private long RecoverFreeBlocks()
{
Trace.TraceWarning("The file store was not closed properly, recovering free blocks.");
using (Stream s = _streamCache.Open(FileAccess.ReadWrite))
using (FileBlock block = new FileBlock(_blockSize, _useAlignedIo))
{
long lastBlock = LastAllocated(s);
long last = 0;
for (long blk = lastBlock; blk > 0; blk -= _blockSize)
{
s.Position = blk & _maskOffset;
block.Read(s, FileBlock.HeaderSize);
Check.Assert <InvalidDataException>((block.BlockId & _maskOffset) == blk);
if ((block.Flags & BlockFlags.BlockDeleted) == BlockFlags.BlockDeleted)
{
block.NextBlockId = last;
last = block.BlockId;
s.Position = blk & _maskOffset;
block.Write(s, FileBlock.HeaderSize);
}
}
return(last);
}
}
private void ReadBlock(long ordinal, FileBlock block, int length, BlockFlags type, bool exactId)
{
using (Stream io = OpenBlock(FileAccess.Read, ordinal))
block.Read(io, length);
if (exactId && block.BlockId != ordinal)
{
throw new InvalidDataException();
}
if ((block.Flags & type) == 0 && type != 0)
{
throw new InvalidDataException();
}
if (block.Length < 0 || block.Length > (_blockSize - FileBlock.HeaderSize))
{
throw new InvalidDataException();
}
}
/// <summary> Used for enumeration of the storage blocks in the file. </summary>
/// <param name="allocatedOnly"> Allows enumeration of all stream, or of just the externally allocated streams </param>
/// <param name="verifyReads"> Determines if the checksum should be verified while reading the block bytes </param>
/// <param name="ignoreException"> A method that returns true to ignore the exception and continue processing </param>
/// <returns>Enumeration of the identity and data stream of each block in the file</returns>
public IEnumerable <KeyValuePair <long, Stream> > ForeachBlock(bool allocatedOnly, bool verifyReads, Converter <Exception, bool> ignoreException)
{
using (Stream s = _streamCache.Open(FileAccess.ReadWrite))
using (FileBlock block = new FileBlock(_blockSize, _useAlignedIo))
{
long lastBlock = LastAllocated(s);
for (long blk = lastBlock; blk > 0; blk -= _blockSize)
{
s.Position = blk & _maskOffset;
block.Read(s, FileBlock.HeaderSize);
byte[] bytes;
try
{
if ((block.BlockId & _maskOffset) != blk)
{
throw new InvalidDataException();
}
if (allocatedOnly && (block.Flags & BlockFlags.ExternalBlock) != BlockFlags.ExternalBlock)
{
continue;
}
using (Stream reader = new BlockStreamReader(this, block.BlockId, BlockFlags.None, verifyReads))
bytes = IOStream.ReadAllBytes(reader);
}
catch (Exception error)
{
if (ignoreException != null && ignoreException(error))
{
continue;
}
throw;
}
using (Stream ms = new MemoryStream(bytes, false))
yield return(new KeyValuePair <long, Stream>(block.BlockId, ms));
}
}
}
private long AllocBlock(FileBlock block, BlockFlags type)
{
using (new SafeLock(_syncFreeBlock))
{
long blockId = _nextFree;
if (blockId == 0 && _reallocSize > 0)
{
long fsize;
using (Stream s = _streamCache.Open(FileAccess.Read))
fsize = LastAllocated(s);
ResizeFile(fsize + _blockSize, fsize + _reallocSize);
blockId = _nextFree;
}
if (blockId <= 0)
{
throw new IOException();
}
using (Stream io = OpenBlock(FileAccess.Read, blockId))
block.Read(io, FileBlock.HeaderSize);
if ((block.BlockId & _maskOffset) != (blockId & _maskOffset) || (block.Flags & BlockFlags.BlockDeleted) == 0)
{
throw new InvalidDataException();
}
_nextFree = block.NextBlockId;
block.BlockId = blockId;
block.IncrementId(_maskVersion);
block.NextBlockId = 0;
block.Flags = type == BlockFlags.ExternalBlock ? (type | BlockFlags.Temporary) : type;
block.Length = 0;
WriteBlock(block.BlockId, block, FileBlock.HeaderSize);
return(block.BlockId);
}
}
/// <summary> Internal use to specify aligned IO when using NoBuffering file option </summary>
protected FragmentedFile(IFactory <Stream> streamFactory, int blockSize, int growthRate, int cacheLimit, FileOptions options)
{
_useAlignedIo = (options & NoBuffering) == NoBuffering;
_streamCache = new StreamCache(streamFactory, cacheLimit);
_header = new FileBlock(blockSize, _useAlignedIo);
_syncFreeBlock = new object();
try
{
long fallocated;
bool canWrite;
using (Stream s = _streamCache.Open(FileAccess.ReadWrite))
{
canWrite = s.CanWrite;
if (!s.CanRead)
{
throw new InvalidOperationException("The stream does not support Read access.");
}
_header.Read(s, blockSize);
if ((_header.Flags & ~BlockFlags.HeaderFilter) != BlockFlags.HeaderFlags)
{
throw new InvalidDataException();
}
_nextFree = _header.NextBlockId;
SetBlockSize(_header.Length, out _blockSize, out _maskVersion, out _maskOffset);
if (blockSize != _blockSize)
{
throw new ArgumentOutOfRangeException("blockSize");
}
fallocated = LastAllocated(s);
_reallocSize = growthRate * _blockSize;
if (canWrite)
{
s.Position = 0;
_header.NextBlockId = long.MinValue;
_header.Write(s, FileBlock.HeaderSize);
}
}
if (canWrite)
{
if ((_header.Flags & BlockFlags.ResizingFile) == BlockFlags.ResizingFile && _nextFree > 0)
{
ResizeFile(_nextFree, Math.Max(fallocated, _nextFree + _reallocSize));
}
if (_nextFree == long.MinValue)
{
_nextFree = RecoverFreeBlocks();
}
}
}
catch
{
_streamCache.Dispose();
throw;
}
}
private void ReadBlock(long ordinal, FileBlock block, int length, BlockFlags type, bool exactId)
{
using (Stream io = OpenBlock(FileAccess.Read, ordinal))
block.Read(io, length);
if (exactId && block.BlockId != ordinal)
throw new InvalidDataException();
if ((block.Flags & type) == 0 && type != 0)
throw new InvalidDataException();
if (block.Length < 0 || block.Length > (_blockSize - FileBlock.HeaderSize))
throw new InvalidDataException();
}
private long AllocBlock(FileBlock block, BlockFlags type)
{
using (new SafeLock(_syncFreeBlock))
{
long blockId = _nextFree;
if (blockId == 0 && _reallocSize > 0)
{
long fsize;
using (Stream s = _streamCache.Open(FileAccess.Read))
fsize = LastAllocated(s);
ResizeFile(fsize + _blockSize, fsize + _reallocSize);
blockId = _nextFree;
}
if (blockId <= 0)
throw new IOException();
using (Stream io = OpenBlock(FileAccess.Read, blockId))
block.Read(io, FileBlock.HeaderSize);
if ((block.BlockId & _maskOffset) != (blockId & _maskOffset) || (block.Flags & BlockFlags.BlockDeleted) == 0)
throw new InvalidDataException();
_nextFree = block.NextBlockId;
block.BlockId = blockId;
block.IncrementId(_maskVersion);
block.NextBlockId = 0;
block.Flags = type == BlockFlags.ExternalBlock ? (type | BlockFlags.Temporary) : type;
block.Length = 0;
WriteBlock(block.BlockId, block, FileBlock.HeaderSize);
return block.BlockId;
}
}
/// <summary> Used for enumeration of the storage blocks in the file. </summary>
/// <param name="allocatedOnly"> Allows enumeration of all stream, or of just the externally allocated streams </param>
/// <param name="verifyReads"> Determines if the checksum should be verified while reading the block bytes </param>
/// <param name="ignoreException"> A method that returns true to ignore the exception and continue processing </param>
/// <returns>Enumeration of the identity and data stream of each block in the file</returns>
public IEnumerable<KeyValuePair<long, Stream>> ForeachBlock(bool allocatedOnly, bool verifyReads, Converter<Exception, bool> ignoreException)
{
using (Stream s = _streamCache.Open(FileAccess.ReadWrite))
using (FileBlock block = new FileBlock(_blockSize, _useAlignedIo))
{
long lastBlock = LastAllocated(s);
for (long blk = lastBlock; blk > 0; blk -= _blockSize)
{
s.Position = blk & _maskOffset;
block.Read(s, FileBlock.HeaderSize);
byte[] bytes;
try
{
if ((block.BlockId & _maskOffset) != blk)
throw new InvalidDataException();
if (allocatedOnly && (block.Flags & BlockFlags.ExternalBlock) != BlockFlags.ExternalBlock)
continue;
using (Stream reader = new BlockStreamReader(this, block.BlockId, BlockFlags.None, verifyReads))
bytes = IOStream.ReadAllBytes(reader);
}
catch (Exception error)
{
if (ignoreException != null && ignoreException(error))
continue;
throw;
}
using (Stream ms = new MemoryStream(bytes, false))
yield return new KeyValuePair<long, Stream>(block.BlockId, ms);
}
}
}
private long RecoverFreeBlocks()
{
Trace.TraceWarning("The file store was not closed properly, recovering free blocks.");
using (Stream s = _streamCache.Open(FileAccess.ReadWrite))
using (FileBlock block = new FileBlock(_blockSize, _useAlignedIo))
{
long lastBlock = LastAllocated(s);
long last = 0;
for (long blk = lastBlock; blk > 0; blk -= _blockSize)
{
s.Position = blk & _maskOffset;
block.Read(s, FileBlock.HeaderSize);
Check.Assert<InvalidDataException>((block.BlockId & _maskOffset) == blk);
if ((block.Flags & BlockFlags.BlockDeleted) == BlockFlags.BlockDeleted)
{
block.NextBlockId = last;
last = block.BlockId;
s.Position = blk & _maskOffset;
block.Write(s, FileBlock.HeaderSize);
}
}
return last;
}
}
/// <summary> Internal use to specify aligned IO when using NoBuffering file option </summary>
protected FragmentedFile(IFactory<Stream> streamFactory, int blockSize, int growthRate, int cacheLimit, FileOptions options)
{
_useAlignedIo = (options & NoBuffering) == NoBuffering;
_streamCache = new StreamCache(streamFactory, cacheLimit);
_header = new FileBlock(blockSize, _useAlignedIo);
_syncFreeBlock = new object();
try
{
long fallocated;
bool canWrite;
using (Stream s = _streamCache.Open(FileAccess.ReadWrite))
{
canWrite = s.CanWrite;
if (!s.CanRead)
throw new InvalidOperationException("The stream does not support Read access.");
_header.Read(s, blockSize);
if ((_header.Flags & ~BlockFlags.HeaderFilter) != BlockFlags.HeaderFlags)
throw new InvalidDataException();
_nextFree = _header.NextBlockId;
SetBlockSize(_header.Length, out _blockSize, out _maskVersion, out _maskOffset);
if (blockSize != _blockSize) throw new ArgumentOutOfRangeException("blockSize");
fallocated = LastAllocated(s);
_reallocSize = growthRate * _blockSize;
if (canWrite)
{
s.Position = 0;
_header.NextBlockId = long.MinValue;
_header.Write(s, FileBlock.HeaderSize);
}
}
if (canWrite)
{
if ((_header.Flags & BlockFlags.ResizingFile) == BlockFlags.ResizingFile && _nextFree > 0)
ResizeFile(_nextFree, Math.Max(fallocated, _nextFree + _reallocSize));
if (_nextFree == long.MinValue)
_nextFree = RecoverFreeBlocks();
}
}
catch
{
_streamCache.Dispose();
throw;
}
}
