/**
* Collect bucket statistics
*
* @returns {string[]} Array of strings that can be written to a file
* @api public
*/
public string[] CollectStatistics()
{
List<string> lines = new List<string>();
List<int> chain = new List<int>();
Dictionary<int, int> chain_count = new Dictionary<int, int>();
float chain_avg = 0F;
float total_length_avg = 0F;
float total_length = 0F;
float non_zero_length_buckets = 0F;
for (int i = 20; i < MAX_BUCKETS; ++i)
{
// if overflow is set
if (this.table[i].overflow != -1)
{
// if overflow is greater than table size, do some weird math stuff.
// this accounts for overflows of overflows.
// else add to the list normally.
if (this.table[i].overflow + 1 >= PRIMARY_TABLE_SIZE)
{
chain.Add((this.table[i].overflow + 1) - (PRIMARY_TABLE_SIZE - 1));
}
else
{
chain.Add(this.table[i].overflow + 1);
}
}
else
{
//if no overflow is set, just add 0 (not -1)
chain.Add(0);
}
// if the chain_count dicitionary contains this key and overflow is also set
if (!chain_count.ContainsKey(i) && this.table[i].overflow != -1)
{
// ternary statement. this math accounts for overflow of overflows.
int index = (this.table[i].overflow + 1 >= PRIMARY_TABLE_SIZE) ?
(this.table[i].overflow + 1) - (PRIMARY_TABLE_SIZE - 1) : this.table[i].overflow + 1;
// counts number of instance index appears in the dictionary
chain_count[index] = chain.Count(v => v == index);
// add to the collission chain average
chain_avg += chain_count[index];
}
}
// calculate the collission chain avrage
chain_avg /= chain_count.Count();
for (int i = 0; i < PRIMARY_TABLE_SIZE; ++i)
{
// grab the total length of each bucket
total_length += this.table[i].count;
// write to the list, which then will be returned and can be used to write to a file.
lines.Add("Bucket " + (i + 1) + ":");
lines.Add("\tTotal Length: " + this.table[i].count);
lines.Add("\n");
// if count is greater than 1,
// +1 to the number of buckets which have a more than one slot filled
// the requirements state not to cound zero length buckets in the average caluclations
if (this.table[i].count != 0)
{
++non_zero_length_buckets;
}
}
// calculate the average total length of all primary buckets
total_length_avg = total_length / non_zero_length_buckets;
lines.Add("Total Length Average is " + total_length_avg);
lines.Add("Collission Chain Average is " + chain_avg);
return lines.ToArray();
}
