Ejemplo n.º 1
0
        public override void WriteClusters(long startVcn, int count, byte[] buffer, int offset)
        {
            if (buffer.Length < (count * _bytesPerCluster) + offset)
            {
                throw new ArgumentException("Cluster buffer too small", "buffer");
            }

            int runIdx       = 0;
            int totalWritten = 0;

            while (totalWritten < count)
            {
                long focusVcn = startVcn + totalWritten;

                runIdx = _cookedRuns.FindDataRun(focusVcn, runIdx);
                CookedDataRun run = _cookedRuns[runIdx];

                if (run.IsSparse)
                {
                    throw new NotImplementedException("Writing to sparse datarun");
                }

                int toWrite = (int)Math.Min(count - totalWritten, run.Length - (focusVcn - run.StartVcn));

                long lcn = _cookedRuns[runIdx].StartLcn + (focusVcn - run.StartVcn);
                _fsStream.Position = lcn * _bytesPerCluster;
                _fsStream.Write(buffer, offset + (totalWritten * _bytesPerCluster), toWrite * _bytesPerCluster);

                totalWritten += toWrite;
            }
        }
Ejemplo n.º 2
0
        public int FindDataRun(long vcn, int startIdx)
        {
            int numRuns = _runs.Count;

            if (numRuns > 0)
            {
                CookedDataRun run = _runs[numRuns - 1];
                if (vcn >= run.StartVcn)
                {
                    if (run.StartVcn + run.Length > vcn)
                    {
                        return(numRuns - 1);
                    }
                    else
                    {
                        throw new IOException("Looking for VCN outside of data runs");
                    }
                }

                for (int i = startIdx; i < numRuns; ++i)
                {
                    run = _runs[i];
                    if (run.StartVcn + run.Length > vcn)
                    {
                        return(i);
                    }
                }
            }

            throw new IOException("Looking for VCN outside of data runs");
        }
Ejemplo n.º 3
0
        public void MakeSparse(int index)
        {
            if (index < _firstDirty)
            {
                _firstDirty = index;
            }

            if (index > _lastDirty)
            {
                _lastDirty = index;
            }

            long          prevLcn = index == 0 ? 0 : _runs[index - 1].StartLcn;
            CookedDataRun run     = _runs[index];

            if (run.IsSparse)
            {
                throw new ArgumentException("Run is already sparse", "index");
            }

            _runs[index] = new CookedDataRun(new DataRun(0, run.Length, true), run.StartVcn, prevLcn, run.AttributeExtent);
            run.AttributeExtent.ReplaceRun(run.DataRun, _runs[index].DataRun);

            for (int i = index + 1; i < _runs.Count; ++i)
            {
                if (!_runs[i].IsSparse)
                {
                    _runs[i].DataRun.RunOffset += run.StartLcn - prevLcn;
                    break;
                }
            }
        }
Ejemplo n.º 4
0
        public void MakeNonSparse(int index, IEnumerable <DataRun> rawRuns)
        {
            if (index < _firstDirty)
            {
                _firstDirty = index;
            }

            if (index > _lastDirty)
            {
                _lastDirty = index;
            }

            long          prevLcn = index == 0 ? 0 : _runs[index - 1].StartLcn;
            CookedDataRun run     = _runs[index];

            if (!run.IsSparse)
            {
                throw new ArgumentException("Run is already non-sparse", "index");
            }

            _runs.RemoveAt(index);
            int insertIdx = run.AttributeExtent.RemoveRun(run.DataRun);

            CookedDataRun lastNewRun = null;
            long          lcn        = prevLcn;
            long          vcn        = run.StartVcn;

            foreach (var rawRun in rawRuns)
            {
                CookedDataRun newRun = new CookedDataRun(rawRun, vcn, lcn, run.AttributeExtent);

                _runs.Insert(index, newRun);
                run.AttributeExtent.InsertRun(insertIdx, rawRun);

                vcn += rawRun.RunLength;
                lcn += rawRun.RunOffset;

                lastNewRun = newRun;
                insertIdx++;

                index++;
            }

            for (int i = index; i < _runs.Count; ++i)
            {
                if (_runs[i].IsSparse)
                {
                    _runs[i].StartLcn = lastNewRun.StartLcn;
                }
                else
                {
                    _runs[i].DataRun.RunOffset = _runs[i].StartLcn - lastNewRun.StartLcn;
                    break;
                }
            }
        }
Ejemplo n.º 5
0
        public bool AreAllClustersStored(long vcn, int count)
        {
            int  runIdx   = 0;
            long focusVcn = vcn;

            while (focusVcn < vcn + count)
            {
                runIdx = _cookedRuns.FindDataRun(focusVcn, runIdx);

                CookedDataRun run = _cookedRuns[runIdx];
                if (run.IsSparse)
                {
                    return(false);
                }

                focusVcn = run.StartVcn + run.Length;
            }

            return(true);
        }
Ejemplo n.º 6
0
        public void SplitRun(int runIdx, long vcn)
        {
            if (runIdx < _firstDirty)
            {
                _firstDirty = runIdx;
            }

            if (runIdx > _lastDirty)
            {
                _lastDirty = runIdx;
            }

            CookedDataRun run = _runs[runIdx];

            if (run.StartVcn >= vcn || run.StartVcn + run.Length <= vcn)
            {
                throw new ArgumentException("Attempt to split run outside of it's range", "vcn");
            }

            long          distance = vcn - run.StartVcn;
            long          offset   = run.IsSparse ? 0 : distance;
            CookedDataRun newRun   = new CookedDataRun(new DataRun(offset, run.Length - distance, run.IsSparse), vcn, run.StartLcn, run.AttributeExtent);

            run.Length = distance;

            _runs.Insert(runIdx + 1, newRun);
            run.AttributeExtent.InsertRun(run.DataRun, newRun.DataRun);

            for (int i = runIdx + 2; i < _runs.Count; ++i)
            {
                if (_runs[i].IsSparse)
                {
                    _runs[i].StartLcn += offset;
                }
                else
                {
                    _runs[i].DataRun.RunOffset -= offset;
                    break;
                }
            }
        }
Ejemplo n.º 7
0
        public void ReleaseClusters(long startVcn, int count)
        {
            int runIdx = 0;

            long focus = startVcn;

            while (focus < startVcn + count)
            {
                runIdx = _cookedRuns.FindDataRun(focus, runIdx);
                CookedDataRun run = _cookedRuns[runIdx];

                if (run.IsSparse)
                {
                    focus += run.Length;
                }
                else
                {
                    if (focus != run.StartVcn)
                    {
                        _cookedRuns.SplitRun(runIdx, focus);
                        runIdx++;
                        run = _cookedRuns[runIdx];
                    }

                    long numClusters = Math.Min((startVcn + count) - focus, run.Length);
                    if (numClusters != run.Length)
                    {
                        _cookedRuns.SplitRun(runIdx, focus + numClusters);
                        run = _cookedRuns[runIdx];
                    }

                    _context.ClusterBitmap.FreeClusters(new Range <long, long>(run.StartLcn, run.Length));
                    _cookedRuns.MakeSparse(runIdx);

                    focus += numClusters;
                }
            }
        }
Ejemplo n.º 8
0
        public override void ReadClusters(long startVcn, int count, byte[] buffer, int offset)
        {
            if (buffer.Length < (count * _bytesPerCluster) + offset)
            {
                throw new ArgumentException("Cluster buffer too small", "buffer");
            }

            int runIdx    = 0;
            int totalRead = 0;

            while (totalRead < count)
            {
                long focusVcn = startVcn + totalRead;

                runIdx = _cookedRuns.FindDataRun(focusVcn, runIdx);
                CookedDataRun run = _cookedRuns[runIdx];

                int toRead = (int)Math.Min(count - totalRead, run.Length - (focusVcn - run.StartVcn));

                if (run.IsSparse)
                {
                    Array.Clear(buffer, offset + (totalRead * _bytesPerCluster), toRead * _bytesPerCluster);
                }
                else
                {
                    long lcn = _cookedRuns[runIdx].StartLcn + (focusVcn - run.StartVcn);
                    _fsStream.Position = lcn * _bytesPerCluster;
                    int numRead = Utilities.ReadFully(_fsStream, buffer, offset + (totalRead * _bytesPerCluster), toRead * _bytesPerCluster);
                    if (numRead != toRead * _bytesPerCluster)
                    {
                        throw new IOException(string.Format(CultureInfo.InvariantCulture, "Short read, reading {0} clusters starting at LCN {1}", toRead, lcn));
                    }
                }

                totalRead += toRead;
            }
        }
Ejemplo n.º 9
0
        public void AllocateClusters(long startVcn, int count)
        {
            if (startVcn + count > _cookedRuns.NextVirtualCluster)
            {
                throw new IOException("Attempt to allocate unknown clusters");
            }

            int runIdx = 0;

            long focus = startVcn;

            while (focus < startVcn + count)
            {
                runIdx = _cookedRuns.FindDataRun(focus, runIdx);
                CookedDataRun run = _cookedRuns[runIdx];

                if (run.IsSparse)
                {
                    if (focus != run.StartVcn)
                    {
                        _cookedRuns.SplitRun(runIdx, focus);
                        runIdx++;
                        run = _cookedRuns[runIdx];
                    }

                    long numClusters = Math.Min((startVcn + count) - focus, run.Length);
                    if (numClusters != run.Length)
                    {
                        _cookedRuns.SplitRun(runIdx, focus + numClusters);
                        run = _cookedRuns[runIdx];
                    }

                    long nextCluster = -1;
                    for (int i = runIdx - 1; i >= 0; --i)
                    {
                        if (!_cookedRuns[i].IsSparse)
                        {
                            nextCluster = _cookedRuns[i].StartLcn + _cookedRuns[i].Length;
                            break;
                        }
                    }

                    var alloced = _context.ClusterBitmap.AllocateClusters(numClusters, nextCluster, _isMft, AllocatedClusterCount);

                    List <DataRun> runs = new List <DataRun>();

                    long lcn = runIdx == 0 ? 0 : _cookedRuns[runIdx - 1].StartLcn;
                    foreach (var allocation in alloced)
                    {
                        runs.Add(new DataRun(allocation.First - lcn, allocation.Second, false));
                        lcn = allocation.First;
                    }

                    _cookedRuns.MakeNonSparse(runIdx, runs);

                    focus += numClusters;
                }
                else
                {
                    focus = run.StartVcn + run.Length;
                }
            }
        }
Ejemplo n.º 10
0
        public void Append(DataRun rawRun, NonResidentAttributeRecord attributeExtent)
        {
            CookedDataRun last = Last;

            _runs.Add(new CookedDataRun(rawRun, NextVirtualCluster, last == null ? 0 : last.StartLcn, attributeExtent));
        }