory.GetPointer(0);
for (int i = 0; i < _blockCount; i++)
{
SetBlockStatus(blockStart, BlockStatusFree);
}
_endBlock = _memory.GetPointer(_blockSize * _blockCount);
}
private Pointer GetBlockStart(Pointer dataStart)
{
return dataStart.Sub(SystemDataSize);
}
private uint GetBlockStatus(Pointer address)
{
return _memory.ReadUint(address);
}
public byte Read(Pointer address)
{
return _memory[address.Address];
}
private Pointer GetBlockDataStart(Pointer blockStart)
{
return blockStart.Add(SystemDataSize);
}
private Pointer AddBlocks(Pointer address, uint count)
{
return address.Add(_blockSize * count);
}
private Pointer AddBlock(Pointer address)
{
return address.Add(_blockSize);
}
public void WriteUint(Pointer address, uint value)
{
uint input = value;
byte[] data = new byte[4];
for (int i = 0; i < 4; i++)
{
data[i] = (byte)(input & 0xFF);
input >>= 8;
}
Write(address, data);
}
public void Write(Pointer start, byte[] data)
{
for (int i = 0; i < data.Length; i++)
{
_memory[start.Address + i] = data[i];
}
}
public void Write(Pointer address, byte value)
{
_memory[address.Address] = value;
}