public Filesystem(Stream basestream, string pswd, int seglen, long partitionLen)
{
_seglen = seglen;
bool empty = basestream.Length <16389;
Stream mstream = SeekableCryptoStream.CreateUltraSecureStream(pswd,seglen, basestream);
fstream = mstream;
if (empty)
{
BinaryWriter mwriter = new BinaryWriter(fstream);
mwriter.Write("IC80v3");
long cpos = fstream.Position;
mwriter.Write(new char[256]);
mwriter.Write(partitionLen);
mwriter.Write(false);
fragments.Add(-1, new List<IC80Fragment>());
IC80Fragment lament = new IC80Fragment();
lament.name = -1;
lament.size = partitionLen;
lament.FragmentPosition = cpos;
fragments[-1].Add(lament);
mwriter.Flush();
}
else
{
BinaryReader mreader = new BinaryReader(fstream);
string xt = mreader.ReadString();
if (xt != "IC80v3")
{
throw new Exception("This library only supports IC80 version 3 file systems.");
}
while (true)
{
IC80Fragment mf = new IC80Fragment();
mf.Read(mreader);
if (!fragments.ContainsKey(mf.name))
{
fragments.Add(mf.name, new List<IC80Fragment>());
}
fragments[mf.name].Add(mf);
if (!mf.hasNextFile)
{
break;
}else {
fstream.Position +=mf.size;
}
}
}
FreeSpace.ToString();
}
/// <summary>
/// Allocs a contiguous region of free space
/// </summary>
/// <param name='file'>
/// File name
/// </param>
/// <param name='len'>
/// Length to allocate (in bytes)
/// </param>
public void AllocSpace(long file,long len)
{
if(!fragments.ContainsKey(file)) {
fragments.Add(file,new List<IC80Fragment>());
}
lock(fragments[-1]) {
foreach (IC80Fragment et in fragments[-1])
{
if (et.size > len + IC80Fragment.GetSize())
{
fragments[-1].Remove(et);
et.name = file;
et.haschanged = true;
et.hasNextFile = true;
IC80Fragment freefrag = new IC80Fragment();
freefrag.name = -1;
freefrag.haschanged = true;
//Compute fragment position. Immediately after this file
freefrag.FragmentPosition = len + et.FragmentPosition + IC80Fragment.GetSize();
freefrag.size = et.size - len;
et.size = len;
fragments[file].Add(et);
Console.WriteLine("File " + file.ToString() + " has " + fragments[file].Count.ToString() + " fragments");
fragments[-1].Add(freefrag);
break;
}
}
}
}
IC80Fragment GetAdjacentFragment(IC80Fragment src)
{
foreach(KeyValuePair<long,List<IC80Fragment>> et in fragments) {
foreach(IC80Fragment ett in et.Value) {
if(ett.FragmentPosition >= src.FragmentPosition+src.size+IC80Fragment.GetSize()) {
return ett;
}
}
}
return null;
}
/// <summary>
/// Allocs a contiguous region of free space
/// </summary>
/// <param name='file'>
/// File name
/// </param>
/// <param name='len'>
/// Length to allocate (in bytes)
/// </param>
public void AllocSpace(long file,long len)
{
if(!fragments.ContainsKey(file)) {
fragments.Add(file,new List<IC80Fragment>());
}
lock(fragments[-1]) {
if (fragments[file].Count > 0)
{
IC80Fragment endfrag = null;
long maxpos = -8;
foreach(IC80Fragment et in fragments[file]) {
if(et.FragmentPosition>maxpos) {
maxpos = et.FragmentPosition;
endfrag = et;
}
}
long lastfrag_end = endfrag.FragmentPosition + endfrag.size + IC80Fragment.GetSize();
foreach (IC80Fragment et in fragments[-1])
{
//TODO: This has been disabled for testing purposes
break;
bool foundbug = false;
if (et.FragmentPosition == lastfrag_end && et.size>len)
{
//Resize existing fragment, without creating a new one
foreach(KeyValuePair<long,List<IC80Fragment>> fraglist in fragments) {
foreach(IC80Fragment frag in fraglist.Value) {
if(frag !=et) {
if(et.FragmentPosition+len>=frag.FragmentPosition && et.size+et.FragmentPosition+len<=frag.size+frag.FragmentPosition+IC80Fragment.GetSize()) {
foundbug = true;
break;
}
}
}
if(foundbug) {
break;
}
}
if(foundbug) {
break;
}
et.FragmentPosition += len;
et.size -= len;
endfrag.size += len;
endfrag.haschanged = true;
et.haschanged = true;
commit();
return;
}
}
}
foreach (IC80Fragment et in fragments[-1])
{
if (et.size > len + IC80Fragment.GetSize()+IC80Fragment.GetSize())
{
//Mark free space as being occupied by Wall Street
fragments[-1].Remove(et);
et.name = file;
et.haschanged = true;
//Create new free democracy
IC80Fragment freefrag = new IC80Fragment();
freefrag.name = -1;
freefrag.haschanged = true;
//Compute fragment position. Immediately after this file
freefrag.FragmentPosition = len + et.FragmentPosition + IC80Fragment.GetSize();
//We use some free space for our file fragment, and also free space is used for the free space segment
//itself.
freefrag.size = et.size - len-IC80Fragment.GetSize();
et.hasNextFile = true;
IC80Fragment adjfrag = GetAdjacentFragment(freefrag);
if(adjfrag !=null) {
freefrag.hasNextFile = true;
}
et.size = len;
fragments[file].Add(et);
fragments[-1].Add(freefrag);
if(GetAdjacentFragment(et) == null) {
throw new Exception("Well here's your problem!");
}
break;
}
}
}
commit();
}
