private void FlushSingletons(MerCollection singletons, int partitionNo, int flushNo)
{
int singletonCapacity = 0;
int singletonsCount = 0;
int merIdx = 0;
int inactiveSingletons = 0;
ulong[] sortedSingletons = null;
if (singletons != null)
{
// get this now before the Sort clears away the HashTable structures
singletonCapacity = singletons.Capacity;
// extract the actual singleton mers from the MerCollection Entries
singletonsCount = singletons.Sort();
// get a pointer to this singletons array
sortedSingletons = singletons.sortedKeys;
// compress the singletons array in-place by skipping over inactive entries (shift active towards the start of the array)
for (int s = 0; s < singletonsCount; s++)
{
ulong mer = sortedSingletons[s];
if ((mer & singletonActiveFlagMask) != 0)
{
sortedSingletons[merIdx] = mer;
merIdx++;
}
else
{
inactiveSingletons++;
}
}
}
// if we're writing out few active singletons, save this load for the next flush
if (inactiveSingletons > singletonsCount / 2)
{
if (singletonsWaitingFlush[partitionNo] == null)
{
singletonsWaitingFlush[partitionNo] = new List <MerCollection>();
singletonsWaitingFlushCounts[partitionNo] = new List <int>();
}
singletonsWaitingFlush[partitionNo].Add(singletons);
singletonsWaitingFlushCounts[partitionNo].Add(merIdx);
//Console.WriteLine("deferring singleton write[" + partitionNo + "] " + merIdx + " mers");
}
else
{
// got a singleton set worth flushing so add any pending singleton sets to it (or we're finishing up)
if (singletonsWaitingFlush[partitionNo] != null && singletonsWaitingFlush[partitionNo].Count != 0)
{
int startingWaiter = 0;
// find out how many singletons are waiting
int sumWaiting = 0;
foreach (int s in singletonsWaitingFlushCounts[partitionNo])
{
sumWaiting += s;
}
// if we're just flushing at end then turn the first waiting set into the base set for the merge
if (singletons == null)
{
sortedSingletons = singletonsWaitingFlush[partitionNo][0].sortedKeys;
singletonCapacity = sortedSingletons.Length;
startingWaiter = 1;
merIdx = singletonsWaitingFlushCounts[partitionNo][0];
sumWaiting -= merIdx;
}
// ensure the buffer is big enough
if (merIdx + sumWaiting > singletonCapacity)
{
Array.Resize <ulong>(ref sortedSingletons, merIdx + sumWaiting);
}
// copy the waiting singletons into this buffer
for (int i = startingWaiter; i < singletonsWaitingFlush[partitionNo].Count; i++)
{
int singlesInArray = singletonsWaitingFlushCounts[partitionNo][i];
ulong[] pendingSingles = singletonsWaitingFlush[partitionNo][i].sortedKeys;
for (int s = 0; s < singlesInArray; s++)
{
sortedSingletons[merIdx] = pendingSingles[s];
merIdx++;
}
}
singletonsWaitingFlush[partitionNo].Clear();
singletonsWaitingFlushCounts[partitionNo].Clear();
// and re-sort all the singletons
Array.Sort <ulong>(sortedSingletons, 0, merIdx);
}
if (merIdx > 0)
{
// and write out the (possibly augmented) set of singletons
//Console.WriteLine("wrote " + merIdx + "/" + singletonsCount + " singletons for flush " + partitionNo + "-" + flushNo);
// Add process ID at the beginning of the file name
int processID = Process.GetCurrentProcess().Id;
string binaryfileName = tempDirectory + processID + "_" + partitionNo + "_" + flushNo + ".bst";
// Binary writer
BinaryWriter flushWriter = new BinaryWriter(File.Open(binaryfileName, FileMode.Create, FileAccess.Write));
// Write the number of k-mers in the flush file at the start
flushWriter.Write(merIdx);
// Write out the in-use singletons
for (int i = 0; i < merIdx; i++)
{
flushWriter.Write(sortedSingletons[i]);
}
flushWriter.Close();
flushedSingletonFNs[partitionNo].Add(binaryfileName); // Add name of file to list of flush files for the partition
firstFlushedSingletonMer[partitionNo].Add(sortedSingletons[0] & singletonMerMask); // remember lowest and highest mer in each flush file
lastFlushedSingletonMer[partitionNo].Add(sortedSingletons[merIdx - 1] & singletonMerMask); // (without the RC bit)
if (singletons != null)
{
singletons.sortedKeys = null;
}
}
}
}
// constructor
public MerTables(long dictionarySize, string tempDir, int noThreads)
{
// scale genome size to compensate for the number of repeated error k-mers
dictionarySize = dictionarySize * 2;
// how many shared mer partitions are needed to safely hold this many distinct k-mers?
this.noOfPartitions = (int)(dictionarySize / maxTableSize + 1);
if (this.noOfPartitions < 1)
{
this.noOfPartitions = 1;
}
// and how big should the partitions be?
int partitionSize = (int)(dictionarySize / noOfPartitions);
if (partitionSize < minTableSize)
{
partitionSize = minTableSize;
}
// how many singleton partitions are desirable?
// per-partition singleton tables can use of a considerable amount of memory, but too few will increase the number of concurrently open files during merge
if (noOfPartitions > 64)
{
noSingletonPartitions = 32;
singletonPrefixBits = 5;
}
if (noOfPartitions <= 64)
{
noSingletonPartitions = 16;
singletonPrefixBits = 4;
}
if (noOfPartitions <= 16)
{
noSingletonPartitions = 4;
singletonPrefixBits = 2;
}
if (noOfPartitions <= 4)
{
noSingletonPartitions = 1;
singletonPrefixBits = 0;
}
this.tempDirectory = tempDir;
repeatedMers = new MerDictionary[noOfPartitions]; // create partitioned dictionaries
repeatedMersFull = new bool[noOfPartitions]; // create full flags array (default is false)
overflowMers = new MerDictionary[noThreads]; // create per-thread overflow tables
singletonFilters = new MerCollection[noSingletonPartitions]; // create partitioned singleton filters
singletonsWaitingFlush = new List <MerCollection> [noSingletonPartitions];
singletonsWaitingFlushCounts = new List <int> [noSingletonPartitions];
flushedSingletonFNs = new List <string> [noSingletonPartitions];
firstFlushedSingletonMer = new List <ulong> [noSingletonPartitions];
lastFlushedSingletonMer = new List <ulong> [noSingletonPartitions];
flushSingletonNumber = new int[noSingletonPartitions];
maxSingletonCapacity = new int[noSingletonPartitions];
flushedLowRepsFNs = new List <string>();
firstFlushedLowRepsMer = new List <ulong>();
lastFlushedLowRepsMer = new List <ulong>();
// initialise per-partition structures
for (int i = 0; i < noOfPartitions; i++)
{
repeatedMers[i] = new MerDictionary(partitionSize, fullMerMask);
}
// initialise per-singleton-partition structures
for (int i = 0; i < noSingletonPartitions; i++)
{
int scaledSingletonSize = 3 * partitionSize / noSingletonPartitions * (noSingletonPartitions - i);
scaledSingletonSize = Math.Min(scaledSingletonSize, maxSingletonSize);
scaledSingletonSize = Math.Max(scaledSingletonSize, minSingletonSize);
singletonFilters[i] = new MerCollection(scaledSingletonSize, singletonMerMask);
maxSingletonCapacity[i] = singletonFilters[i].length * 9 / 10;
flushedSingletonFNs[i] = new List <string>();
flushSingletonNumber[i] = 1;
firstFlushedSingletonMer[i] = new List <ulong>();
lastFlushedSingletonMer[i] = new List <ulong>();
}
// initialise per-thread structures
for (int i = 0; i < noThreads; i++)
{
// overflowMers[i] = new MerDictionary(singletonSize); // allocated when first used to save on memory space
}
}
public void AddOrIncrement(ulong mer, int threadNo)
{
long addingIncrement = 0x0000000100000000; // assume we've got the as-read form is the canonical form
ulong rcFlagToBeSet = 0x0; // and that we don't want to set the RC flag
// generate canonical k-mer first
ulong rcMer = MerStrings.ReverseComplement(mer);
if (rcMer < mer)
{
mer = rcMer;
addingIncrement = 0x0000000000000001; // increment the low part of the count pair
rcFlagToBeSet = singletonRCFlagMask; // remember if the canonical k-mer was the RC form
}
int absMerHashCode = mer.GetHashCode() & int31Mask;
int partitionNo = absMerHashCode % noOfPartitions;
int singletonPartitionNo = singletonPrefixBits == 0 ? 0 : (int)(mer >> (64 - singletonPrefixBits));
// this mer may have been seen before, so first try updating it in one of the repeated mer tables
bool updatedRepeat = UpdateRepeatedMer(partitionNo, mer, threadNo, mer, addingIncrement);
if (updatedRepeat)
{
return;
}
// handling a k-mer for the first time - try adding it to the singletons table
// ----------------------------------------------------------------------------
// get a stable pointer to the current singetons table (in case someone else fills it and initiates a flush while we're still busy with it)
MerCollection thisSingletonPartition = singletonFilters[singletonPartitionNo];
Interlocked.Increment(ref thisSingletonPartition.activeCount);
// try to add this mer to this partition's singletons collection (and fetch the existing singleton+flag if it's already there)
int filterIdx;
ulong fMer = mer | rcFlagToBeSet | singletonActiveFlagMask;
bool added = thisSingletonPartition.TryInsertKey(fMer, out filterIdx);
if (added)
{
// successfully added this mer so we must be seeing it for the first time
// if singleton table is already full enough, flush it out and empty the table
if (thisSingletonPartition.Count >= maxSingletonCapacity[singletonPartitionNo])
{
bool flushNeeded = true;
int flushNumberToUse = 0;
// lock this section to avoid two threads trying to flush/replace the same singleton buffer concurrently
lock (lockSingletons)
{
// test entry condition now that we have the lock (filter may have been reset while we were waiting)
if (!thisSingletonPartition.flushed)
{
// allocate a replacement table for the other threads to use while we're flushing this one
int newSingletonLength = thisSingletonPartition.length + thisSingletonPartition.length / 4;
if (newSingletonLength > maxSingletonSize)
{
newSingletonLength = maxSingletonSize;
}
MerCollection emptySingletonFilter = new MerCollection(newSingletonLength, singletonMerMask); // allocate new local filter for the partition
singletonFilters[singletonPartitionNo] = emptySingletonFilter; // make it visible to the concurrent threads (single point assignment)
maxSingletonCapacity[singletonPartitionNo] = newSingletonLength * 8 / 10;
thisSingletonPartition.flushed = true;
flushNumberToUse = flushSingletonNumber[singletonPartitionNo];
flushSingletonNumber[singletonPartitionNo]++;
}
else
{
flushNeeded = false;
}
}
if (flushNeeded)
{
while (thisSingletonPartition.activeCount > 1)
{
// pause briefly to let any inflight updates to this table to complete
Thread.Sleep(100);
}
FlushSingletons(thisSingletonPartition, singletonPartitionNo, flushNumberToUse);
}
//flushes++;
}
}
else
{
// Insert failed, so must be seeing this k-mer for second (or rarely more) time. Mark as inactive in singletons and add to a repeats table with appropriate counts.
// There can be a race here with two threads trying to concurrently promote the same singleton. This is resolved by atomically clearing the singleton
// active flag - and only one of the threads will get the 'active' flag returned from the Exchange. This thread does the promotion - and then sets the
// promotion-complete bit for the singleton. The other threads will spin until they find this bit has been set.
if (tracing)
{
lock (traceUpdates)
{
traceUpdates.Enqueue(new TraceEntry(threadNo, 1, singletonPartitionNo, filterIdx, (ulong)thisSingletonPartition.entries[filterIdx].key));
if (traceUpdates.Count > maxTrace)
{
traceUpdates.Dequeue();
}
}
}
// get the current value of this singleton entry (safe because the promotion changes are progressive)
ulong merFromFilter = (ulong)thisSingletonPartition.entries[filterIdx].key;
// and see if this singleton may have already been promoted
bool activeSingleton = (merFromFilter & singletonActiveFlagMask) != 0;
// if this singleton may be 'active', try to promote it
if (activeSingleton)
{
ulong inactiveMer = mer & singletonMerMask; // build what the inactive-but-being-promoted entry should look like
// if no-one else has altered the singleton entry, then set it to inactive-but-being-promoted
long currentMerFromFilter = Interlocked.CompareExchange(ref thisSingletonPartition.entries[filterIdx].key, (long)inactiveMer, (long)merFromFilter);
if (tracing)
{
lock (traceUpdates)
{
traceUpdates.Enqueue(new TraceEntry(threadNo, 2, singletonPartitionNo, filterIdx, (ulong)currentMerFromFilter));
if (traceUpdates.Count > maxTrace)
{
traceUpdates.Dequeue();
}
}
}
// if this thread successfully set the singleton to 'inactive', it will take care of the promotion
if (currentMerFromFilter == (long)merFromFilter)
{
ulong rcFlag = merFromFilter & singletonRCFlagMask; // non-zero --> RC found in singletons
long initialCount = 0;
if (rcFlag != 0) // singleton was seen in RC form
{
initialCount = 0x0000000000000001;
}
else // singleton was seen in as-is form
{
initialCount = 0x0000000100000000;
}
if (repeatedMersFull[partitionNo])
{
if (overflowMers[threadNo] == null)
{
overflowMers[threadNo] = new MerDictionary(repeatedMers[partitionNo].lengthEntries / 10, fullMerMask);
//Console.WriteLine("added overflow for thread " + threadNo + " for [" + partitionNo + "]");
}
bool full = overflowMers[threadNo].Add(mer, initialCount);
if (full)
{
overflowMers[threadNo].Resize();
}
}
else
{
bool full = repeatedMers[partitionNo].Add(mer, initialCount);
if (full)
{
repeatedMersFull[partitionNo] = true;
}
}
// now that the mer has been promoted, set the 'promoted' flag
inactiveMer = inactiveMer | (long)singletonPromotedFlagMask;
thisSingletonPartition.entries[filterIdx].key = (long)inactiveMer;
if (tracing)
{
lock (traceUpdates)
{
traceUpdates.Enqueue(new TraceEntry(threadNo, 3, singletonPartitionNo, filterIdx, (ulong)thisSingletonPartition.entries[filterIdx].key));
if (traceUpdates.Count > maxTrace)
{
traceUpdates.Dequeue();
}
}
}
}
}
// singleton is now known to be no longer active, so wait (if necessary) for the 'promoted' flag to be set and increment the repeat counter
merFromFilter = (ulong)thisSingletonPartition.entries[filterIdx].key;
if (tracing)
{
lock (traceUpdates)
{
traceUpdates.Enqueue(new TraceEntry(threadNo, 4, singletonPartitionNo, filterIdx, merFromFilter));
if (traceUpdates.Count > maxTrace)
{
traceUpdates.Dequeue();
}
}
}
bool promotionComplete = (merFromFilter & singletonPromotedFlagMask) != 0;
bool alreadySlept = false;
while (!promotionComplete)
{
promotionComplete = (((ulong)thisSingletonPartition.entries[filterIdx].key & singletonPromotedFlagMask) != 0);
if (alreadySlept && !promotionComplete)
{
if (tracing)
{
lock (traceUpdates)
{
StreamWriter trace = new StreamWriter("trace.txt");
foreach (TraceEntry t in traceUpdates)
{
trace.WriteLine(t.place + "\t" + t.thread + "\t" + t.partition + "\t" + t.index + "\t" + t.value.ToString("x16"));
}
trace.Close();
}
Console.WriteLine("promotion still not complete after sleep");
}
}
if (!promotionComplete)
{
Thread.Sleep(100);
}
alreadySlept = true;
}
UpdateRepeatedMerAfterPromotion(partitionNo, mer, threadNo, mer, addingIncrement);
//if (!updateSucceeded)
//{
// lock (traceUpdates)
// {
// StreamWriter trace = new StreamWriter("trace.txt");
// foreach (TraceEntry t in traceUpdates)
// trace.WriteLine(t.thread + "\t" + t.place + "\t" + t.partition + "\t" + t.index + "\t" + t.value.ToString("x16"));
// trace.Close();
// }
// Console.WriteLine("UpdateRepeatedMerRetry failed after waiting for promotion to complete");
//}
}
Interlocked.Decrement(ref thisSingletonPartition.activeCount);
}