private void CompactLevels()
{
var newIds = new List <ulong>();
const int LEVEL_TARGET_SIZE = BASE_TARGET_SIZE * 4;
var mj = new UniqueMemoryJournal();
var threadCount = Math.Max(2, Math.Min(3, Environment.ProcessorCount));
var queue = new BlockingCollection <UniqueMemoryJournal>(threadCount);
var flushThreads = Enumerable.Range(0, threadCount).Select(t => {
var thread = new Thread(() => {
foreach (var mjournal in queue.GetConsumingEnumerable())
{
if (mjournal.IsEmpty)
{
continue;
}
var newId = state.Manifest.AllocateIdentifier();
var sst = state.Manifest.FindFile(newId);
using var builder =
new SSTableBuilder(
new FileStream(sst.FullName, FileMode.CreateNew, FileAccess.Write, FileShare.None, 1),
options);
mjournal.CopyTo(builder);
lock (newIds) {
newIds.Add(newId);
}
}
})
{
IsBackground = false, Name = $"Plane-CompactFlush-{t}"
};
thread.Start();
return(thread);
}).ToArray();
foreach (var item in this)
{
mj.Put(item.Key, item.Value);
if (mj.Length < LEVEL_TARGET_SIZE)
{
continue;
}
queue.Add(mj);
mj = new UniqueMemoryJournal();
}
if (!mj.IsEmpty)
{
queue.Add(mj);
}
queue.CompleteAdding();
foreach (var flushThread in flushThreads)
{
flushThread.Join();
}
for (byte level = 0x0; level <= Math.Max((byte)0x1, state.Manifest.GetHighestLevel(family)); ++level)
{
if (level == 0x1)
{
state.Manifest.CommitLevel(family, level, newIds.ToArray());
}
else
{
state.Manifest.CommitLevel(family, level);
}
}
ReopenSSTables();
MaybeMergeInternal(true);
}
private void MaybeMergeInternal(bool force = false)
{
for (byte level = 0x00; level <= state.Manifest.GetHighestLevel(family); ++level)
{
var maxFiles = force ? level < 2 ? 1 : 8 :
level == 0 ? 12 : 16;
KeyValuePair <ulong, SSTable>[] mergeSequence;
bool needsTombstones;
List <ulong> newUpper;
var readWriteLock = state.ReadWriteLock;
readWriteLock.EnterReadLock();
try {
if (!state.Manifest.TryGetLevelIds(family, level, out var ids) || ids.Length < maxFiles)
{
continue;
}
state.Manifest.TryGetLevelIds(family, (byte)(level + 1), out var upperIds);
newUpper = upperIds.ToList();
ulong[] DropOneUpper()
{
if (newUpper.Count == 0)
{
return(Array.Empty <ulong>());
}
var rv = newUpper[0];
newUpper.RemoveAt(0);
return(new[] { rv });
}
mergeSequence = ids.Concat(DropOneUpper()).OrderByDescending(i => i)
.Select(i => tables.First(t => t.Key == i)).ToArray();
foreach (var kv in mergeSequence)
{
kv.Value.AddRef();
}
needsTombstones = newUpper.Count > 0 || level < state.Manifest.GetHighestLevel(family) - 1;
}
finally {
readWriteLock.ExitReadLock();
}
try {
var targetSize = BASE_TARGET_SIZE * (1 << (level + 1));
var mj = new UniqueMemoryJournal();
var threadCount = Math.Max(2, Math.Min(targetSize > 128 << 20 ? 2 : 5, Environment.ProcessorCount));
var queue = new BlockingCollection <UniqueMemoryJournal>(threadCount);
var flushThreads = Enumerable.Range(0, threadCount).Select(t => {
var thread = new Thread(() => {
foreach (var mjournal in queue.GetConsumingEnumerable())
{
if (mjournal.IsEmpty)
{
continue;
}
var newId = state.Manifest.AllocateIdentifier();
var sst = state.Manifest.FindFile(newId);
using var builder =
new SSTableBuilder(
new FileStream(sst.FullName, FileMode.CreateNew, FileAccess.Write, FileShare.None, 1),
options);
mjournal.CopyTo(builder);
lock (newUpper) {
newUpper.Add(newId);
}
}
})
{
IsBackground = false, Name = $"Plane-MergeFlush-{t}"
};
thread.Start();
return(thread);
}).ToArray();
foreach (var item in EnumerateSortedTables(mergeSequence.Select(i => i.Value.Enumerate()).ToArray(),
options.Comparer))
{
if (item.Value == null)
{
if (needsTombstones)
{
mj.Remove(item.Key);
}
}
else
{
mj.Put(item.Key, item.Value);
}
if (mj.Length < targetSize)
{
continue;
}
queue.Add(mj);
mj = new UniqueMemoryJournal();
}
queue.Add(mj);
queue.CompleteAdding();
foreach (var flushThread in flushThreads)
{
flushThread.Join();
}
readWriteLock.EnterWriteLock();
try {
var gone = mergeSequence.Select(e => e.Key).ToHashSet();
state.Manifest.CommitLevel(
family, (byte)(level + 1),
state.Manifest.TryGetLevelIds(family, (byte)(level + 1), out var existing)
? existing.Where(i => !gone.Contains(i)).Concat(newUpper).OrderBy(i => i).ToArray()
: newUpper.OrderBy(i => i).ToArray());
if (state.Manifest.TryGetLevelIds(family, level, out existing))
{
state.Manifest.CommitLevel(family, level, existing.Where(i => !gone.Contains(i)).ToArray());
}
}
finally {
readWriteLock.ExitWriteLock();
}
try {
OnMergedTables?.Invoke(this, this);
}
catch {
// ignored
}
}
finally {
foreach (var kv in mergeSequence)
{
kv.Value.Dispose();
}
readWriteLock.EnterWriteLock();
try {
ReopenSSTables();
}
finally {
readWriteLock.ExitWriteLock();
}
}
}
}