public bool Build(IList <string> keyList, IList <int> valList, double max_slot_usage_rate_threshold = 0.95)
{
if (keyList == null)
{
Console.WriteLine("Key list is empty");
return(false);
}
if (valList == null)
{
Console.WriteLine("Value list is empty");
return(false);
}
if (keyList.Count != valList.Count)
{
Console.WriteLine("The size of key list and value list is not equal");
return(false);
}
for (int i = 0; i < valList.Count; i++)
{
if (valList[i] <= -1)
{
Console.WriteLine("Invalidated value {0} at index {1}", valList[i], i);
return(false);
}
}
MAX_SLOT_USAGE_RATE_THRESHOLD = max_slot_usage_rate_threshold;
slot_usage_rate_threshold_ = max_slot_usage_rate_threshold;
progress_ = 0;
key_ = keyList;
val_ = valList;
startDT = DateTime.Now;
array = new VarBigArray <unit_t>(key_.Count * 5);
used = new VarBigArray <int>(key_.Count * 5);
array[0] = new unit_t();
array[0].base1 = 1;
used[0] = 1;
next_chk_pos_ = 0;
Node root_node = new Node();
root_node.left = 0;
root_node.right = key_.Count;
root_node.depth = 0;
List <Node> siblings = new List <Node>();
Fetch(root_node, siblings);
Insert(siblings);
return(true);
}
int Insert(List <Node> siblings)
{
Random rnd = new Random(DateTime.Now.Millisecond + Thread.CurrentThread.ManagedThreadId);
int begin = 0;
bool cont = true;
int nonzeronum = 0;
while (used[next_chk_pos_] == 1)
{
Interlocked.Increment(ref next_chk_pos_);
}
int pos = next_chk_pos_;
int startpos = pos;
//search begin position
pos--;
while (cont == true)
{
pos++;
if (used[pos] == 0)
{
//Check whether slots are available, if not go on to search,
cont = false;
foreach (Node n in siblings)
{
if (used[pos + n.code] == 1 || array[pos + n.code] != null)
{
cont = true;
break;
}
}
}
else
{
nonzeronum++;
}
}
begin = pos;
//check average slot usage rate. If the rate is no less than the threshold, update next_chk_pos_ to
//pos whose slot range has much less conflict.
//note that, the higher rate threshold, the higher slot space usage rate, however, the timing-cost for tri-tree build
//will also become more higher.
if ((double)nonzeronum / (double)(pos - startpos + 1) >= slot_usage_rate_threshold_ &&
pos > next_chk_pos_)
{
System.Threading.Interlocked.Exchange(ref next_chk_pos_, pos);
}
//double check whether slots are available
//the reason why double check is because:
//1. in entire slots space, conflict rate is different. the conflict rate of array's tail
// is much lower than that of its header and body
//2. roll back cost is heavy. So in high conflict rate range, we just check conflict and no other action (first check)
// once we find a availabe range without conflict, we try to allocate memory on this range and double check conflict
bool bAllNull;
bool bZeroCode = false;
foreach (Node n in siblings)
{
if (n.code == 0)
{
bZeroCode = true;
break;
}
}
if (bZeroCode == false)
{
Node sNode = new Node();
sNode.code = 0;
siblings.Add(sNode);
}
do
{
bAllNull = true;
//Test conflict in multi-threads
int cnt = 0;
foreach (Node n in siblings)
{
int nBlock = (begin + n.code) >> VarBigArray <int> .moveBit;
long offset = (begin + n.code) & (VarBigArray <int> .sizePerBlock - 1);
if (used[begin + n.code] == 1 ||
System.Threading.Interlocked.CompareExchange(ref used.arrList[nBlock][offset], 1, 0) != 0)
{
bAllNull = false;
foreach (Node revertNode in siblings.GetRange(0, cnt))
{
used[begin + revertNode.code] = 0;
}
begin += rnd.Next(thread_num_) + 1;
break;
}
cnt++;
}
} while (bAllNull == false);
if (bZeroCode == false)
{
siblings.RemoveAt(siblings.Count - 1);
}
for (int i = 0; i < siblings.Count; i++)
{
List <Node> new_siblings = new List <Node>();
Node sibling = siblings[i];
int offset = begin + sibling.code;
array[offset] = new unit_t();
array[offset].check = begin;
if (Fetch(sibling, new_siblings) == 0)
{
if (val_ != null)
{
array[offset].base1 = -val_[sibling.left] - 1;
}
else
{
array[offset].base1 = -siblings[i].left - 1;
}
if (Interlocked.Increment(ref progress_) % 10000 == 0)
{
//Try to adjust slot usage rate in order to keep high performance
TimeSpan ts = DateTime.Now - startDT;
double currQPS = progress_ / (ts.TotalSeconds + 1);
double currQPSDelta = currQPS - lastQPS;
if (currQPS < lastQPS && currQPSDelta < lastQPSDelta)
{
//Average QPS becomes slow down, need to reduce slot usage rate
slot_usage_rate_threshold_ -= 0.1;
if (slot_usage_rate_threshold_ < MIN_SLOT_USAGE_RATE_THRESHOLD)
{
slot_usage_rate_threshold_ = MIN_SLOT_USAGE_RATE_THRESHOLD;
}
}
else
{
//Average QPS becomes fast, need to add slot usage rate
slot_usage_rate_threshold_ += 0.1;
if (slot_usage_rate_threshold_ > MAX_SLOT_USAGE_RATE_THRESHOLD)
{
slot_usage_rate_threshold_ = MAX_SLOT_USAGE_RATE_THRESHOLD;
}
}
lastQPSDelta = currQPSDelta;
lastQPS = currQPS;
if (progress_ % 100000 == 0)
{
//Show current progress on console
Console.Write("{0}...", progress_);
}
}
}
else
{
int b = Insert(new_siblings);
array[offset].base1 = b;
}
}
return(begin);
}
