// high frequency key value store
public KeyStoreHF(string folder)
{
_Path = folder;
Directory.CreateDirectory(_Path);
if (_Path.EndsWith(_S) == false) _Path += _S;
if (File.Exists(_Path + _dirtyFilename))
{
_log.Error("Last shutdown failed, rebuilding data files...");
RebuildDataFiles();
}
_datastore = new StorageFileHF(_Path + "data.mghf", Global.HighFrequencyKVDiskBlockSize);
_keys = new MGIndex<string>(_Path, "keys.idx", 255, Global.PageItemCount, false);
_BlockSize = _datastore.GetBlockSize();
}
public void CompactStorageHF()
{
lock (_lock)
{
try
{
_log.Debug("Compacting storage file ...");
if (Directory.Exists(_Path + "temp"))
Directory.Delete(_Path + "temp", true);
KeyStoreHF newfile = new KeyStoreHF(_Path + "temp");
string[] keys = _keys.GetKeys().Cast<string>().ToArray();
_log.Debug("Number of keys : " + keys.Length);
foreach (var k in keys)
{
newfile.SetObjectHF(k, GetObjectHF(k));
}
newfile.Shutdown();
_log.Debug("Compact done.");
// shutdown and move files and restart here
if (Directory.Exists(_Path + "old"))
Directory.Delete(_Path + "old", true);
Directory.CreateDirectory(_Path + "old");
_datastore.Shutdown();
_keys.Shutdown();
_log.Debug("Moving files...");
foreach (var f in Directory.GetFiles(_Path, "*.*"))
File.Move(f, _Path + "old" + _S + Path.GetFileName(f));
foreach (var f in Directory.GetFiles(_Path + "temp", "*.*"))
File.Move(f, _Path + Path.GetFileName(f));
Directory.Delete(_Path + "temp", true);
//Directory.Delete(_Path + "old", true); // FEATURE : delete or keep?
_log.Debug("Re-opening storage file");
_datastore = new StorageFileHF(_Path + "data.mghf", Global.HighFrequencyKVDiskBlockSize);
_keys = new MGIndex<string>(_Path, "keys.idx", 255, Global.PageItemCount, false);
_BlockSize = _datastore.GetBlockSize();
}
catch (Exception ex)
{
_log.Error(ex);
}
}
}
private void RebuildDataFiles()
{
MGIndex<string> keys = null;
try
{
// remove old free list
if (File.Exists(_Path + "data.bmp"))
File.Delete(_Path + "data.bmp");
_datastore = new StorageFileHF(_Path + "data.mghf", Global.HighFrequencyKVDiskBlockSize);
_BlockSize = _datastore.GetBlockSize();
if (File.Exists(_Path + "keys.idx"))
{
_log.Debug("removing old keys index");
foreach (var f in Directory.GetFiles(_Path, "keys.*"))
File.Delete(f);
}
keys = new MGIndex<string>(_Path, "keys.idx", 255, Global.PageItemCount, false);
WAHBitArray visited = new WAHBitArray();
int c = _datastore.NumberofBlocks();
for (int i = 0; i < c; i++) // go through blocks
{
if (visited.Get(i))
continue;
byte[] b = _datastore.ReadBlockBytes(i, _blockheader.Length + 255);
int bnum = Helper.ToInt32(b, 0);
if (bnum > 0) // check if a start block
{
visited.Set(i, true);
_datastore.FreeBlock(i); // mark as free
continue;
}
AllocationBlock ab = new AllocationBlock();
// start block found
int blocknumexpected = 0;
int next = ParseBlockHeader(ab, b, blocknumexpected);
int last = 0;
bool freelast = false;
AllocationBlock old = null;
if (keys.Get(ab.key, out last))
{
old = this.FillAllocationBlock(last);
freelast = true;
}
blocknumexpected++;
bool failed = false;
if (ab.deleteKey == false)
{
while (next > 0) // read the blocks
{
ab.Blocks.Add(next);
b = _datastore.ReadBlockBytes(next, _blockheader.Length + ab.keylen);
next = ParseBlockHeader(ab, b, blocknumexpected);
if (next == -1) // non matching block
{
failed = true;
break;
}
blocknumexpected++;
}
}
else
{
failed = true;
keys.RemoveKey(ab.key);
}
// new data ok
if (failed == false)
{
keys.Set(ab.key, ab.blocknumber);// valid block found
if (freelast)// free the old blocks
_datastore.FreeBlocks(old.Blocks);
}
visited.Set(i, true);
}
// all ok delete temp.$ file
if (File.Exists(_Path + _dirtyFilename))
File.Delete(_Path + _dirtyFilename);
}
catch (Exception ex)
{
_log.Error(ex);
}
finally
{
_log.Debug("Shutting down files and index");
_datastore.Shutdown();
keys.SaveIndex();
keys.Shutdown();
}
}
private void CreateIndex()
{
_index = new MGIndex<string>(_fs, new Path(@"c:\index.mgidx"), KeyLength, 300);
}
