/**
* Load the block, extending the underlying stream if needed
*/
public override ByteBuffer CreateBlockIfNeeded(int offset)
{
bool firstInStore = false;
// If we are the first block to be allocated, initialise the stream
if (_mini_stream.GetStartBlock() == POIFSConstants.END_OF_CHAIN)
{
firstInStore = true;
}
// Try to Get it without extending the stream
if (!firstInStore)
{
try
{
return(GetBlockAt(offset));
}catch (IndexOutOfRangeException) {}
}
// Need to extend the stream
// TODO Replace this with proper append support
// For now, do the extending by hand...
// Ask for another block
int newBigBlock = _filesystem.GetFreeBlock();
_filesystem.CreateBlockIfNeeded(newBigBlock);
// If we are the first block to be allocated, initialise the stream
if (firstInStore)
{
_filesystem.PropertyTable.Root.StartBlock = (newBigBlock);
_mini_stream = new NPOIFSStream(_filesystem, newBigBlock);
}
else
{
// Tack it onto the end of our chain
ChainLoopDetector loopDetector = _filesystem.GetChainLoopDetector();
int block = _mini_stream.GetStartBlock();
while (true)
{
loopDetector.Claim(block);
int next = _filesystem.GetNextBlock(block);
if (next == POIFSConstants.END_OF_CHAIN)
{
break;
}
block = next;
}
_filesystem.SetNextBlock(block, newBigBlock);
}
_filesystem.SetNextBlock(newBigBlock, POIFSConstants.END_OF_CHAIN);
// Now try again, to get the real small block
return(CreateBlockIfNeeded(offset));
}
public void TestReadFailsOnLoop()
{
NPOIFSFileSystem fs = new NPOIFSFileSystem(_inst.GetFile("BlockSize512.zvi"));
// Hack the FAT so that it goes 0->1->2->0
fs.SetNextBlock(0, 1);
fs.SetNextBlock(1, 2);
fs.SetNextBlock(2, 0);
// Now try to read
NPOIFSStream stream = new NPOIFSStream(fs, 0);
IEnumerator<ByteBuffer> i = stream.GetBlockIterator();
//1st read works
Assert.AreEqual(true, i.MoveNext());
// 1st read works
// i.MoveNext();
// 2nd read works
Assert.AreEqual(true, i.MoveNext());
// i.MoveNext();
// Assert.AreEqual(true, i.MoveNext());
// 3rd read works
//i.MoveNext();
Assert.AreEqual(true, i.MoveNext());
// 4th read blows up as it loops back to 0
try
{
i.MoveNext();
Assert.AreEqual(true, i.MoveNext());
Assert.Fail("Loop should have been detected but wasn't!");
}
catch (Exception)
{
// Good, it was detected
}
// Assert.AreEqual(true, i.MoveNext());
}
/**
* Load the block, extending the underlying stream if needed
*/
public override ByteBuffer CreateBlockIfNeeded(int offset)
{
// Try to Get it without extending the stream
try
{
return(GetBlockAt(offset));
}
catch (IndexOutOfRangeException)
{
// Need to extend the stream
// TODO Replace this with proper append support
// For now, do the extending by hand...
// Ask for another block
int newBigBlock = _filesystem.GetFreeBlock();
_filesystem.CreateBlockIfNeeded(newBigBlock);
// Tack it onto the end of our chain
ChainLoopDetector loopDetector = _filesystem.GetChainLoopDetector();
int block = _mini_stream.GetStartBlock();
while (true)
{
loopDetector.Claim(block);
int next = _filesystem.GetNextBlock(block);
if (next == POIFSConstants.END_OF_CHAIN)
{
break;
}
block = next;
}
_filesystem.SetNextBlock(block, newBigBlock);
_filesystem.SetNextBlock(newBigBlock, POIFSConstants.END_OF_CHAIN);
// Now try again to Get it
return(CreateBlockIfNeeded(offset));
}
}
public void TestWriteFailsOnLoop()
{
NPOIFSFileSystem fs = new NPOIFSFileSystem(_inst.GetFile("BlockSize512.zvi"));
// Hack the FAT so that it goes 0->1->2->0
fs.SetNextBlock(0, 1);
fs.SetNextBlock(1, 2);
fs.SetNextBlock(2, 0);
// Try to write a large amount, should fail on the write
byte[] data = new byte[512 * 4];
NPOIFSStream stream = new NPOIFSStream(fs, 0);
try
{
stream.UpdateContents(data);
Assert.Fail("Loop should have been detected but wasn't!");
}
catch (Exception) { }
// Now reset, and try on a small bit
// Should fail during the freeing set
fs.SetNextBlock(0, 1);
fs.SetNextBlock(1, 2);
fs.SetNextBlock(2, 0);
data = new byte[512];
stream = new NPOIFSStream(fs, 0);
try
{
stream.UpdateContents(data);
Assert.Fail("Loop should have been detected but wasn't!");
}
catch (Exception) { }
}
public void TestWriteNewStreamExtraFATs()
{
NPOIFSFileSystem fs = new NPOIFSFileSystem(_inst.OpenResourceAsStream("BlockSize512.zvi"));
// Allocate almost all the blocks
Assert.AreEqual(POIFSConstants.FAT_SECTOR_BLOCK, fs.GetNextBlock(99));
Assert.AreEqual(POIFSConstants.UNUSED_BLOCK, fs.GetNextBlock(100));
Assert.AreEqual(POIFSConstants.UNUSED_BLOCK, fs.GetNextBlock(127));
for (int i = 100; i < 127; i++)
{
fs.SetNextBlock(i, POIFSConstants.END_OF_CHAIN);
}
Assert.AreEqual(POIFSConstants.UNUSED_BLOCK, fs.GetNextBlock(127));
Assert.AreEqual(true, fs.GetBATBlockAndIndex(0).Block.HasFreeSectors);
// Write a 3 block stream
byte[] data = new byte[512 * 3];
for (int i = 0; i < data.Length; i++)
{
data[i] = (byte)(i % 256);
}
NPOIFSStream stream = new NPOIFSStream(fs);
stream.UpdateContents(data);
// Check we got another BAT
Assert.AreEqual(false, fs.GetBATBlockAndIndex(0).Block.HasFreeSectors);
Assert.AreEqual(true, fs.GetBATBlockAndIndex(128).Block.HasFreeSectors);
// the BAT will be in the first spot of the new block
Assert.AreEqual(POIFSConstants.END_OF_CHAIN, fs.GetNextBlock(126));
Assert.AreEqual(129, fs.GetNextBlock(127));
Assert.AreEqual(POIFSConstants.FAT_SECTOR_BLOCK, fs.GetNextBlock(128));
Assert.AreEqual(130, fs.GetNextBlock(129));
Assert.AreEqual(POIFSConstants.END_OF_CHAIN, fs.GetNextBlock(130));
Assert.AreEqual(POIFSConstants.UNUSED_BLOCK, fs.GetNextBlock(131));
}
public void TestGetFreeBlockWithNoneSpare()
{
NPOIFSFileSystem fs = new NPOIFSFileSystem(_inst.OpenResourceAsStream("BlockSize512.zvi"));
int free;
Assert.AreEqual(POIFSConstants.FAT_SECTOR_BLOCK, fs.GetNextBlock(99));
assertBATCount(fs, 1, 0);
for (int i = 100; i < 128; i++)
Assert.AreEqual(POIFSConstants.UNUSED_BLOCK, fs.GetNextBlock(i));
Assert.AreEqual(true, fs.GetBATBlockAndIndex(0).Block.HasFreeSectors);
for (int i = 100; i < 128; i++)
fs.SetNextBlock(i, POIFSConstants.END_OF_CHAIN);
Assert.AreEqual(false, fs.GetBATBlockAndIndex(0).Block.HasFreeSectors);
try
{
Assert.AreEqual(false, fs.GetBATBlockAndIndex(128).Block.HasFreeSectors);
Assert.Fail("Should only be one BAT");
}
//catch (IndexOutOfRangeException)
catch (ArgumentOutOfRangeException)
{
}
assertBATCount(fs, 1, 0);
// Now ask for a free one, will need to extend the file
Assert.AreEqual(129, fs.GetFreeBlock());
Assert.AreEqual(false, fs.GetBATBlockAndIndex(0).Block.HasFreeSectors);
Assert.AreEqual(true, fs.GetBATBlockAndIndex(128).Block.HasFreeSectors);
Assert.AreEqual(POIFSConstants.FAT_SECTOR_BLOCK, fs.GetNextBlock(128));
Assert.AreEqual(POIFSConstants.UNUSED_BLOCK, fs.GetNextBlock(129));
// We now have 2 BATs, but no XBATs
assertBATCount(fs, 2, 0);
// Fill up to hold 109 BAT blocks
for (int i = 0; i < 109; i++)
{
fs.GetFreeBlock();
int startOffset = i * 128;
while (fs.GetBATBlockAndIndex(startOffset).Block.HasFreeSectors)
{
free = fs.GetFreeBlock();
fs.SetNextBlock(free, POIFSConstants.END_OF_CHAIN);
}
}
Assert.AreEqual(false, fs.GetBATBlockAndIndex(109 * 128 - 1).Block.HasFreeSectors);
try
{
Assert.AreEqual(false, fs.GetBATBlockAndIndex(109 * 128).Block.HasFreeSectors);
Assert.Fail("Should only be 109 BATs");
}
// catch (IndexOutOfRangeException)
catch (ArgumentOutOfRangeException)
{
}
// We now have 109 BATs, but no XBATs
assertBATCount(fs, 109, 0);
// Ask for it to be written out, and check the header
HeaderBlock header = WriteOutAndReadHeader(fs);
Assert.AreEqual(109, header.BATCount);
Assert.AreEqual(0, header.XBATCount);
free = fs.GetFreeBlock();
Assert.AreEqual(false, fs.GetBATBlockAndIndex(109 * 128 - 1).Block.HasFreeSectors);
Assert.AreEqual(true, fs.GetBATBlockAndIndex(110 * 128 - 1).Block.HasFreeSectors);
try
{
Assert.AreEqual(false, fs.GetBATBlockAndIndex(110 * 128).Block.HasFreeSectors);
Assert.Fail("Should only be 110 BATs");
}
//catch (IndexOutOfRangeException)
catch (ArgumentOutOfRangeException)
{
}
assertBATCount(fs, 110, 1);
header = WriteOutAndReadHeader(fs);
Assert.AreEqual(110, header.BATCount);
Assert.AreEqual(1, header.XBATCount);
for (int i = 109; i < 109 + 127; i++)
{
fs.GetFreeBlock();
int startOffset = i * 128;
while (fs.GetBATBlockAndIndex(startOffset).Block.HasFreeSectors)
{
free = fs.GetFreeBlock();
fs.SetNextBlock(free, POIFSConstants.END_OF_CHAIN);
}
assertBATCount(fs, i + 1, 1);
}
// Should now have 109+127 = 236 BATs
Assert.AreEqual(false, fs.GetBATBlockAndIndex(236 * 128 - 1).Block.HasFreeSectors);
try
{
Assert.AreEqual(false, fs.GetBATBlockAndIndex(236 * 128).Block.HasFreeSectors);
Assert.Fail("Should only be 236 BATs");
}
catch (ArgumentOutOfRangeException)
{
}
assertBATCount(fs, 236, 1);
// Ask for another, will get our 2nd XBAT
free = fs.GetFreeBlock();
Assert.AreEqual(false, fs.GetBATBlockAndIndex(236 * 128 - 1).Block.HasFreeSectors);
Assert.AreEqual(true, fs.GetBATBlockAndIndex(237 * 128 - 1).Block.HasFreeSectors);
try
{
Assert.AreEqual(false, fs.GetBATBlockAndIndex(237 * 128).Block.HasFreeSectors);
Assert.Fail("Should only be 237 BATs");
}
// catch (IndexOutOfRangeException) { }
catch (ArgumentOutOfRangeException)
{
}
// Check the counts now
assertBATCount(fs, 237, 2);
// Check the header
header = WriteOutAndReadHeader(fs);
// Now, write it out, and read it back in again fully
fs = WriteOutAndReadBack(fs);
// Check that it is seen correctly
assertBATCount(fs, 237, 2);
Assert.AreEqual(false, fs.GetBATBlockAndIndex(236 * 128 - 1).Block.HasFreeSectors);
Assert.AreEqual(true, fs.GetBATBlockAndIndex(237 * 128 - 1).Block.HasFreeSectors);
try
{
Assert.AreEqual(false, fs.GetBATBlockAndIndex(237 * 128).Block.HasFreeSectors);
Assert.Fail("Should only be 237 BATs");
}
catch (ArgumentOutOfRangeException) { }
fs.Close();
}
public void TestGetFreeBlockWithSpare()
{
NPOIFSFileSystem fs = new NPOIFSFileSystem(_inst.GetFile("BlockSize512.zvi"));
Assert.AreEqual(true, fs.GetBATBlockAndIndex(0).Block.HasFreeSectors);
Assert.AreEqual(POIFSConstants.UNUSED_BLOCK, fs.GetNextBlock(100));
Assert.AreEqual(POIFSConstants.UNUSED_BLOCK, fs.GetNextBlock(101));
Assert.AreEqual(POIFSConstants.UNUSED_BLOCK, fs.GetNextBlock(102));
Assert.AreEqual(POIFSConstants.UNUSED_BLOCK, fs.GetNextBlock(103));
Assert.AreEqual(100, fs.GetFreeBlock());
Assert.AreEqual(100, fs.GetFreeBlock());
fs.SetNextBlock(100, POIFSConstants.END_OF_CHAIN);
Assert.AreEqual(101, fs.GetFreeBlock());
fs.Close();
}
public void TestGetFreeBlockWithNoneSpare()
{
NPOIFSFileSystem fs = new NPOIFSFileSystem(_inst.OpenResourceAsStream("BlockSize512.zvi"));
int free;
Assert.AreEqual(POIFSConstants.FAT_SECTOR_BLOCK, fs.GetNextBlock(99));
for (int i = 100; i < 128; i++)
Assert.AreEqual(POIFSConstants.UNUSED_BLOCK, fs.GetNextBlock(i));
Assert.AreEqual(true, fs.GetBATBlockAndIndex(0).Block.HasFreeSectors);
for (int i = 100; i < 128; i++)
fs.SetNextBlock(i, POIFSConstants.END_OF_CHAIN);
Assert.AreEqual(false, fs.GetBATBlockAndIndex(0).Block.HasFreeSectors);
try
{
Assert.AreEqual(false, fs.GetBATBlockAndIndex(128).Block.HasFreeSectors);
Assert.Fail("Should only be one BAT");
}
//catch (IndexOutOfRangeException)
catch(ArgumentOutOfRangeException)
{
}
// Now ask for a free one, will need to extend the file
Assert.AreEqual(129, fs.GetFreeBlock());
Assert.AreEqual(false, fs.GetBATBlockAndIndex(0).Block.HasFreeSectors);
Assert.AreEqual(true, fs.GetBATBlockAndIndex(128).Block.HasFreeSectors);
Assert.AreEqual(POIFSConstants.FAT_SECTOR_BLOCK, fs.GetNextBlock(128));
Assert.AreEqual(POIFSConstants.UNUSED_BLOCK, fs.GetNextBlock(129));
// Fill up to hold 109 BAT blocks
for (int i = 0; i < 109; i++)
{
fs.GetFreeBlock();
int startOffset = i * 128;
while (fs.GetBATBlockAndIndex(startOffset).Block.HasFreeSectors)
{
free = fs.GetFreeBlock();
fs.SetNextBlock(free, POIFSConstants.END_OF_CHAIN);
}
}
Assert.AreEqual(false, fs.GetBATBlockAndIndex(109 * 128 - 1).Block.HasFreeSectors);
try
{
Assert.AreEqual(false, fs.GetBATBlockAndIndex(109 * 128).Block.HasFreeSectors);
Assert.Fail("Should only be 109 BATs");
}
// catch (IndexOutOfRangeException)
catch(ArgumentOutOfRangeException)
{
}
free = fs.GetFreeBlock();
Assert.AreEqual(false, fs.GetBATBlockAndIndex(109 * 128 - 1).Block.HasFreeSectors);
Assert.AreEqual(true, fs.GetBATBlockAndIndex(110 * 128 - 1).Block.HasFreeSectors);
try
{
Assert.AreEqual(false, fs.GetBATBlockAndIndex(110 * 128).Block.HasFreeSectors);
Assert.Fail("Should only be 110 BATs");
}
//catch (IndexOutOfRangeException)
catch(ArgumentOutOfRangeException)
{
}
for (int i = 109; i < 109 + 127; i++)
{
fs.GetFreeBlock();
int startOffset = i * 128;
while (fs.GetBATBlockAndIndex(startOffset).Block.HasFreeSectors)
{
free = fs.GetFreeBlock();
fs.SetNextBlock(free, POIFSConstants.END_OF_CHAIN);
}
}
// Should now have 109+127 = 236 BATs
Assert.AreEqual(false, fs.GetBATBlockAndIndex(236 * 128 - 1).Block.HasFreeSectors);
try
{
Assert.AreEqual(false, fs.GetBATBlockAndIndex(236 * 128).Block.HasFreeSectors);
Assert.Fail("Should only be 236 BATs");
}
catch (ArgumentOutOfRangeException)
{
}
// Ask for another, will get our 2nd XBAT
free = fs.GetFreeBlock();
Assert.AreEqual(false, fs.GetBATBlockAndIndex(236 * 128 - 1).Block.HasFreeSectors);
Assert.AreEqual(true, fs.GetBATBlockAndIndex(237 * 128 - 1).Block.HasFreeSectors);
try
{
Assert.AreEqual(false, fs.GetBATBlockAndIndex(237 * 128).Block.HasFreeSectors);
Assert.Fail("Should only be 237 BATs");
}
// catch (IndexOutOfRangeException) { }
catch (ArgumentOutOfRangeException)
{
}
// Check the counts
int numBATs = 0;
int numXBATs = 0;
for (int i = 0; i < 237 * 128; i++)
{
if (fs.GetNextBlock(i) == POIFSConstants.FAT_SECTOR_BLOCK)
{
numBATs++;
}
if (fs.GetNextBlock(i) == POIFSConstants.DIFAT_SECTOR_BLOCK)
{
numXBATs++;
}
}
Assert.AreEqual(237, numBATs);
#if !HIDE_UNREACHABLE_CODE
if (1 == 2)
{
// TODO Fix this - actual is 128
Assert.AreEqual(2, numXBATs);
}
#endif
MemoryStream stream = new MemoryStream();
fs.WriteFilesystem(stream);
HeaderBlock header = new HeaderBlock(new MemoryStream(stream.ToArray()));
Assert.AreEqual(237, header.BATCount);
#if !HIDE_UNREACHABLE_CODE
if (1 == 2) // TODO Fix this - actual is 128
{
Assert.AreEqual(2, header.XBATCount);
fs = new NPOIFSFileSystem(new MemoryStream(stream.ToArray()));
}
#endif
}
